JP5091423B2 - Transfer mechanism and image forming apparatus using the same - Google Patents

Description

  The present invention relates to a transfer mechanism such as a printer or a copying machine that forms an image by transferring powdery toner to a recording medium and an image forming apparatus using the transfer mechanism, and more particularly to a printer using a continuous recording medium. The present invention relates to a transfer mechanism for efficiently transferring a toner image onto a recording medium and an image forming apparatus using the transfer mechanism.

  In the electrophotographic system, a visible image (toner image) is formed by developing an electrostatic latent image with a toner of colored powder charged. The image carrier on which the toner image is formed is a photoreceptor or an intermediate transfer body to which the toner image is transferred from the photoreceptor.

  The toner image is transferred from the photosensitive member or the intermediate transfer member onto a recording medium such as paper, and then fixed on the recording medium with heat and pressure to form a printed image.

  Transfer of the toner image to the recording medium is performed electrostatically by utilizing the fact that the toner is a charged powder.

Patent Document 1 describes a corona transfer method using corona discharge.
In order to realize stable image transfer, it is necessary to stably contact the recording medium and the toner image carrier. However, in the corona transfer system, the corona discharger as a transfer means is not in contact, and it is difficult to stably contact the recording medium and the toner image carrier.

  Patent Document 1 provides a roller assembly 220 as a movable guide for stably contacting a recording sheet and a toner image carrier with respect to this problem. In the corona transfer system, besides patent document 1, many inventions relating to guides for controlling the behavior of a recording medium have been filed.

  Japanese Patent Application Laid-Open No. 2004-228561 describes a system that can increase the transfer efficiency of a toner image onto a recording medium and can be satisfactorily transferred to a recording medium having uneven surfaces such as rough paper. In this method, vibration energy is applied from the back surface of the image carrier, thereby mechanically reducing the adhesion between the image carrier and the toner and improving the transfer capability.

  Japanese Patent Application Laid-Open No. 2004-228561 describes a configuration using an intermediate transfer belt and having a guide member and a vibrator. The vibrator improves the transferability of the toner image onto the recording medium, and the guide member constitutes auxiliary transfer means.

  Japanese Patent Application Laid-Open No. H10-228561 describes a configuration in which air is ejected from a roller to prevent wear of an image carrier (intermediate transfer belt).

JP 2004-118192 A Japanese Patent Laid-Open No. 07-152264 JP 2005-338441 A JP 05-289534 A

  In the electrophotographic system, a toner image formed on an image carrier is electrostatically transferred onto a recording medium. Therefore, it is necessary to reverse the direction of the adhesive force of the toner image electrostatically attached on the image carrier by applying an electric charge from the back surface of the recording medium in the transfer area.

  As a method for applying a charge to a recording medium, a corona transfer method using a corona discharger and a transfer roller method using a transfer roller are known.

  In the case of the transfer roller method, the contact between the recording medium and the image carrier can be stabilized by sandwiching the recording medium and the image carrier with the transfer roller and the roller on the back of the image carrier opposite to the transfer roller.

  However, since the transfer roller comes into contact with the recording medium, there is a problem of surface contamination. On the other hand, when a transfer roller cleaning mechanism is provided, there is a problem that the life of the transfer roller is limited by the contact.

  On the other hand, when the corona transfer method is used, there is no problem with the life because it is not in contact with the recording medium, but there is a problem that the contact between the recording medium and the image carrier is not stable. Unstable contact causes image deterioration such as toner image scattering and density unevenness.

  Therefore, a method of stabilizing the contact between the recording medium and the image carrier using a guide as in Patent Document 1 has been devised. However, since the charge from the corona discharger is supplied to the back side of the recording medium, the recording medium cannot be guided by the corona discharge part, which has the greatest effect on transfer, and the contact between the recording medium and the image carrier is always stable. It is difficult to make it. That is, in Patent Document 1, a roller assembly 220 as a movable guide for stably contacting a recording sheet and a toner image carrier is on the same side as the corona generating unit 28, and charges from the corona generating unit are transferred to the back surface of the recording medium. Since the recording medium is supplied, the recording medium cannot be guided directly under the corona generating portion that most affects the transfer, and it is difficult to always stabilize the contact between the recording medium and the image carrier.

  Patent Document 2 is a method in which vibration energy is applied from the back of the toner carrier. However, in this method as well, the recording medium cannot be guided by the corona discharge portion, and it is difficult to always stabilize the contact between the recording medium and the image carrier.

