JPH11327403A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the difference of speed between a photoreceptor and an intermediate transfer body at the starting of driving or at the finishing of driving and to prevent damage due to the difference of speed. SOLUTION: This image forming device is equipped with a photoreceptor 3, a 1st driving means 11 rotating and driving the photoreceptor 3, the intermediate transfer body 4 to which a toner image on the photoreceptor 3 is transferred and which has rotational resistance different from the photoreceptor 3, and a 2nd driving means 12 rotating and driving the transfer body 4. The device is provided with a timing control means 13 making driving start timing between the means 11 and 12 different by a specified time in the case of starting the driving, and a driving speed control means 13 controlling the driving speed of the means 11 and 12 after starting the driving so that the circumferential speed of the photoreceptor 3 and the transfer body 4 may coincide with each other from the time of starting the driving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, such as a copying machine or a printer, for forming an image using an electrophotographic system, and more particularly to an intermediate transfer member for temporarily carrying a toner image. The present invention relates to an image forming apparatus having the same.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus, for example, FIG.
As shown in FIG. 1A, a printer having an endless belt-shaped intermediate transfer member is known. In this image forming apparatus, when an image is output on recording paper, a photosensitive drum 3 is formed by using a laser ROS (Raster Output Scanner) 1 for writing a latent image and a developing device 2 for developing a toner image.
After the toner image is formed thereon, the toner image on the photosensitive drum 3 is transferred onto an intermediate transfer belt 4 functioning as an intermediate transfer member. At this time, if a color image is to be output, Y (yellow), M (magenta), C (cyan), and K each time the intermediate transfer belt 4 rotates once.
The toner images of each color (black) are transferred, and the toner images of four colors are synthesized on the intermediate transfer member belt 4. And
After the intermediate transfer belt 4 once carries the toner image, the toner image on the intermediate transfer belt 4 is then transferred onto recording paper, and the image is output on recording paper.

In recent years, separately from the so-called single-drum type image forming apparatus having one photosensitive drum 3 as described above, for example, as shown in FIG.
There is also a so-called tandem type provided with a plurality of photosensitive drums 3 corresponding to each color of M, C, and K. In the tandem-type image forming apparatus, the transfer from each photosensitive drum 3 to the intermediate transfer belt 4 is performed in order. Therefore, when the intermediate transfer belt 4 rotates once, the intermediate transfer belt 4 Then, the toner images of the respective colors of Y, M, C, and K are combined, and the speed of the color image output can be increased as compared with the single drum type.

[0004]

By the way, the above-mentioned image forming apparatus (single-drum type and tandem type)
, The intermediate transfer member belt 4 is formed in an endless belt shape, and is rotatably driven by a roll 4a that supports the belt.

On the other hand, the photosensitive drum 3 is required to have a stable rotation characteristic in order to improve the image quality. Therefore, the diameter of the photosensitive drum 3 is formed so as to increase the moment of inertia.
Moreover, it has a flywheel. Further, a blade 5 as a cleaning unit is constantly in sliding contact with the image forming surface of the photosensitive drum 3 in order to remove residual toner after the transfer of the toner image. Since the blade 5 is formed of a material having a relatively large friction coefficient, such as urethane, the driving load on the photosensitive drum 3 is large.

For this reason, the photosensitive drum 3 has a delay in the rise and fall of the rotation as compared with the intermediate transfer belt 4 which is driven to rotate by a roll 4a having a relatively small diameter and immediately responds to an instruction to start driving. Will occur. For example, when an instruction to start driving is given to both the photosensitive drum 3 and the intermediate transfer belt 4 at the same time, only the photosensitive drum 3 starts rotating after a lapse of a predetermined time from the instruction. This is because when a driving source (motor or the like) for driving the photosensitive drum 3 rotates, a driving system up to the photosensitive drum 3 bends, and an elastic energy corresponding to the rotational load torque of the photosensitive drum 3 is applied to the driving system. This is because the photoreceptor drum 3 starts rotating after is stored.

In other words, when a drive start instruction is given at the same time between the photosensitive drum 3 and the intermediate transfer belt 4, each of them starts to rotate (at the start of driving).
And just before stopping to stop rotation (at the end of driving)
And the largest speed (peripheral speed) difference occurs.

