JP3295750B2 - Image recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus for recording an image on a continuous recording medium such as paper or a sheet-like plastic film by an electrophotographic method, and more particularly, to a method for reliably conveying a continuous recording medium by friction. The present invention relates to an image recording apparatus provided with means for performing the above.

[0002]

2. Description of the Related Art In a conventional paper transporting method of a continuous paper transporting method, a paper is transported by fitting a transporting pin and a transporting pin at both ends of the paper, and attention is paid to deformation and tear of the transporting hole. However, the user was not conscious of the paper suction force at the transfer unit of the electrophotographic image recording apparatus.

[0003] Feeding of continuous paper by the feed hole method has the advantage that feeding is assured to some extent and meandering does not accumulate. However, it is necessary to form feed holes at both ends of the paper, which increases the cost. In addition, there is a problem that freedom of paper selection is restricted.

Therefore, an image recording apparatus that conveys continuous paper to an image recording unit by roller frictional conveyance and records an image has been developed.
"Precision Machinery" Vol. 47, No. 4, pp. 32-37, Nishimura, "Study on Meandering Correction Method in Paper Roller Feeding", JP-A-4-256654
No. 6,009,036.

[0005]

The prior art relating to the above-mentioned roller frictional conveyance shows a method for correcting the meandering of a continuous recording body such as a paper or a sheet-like plastic film in an image recording apparatus.

However, there is no mention of frictional conveyance of a recording medium in the case where a transfer section for transferring a toner image is provided by a so-called electrophotographic image recording method. In an electrophotographic image recording apparatus, an electrostatic latent image on a photoreceptor is developed with a charged toner, and a charge having a polarity opposite to that of the toner is transferred from a surface of the recording medium opposite to the toner image. The toner image is transferred onto a recording medium by a Coulomb force, that is, an electrostatic force. At this time, since the recording medium itself is also charged, it is attracted by the Coulomb force to the surface of the photoconductor having no toner image, that is, the surface of the photoconductor having the same polarity as the toner. When the printing rate is high and there is a large amount of image toner on the photoreceptor, the suction area between the recording body and the photoreceptor is small, so the suction force is small. The area becomes large, and the force with which the recording medium is attracted to the photoconductor is large. This suction force acts as a load on the frictional conveyance of the recording medium, causes slippage in the frictional conveyance section, and adversely affects normal frictional conveyance.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image recording apparatus of an electrophotographic type, which is provided with a means for reliably transporting a continuous recording material such as paper or a sheet-like plastic film having no feed holes. That is.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a recording medium conveying means for frictionally conveying a continuous recording medium, an image recording section for electrostatically forming a toner image, and
A transfer unit for transferring a toner image onto a recording medium, wherein a recording medium transport unit is provided downstream of the transfer unit in the recording medium transport direction, and is located at both ends of the recording medium outside the image transfer area. The present invention proposes an image recording apparatus including one roller and a roller disposed on the back side of an image transfer, and including a friction conveying unit that sandwiches and conveys a recording medium.

In order to achieve the above object, the present invention also provides a recording medium conveying means for frictionally conveying a continuous recording medium,
In an image recording apparatus having an image recording unit that electrostatically forms a toner image and a transfer unit that transfers a toner image to a recording medium, a recording medium transport unit is provided downstream of the transfer unit in the recording medium transport direction. A driven roller disposed at both ends of the recording medium outside the image transfer area, and a driving roller disposed on the back side of the image transfer, and including friction conveyance means for sandwiching and conveying the recording medium; The present invention proposes an image recording apparatus in which rollers each include a pressing unit for pressing a driving roller.

Each of the pressing means may include a pressing force adjusting means.

In order to achieve the above object, the present invention further provides a photoconductor for forming a toner image in an electrophotographic system, a charging member for uniformly charging the photoconductor, and an electrostatic latent image formed on the photoconductor. Image recording section having an optical member to be developed and a developing member for developing a latent image with toner, a recording medium transport means for frictionally transporting a continuous recording medium, and a transfer section for transferring a toner image to the recording medium In the apparatus, a recording medium conveying means is provided downstream of the transfer section in the recording medium conveyance direction, and two driven rollers located at both ends of the recording medium outside the image transfer area, and a driving roller disposed on the image transfer back side And includes a friction conveyance means for sandwiching and conveying the recording medium,
The two driven rollers each have a pressing unit for pressing the drive roller side, and a tangential direction of the photoconductor at the transfer unit and a recording material conveyance direction are formed with respect to a suction force Fq between the recording material and the photoconductor. Assuming that the angle is θ, the friction coefficient between the recording medium and the photoconductor is μd, and the friction coefficient between the recording medium and the drive roller is μr, the pressing means has a pressing force of μd · Fq / (μr · cos θ) or more. Is proposed.