  Since Patent Document 3 does not consider the guide of the recording medium at the corona discharge portion that most affects the transfer, it is difficult to always stabilize the contact between the recording medium and the image carrier.

In Patent Document 4, the transfer to the recording medium is a transfer using a roller, and the life extension of the portion is not considered. Also, if the power sale row at the site radius of curvature is small, as the rollers forming the air layer, an image bearing member per winding angle (intermediate transfer belt) contact area is small, the pressing force of the roller by the tension of the image bearing member However, it is relatively large with respect to the area forming the air layer, and high air pressure is required to form the air layer, and a complicated high-pressure pump is required.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a transfer mechanism capable of transferring a high-quality image onto a recording medium having a long life, high transfer efficiency, high image quality, and unevenness such as rough paper, and an image forming apparatus using the transfer mechanism. It is to be.

  In order to achieve the above object, the transfer mechanism of the present invention has the following configuration.

A medium conveying means for conveying a continuous recording medium, a belt-like image carrier conveyed by the conveying means, and an image of toner, which is a colored fine powder formed on the image carrier, is transferred to the recording medium. An image forming apparatus comprising: a charge injection unit that injects an electric charge from the back surface of the recording medium; and a tension applying unit that adjusts a tension in a conveyance direction of the recording medium. The transcription mechanism in
A main guide member having a convex push-in portion, and the upstream side of the image carrier at the contact portion of the image carrier with the recording medium with respect to the radius of curvature of the convex push-in portion of the main guide member The curvature radius of a guide member and a downstream guide member is small, It is characterized by the above-mentioned.

  Further, in addition to the above, there is provided a vibration applying means that has at least the width of the image forming area of the image carrier and applies vibrations to the image carrier, and the main body so as to surround or surround the vibration applying means. A guide member is disposed.

  Further, in addition to the above, the main guide member includes a plurality of air blowing holes on the image carrier side and air supply means for supplying air to the air blowing holes.

  According to the present invention, it is possible to apply tension to a recording medium by using a continuous recording medium and its tension applying means. That is, the recording medium is pressed against the image carrier by its own tension by pushing the image carrier toward the recording medium by the convex main guide member. This pressing force stabilizes the contact between the image carrier and the recording medium, improves the transfer efficiency, and improves the image quality.

When the radius of curvature of the main guide member is increased, the contact force between the recording medium and the image carrier is not excessive even in the case of a thick and highly rigid recording medium, and image disturbance due to toner adhesion does not occur. When the curvature radius is reduced at the contact start portion and the separation portion between the recording medium and the image carrier on the upstream side and the downstream side with respect to the conveyance direction of the image carrier, the length of the minute gap portion can be shortened, and the toner due to discharge There is no image distortion.

  Further, when a roller-type upstream guide member and a downstream guide member that define a contact area between the image carrier and the recording medium are disposed on the upstream side and the downstream side in the image carrier transport direction of the main guide member, the main guide member and The frictional resistance of the image carrier is reduced, the size of the conveying means can be reduced, and contact wear of the image carrier is caused to increase the life.

  Furthermore, by providing the vibration applying means, stable transfer can be performed on a recording medium having irregularities such as rough paper. Further, since the contact force between the vibration applying means and the image carrier can be reduced by the main guide member, the life of the vibration applying means can be extended.

  In addition, an air outlet is provided in the main guide member, and air is blown out from the air to form an air layer between the main guide member and the image carrier, greatly reducing the conveyance resistance of the image carrier and driving. The mechanism can be downsized and the life of the image carrier can be extended.

Further, the use of non-contact charge injection means can extend the life. In addition, the main guide member is non-rotating and the radius of curvature can be increased, and the pressing force against the roller due to the tension of the image carrier relative to the area of the contact portion is relatively reduced. The contact can be made and the life can be extended.

Embodiments of the present invention will be described below with reference to the drawings.
First, a configuration example of a transfer mechanism of an image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a longitudinal sectional view of a transfer mechanism according to this embodiment. FIG. 2 is a top view of the main guide member 71 of FIG. 1 viewed from the intermediate transfer belt 3 side.

  The image carrier in this embodiment is an intermediate transfer belt 3 and is conveyed in the direction of arrow B in the figure by a conveying means (not shown). The recording medium is continuous paper 25 and is conveyed in the direction of arrow A in the figure by a conveying means (not shown). Further, the continuous paper 25 is given tension in the directions of arrows C and D in the figure by a tension applying means (not shown).