[0008] Such a difference in peripheral speed becomes a factor of generating a scratch between the photosensitive drum 3 and the intermediate transfer belt 4 for the following reason. Usually, the intermediate transfer belt 4 is always in contact with the toner image forming surface of the photosensitive drum 3 for transferring the toner image from the photosensitive drum 3. In addition, since its rigidity is lower than that of the photosensitive drum 3, in order to stabilize the transfer of the toner image,
It is urged against the image forming surface of the photosensitive drum 3 by some assist means. Therefore, if a difference in peripheral speed occurs between the photosensitive drum 3 and the intermediate transfer belt 4 in this state, abrasion occurs between them, and due to the abrasion, any of the soft members, for example, the photosensitive drum 3) The surface will be damaged.

This flaw can become large each time the image forming process is repeated, and appears as white spots or black streaks on the image when the image is output, and the image quality of the output image may be significantly impaired. It is something with. for that reason,
A user or a maintenance person of the image forming apparatus must frequently perform maintenance of the photosensitive drum 3 and the like in order to prevent such image quality defects from occurring. It leads to high cost.

The difference in the peripheral speed between the photosensitive drum 3 and the intermediate transfer belt 4, which causes the generation of the scratches, is maximized at the start of driving and at the end of driving, as described above. Therefore, it is conceivable to increase the rigidity of the drive system related to the photosensitive drum 3 to improve the followability to the drive of the drive source, and to suppress the difference in the peripheral speed with the intermediate transfer belt 4 at the start or end of the drive. Can be However, in this case, the rigidity of the drive system increases the device cost, which is not advantageous from the viewpoint of cost. Further, there is a disadvantage that high-frequency vibrations are easily picked up and another image quality defect is generated.

It is also conceivable that the peripheral speeds of the photosensitive drum 3 and the intermediate transfer belt 4 are made equal by performing feedback control. In particular,
For example, as disclosed in Japanese Patent Application Laid-Open No. 64-72176, between the photosensitive drum 3 and the intermediate transfer belt 4, one speed is detected using an encoder or the like, and based on the detection result. To turn on the other drive source
By turning OFF, one speed may be made to follow the other. However, in this case, in order to make one speed follow the other speed, the other speed is corrected by ON / OFF of the driving source, so that the position between the photosensitive drum 3 and the intermediate transfer belt 4 is changed. Although the relationship is always kept constant, the speed difference between them becomes large instantaneously at the time of speed correction, so that it is easily guessed that as a result, the area where scratches occur is increased.

Further, the occurrence of the flaw is caused by the photosensitive drum 3
When the driving start or the driving end is repeated when the positional relationship between the belt and the intermediate transfer belt 4 is the same, the degree becomes the most remarkable. Therefore, for example, it is conceivable that the stop positions of the photosensitive drums 3 are not set at the same position. However, this does not eliminate the occurrence of wear due to the difference in the peripheral speed, which leads to the occurrence of scratches. It's just an extension of time, not an essential solution.

Accordingly, the present invention does not require the rigidity of the drive system or the like, or the feedback control using a sensor or an encoder, so that the speed between the photosensitive member and the intermediate transfer member at the start or end of the drive can be reduced. It is an object of the present invention to provide an image forming apparatus that can prevent a difference from occurring and can suppress the occurrence of a scratch due to the speed difference.

[0014]

According to the present invention, there is provided an image forming apparatus comprising: a photosensitive member on which a toner image is formed; A first driving unit for rotating the photoconductor, and an intermediate transfer member that comes into contact with the toner image forming surface on the photoconductor, transfers the toner image at the contact portion, and has a rotation resistance different from that of the photoconductor. A second driving unit that rotationally drives the intermediate transfer body, and a timing control unit that, when starting driving by the first driving unit and the second driving unit, causes a driving start timing between each to differ by a predetermined time; When both the first drive unit and the second drive unit start driving, so that the peripheral speeds of the photoconductor and the intermediate transfer body at the contact point from that time coincide.
A drive speed control means for controlling the drive speed of the first drive means and the second drive means is provided.

In the image forming apparatus configured as described above,
When the first and second driving means start driving, the timing control means makes the driving start timing different between them. Therefore, even if the rotation resistance of the photoreceptor and the intermediate transfer member are different, the drive start timing of the smaller rotation resistance can be delayed for a predetermined time, so that the speed due to the delay of the rotation start of the larger rotation resistance is increased. There is no difference. In addition, after the driving by the first and second driving units is started, the driving speed control unit controls these driving speeds.
Therefore, even if the drive start timings are different between these, after the start of both drive, the respective peripheral velocities at the contact points between the photosensitive member and the intermediate transfer member become the same.