In any of the image recording apparatuses, when at least one of the two rollers located at both ends is provided so as to be movable in the width direction of the recording medium, a sensor for detecting the position of the movable roller is provided. Is desirable.

In these image recording apparatuses of the present invention, since at least one of the recording medium transport means is provided downstream of the transfer section in the recording medium transport direction, the toner image is transferred from the image recording section to the recording medium. In this case, a continuous recording body without a feed hole can be reliably transported by friction against the suction force between the member forming the toner image and the recording body. In particular, since the sheet is frictionally conveyed by the two rollers positioned outside the image transfer area of the recording medium, friction conveyance can be performed without disturbing the unfixed image on the recording medium.

According to the second image recording apparatus,
Since the two driven rollers of the friction conveying means provided on the downstream side of the transfer section in the recording medium conveying direction are independently pressed toward the driving rollers, the set pressing forces of the two driven rollers can be easily equalized. The meandering of the recording medium due to pressure imbalance is eliminated.

According to the fourth image recording apparatus, the pressing force adjusting mechanism of each driven roller is provided, and the set pressing force can be adjusted more finely.

Further, according to the fourth image recording apparatus, the set pressing force of the two driven rollers provided on the downstream side of the transfer section in the recording medium conveyance direction is set to μd · Fq / (μr · cos θ) or more. Thereby, frictional conveyance can be reliably performed against the suction force between the member forming the toner image in the transfer portion and the recording medium.

FIG. 6 is a diagram showing an example of a model serving as a basis for calculating a suction force according to the present invention for a toner image forming member, that is, a photosensitive member and a recording member in a transfer portion. In the calculation model of FIG. 6, the recording medium is a dielectric having a relative dielectric constant of 2.9, the transfer member on the back surface of the recording medium is a uniform electrode, and electric charges are distributed on the surface of the photoconductor. Using this calculation model, the relationship between the gap between the recording medium and the photoconductor and the force that the recording medium receives from the photoconductor, that is, the suction force, was calculated.

FIG. 7 is a diagram showing a result of a suction force calculation based on the model of FIG. FIG. 7 shows the gap between the recording medium and the photoreceptor as the horizontal axis, the potential difference between the surface of the photoreceptor and the transfer member as a parameter, and the suction force per unit area as the vertical axis. In the transfer portion, the recording member and the photosensitive member are in contact with each other via the toner.
m. The set potential difference between the photosensitive member surface and the transfer member depends on the developing conditions and the recording speed of the image recording apparatus, but is considered to be approximately 2 kV to 7 kV. Therefore, the suction force fq at the transfer unit is 0.0016 to 0.1.
2N / mm. The actual suction force Fq is the product of this value and the transfer area S. The force for transporting the recording body in the tangential direction of the photoconductor is represented by F, where F is the tension in the transport direction of the recording body and θ is the angle between the tangential direction of the photoconductor in the transfer unit and the transport direction of the recording body.・ Because it becomes cosθ, necessary tension F is
Assuming that the friction coefficient between the recording medium and the photoconductor is μd, F> μd · Fq / cosθ∴F> μd · fq · S / cosθ.

Therefore, if the friction coefficient between the driving roller of the conveying means and the recording medium is μr, the pressing force P of the driven roller
Is given by P> μd · Fq / (μr · cos θ) since F = μr · P.

For example, the gap between the photosensitive member surface and the transfer member is 0.05 mm, the set potential difference is 6 kV, the width of the transfer member is 13.5 mm, the length is 17 inches (431.88 mm), When the angle θ is 45 ° and μd = 1,
F> 120N. If the friction coefficient between the drive roller of the means for conveying the recording medium provided downstream of the transfer unit and the recording medium and the recording medium is set to μr = 1, if the set pressing force of the two driven rollers is set to 120 N or more, Therefore, frictional conveyance can be reliably performed against the suction force between the member that forms the toner image at the transfer unit and the recording medium.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an image recording apparatus according to the present invention will be described by taking a laser printer as an example, but the present invention is not limited to a laser printer. The present invention can be applied to any image recording apparatus that develops an electrostatic latent image with toner to form a toner image, and transfers the toner image to a recording medium.