The contact area 100 between the continuous paper 25 and the intermediate transfer belt 3 has a predetermined radius of curvature of the guide, and a corona discharge device 90 that charges the continuous paper 25 is disposed near the center and on the back side of the continuous paper 25. The

In the contact region 100 between the upstream roller (upstream guide member) 65 and the downstream roller (downstream guide member) 66, along the guide curvature radius in order toward the conveyance direction of the continuous paper 25, It arrange | positions so that the surface of the upstream main guide member 71, the ultrasonic vibrator 80, and the downstream main guide member 71 may be located. The main guide member 71 has a surface along the guide radius of curvature, and is provided with a pushing portion 74 that pushes the intermediate transfer belt (image carrier) 3 in a convex shape toward the continuous paper (recording medium) 25 side. .

  As is clear from FIG. 2, the upstream and downstream main guide members 71 in the present embodiment are integrally formed, and the horn 81 of the ultrasonic vibrator 80 is placed in the long groove 72 provided in the center thereof. Is arranged. The long groove 72 of the main guide member 71 is not limited to one, and a plurality of long grooves 72 may be provided along the contact region 100, and the horn 81 of the ultrasonic vibrator 80 may be disposed in each groove.

  In the present embodiment, the contact area 100 has a start portion near the contact start portion between the intermediate transfer belt 3 and the continuous paper 25 and an end portion near the contact end portion between the intermediate transfer belt 3 and the continuous paper 25.

On the intermediate transfer belt 3 side of the main guide member 71, a convex push-in portion 74 having a plurality of air holes 73 is provided, and air sent by air supply means (not shown) is intermediate from the air holes 73. Jetted to the transfer belt 3 side. The surface of the main guide member 71 on the intermediate transfer belt 3 side, that is, the surface of the pushing portion 74 is configured as a part of an arc. Compared to guide the radius of curvature of the surface of the pushing portion 74, the radius of curvature of the upstream roller 65 and the downstream roller 66 is small.

  The ultrasonic vibrator 80 includes a horn 81 that resonates in an ultrasonic region of 20 to 100 KHz, a piezoelectric element 82, and a base member 83 that is fixed to the main body of the image forming apparatus. The piezoelectric element 82 is driven by high-frequency driving means (not shown).

  The horn 81 of the ultrasonic vibrator 80 is at least larger than the image printing width of the intermediate transfer belt 3, and the main guide member 71 is disposed so as to surround the horn 81.

  Note that the intermediate transfer belt 3 can be vibrated by a coil disposed in a magnetic field and a vibration transmitting member connected thereto instead of the ultrasonic vibrator using a piezoelectric element. Or you may comprise as a convex main guide member which abbreviate | omitted the long groove | channel and the ultrasonic vibrator 80. FIG.

Next, a specific configuration example, operation, and effect of the present embodiment will be described with reference to FIG.
In the contact area 100, the vicinity P1 of the contact start portion between the intermediate transfer belt 3 and the continuous paper 25 is a start portion, and the vicinity P2 of the contact end portion of the intermediate transfer belt 3 and the continuous paper 25 is an end portion. R >> r1, R >> r2 where R is the guide radius of curvature of the contact area 100 of the continuous paper 25 and the intermediate transfer belt 3, r1 is the radius of curvature of the upstream roller 65, and r2 is the radius of curvature of the downstream roller 66. .

A configuration example of each member in the vicinity of the contact region 100 is as follows.
With respect to the height of the convex pushing portion 74 of the main guide member, that is, the height T in the vicinity of the center of the main guide member (near the long groove) with respect to the line segment connecting P1-P2. The feed width is 60 mm, and the guide curvature radius is in the range of R = 100 to 300 mm. The contact width between the continuous paper and the intermediate transfer belt is about 100 mm. The dimensions of the horn 81 are 3 to 6 mm in width and 15 to 25 mm in length. The upstream roller 65 and the downstream roller 66 have a diameter of 20 to 40 mm (r1, r2 = 10 to 20 mm).

According to this embodiment, a convex main body provided along the guide radius of curvature R from the back surface of the intermediate transfer belt 3 to the continuous paper 25 applied with tension in the directions of arrows C and D in the drawing by the tension applying means. By pushing the guide member 71, the continuous paper 25 and the intermediate transfer belt 3 are stably in contact with each other over almost the entire contact area 100. By applying a charge by the corona discharger 90 in the contact area where the contact is stable, the toner image on the intermediate transfer belt 3 can be stably transferred to the continuous paper 25, and a high-quality image can be obtained.