According to a second aspect of the present invention, there is provided an image forming apparatus, wherein: a photosensitive member on which a toner image is formed; first driving means for rotating the photosensitive member; and a toner image forming surface on the photosensitive member. The toner image is transferred at the contact point, an intermediate transfer member having a different rotational inertia from the photoconductor, and a second drive unit that rotationally drives the intermediate transfer member;
At the end of driving by the first driving unit and the second driving unit, one of the first driving unit and the second driving unit; Even if the drive ends, until both the photosensitive member and the intermediate transfer member stop rotating, the peripheral speeds of the photosensitive member and the intermediate transfer member at the contact point match, And a drive speed control means for controlling the drive speed of the first drive means and the second drive means.

In the image forming apparatus configured as described above,
When the first and second driving means end driving, the timing control means makes the driving end timing different between them. Therefore, even if the rotational inertia of the photosensitive member and the intermediate transfer member are different, the drive end timing of the smaller rotational inertia can be delayed for a predetermined time, so that the speed difference due to the stop delay of the larger rotational inertia can be reduced. It does not happen. In addition, the drive speed control means controls the drive speeds of the first and second drive means until both the photoconductor and the intermediate transfer body stop rotating. Therefore, even if the drive end timings of the first and second drive units are different, until both the photosensitive member and the intermediate transfer member driven by them stop rotating, each of the contact portions between them is stopped. Of the peripheral speeds are equal.

According to a third aspect of the present invention, there is provided an image forming apparatus, comprising: a photosensitive member on which a toner image is formed; first driving means for rotating the photosensitive member; and a toner image forming surface on the photosensitive member. An intermediate transfer member having a rotation resistance and a rotational inertia different from that of the photoconductor, the toner image being transferred at the contact portion, a second driving unit for driving the intermediate transfer member to rotate, When both the first driving unit and the second driving unit start driving, the timing control unit that makes the driving start timing and the driving end timing between the driving unit and the second driving unit differ from each other by a predetermined time, From that time until the rotation of both the photoconductor and the intermediate transfer member is stopped, the first speed is adjusted so that the peripheral speeds of the photoconductor and the intermediate transfer member at the contact location match. It is characterized in further comprising a driving speed control means for controlling the driving speed of the moving means and the second driving means.

In the image forming apparatus configured as described above,
When the first and second driving means start driving, the timing control means makes the driving start timing different between them. Therefore, even if the rotation resistance of the photoreceptor and the intermediate transfer member are different, the drive start timing of the smaller rotation resistance can be delayed for a predetermined time, so that the speed due to the delay of the rotation start of the larger rotation resistance is increased. There is no difference. Further, when the first and second driving means end driving, the timing control means makes the driving end timing between them different. Therefore, even if the rotational inertia of the photosensitive member and the intermediate transfer member are different, the drive end timing of the smaller rotational inertia can be delayed for a predetermined time, so that the speed difference due to the stop delay of the larger rotational inertia can be reduced. It does not happen. Moreover, in this image forming apparatus, the drive speed control means controls the drive speeds of the first and second drive means. Therefore, even if the drive start timing and the drive end timing of the first and second drive units are different from each other, the contact between the photosensitive member and the intermediate transfer member after the start of the drive until the rotation is stopped is started. The respective peripheral velocities at the location become the same.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 1 illustrates the present invention.
FIG. 2 is a schematic configuration diagram when applied to a so-called single drum type image forming apparatus. In FIG. 1, the same components as those of the above-described conventional image forming apparatus (see FIG. 3) are given the same reference numerals.

As shown in FIG. 1, the image forming apparatus of this embodiment includes a laser ROS1 for writing a latent image, a developing device 2 for developing the latent image, and a laser ROS1 for developing the latent image.
A photoreceptor drum 3 on which a toner image is formed by the OS 1 and the developing device 2; an intermediate transfer member belt 4 in contact with the toner image forming surface of the photoreceptor drum 3 and transferring the toner image at the contact location; And a blade (cleaner) 5 for removing residual toner on the photosensitive drum 3 later. When the intermediate transfer belt 4 carries a toner image, the toner image is transferred onto recording paper. It is configured to output an image.

