JPH05241455A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device for a color digital copying machine, etc., capable of obtaining high reliability, without distorting the formation and development of a latent image on a photosensitive drum. CONSTITUTION:In a transfer drum 78 rotated together with the photosensitive drum 75, and holding/carrying a transfer material to a transfer part, buffer members 114, guiding a pressing plate for a sucking part and a pressing plate for the transfer part 89, are disposed on the rear side of a connecting member 112 connecting two cylindrical frames 110 and 111 and the downstream side in the rotational direction of a transfer drum 78.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer type color image forming apparatus such as a color digital copying machine or a color laser printer, and more particularly to an image forming apparatus using a transfer drum.

[0002]

2. Description of the Related Art For example, in a transfer type color image forming apparatus such as a color digital copying machine, a photosensitive drum as an image bearing member and a transfer drum as a transfer material conveying member are brought into contact with each other. Is rotated synchronously, an electrostatic latent image is formed by scanning the beam light on the photosensitive drum, the formed electrostatic latent image is developed into a color toner image, and each developed color toner image is held by the transfer drum. Then, the toner images on the transfer material are heat-fixed by sequentially transferring and superposing them on the transferred transfer material.

In the transfer drum in such a color image forming apparatus, two cylindrical frames having the same outer diameter are coaxially arranged, and these two cylindrical frames are slender plates arranged in parallel with the axis thereof. And a flexible transfer material carrier are wound so as to cover the two cylindrical frames.

As described above, the two cylindrical frames are connected by the connecting member arranged parallel to the axis of the cylindrical frame.
In order to increase the strength of the connecting member, a connecting member that is bent in its longitudinal direction inward of the transfer drum is used.

On the other hand, the transfer material is adsorbed at the suction portion that holds the transfer material on the surface of the transfer drum and the transfer portion that transfers the toner image on the photosensitive drum onto the transfer material held on the surface of the transfer drum. In order to perform transfer, the transfer material carrier is pushed out from the back surface side of the transfer material carrier of the transfer drum to the front surface side of the transfer drum by a pressing plate having a torsion spring. That is, the pressing plate of the suction unit and the pressing plate of the transfer unit are of a type in which the connecting member is integrated with the rotating transfer drum so as to get over the connecting member inward.

[0006]

However, as described above, in the connecting member having the bending inward of the transfer drum in the longitudinal direction of the connecting member, the rear end of the connecting member over which the pressing plate rides, After passing over, the distance of the contacting transfer material carrier becomes large, so the pressing plate with the torsion spring violently collides with the back surface of the transfer material carrier after overcoming the connecting member, and the vibration generated at this time occurs. There is a problem that it is transmitted from the transfer drum to the photoconductor drum and causes distortion in latent image formation and development on the photoconductor drum, resulting in poor reliability. Therefore, an object of the present invention is to provide an image forming apparatus that can obtain high reliability without causing distortion in latent image formation and development on an image carrier.

[0007]

An image forming apparatus according to a first aspect of the present invention comprises a latent image forming means for forming a latent image on the surface of a rotating drum-shaped image bearing member, and the latent image forming means. And a developing means for developing the latent image on the image carrier with a developer, at least two cylindrical frames having the same outer diameter, which are arranged coaxially, and arranged parallel to the axes of these cylindrical frames. A connecting member that connects two cylindrical frames, a flexible transfer material carrier wound so as to cover the two cylindrical frames, and a transfer material that holds the transfer material on the surface of the transfer material carrier. A drum-shaped transfer material carrier that is configured to include a holding unit and rotates together with the image carrier while the surface of the transfer material carrier is in contact with the surface of the image carrier; and a transfer material carrier of the transfer material carrier. The image developed by the developing means on the transfer material held on the body A transfer unit that transfers the developer image on the holding member, and a pressing member that is fixedly provided in the vicinity of the transfer unit and that pushes out the transfer material carrier of the transfer material transporter from the back surface side to the front surface side. The transfer material transporting body further includes a cushioning member for guiding the pressing member on the back side of the connecting member and on the downstream side in the rotation direction of the transfer material transporting body.