Further, by increasing the radius of curvature R of the contact area 100 between the intermediate transfer belt 3 and the continuous paper 25, even when the continuous paper 25 is thick and rigid, the contact pressure does not become excessive, and image defects due to toner adhesion or the like occur. Absent. Further, since it is non-contact charging by the corona discharger 90, the life can be extended compared to the transfer roller system.

Further, an upstream roller 65 and a downstream roller 66 disposed upstream and downstream of the main guide member 71 in the conveyance direction of the intermediate transfer belt 3 are disposed at a contact portion 100 between the continuous paper 25 and the intermediate transfer belt 3. Further, since the radius of curvature r1 and r2 is smaller than the radius of curvature R of the pushing portion 74 of the main guide member 71, the intermediate transfer belt 3 and the continuous paper at the entrance and the exit of the contact area 100 of the intermediate transfer belt 3 and the continuous paper 25 are provided. The regions (G1, G2) having a narrow interval 25 are reduced, and there is no image deterioration such as toner scattering due to discharge. Further, the main guide member 71 has a non-rotating structure, and the curvature radius R can be increased. For this reason, the pressing force against the roller due to the tension of the intermediate transfer belt with respect to the area of the contact area is relatively lowered, so that an air layer is formed with a simple pump so as to be non-contacted, thereby extending the life.

FIG. 4 shows an example of the relationship between the tension of the continuous paper and the guide curvature radius R and the image deterioration in the embodiment of the present invention.
When the tension of the continuous paper is constant, the contact between the continuous paper 25 and the intermediate transfer belt 3 is stabilized in the contact region over the range of the guide curvature radius R = 100 to 300 mm. to degrade. In addition, when the tension of the continuous paper is low, the degree of image deterioration outside the contact area increases.

An image forming apparatus according to an embodiment of the present invention will be described with reference to FIG.
FIG. 5 is a side view of the image forming apparatus 1 using the transfer mechanism according to the embodiment of the present invention.

  The image forming apparatus 1 arranges developing units of respective colors on an intermediate transfer belt 3 that is an image carrier, forms a color image with toner on the intermediate transfer belt 3, and conveys the color image from the continuous paper stacking unit 20. The recording medium is transferred to a continuous paper 25, and the fixing device 6 melts and fixes the toner with heat and pressure to form a color image.

  There are four developing units, and the photosensitive means is a drum. A K developing unit 501 having black toner, a C developing unit 502 having cyan toner, an M developing unit 503 having magenta toner, and a Y developing unit 504 having yellow toner, respectively. The developing unit includes a toner hopper 53 that stores toner, a developing roller 52 that forms a toner layer and contacts the photosensitive drum 54 with the toner, a drum cleaner 57 that cleans the photosensitive drum 54, and a charger that charges the photosensitive drum 54. 55, an exposure unit 56 for writing an electrostatic latent image on the photosensitive drum 54.

The intermediate transfer belt 3 is conveyed in the direction of arrow B in the figure by a driving roller 27 that is rotated by a driving means (not shown).
The belt cleaner 91 removes residual toner on the intermediate transfer belt 3.
A primary transfer roller 58 serving as a first transfer unit is disposed inside the intermediate transfer belt 3 so as to face the photosensitive drum 54.

  The continuous paper 25 is fed out from the continuous paper stacking means 20 for depositing the continuous paper 25 by the drawing roller pair 31 and passes through the idler roller a32, the buffer roller 29, the idler roller b33, and the tension adjusting roller pair 23, and the continuous paper 25 The contact area 100 of the intermediate transfer belt 3 is reached. In this embodiment, the idler roller a <b> 32, the buffer roller 29, the idler roller b <b> 33, and the tension adjusting roller pair 23 function as tension applying means for the continuous paper 25.

  As shown in FIG. 2, a plurality of air holes 73 are arranged in the main guide member 71, and air fed by an air supply means (not shown) is ejected to form an air layer between the main guide member and the intermediate transfer belt 3. Thus, the frictional load caused by the contact with the intermediate transfer belt 3 is not generated, and the life of these members is extended. That is, wear of the main guide member 71 and the intermediate transfer belt 3 due to friction can be prevented, the conveyance resistance of the intermediate transfer belt can be greatly reduced, and the drive mechanism can be downsized and the life of the intermediate transfer belt can be extended.

  The buffer roller 29 that is one of the tension applying means is movable in the direction of arrow E in the figure, and thereby absorbs the slack of the continuous paper 25.