The photosensitive drum 3 has a diameter of, for example, 84 mm and a driving load of 5 kgfcm. On the other hand, the endless intermediate transfer belt 4 supported by a plurality of rolls is driven by a roll 4a having a diameter of 30 mm, for example, and has a driving load of 1.5 kgfcm. Therefore, comparing these, the photosensitive drum 3 has a larger moment of inertia and a driving load, and its rotational resistance and rotational inertia are larger. Here, the rotation resistance corresponds to the difficulty of rising the rotation at the start of driving, and the rotation inertia corresponds to the difficulty of falling of the rotation at the end of driving.

The photosensitive drum 3 is connected to a drum drive motor 11 via a drive system such as gears, and is driven to rotate by the drum drive motor 11. The drum drive motor 11 is composed of a stepping motor, a servo motor, or the like, and operates according to a pulse signal from a controller 13 connected to the drum drive motor 11.

On the other hand, the intermediate transfer belt 4 is driven to rotate by a belt drive motor 12 connected to a roll 4a supporting the intermediate transfer belt 4 via a drive system such as a gear. Has become. The belt drive motor 12 is also composed of a stepping motor, a servo motor, or the like, like the drum drive motor 11, and operates according to a pulse signal from a controller 13 connected to the belt drive motor 12.

That is, the drum driving motor 11 and the belt driving motor 12 function as the first driving means and the second driving means in the present invention, and both of them operate by a pulse signal given from the controller 13. It is controlled.

Here, the drive control of the drum drive motor 11 and the belt drive motor 12 by the controller 13 will be described in detail with reference to FIG.

The controller 13 includes the drum driving motor 1
In starting the drive of the belt drive motor 1 and the belt drive motor 12, first, a pulse signal is given only to the drum drive motor 11. As a result, the drum drive motor 11 starts rotating the photosensitive drum 3.

However, at this time, the photosensitive drum 3
The drive system between the drum drive motor 11 and the photosensitive drum 3 bends, and after the drive system stores elastic energy corresponding to the rotational load torque of the photosensitive drum 3, it starts rotating. That is, the photosensitive drum 3 is driven for a certain period of time from the start of driving by the drum driving motor 11 (A in the figure).
Will start rotating after elapse. This delay amount is a fixed value that can be derived in advance from the rotational resistance of the photosensitive drum 3, that is, the moment of inertia and the driving load, and is specifically about 15 msec. After the rotation starts, the peripheral speed of the photosensitive drum 3 increases with time (B in the figure). This is because the controller 13 gives an exponential function type pulse to the drum drive motor 11.

When the driving of the drum driving motor 11 is started in this way, the controller 13 then gives a pulse signal to the belt driving motor 12 after a predetermined time has elapsed (C in the figure). That is, the controller 13 delays the generation timing of the pulse signal for the belt drive motor 12 by a predetermined time as compared with that for the drum drive motor 11. This predetermined time corresponds to a delay amount (fixed value) of the rise at the start of rotation of the photosensitive drum 3, and can be set in advance.

Further, when giving a pulse signal to the belt drive motor 12, the controller 13 has the same peripheral speed at the contact point between the photosensitive drum 3 and the intermediate transfer belt 4 from the start of the drive. To do. Specifically, the controller 13 does not start up the belt drive motor 12 from the speed “0”, but gives a pulse signal of the number of pulses at which the drive speed becomes a predetermined speed from the start of the start (D in the figure). Also gives pulse signals of the number of pulses whose peripheral speeds match (E in the figure). The number of pulses at this time can be determined in advance from the number of pulses of the pulse signal (exponential function type pulse) given to the drum drive motor 11 and the difference amount (predetermined time) of the generation timing of the pulse signal. is there.

That is, the controller 13 sets the drive start timings of the drum drive motor 11 and the belt drive motor 12 to be different from each other by a predetermined time in accordance with a predetermined programming when starting the drive. Photoconductor drum 3 from time
The number of pulses (driving speed) given to each of them is controlled so that the peripheral speed at the contact point between the belt and the intermediate transfer belt 4 is the same. As a result, the peripheral speed profiles (changes in peripheral speed) of the photosensitive drum 3 and the intermediate transfer belt 4 at the start of driving are the same.