An image forming apparatus according to a second aspect of the present invention comprises a latent image forming means for forming a latent image on the surface of a rotating drum-shaped image bearing body, and the latent image forming means formed on the image bearing body. Developing means for developing the latent image of the above with a developer, at least two cylindrical frames of the same outer diameter arranged coaxially, and arranged parallel to the axis of these cylindrical frames, and connecting the two cylindrical frames. A connecting member, a flexible transfer material carrier wound so as to cover the two cylindrical frames, and a transfer material holding means for holding the transfer material on the surface of the transfer material carrier,
A drum-shaped transfer material carrier that rotates together with the image carrier in a state where the surface of the transfer material carrier is in contact with the surface of the image carrier, and the transfer material carrier of the transfer material carrier holds the transfer material carrier. A transfer means for transferring the developer image on the image carrier developed by the developing means onto the existing transfer material, and a transfer material carrier of the transfer material carrier, which is fixedly provided in the vicinity of the transfer means. And a pressing member that pushes the transfer material from the back surface side to the front surface side, and the connecting member of the transfer material transport body has a back side on the downstream side in the rotation direction of the transfer material transport body that is inclined toward the surface of the cylindrical frame. It is characterized by having a shape having.

[0009]

According to the first aspect of the present invention, by providing a cushioning member for guiding the pressing member on the back side of the connecting member in the transfer material conveying body and on the downstream side in the rotation direction of the transfer material conveying body, the transfer material conveying body is provided. The pressing member, which has surpassed the connecting member in accordance with the rotation, moves gently from the rear end of the connecting member to the back surface side of the transfer material carrier along the buffer member. Therefore, no distortion is caused in the latent image formation and development on the image carrier.

According to the second aspect of the present invention, the connecting member of the transfer material conveying body is shaped such that the back side of the transfer material conveying body on the downstream side in the rotational direction has a gradient toward the surface of the transfer material conveying body. The pressing member that has passed over the connecting member along with the rotation of the transfer material conveying body moves gently from the rear end to the back surface side of the transfer material carrying body along the gradient of the connecting member. Therefore, no distortion is caused in the latent image formation and development on the image carrier.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 schematically shows the structure of a color digital copying machine according to this embodiment.
The image processing unit 2, the memory unit 3, the input / output unit 4, the system bus 5, and the image bus 6 are included, and each unit will be described in detail below.

The basic system section 1 is a C that performs various controls.
PU (Central Processing Unit) 10,
A keyboard 11 for inputting data, a display panel 12 for displaying various states, a main memory 13 in which programs for controlling the entire system are stored, and an external input / output interface that enables connection with external devices. It is composed of 14.

The image processing section 2 includes an image processing module 20 for performing various kinds of image processing, and a compression / expansion processing section (CODE) for performing compression or expansion processing of image information.
C) 21.

The memory unit 3 is used, for example, as a page memory 30 having a storage capacity of several pages of A3 size image information, and as a temporary storage location of image information, for example, several tens of pages of A3 size image. The buffer memory 31 has a storage capacity for information.

The input / output unit 4 optically reads image information such as document information and converts it into a time-series electrical signal, ie, a scanner 40 as an original reading unit, a printer 41 as an image output unit for printing the image information, Further, it is configured by a scanner interface 42 and a printer interface 43 that connect them to the basic system unit 1.

The system bus 5 is a control bus for the entire system, and controls the basic system unit 1, the image processing unit 2, the memory unit 3, and the input / output unit 4, respectively. Also,
The image bus 6 is a bus dedicated to image information, and enables high-speed transfer of image information among the image processing unit 2, the memory unit 3, and the input / output unit 4.