  In the contact region 100, the corona discharger 90 is disposed on the back side of the continuous paper 25 of the main guide member 71.

  The intermediate transfer belt 3 is bent by the upstream roller 65, conveyed along the main guide member 71, further conveyed along the main guide member 71 while being in contact with the horn 81, and bent and conveyed by the downstream roller 66. Is done.

  The horn 81 is driven by a vibration member 82 such as a piezoelectric element that is driven by a high frequency driving means, and vibrates the intermediate transfer belt 3. Due to this vibration, the adhesion of the toner on the intermediate transfer belt 3 to the intermediate transfer belt 3 is reduced, and in some cases, the toner can be satisfactorily transferred to uneven paper such as rough paper. become. In addition, since the main guide member 71 receives the force toward the intermediate transfer belt 3 generated by the tension of the continuous paper 25, the contact force between the tip of the horn 81 and the intermediate transfer belt 3 is reduced, and these members are not easily worn. Life expectancy is possible.

On the other hand, since the intermediate transfer belt 3 is bent with a smaller radius of curvature by the upstream roller 65 and the downstream roller 66 in the contact region 100, the gap with the continuous paper 25 is gradually narrowed, and a minute interval is formed in this portion. Area is reduced. For this reason, image disturbance due to the discharge generated in the contact region 100 is less likely to occur. Even if the intermediate transfer belt 3 is bent largely with a small radius of curvature , the intermediate transfer belt 3 is supported by a roller so that the frictional load is small, the driving means can be reduced in size, and the intermediate transfer belt 3 is worn. It can be prevented and the service life can be extended.

Next, the continuous paper 25 passes through the idler roller 34 and reaches the fixing device 6.
The conveying speed of the continuous paper 25 by the fixing device 6 is set to be 0 to 1% faster than the conveying speed of the intermediate transfer belt 3. Thereby, loosening of the continuous paper 25 is prevented.

  Conversely, the conveyance speed of the continuous paper 25 by the tension adjustment roller pair 23 is 0 to several percent slower than the conveyance speed of the intermediate transfer belt 3, and the tension adjustment roller pair 23 is driven via a torque limiter (not shown). Therefore, a tension according to the setting of the torque limiter is generated on the continuous paper 25 between the fixing device 6 and the tension adjusting roller pair 23.

In addition to the tension and the pushing of the main guide member 71, the radius of curvature of the contact region 100 stabilizes the contact between the continuous paper 25 and the intermediate transfer belt 3, and enables good toner transfer, resulting in a high-quality image. .

  The continuous paper 25 after the fixing device 6 passes through the curl correction roller pair 35 and the paper discharge roller pair 36 and reaches the printing paper stacking means 21.

  When an image is formed by each of the developing units 501 to 504, the photosensitive drum 54 is charged by the charger 55, and light corresponding to the image is applied by the exposure device 56 to drop the potential on the photosensitive drum 54. The portion reaches the developing roller 52 by the rotation of the photosensitive drum 54, and when it comes into contact with the toner layer, the charged toner adheres to the image position.

  The toner image on the photosensitive drum 54 is transferred onto the intermediate transfer belt 3 at a portion where the primary transfer roller 58 presses the intermediate transfer belt 3.

  The toner image on the photosensitive drum of each developing unit is transferred onto the intermediate transfer belt 3 to form a color toner image. Then, the toner image is transferred onto the conveyed continuous paper 25 in the vicinity of the corona discharger 90 in the contact area 100 by the conveyance of the intermediate transfer belt 3.

  Heat and pressure are applied to the continuous paper 25 onto which the toner image has been transferred by the fixing device 6 to melt and fix the toner, thereby forming a color image.

According to the image forming apparatus of the present embodiment, it is possible to obtain a high-quality image with a long lifetime. That is, the recording medium is pressed against the intermediate transfer belt by its own tension by pushing the intermediate transfer belt toward the recording medium by the main guide member provided in the contact area between the continuous paper 25 and the intermediate transfer belt 3. This stabilizes the contact between the intermediate transfer belt and the recording medium, improves the transfer efficiency, and improves the image quality. Further, by reducing the radius of curvature at the contact start portion and the separation portion of the contact area, the length of the minute interval portion can be shortened, and the toner image is not disturbed by discharge.

  Further, by arranging the vibration applying means on the main guide member, it is possible to form a high-quality image even on continuous paper having irregularities such as rough paper.