Thereafter, when the driving of the drum driving motor 11 and the belt driving motor 12 is terminated, the controller 13 supplies an exponential function type pulse signal to both of them, and the controller 13 supplies the photosensitive drum 3 and the intermediate transfer belt. The peripheral speed of No. 4 is reduced with the passage of time (F in the figure). However, immediately before the stop of the photosensitive drum 3 and the intermediate transfer belt 4, the controller 13 sets the end timing of the pulse signal to the belt drive motor 12 to
It is delayed for a predetermined time from that for the drum drive motor 11 (G in the figure). This predetermined time is equivalent to a fall delay amount (fixed value) at the end of the rotation of the photosensitive drum 3, and can be set in advance.

In addition, the controller 13 continues to operate until both the photosensitive drum 3 and the intermediate transfer belt 4 stop.
The peripheral speeds at the contact points between them are made to match. More specifically, the controller 13 stops driving the drum drive motor 11 based on the delay amount of the fall of the rotation of the photosensitive drum 3 and the difference amount (predetermined time) of the end timing of the pulse signal, and then controls the belt drive motor 12 The number of pulses of the pulse signal to the exponential function.

That is, when the drive by the drum drive motor 11 and the belt drive motor 12 is completed, the controller 13 makes the drive end timing between them different by a predetermined time in accordance with a pre-programmed programming. Until both the transfer belt 4 and the transfer member 4 stop rotating, the number of pulses (driving speed) given to each of them is controlled so that the peripheral speeds at the contact points between them become the same. As a result, the peripheral speed profiles of the photosensitive drum 3 and the intermediate transfer belt 4 at the end of driving are the same.

As described above, in the image forming apparatus of the present embodiment, the controller 13 has the functions of the timing control means and the drive speed control means in the present invention, and the drum drive motor 11 and the belt drive motor 12 The drive start timing and the drive end timing are different from each other by a predetermined time, and the photosensitive drum 3 and the intermediate transfer belt 4
Until both stop rotating, the drum drive motor 1 is controlled so that the peripheral speeds at the contact points between them are the same.
1 and the number of pulses of a pulse signal for the belt drive motor 12 are controlled.

Therefore, in this image forming apparatus, even if the rotational resistance or the rotational inertia of the photosensitive drum 3 and the intermediate transfer belt 4 are different, the drive start timing or the rotational inertia of the smaller rotational resistance is smaller. Since the drive end timing can be delayed by a predetermined time, there is no occurrence of a speed difference between these at the start of drive or at the end of drive. In addition, even if the drive start timing or the drive end timing of the drum drive motor 11 and the belt drive motor 12 are different, after the drive of the photosensitive drum 3 and the intermediate transfer belt 4 is started by these, the rotation is stopped. The peripheral speeds at the contact points between them are the same.

Therefore, in this image forming apparatus, the occurrence of flaws due to the difference in peripheral speed between the photosensitive drum 3 and the intermediate transfer belt 4, particularly the flaws at the start or end of driving, is prevented. It can be suppressed.

Specifically, by using this image forming apparatus, the rate of occurrence of image quality defects due to the generation of scratches can be suppressed as follows. For example, in the conventional apparatus (see FIG. 3), about 10% of the image forming process performed after the photosensitive drum 3 has rotated 10,000 times, and the image forming process has been performed after the photosensitive drum 3 has rotated 100,000 times. In about 50% of the processed images, image quality defects due to the occurrence of scratches occurred, whereas in this image forming apparatus, about 1%, 10% even after the photosensitive drum 3 rotated 10,000 times. Even after 10,000 rotations, the occurrence rate of image quality defects can be suppressed to about 5%.

Therefore, if an image forming process is performed using this image forming apparatus, the image quality of the output image will not be impaired due to white spots or black streaks on the image due to the above-mentioned scratches. . Further, since image defects due to the occurrence of scratches can be suppressed more than before, there is no need for the user or maintenance personnel to frequently maintain the photosensitive drum 3 or the like.
There is no reduction in the reliability of the components of the image forming apparatus or an increase in running costs. Moreover, in the image forming apparatus, these are achieved by the control of the controller 13, so that it is not necessary to increase the rigidity of the drive system relating to the photosensitive drum 3 or to perform feedback control using a sensor or an encoder. In addition, the cost of the apparatus is not improved.