The scanner 40, which is not shown in the drawing, has a first mirror and a first mirror having a fluorescent lamp as a light source.
Second with carriage, second mirror and third mirror
It is composed of a carriage, an imaging lens, a CCD line sensor with a color filter, and the like. Since the brightness of a fluorescent lamp is sensitive to temperature and the color temperature changes with the light emission time, a heater is installed in the fluorescent lamp so that the fluorescent energy is always maintained at a constant temperature and the emission energy is kept constant. As the reading optical system, a reduction reading system using a reduction lens and a three-color separation optical system is used.

A color document placed face down on a document table is illuminated by a fluorescent lamp, and the reflected light thereof is passed through the first to third mirrors and the imaging lens to form a plurality of light receiving elements arranged in a line. The CCD type line sensor with R, G, and B color filters having the above is configured to collect light on the light receiving surface.

An image of a color original document illuminated by a fluorescent lamp is color-separated into R, G, B by a line sensor, and respective analog signals are sent to an A / D converter.
Here, it is converted into an 8-bit digital signal. The signal converted into the 8-bit digital signal is then subjected to shading correction. The purpose of the shading correction is to correct the sensitivity variation for each pixel of the line sensor and to correct the uneven illumination.

In the correction method, first, a standard white plate (shading correction plate) is read. The image data at this time is temporarily stored in the RAM as shading data, and then the CPU calculates the reciprocal 1 / XW of the shading correction data and stores it again in the RAM.
Next, when reading the original, the image information is sent to the multiplier, at the same time, the shading correction data is read from the RAM, and the calculation X '= X * (1 / XW) * 255 is performed.

In this way, the 8-bit digital signal sent from the A / D converter becomes 8-bit correction data X ', which is converted into 8-bit R, G, B digital signals, and the scanner interface 42. Is output to. This signal is sent to the image processing module 20.

FIG. 6 shows a flowchart of image processing.
The spectral characteristics of the line sensor of the scanner 40 are usually deviated from the ideal characteristics due to restrictions such as dyes. Therefore, for example, a linear calculation using a 3 × 3 matrix is performed by a matrix calculation to perform color correction as luminance data.

The color-corrected image information is R, G, B.
Density conversion from data to density data of Y, M and C is performed. In each processing unit, processing such as masking and inking is performed based on the density information of Y, M, and C. By performing γ conversion on the image information after color conversion, the contrast and brightness are adjusted. Here, it becomes possible to perform the output suitable for the printer by adjusting the dynamic range and gradation of the printer.

One of digital halftone reproduction methods is gradation expression by a multivalued method. Since the optical output of the laser oscillator is used for the image signal, this is a method of expressing gradation by multi-valued in one dot. This is a method in which the optical output of the semiconductor laser oscillator is fixed and pulse width modulation is performed. The optical output of the laser oscillator is binary output, and gradation is produced by controlling the oscillation time. Is. However, as the pulse width becomes shorter, the peak value of the pulse may decrease, and the potential may be represented in an analog manner. In order to avoid this, it is necessary to make the light output constant and make the spot diameter as small as possible.

However, to reduce the spot diameter,
Due to the reduction of the pitch in the sub-scanning direction, the number of scanning lines has to be increased, resulting in a decrease in print speed. In order to improve this, the spot diameter is made elliptical so that the main scanning direction is a single axis and the sub scanning direction is a long axis. Then, one dot was multivalued to express gradation. A print image is formed and output according to the above signal processing.

FIG. 4 schematically shows the internal structure of the printer 41. The printer 41 includes a laser optical system,
It is composed of an image forming section in which a transfer material is combined with an electrophotographic system capable of forming an image. That is, page memory 3
0 to the image bus 6 and the printer interface 43
The image information, which has been subjected to the above-mentioned processing and is sent via, is synchronized by an image information processing circuit (not shown),
Laser beam light is output by driving a semiconductor laser oscillator (not shown) in the optical system unit 70.