Embodiment 1 Next, an embodiment of an image recording apparatus according to the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view showing a structure of a laser printer as an embodiment of an image recording apparatus according to the present invention, and FIG. 2 is a cross-sectional view showing an example of a structure of a recording medium transport unit of the image recording apparatus of FIG. FIG. 3 is a perspective view showing a recording medium transport unit of the image recording apparatus of FIG.

First, the overall configuration of an embodiment of the image recording apparatus according to the present invention will be described with reference to FIG. A recording unit for forming a toner image includes a rotatable photoconductor drum 402 having a photoconductor layer coated on a metal drum surface, and a photoconductor drum 40.
The photosensitive drum 4 includes a charger 404 for uniformly charging the surface of the photosensitive drum 2, a laser light source 406, a mirror, a lens, and the like.
2, an optical system 408 for forming an electrostatic latent image on the recording medium 100, a developing unit 410 for visualizing the electrostatic latent image with toner to form a toner image, and a transfer unit for transferring the toner image to the recording medium 100 Corotron 412 and drum cleaner 414 for removing residual toner after transfer on photoconductor drum 402
Consists of

The recording material transporting section for transporting the continuous recording material 100 includes an auxiliary roller 2 which guides the recording material 100 supplied from recording material supply means (not shown) by bending the direction of the recording material 100.
02, an electricity removing guide 204 provided with an electricity removing brush at the end where the recording medium 100 contacts, an auxiliary roller 206, and a recording medium 1 when the recording medium 100 is first mounted on the recording medium transport unit.
A guide 302 for regulating the end position in the width direction of 00;
Line sensor 304 such as a CD image sensor and its light source
(LED light source) 306 detecting means for detecting a displacement of the recording medium 100 in the width direction, a recording medium position correcting means 300 for correcting the displacement of the recording medium 100 in the width direction, and a recording medium guide 5
02, a recording medium guide 504 disposed downstream of the transfer corotron 412 in the transfer section, and driven rollers provided at both ends of the recording medium 100 outside the image transfer area so as not to contact the transferred image on the recording medium 100 A feed roller 506 including a drive roller 508 having a length corresponding to the entire width of the recording medium 100;
A tensioner 540 for applying a constant tension to the recording medium 100
When the recording medium 100 is set for the first time, the recording medium feed belt 602 moves in the direction of the arrow to feed the recording medium 100.
, An auxiliary feed roller pair 604, and an auxiliary roller 802 for guiding the recording medium 100 to the outside.

The fixing section includes a heat panel 702, a heat roller 704, and a backup roller 706 to heat and press the toner of the transferred image on the recording medium 100 to a predetermined temperature to fix the toner.

Next, referring to FIGS. 1 to 3, the details of the recording medium transport section of an embodiment of the image recording apparatus according to the present invention will be described. The recording medium transport unit of the present embodiment employs a mechanism that frictionally transports the recording medium 100 based on the end of the recording medium 100. At the end of the passage area of the recording body 100, a detection unit including a line sensor 304 and an LED light source 306, and a guide 302 are attached to a case (not shown). The line sensor 304 is attached such that the substantially center of the detection unit is the same as the position a of the guide 302 that regulates the end position of the recording medium 100 in the width direction. At the bottom of the guide 302, a solenoid that linearly moves in both directions is provided. The guide 302 moves between the positions a and b in FIG. 3 by driving the solenoid, and can retreat to the position b during printing. desirable.

The output of the line sensor 304 for detecting the end position of the recording medium 100 is taken into position correction value calculating means (not shown). The position correction value calculation means calculates a position correction value and outputs this to a position correction control means (not shown). The position correction control unit outputs a control signal to the control motor 308 of the position correction unit 300 to generate a difference in the pressing force acting on both ends of the correction roller 310 provided over the paper width of the recording medium 100.

The correction roller 310 and the drive roller 312 convey the recording body 100 whose position has been corrected to the transfer section.

As shown in FIG. 3, on the downstream side of the transfer corotron 412 of the transfer section, driven rollers 506 located at both ends outside the image transfer area of the recording medium 100 so as not to contact the transferred image on the recording medium 100 are provided. , And a holder 516 so as to be rotatable. The holder 516 holds the carrier 51
2, the carrier 512 is provided on a shaft 514 attached to a side plate (not shown) so as to be movable in the left-right direction, and is movable in accordance with the width of the recording medium 100. However, the driven roller 506 on the reference position side of the recording medium 100 provided with the guide 302 may adopt a method of fixing the position regardless of the width of the recording medium 100. A tension spring 518 is provided between the end of the holder 516 where the driven roller 506 is not attached and the carrier 512, and the holder 516 is provided with a pin 510.
The driven roller 506 is pressed against the drive roller 508 with the joint between the carrier 6 and the carrier 512 as a fulcrum.