In this embodiment, the case where the present invention is applied to a single-drum type image forming apparatus has been described. However, the present invention is not limited to this, and temporarily holds a toner image. As long as the image forming apparatus has an intermediate transfer member, the image forming apparatus can be similarly applied to a tandem type image forming apparatus.

In the present embodiment, the photosensitive drum 3
Is formed in a drum shape and the intermediate transfer body belt 4 is formed in an endless belt shape.
The present invention is not limited to this. That is, if the photosensitive member and the intermediate transfer member are driven by independent driving sources, and the rotational resistance or the rotational inertia between them is different, for example, the intermediate transfer member is formed in a drum shape. Even if the present invention is applied to the present invention, the same effects as those described above can be obtained.

[0042]

As described above, according to the image forming apparatus of the present invention, even if the rotation resistance or the rotation inertia of the photosensitive member and the intermediate transfer member are different, the drive start timing or the drive end timing is predetermined. Since the time can be made different, there is no speed difference between them at the start of driving or at the end of driving. In addition, even if the driving start timing or the driving end timing is different, the speed control for the first and second driving means allows
From the start of the drive of the photoconductor and the intermediate transfer member to the stop of the rotation of both, the peripheral speeds at the contact points between them are the same.

Therefore, in this image forming apparatus, it is possible to suppress the occurrence of scratches due to the difference in the peripheral speed at the start of driving or at the end of driving without increasing the rigidity of the drive system or performing feedback control. . That is,
If image forming processing is performed using this image forming apparatus, image defects due to the occurrence of scratches can be suppressed more than before, resulting in reduced component reliability and higher running costs of the image forming apparatus. Nor.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing a specific example of drive control at the start and end of driving in the image forming apparatus of FIG. 1;

FIG. 3 is a schematic configuration diagram of a conventional image forming apparatus;
(A) is a diagram showing a single-drum type image forming apparatus,
FIG. 2B is a diagram illustrating a tandem type image forming apparatus.

[Explanation of symbols]

3 photoconductor drum, 4 intermediate transfer belt, 11 drum drive motor, 12 belt drive motor, 13 controller

Claims (3)

[Claims] A photoconductor on which a toner image is formed; first driving means for rotating the photoconductor; and a toner image forming surface on the photoconductor. Transferred, and an intermediate transfer member having a rotation resistance different from that of the photoreceptor; a second drive unit for driving the intermediate transfer member to rotate; and a start of driving by the first drive unit and the second drive unit. A timing control unit that makes a drive start timing different between them by a predetermined time; and when both the first drive unit and the second drive unit start driving, the photoconductor and the photoconductor at the contact point are started from that time. An image forming apparatus comprising: a driving speed control unit configured to control driving speeds of the first driving unit and the second driving unit so that a peripheral speed of the intermediate transfer body coincides with that of the intermediate transfer body. . 2. A photoreceptor on which a toner image is formed, first driving means for driving the photoreceptor to rotate, and a contact with a toner image forming surface on the photoreceptor. Transferred, and an intermediate transfer member having a rotational inertia different from that of the photoreceptor; a second drive unit for rotationally driving the intermediate transfer member; and upon completion of driving by the first drive unit and the second drive unit. A timing control unit that makes drive end timings different from each other by a predetermined time; and the photosensitive member and the intermediate transfer member, even if one of the first drive unit and the second drive unit ends driving. Until both stop rotating, so that the peripheral speeds of the photoconductor and the intermediate transfer body at the contact location match,
An image forming apparatus comprising: a driving speed control unit that controls a driving speed of the first driving unit and the second driving unit. 3. A photoreceptor on which a toner image is formed, first driving means for rotating the photoreceptor, and a toner image forming surface on the photoreceptor. Transferred, and an intermediate transfer member having a rotation resistance and rotational inertia different from that of the photoreceptor, a second drive unit for driving the intermediate transfer member to rotate, and the first drive unit and the second drive unit A timing control unit that makes a drive start timing and a drive end timing different from each other by a predetermined time, and when both the first drive unit and the second drive unit start driving, the photoconductor and the intermediate transfer are started from that time. Until both the body and the body stop rotating, the first driving unit and the second driving unit are so controlled that the peripheral speeds of the photoconductor and the intermediate transfer body at the contact location match. An image forming apparatus comprising: a driving speed control means for controlling the moving speed.