The laser beam light output from the semiconductor laser oscillator is shaped in the optical system unit 70 by a beam shaping optical system including, for example, a cylindrical lens, and then rotationally driven by a high speed rotation motor using an air bearing. It is deflected by the rotating polygon mirror (polygon mirror) and output from the optical system unit 70.

The laser beam light 71 output from the optical system unit 70 passes through the fθ lens (not shown),
Reflected by the mirrors 72 and 73, a spot image having a required resolution is formed at a position 74 of an exposure position on the photoconductor drum 75 as an image carrier, and scanning exposure is performed to electrostatically form an image on the photoconductor drum 75. Form a latent image. The deflected laser beam light 71 is synchronized in the main scanning direction (horizontal direction) by being detected by a horizontal synchronization detector (not shown) including a photodiode.

Around the photosensitive drum 75, a charger 76 for charging the surface of the photosensitive drum 75, and an electrostatic latent image on the photosensitive drum 75 are developed into a color toner image.
Two developing devices 77a, 77b, 77c, 77d, and a transfer drum 7 as a transfer material transporter that holds and transports the transfer material.
8. Charge removing charger 79 for removing charge from the surface of the photosensitive drum 75, cleaner 8 for cleaning the surface of the photosensitive drum 75
0, and a static elimination lamp (not shown) for keeping the surface potential of the photosensitive drum 75 constant, respectively.

In this embodiment, for example, the developing device 77a is magenta, the developing device 77b is cyan, and the developing device 77 is
c is yellow, and the developing device 77d is for developing black.

The photosensitive drum 75 is rotationally driven at a peripheral speed of V0 by a drive motor (not shown), and the surface thereof is charged by a charger 76 having a grid electrode. Then, an electrostatic latent image is formed by spot-forming the laser beam light 71 at the spot 74 on the charged photosensitive drum 75.

Photosensitive drum 75 on which an electrostatic latent image is formed
Rotates to the point of the developing position at the speed of V0, and at this position, the electrostatic latent image on the photosensitive drum 75 is transferred to the developing device 77a,
Alternatively, the toner image is formed by being developed by the developing device 77b, the developing device 77c, or the developing device 77d.

Photosensitive drum 75 on which a toner image is formed
Continues to rotate at the speed of V0 and reaches the transfer position point 81.
Then, it is transferred by the transfer charger 88 onto the transfer material (paper) on the transfer drum 78, which is supplied at a timing from the paper feeding system.

The photosensitive drum 75 which has passed the transfer position is
It is rotationally driven as it is at the outer peripheral speed V0, and the surface of the cleaner 80 is discharged by the discharging charger 79.
The residual toner and the paper dust are cleaned by the above, the surface potential is adjusted to a constant level by the charge eliminating lamp, and a series of processes from the charging charger 76 is started again if necessary.

The paper feeding system is composed of a pickup roller 82, a feed roller pair 83, a registration roller pair 84, and an adsorption charging device counter electrode 85. Pickup roller 8
The transfer material (paper) lifted from the paper feeding cassette (not shown) by 2 is conveyed to the registration roller pair 84 by the feed roller pair 83. The registration roller pair 84 corrects the posture of the transfer material, and then sends the transfer material to the adsorption charger opposing electrode 85 in the adsorption portion.

In the suction portion, a pressing plate 87 with a torsion spring is fixedly provided as a pressing member, and the pressing plate 87 holds the transfer material of the transfer drum 78. A body 99 (details of which will be described later) is pushed from the back surface side to the front surface side, and the transfer material held on the surface of the transfer drum 78 is brought into pressure contact with the adsorption charger counter electrode 85.