This pressing force is equal to the suction force Fq between the recording body 100 and the photosensitive drum 402 when there is no toner image on the photosensitive drum 402, that is, when the printing rate is 0%.
The angle between the tangential direction of the photosensitive drum 402 and the recording medium transport direction in the transfer unit is θ, the friction coefficient between the recording medium 100 and the photosensitive drum 402 is μd, and the friction coefficient between the recording medium 100 and the drive roller 508 is μr. Then, it is set to at least μd · Fq / (μr · cos θ). In the case of the present embodiment, since two driven rollers 506 are provided at positions where both ends of the recording medium 100 pass, the pressing force of one driven roller 506 is equal to or more than μd · Fq / (2 μr · cos θ).

The mounting portion of the tension spring 518 serves as a point of force, the pin 510 serves as a fulcrum, and the mounting portion of the driven roller 506 serves as a point of application.
The strength of 18 sets the pressing force based on the product of the ratio of the arm from the fulcrum to the point of force and the arm from the fulcrum to the point of action. The pressing mechanism of the driven roller 506 can set the pressing force independently.

The driving roller 508 is rotatably mounted on a side plate (not shown), similarly to the driving roller 312 on the upstream side, and is driven by a motor (not shown).

As shown in FIG. 2, a carrier position sensor 520 for detecting the position of the carrier 512 is provided, and inputs the width of the recording medium 100 mounted on a printer control circuit (not shown). The carrier position sensor 520 detects the carrier 5
The magnet 522 includes a plurality of magnets 522 mounted on a magnet holder extending in the direction perpendicular to the paper of FIG. 12 and a plurality of magnetic sensing elements 524 arranged on a substrate perpendicular to the paper of FIG. 2 to detect the magnetic force of the magnets 522.

Next, the operation of this embodiment will be described. When the recording body 100 is mounted, first, the carrier 512 is moved, and the driven roller 506 is moved to the end of the recording body 100. The position of the carrier 512 is determined by the carrier position sensor 5.
20, the width of the recording body 100 to be mounted is
The photosensitive drum 4 is input to a printer control circuit (not shown).
02 is formed in accordance with the width of the recording medium 100.

A line sensor 306 installed on the upstream side of the position correcting means 300 detects the position of the end of the recording medium 100 and outputs the detected position to a position correction value calculating means (not shown). The position correction value calculation means calculates a correction value and outputs it to a position correction control means (not shown). The position correction control means outputs a control signal for position correction. The control motor 308 rotates by a predetermined angle based on the control signal, and changes the tensile force of each of the springs 324 and 330. This difference in the pulling force is applied to the pulley 32 via wire ropes 320, 324, 338, 328 connected to springs 324, 330.
6, 318, 316, 336, 332, etc., while changing the direction of the force, is transmitted to the point of force such as the arm 314 provided rotatably about the fulcrum, and the correction of the driven side attached to the tip of the arm is performed. The pressure difference between the left and right rollers 310 is obtained.
This pressure difference causes a difference in the conveying force acting in the width direction of the recording medium 100, and corrects the positional deviation of the recording medium 100.
The recording medium 100 that has been subjected to the conveyance force after the positional deviation has been corrected by the position correction unit 300 is conveyed to the transfer unit.

In the transfer section, the toner image on the photosensitive drum 402 is transferred by the electrostatic force of the transfer corotron 412.
The image is transferred onto the recording medium 100. At this time, the recording body 100
The photosensitive drum 402 generates a suction force due to the Coulomb force. This suction force is maximum when there is no toner image on the photosensitive drum 402, that is, when the printing rate is 0%.

Assuming that the maximum suction force is Fq, a driven roller 506 provided at a position where both ends of the recording material 100 outside the image transfer area pass so as not to contact the transferred image on the recording material 100 on the downstream side of the transfer portion. However, since the recording body 100 is pressed against the drive roller 508 with a pressing force of μd · Fq / (μr · cos θ) or more, the recording body 100 is stopped by the suction force of the photosensitive drum 402 at the transfer unit. Transported without. Although the driven roller 506 presses both ends of the recording medium 100, the pressing force can be set independently of each other, and the driven roller 506 includes the driven roller 506 and the driving roller 508 because it is easy to make the pressing force uniform. In the feed roller portion, the recording medium 100 does not meander due to imbalance in roller pressing force.