1 is a cross-sectional view illustrating a transfer mechanism of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a top view of the main guide member shown in FIG. 1 viewed from the intermediate transfer belt side. It is a figure explaining the specific structural example, operation | movement, and effect of the main guide member shown in FIG. 2 shows an example of the relationship between the tension of a continuous paper sheet and the radius of curvature of guide and image deterioration in an embodiment of the present invention. FIG. 2 is a side view of an image forming apparatus employing the main guide member shown in FIG. 1.

  DESCRIPTION OF SYMBOLS 3 ... Intermediate transfer belt, 6 ... Fixing device, 20 ... Continuous paper volume means, 21 ... Printing paper accumulation means, 23 ... Tension adjusting roller pair, 25 ... Continuous paper, 27 ... Drive roller, 29 ... Buffer roller, 31 ... Drawer Roller pair, 32 ... idler roller a, 33 ... idler roller b, 52 ... developing roller, 54 ... photosensitive drum, 55 ... exposure device, 56 ... charger, 57 ... drum cleaner, 58 ... primary transfer roller, 65 ... upstream Side roller (upstream side guide member), 66 ... Downstream side roller (downstream side guide member), 71 ... Main guide member, 73 ... Air hole, 74 ... Push-in part, 80 ... Ultrasonic vibrator, 81 ... Horn, 82 DESCRIPTION OF SYMBOLS ... Piezoelectric element, 83 ... Base member, 90 ... Corona discharger, 91 ... Belt cleaner, 100 ... Contact area, 501 ... K developing unit.

Claims (9)

A medium conveying means for conveying a continuous recording medium, a belt-like image carrier conveyed by the conveying means, and an image of toner, which is a colored fine powder formed on the image carrier, is transferred to the recording medium. An image forming apparatus comprising: a charge injection unit that injects an electric charge from the back surface of the recording medium; and a tension applying unit that adjusts a tension in a conveyance direction of the recording medium. The transcription mechanism in
A main guide member having a convex push-in portion;
The curvature radius of the upstream guide member and the downstream guide member of the image carrier at the contact portion of the image carrier with the recording medium is smaller than the curvature radius of the convex push-in portion of the main guide member. Characteristic transfer mechanism. The transfer mechanism according to claim 1,
A transfer mechanism, wherein a width of the main guide member in a conveying direction of the image carrier is larger than a width of the charge injection unit . The transfer mechanism according to claim 1 or 2,
The radius of curvature of the main guide member is in the range of R = 100 to 300 mm, and the radius of curvature of the upstream guide member and the downstream guide member is in the range of r1, r2 = 10 to 20 mm. . Medium conveying means for conveying a continuous recording medium, a belt-shaped image carrier, a conveying means for conveying the image carrier, and a toner image for forming an image with toner that is a colored fine powder on the image carrier. Forming means, charge injection means for injecting charges from the back surface of the recording medium disposed in a non-contact position with respect to the recording medium in a transfer region for transferring the toner image on the image carrier to the recording medium, and the recording medium An image forming apparatus comprising tension applying means for adjusting the tension in the conveying direction of
A main guide member having a convex push-in portion;
The curvature radius of the upstream guide member and the downstream guide member of the image carrier at the contact portion of the image carrier with the recording medium is smaller than the curvature radius of the convex push-in portion of the main guide member. An image forming apparatus. The image forming apparatus according to claim 4.
The image forming apparatus, wherein the upstream guide member and the downstream guide member are rollers . The image forming apparatus according to claim 5.
The radius of curvature of the main guide member is in the range of R = 100 to 300 mm, and the radius of curvature of the upstream guide member and the downstream guide member is in the range of r1, r2 = 10 to 20 mm. apparatus. The image forming apparatus according to claim 4 or 5 , wherein:
At least a width of an image forming region on the image carrier, and vibration applying means for applying vibration to the image carrier, and the main body so as to surround the vibration applying means before and after the vibration applying means. An image forming apparatus comprising a guide member . The image forming apparatus according to claim 7 .
An arc-shaped contact area where the recording medium and the image carrier are in contact is formed between the upstream guide member and the downstream guide member, and the guide of the contact area corresponding to the radius of curvature of the main guide member is formed. An image forming apparatus , wherein the main guide member and the surface of the vibration applying means are positioned along a radius of curvature . The image forming apparatus according to any one of claims 4 to 6 ,
The image forming apparatus , wherein the main guide member includes a plurality of air blowing holes that open to the image carrier and an air supply unit that supplies air to the air blowing holes .

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