The surface of the opposing electrode 85 of the adsorption charger is brought into contact with the transfer material under pressure. In this state, when the adsorption charging device 86 provided in the transfer drum 78 facing the adsorption charging device counter electrode 85 is operated, the plus corona is discharged from the adsorption charging device 86 and the back surface of the transfer material carrier 99 is discharged. Is charged with a positive charge. As a result, a negative charge is induced on the surface of the transfer material carrier 99, a positive charge is induced on the back surface of the transfer material, and a negative charge is induced on the surface of the transfer material. Due to the induced charges, the transfer material is electrostatically adsorbed and held on the surface of the transfer material carrier 99. The attraction / charging device counter electrode 85 is used to press the transfer material to facilitate the transfer of electric charges and to easily attract the transfer material to the surface of the transfer material carrier 99.

Around the transfer drum 78, an adsorption charging device 86 for adsorbing the transfer material to the surface of the transfer material carrier 99, a transfer charger 88 for transferring the toner image on the photosensitive drum 75 to the transfer material, and a transfer material carrier. A separation charger 90 for easily separating the transfer material from the body 99, a separation claw 91 for separating the transfer material from the transfer material carrying body 99, a static eliminator 96a, 96b for discharging the transfer material carrying body 99 after the transfer material separation, 9
7a, 97b, and a cleaner 98 for cleaning the surface of the transfer material carrier 99 are provided.

The transfer drum 78 is rotationally driven by a drive motor (not shown) at an outer peripheral speed V0 equal to that of the photosensitive drum 75, and the transfer material supplied from the paper feeding system at constant speed V0 is used as described above. Is adsorbed and held on the transfer material carrier 99 by the adsorption charger 86 and the adsorption charger counter electrode 85,
The sheet is conveyed to the transfer position 81 of the transfer section.

At the transfer portion, a pressing plate 89 with a torsion spring is fixedly provided as a pressing member, and this pressing plate 89 holds the transfer material carrier 99 of the transfer drum 78 on its back surface. Side to the front surface side, and the transfer material held on the surface of the transfer drum 78 is brought into pressure contact with the surface of the photoconductor drum 75. At this time, an electrostatic latent image has already been formed on the surface of the photoconductor drum 75 and has been developed by the developing device. When the transfer charger 88 is operated in this state, the discharge from the transfer charger 88 causes
The toner image on the photosensitive drum 75 is transferred to the surface of the transfer material.

The transfer drum 78 rotates a plurality of times, and the color toner is transferred onto the transfer material a plurality of times. Then, the transfer material on which the color toners have been transferred a plurality of times passes through the separation charger 90, is separated from the transfer material carrier 99 by the separation claw 91, and is then conveyed to the fixing device 95 by the conveyance belts 93 and 94. Here, the toner image is fixed and discharged to a paper discharge tray (not shown).

Next, in order to facilitate understanding of the present invention,
A conventional structure of the transfer drum 78 will be described. As shown in FIG. 7, two cylindrical frames 110 and 111 having the same outer diameter are used.
Are coaxially arranged as a transfer drum frame, and these two cylindrical frames 110 and 111 are connected by an elongated plate-shaped connecting member 112 arranged parallel to the axis thereof, and
A flexible transfer material carrier 99 is wound so as to cover the two cylindrical frames 110 and 111. Connection member 1
In order to increase its strength, the reference numeral 12 is formed in a shape in which its longitudinal direction is bent inward of the transfer drum 78.

Then, as described above, the transfer material carrier 9 is used to attract and transfer the transfer material at the adsorption portion and the transfer portion.
The transfer material carrier 99 is pushed out from the back surface side of the sheet 9 to the front surface side of the transfer drum 78 by pressing plates 87 and 89 each having a torsion spring. That is, the pressing plate 87 of the suction unit and the pressing plate 89 of the transfer unit are the methods of overcoming the connecting member 112 inward at the connecting member 112 which is integrated with the rotating transfer drum 78. ing.