The recording medium 100 that has passed through the feed roller section is
The toner image is fixed to a fixing unit including a heat panel 702, a heat roller 704, and a backup roller 706 via a tensioner 540 that applies a constant tension to the recording medium 100. The recording medium 100 after fixing is bent by an auxiliary roller 802, and is conveyed to a post-processing unit such as a cutting device or a reversing device (not shown).

Embodiment 2 Next, another embodiment of the image recording apparatus of the present invention will be described. FIG. 4 is a cross-sectional view illustrating another example of the structure of the recording medium transport unit of the image recording apparatus in FIG. FIG. 5 is an enlarged view showing a feed roller portion of the recording medium transport unit in FIG.

The driven rollers 506 provided at both ends of the recording medium 100 so as not to contact the transferred image on the recording medium 100.
Is rotatably supported by the holder 532. A screw hole is formed in a carrier 534 provided on a shaft 514 attached to a side plate (not shown) so as to be movable in the left-right direction. A spring holder 536 provided with a screw on the outer periphery and having a hole formed in the center is attached to the screw hole. The cylindrical projection of the holder 532 is slidably attached to the center hole of the spring holder 536 with a compression spring 538 interposed therebetween, and presses the driven roller 506 toward the drive roller 508.

The pressing force is set in the same manner as in the embodiment shown in FIG. When there is no toner image on the photoconductor drum 402, that is, when the printing rate is 0%, the tangential direction of the photoconductor at the transfer unit and the recording medium 100 Assuming that the angle formed by the transport direction is θ, the friction coefficient between the recording medium 100 and the photosensitive member is μd, and the friction coefficient between the recording medium 100 and the driving roller is μr, the pressing force is μd · Fq / (μr · cos θ). Above. Since the driven rollers 506 are provided at the passing positions at both ends of the recording body 100, the pressing force of the driven roller 506 on one side is equal to or more than μd · Fq / (2μ · cos θ). The recording medium 100 provided with the guide 302
Of the driven roller 506 on the reference position side of the recording medium 1
The position can be fixed regardless of the width of 00. The carrier 534 is provided with a carrier position sensor 520 for detecting the position, and inputs the width of the mounted recording medium 100 to a printer control circuit (not shown) of the image recording apparatus.

The pressing mechanism of the driven roller 506 of the present embodiment uses a spring 538 by rotating the screw of the spring holder 536.
Can be adjusted, so that the pressing force can be adjusted.

[0043]

According to the present invention, at least one of the recording medium conveying means is provided downstream of the transfer section in the conveying direction of the recording medium, so that the toner image is transferred from the image recording section to the recording medium. At this time, since the frictional conveyance between the toner image forming member and the recording medium can be surely performed against the suction force between the recording medium and the two rollers positioned at both ends of the recording medium outside the image transfer area, the recording medium is frictionally conveyed. It is possible to carry out frictional conveyance without disturbing the unfixed image.

Further, since the two driven rollers of the friction conveying means provided on the downstream side of the transfer section in the conveying direction of the recording medium are independently pressed toward the driving roller, the set pressing force of the two rollers can be easily reduced. The meandering of the recording medium due to the imbalance of the pressing force is eliminated.

Further, if the set pressing force of the two driven rollers provided on the downstream side of the transfer section in the conveyance direction of the recording medium is set to μd · Fq / (μr · cos θ) or more, the member for forming the toner image in the transfer section Friction conveyance can be reliably performed against the suction force with the recording medium.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a laser printer as an embodiment of an image recording apparatus according to the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a structure of a recording medium transport unit of the image recording apparatus of FIG.

FIG. 3 is a perspective view illustrating a recording medium transport unit of the image recording apparatus of FIG. 2;

FIG. 4 is a cross-sectional view illustrating another example of the structure of the recording medium transport unit of the image recording apparatus in FIG. 1;

FIG. 5 is an enlarged view showing a feed roller portion of the recording medium transport unit in FIG. 4;

FIG. 6 is a diagram illustrating an example of a model serving as a basis of the present invention for calculating a suction force between a toner image forming member, that is, a photosensitive member and a recording member in a transfer portion.