However, as described above, in the longitudinal direction,
A connecting member 11 in which the transfer drum 78 is bent inward.
In Fig. 2, since the distance between the rear end of the connecting member over which the pressing plates 87, 89 and the transfer material carrying member 99 in contact with after overcoming becomes large, the pressing plates 87, 87 with torsion springs are attached.
After passing over the connecting member 112, 89 vigorously collides with the back surface of the transfer material carrier 99, and the vibration generated at this time is transmitted from the transfer drum 78 to the photoconductor drum 75 to form a latent image on the photoconductor drum 75. Also, there is a problem that distortion is caused in development.

Next, the structure of the transfer drum 78 according to the present invention will be described. The same parts as those in FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described.

FIG. 1 shows a transfer drum 78 according to the first embodiment.
Is shown. In this embodiment, as shown in the drawing, the cushioning member 1 for guiding the pressing plates 87 and 89 on the back side of the connecting member 112 and on the downstream side in the rotational direction of the transfer drum 78.
14, ... Are arranged. That is, on the back side of the connecting member 112, a plurality of sheet-like buffer members 114 are passed to the downstream side in the rotation direction of the transfer drum 78, for example, from the back side of the connecting member 112 toward the back side of the transfer material carrier 99. As a result, the pressing plates 87 and 89 that have surmounted the connecting member 112 are moved along the cushioning member 114,
From the rear end of the transfer material carrying member 99, the transfer material carrying member 99 is gently moved.

As a result, even if the distance between the rear end of the connecting member 112 and the transfer material carrying member 99 in contact with the rear end of the connecting member 112 is large, the pressing plates 87, 8 with torsion springs are provided.
After passing over the connecting member 112, the member 9 does not vigorously collide with the back surface of the transfer material carrier 99, and the vibration is transmitted from the transfer drum 78 to the photosensitive drum 75 as in the prior art, and the vibration is transferred to the photosensitive drum 75. It also eliminates distortion in latent image formation and development.

FIG. 2 shows a transfer drum 78 according to the second embodiment.
Is shown. In this embodiment, as shown in the drawing, in the cross section of the connecting member 112 taken along a plane perpendicular to the central axis of the transfer drum 78, the back side on the downstream side in the rotation direction of the transfer drum 78 is the surface of the transfer drum 78. It is formed in a shape having a slope toward it.

That is, as shown in detail in FIG. 3, by providing a gradient on the back side of the connecting member 112 and on the downstream side in the rotational direction of the transfer drum 78, the pressing plates 87 and 89 that have passed over the connecting member 112 are provided. As with the cushioning member 114 of the first embodiment, it gently moves from the rear end of the connecting member 112 to the back surface side of the transfer material carrier 99 along the gradient of the connecting member 112.

As a result, even if the distance between the rear end of the connecting member 112 and the transfer material carrying member 99 in contact with the rear end of the connecting member 112 is large, the pressing plates 87, 8 with torsion springs are provided.
After passing over the connecting member 112, the member 9 does not vigorously collide with the back surface of the transfer material carrier 99, and the vibration is transmitted from the transfer drum 78 to the photosensitive drum 75 as in the prior art, and the vibration is transferred to the photosensitive drum 75. It also eliminates distortion in latent image formation and development. At the same time, the suction position of the transfer material remains the same, the sequence time is not shortened, and it is not necessary to enlarge the apparatus, and the impact can be avoided.

In the above embodiment, the case where the transfer material is adsorbed and held on the surface of the transfer drum by the adsorption charger and the opposing electrode of the adsorption charger has been described, but the present invention is not limited to this. For example, the same can be applied to the case where the transfer material is held on the surface of the transfer drum by using a clipper.

In the above embodiment, the case where the invention is applied to the color digital copying machine has been described, but the present invention is not limited to this, and the same applies to, for example, a monochrome digital copying machine or a laser printer. Applicable to Besides, the present invention is not limited to the above-mentioned embodiments, and various modifications can be used without departing from the scope of the invention.

[0054]

As described above in detail, according to the present invention, it is possible to provide an image forming apparatus which can obtain high reliability without causing distortion in latent image formation and development on an image carrier.

[Brief description of drawings]

1A and 1B show a structure of a transfer drum according to a first embodiment, in which FIG. 1A is a partially sectional perspective view and FIG. 1B is a side view.

2A and 2B show a structure of a transfer drum according to a second embodiment, wherein FIG. 2A is a perspective view showing a partial cross section, and FIG. 2B is a side view.

3A and 3B show a structure of a connecting member in a second embodiment, wherein FIG. 3A is a top view, FIG. 3B is a side view, and FIG. 3C is a sectional view taken along the line AA in FIG. 3A. Figure, (d) Figure is (a)
The BB arrow cross section in a figure.

FIG. 4 is a configuration diagram schematically showing an internal configuration of a printer.

FIG. 5 is a block diagram schematically showing the configuration of a color digital copying machine.

FIG. 6 is a flowchart schematically illustrating image processing.

FIG. 7 shows a structure of a conventional transfer drum, (a)
The figure is a perspective view shown in perspective, and the figure (b) is a side view.

[Explanation of symbols]

71 ... Beam light, 75 ... Photosensitive drum (image bearing member), 76 ... Charging charger, 77a to 77d ... Developing device, 78 ... Transfer drum (transfer material conveying member), 85 ...
Adsorption charging device counter electrode, 86 ... Adsorption charging device, 87 ... Pressing plate (pressing member), 88 ... Transfer charger,
89 ... Pressing plate (pressing member), 99 ... Transfer material carrier, 110, 111 ... Cylindrical frame, 112 ... Connecting member.

Claims (2)

[Claims] 1. A latent image forming means for forming a latent image on the surface of a rotating drum-shaped image carrier, and a latent image formed on the image carrier by the latent image forming means is developed with a developer. The developing means, at least two cylindrical frames coaxially arranged with the same outer diameter, and arranged parallel to the axes of these cylindrical frames,
A connecting member that connects two cylindrical frames, a flexible transfer material carrier wound so as to cover the two cylindrical frames, and a transfer material that holds the transfer material on the surface of the transfer material carrier. And a drum-shaped transfer material transporting body that rotates together with the image bearing body in a state where the surface of the transfer material bearing body is in contact with the surface of the image bearing body, and the transfer material of the transfer material transporting body. Transfer means for transferring the developer image on the image carrier developed by the developing means onto the transfer material held on the carrier, and fixedly provided in the vicinity of the transfer means. And a pressing member that pushes the transfer material carrier of the body from the back surface side to the front surface side, the transfer material conveying body is on the back side of the connecting member, on the downstream side in the rotation direction of the transfer material conveying body, A cushioning member for guiding the pressing member, That the image forming apparatus. 2. A latent image forming means for forming a latent image on the surface of a rotating drum-shaped image bearing body, and a latent image formed on the image bearing body by the latent image forming means is developed with a developer. The developing means, at least two cylindrical frames coaxially arranged with the same outer diameter, and arranged parallel to the axes of these cylindrical frames,
A connecting member that connects two cylindrical frames, a flexible transfer material carrier wound so as to cover the two cylindrical frames, and a transfer material that holds the transfer material on the surface of the transfer material carrier. And a drum-shaped transfer material transporting body that rotates together with the image bearing body in a state where the surface of the transfer material bearing body is in contact with the surface of the image bearing body, and the transfer material of the transfer material transporting body. Transfer means for transferring the developer image on the image carrier developed by the developing means onto the transfer material held on the carrier, and fixedly provided in the vicinity of the transfer means. And a pressing member that pushes the transfer material carrier of the body from the back surface side to the front surface side, wherein the connecting member of the transfer material carrier has the cylindrical frame on the back side on the downstream side in the rotation direction of the transfer material carrier. Characterized by having a shape with a gradient toward the surface of Image forming apparatus.