FIG. 7 is a diagram showing a result of a suction force calculation based on the model of FIG. 6;

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 recording medium 202 auxiliary roller 204 static elimination guide 206 auxiliary roller 300 recording medium position correcting means 302 guide 304 image sensor (line sensor) 306 light source (LED light source) 308 control motor 310 correction roller (driven roller) 312 driving roller 314 arm 316 pulley 318 Pulley 320 Wire 322 Spring 324 Wire 326 Pulley 328 Wire 330 Spring 332 Force 334 Pulley 336 Pulley 338 Wire 340 Arm 402 Photoconductor drum 404 Charger 406 Laser light source 408 Optical system 410 Developing unit 412 Transfer coronatron 504 Drum guide 414 Drum 506 driven roller 508 drive roller 510 pin 512 carrier 514 shaft 516 holder 518 if pulled 520 carrier position sensor 522 magnet 524 a magnetic sensing element 532 holder 534 a carrier 536 spring holder 538 compressing spring 540 tensioner 602 recording material field belt 604 auxiliary feed roller pair 702 heat panel 704 heat roller 706 backup roller 802 auxiliary roller

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichi Matsuno 502, Kandachicho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Yasuyoshi Tsuji 2-6-1 Otemachi, Chiyoda-ku, Tokyo Hitachi Koki Co., Ltd. (72) Inventor Hideho Yokokawa 2-6-1, Otemachi, Chiyoda-ku, Tokyo Hitachi Koki Co., Ltd. (72) Inventor Isao Nakajima 2-5-2, Otemachi, Chiyoda-ku, Tokyo Hitachi Koki Co., Ltd. (72) Muneki Akai, Inventor 2-6-1 Otemachi, Chiyoda-ku, Tokyo Hitachi Koki Co., Ltd. (72) Inventor Yoji Hirose 2-5-2, Otemachi, Chiyoda-ku, Tokyo JP-A-52-62026 (JP, A) JP-A-56-141250 (JP, A) JP-A-51-50741 (JP, A) JP-A-60-166781 (JP , A) Actually open 55-13093 (JP, U) Actually open 56-159341 (JP, U) Actually open 1954-109548 (JP, U) Actually open 1962-2546 (JP, U) Actually open 59-183441 (JP, U) JP-A 5-49750 (JP, U) JP-A 63-41059 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65H 20/02

Claims (5)

(57) [Claims] A recording medium conveying unit configured to frictionally convey a continuous recording medium; an image recording unit configured to electrostatically form a toner image;
An image recording apparatus having a transfer unit for transferring the toner image to the recording medium, wherein the recording medium transport unit is provided downstream of the transfer unit in the recording medium transport direction, and is provided outside the image transfer area of the recording medium. An image recording apparatus, comprising: two rollers located at both ends; and rollers arranged on the back side of the image transfer, and including a friction conveyance unit for sandwiching and conveying the recording medium. 2. A recording medium conveying means for frictionally conveying a continuous recording medium, an image recording section for electrostatically forming a toner image,
An image recording apparatus having a transfer unit for transferring the toner image to the recording medium, wherein the recording medium transport unit is provided downstream of the transfer unit in the recording medium transport direction, and is provided outside the image transfer area of the recording medium. It includes two driven rollers located at both ends and a driving roller disposed on the back side of the image transfer, and includes friction conveying means for nipping and conveying the recording medium, wherein the two driven rollers move toward the driving roller. An image recording apparatus comprising a pressing unit. 3. The image recording apparatus according to claim 2, wherein each of the pressing units includes a pressing force adjusting unit. 4. A photoreceptor for forming a toner image in an electrophotographic system, a charging member for uniformly charging the photoreceptor, an optical member for forming an electrostatic latent image on the photoreceptor, and the latent image using toner. An image recording apparatus comprising: an image recording unit having a developing member for developing; a recording medium conveying unit configured to frictionally convey a continuous recording medium; and a transfer unit configured to transfer the toner image onto the recording medium. Means are provided downstream of the transfer unit in the recording medium transport direction, and include two driven rollers located at both ends of the recording medium outside the image transfer area, and a driving roller disposed on the image transfer back side; A friction conveyance unit that sandwiches and conveys the recording medium, wherein the two driven rollers each include a pressing unit that presses the driving roller, and a suction force Fq between the recording medium and the photoconductor, In the transfer section Is the angle between the tangential direction of the photoreceptor and the transport direction of the recording body, θ is the friction coefficient between the recording body and the photoreceptor, and μ is the friction coefficient between the recording body and the drive roller.
An image recording apparatus, wherein each of the pressing means has a pressing force of μd · Fq / (μr · cos θ) or more. 5. The image recording apparatus according to claim 1, wherein at least one of the two rollers located at both ends is:
An image recording apparatus, comprising: a sensor that is provided movably in a width direction of the recording medium and that detects a position of a movable roller.