JP2000214727A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a device capable of forming a high-quality toner image by effectively restraining a speed fluctuation caused on an image carrier at the time of performing image forming operation without lowering the workability at the time of attaching/detaching the image carrier by engaging an elastic member with a driving shaft. SOLUTION: The elastic member is engaged with the driving shaft. This device is provided with an elastic member consisting of a leaf spring for removing backlash 32 in the inside space S of the image carrier 1 divided by an image carrying drum 25 and a flange part 26. The base part 32A of the spring 32 is fixed on the inside surface 26A of the flange part 26 by caulking, for example. It does not matter whether one spring 32 is provided or plural springs 32 are provided, but it is good to provide two springs 32 arranged linearly in the radial direction of the image carrier 1. Then, the springs 32 are respectively disposed in the space between a leaf spring for energizing 30 and the driving shaft 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image bearing drum having a cylindrical shape, an image carrier having a flange fixed to an axial end of the image bearing drum, and an image carrier formed on the flange. A drive shaft removably fitted in the center hole, and a drive pin fixedly mounted on the drive shaft and engaging with a mounting groove formed in the flange portion. The drive shaft rotates the drive shaft. The present invention relates to an image forming apparatus that transmits a toner image to an outer surface of an image bearing drum while transferring the toner image to the image carrier through a pin, and rotating the image carrier, and transferring the toner image to a recording medium.

[0002]

2. Description of the Related Art In an image forming apparatus of the above-mentioned type configured as an electronic copying machine, various printers, facsimile machines or a multifunction machine having at least two of these functions, a drive pin provided on a drive shaft carries an image. Since it is fitted in the mounting groove formed in the flange portion of the body, the rotation of the drive shaft can be reliably transmitted to the image carrier and the image carrier can be driven to rotate. In addition, since the drive pins are engaged with the mounting grooves formed in the flange portion of the image carrier, when attaching and detaching the image carrier to and from the drive shaft, a large operation force is not required for attaching and detaching the image carrier. Can be easily performed by the operator.

When an image forming operation is performed while rotating the image carrier, the image forming element is in contact with the outer peripheral surface of the image carrier drum. Receives an external force due to the contact. Therefore, when the drive pin is loosely fitted in the mounting groove of the flange portion as described above, a slight speed fluctuation occurs in the rotating image carrier, thereby causing the toner image formed on the outer peripheral surface of the image carrier drum. May cause abnormalities.

In order to prevent the above-mentioned problems, an attempt has been made to fit the drive pin into the mounting groove so that the driving pin does not play loosely with the mounting groove, without causing looseness between them. It was done. However, according to this configuration, in order to attach and detach the image carrier to and from the image forming apparatus main body, when the center hole of the flange portion is fitted with the drive shaft or when both are detached, the gap between the drive pin and the mounting groove is formed. Since a large frictional force acts, a large operating force is required at the time of attaching and detaching the image carrier, and the disadvantage that the workability at the time of hitting the image carrier is reduced is inevitable.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to reduce the workability when attaching and detaching an image carrier. Another object of the present invention is to provide an image forming apparatus of the type described at the beginning, which is capable of forming a high-quality toner image by effectively suppressing a speed fluctuation occurring on an image carrier during an image forming operation.

[0006]

According to the present invention, in order to achieve the above object, in an image forming apparatus of the type described at the beginning, a gap in the rotation direction of the image carrier formed between the mounting groove and the driving pin is provided. An image forming apparatus is proposed, wherein an elastic member for suppressing speed fluctuation of the image carrier due to the above is fixed to the image carrier, and the elastic member is detachably engaged with the drive shaft. (Claim 1).

At this time, the elastic member is formed of a play leaf spring, and the play leaf spring does not rattle in a locking groove formed in the drive shaft in the rotation direction of the image carrier. It is advantageous if they are detachably engaged.

Further, in the image forming apparatus according to the first or second aspect, it is advantageous that the elastic member also serves as a current-carrying member of the image carrier (claim 3).

Further, in the image forming apparatus according to the first aspect, the elastic member may include a play leaf spring, and a notch formed in the play leaf spring may be fixed to the drive shaft. Advantageously, the provided locking pin is engaged detachably without rattling in the rotation direction of the image carrier.

The image forming apparatus according to claim 4, wherein the play-back leaf spring is provided in an internal space of an image carrier defined by an image carrier drum and a flange portion. The portion has a through hole through which the locking pin passes when the center shaft formed in the flange portion and the drive shaft are attached to and detached from the drive shaft, and the through hole is formed at the bottom of the mounting groove. (Claim 5).

Further, in the image forming apparatus according to any one of claims 1 to 4, it is advantageous that the elastic member is provided in an internal space of the image carrier defined by the image carrier drum and the flange portion. Claim 6).

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic sectional view showing an example of an image forming apparatus. The image forming apparatus shown here has an image carrier 1 configured as a photosensitive member. FIG. 1 shows only the outline of the image carrier, but as will be described later, the image carrier 1 has a cylindrical shape having a photosensitive layer laminated on the surface of a conductive drum base. An image bearing drum 25;
A flange portion.

The image carrier 1 is rotatably supported by a frame of the image forming apparatus main body, and is driven to rotate clockwise in FIG. 1 by a drive motor described later. At this time, the surface of the image bearing drum 25 is charged by the charging roller 2 which is an example of a charging device. The charging roller 2 rotates while being in contact with the outer surface of the image bearing drum 25. At this time, a voltage of a predetermined polarity is applied to the charging roller 2, whereby the surface of the image bearing drum is uniformly charged to that polarity. You. The charged surface is irradiated with light-modulated laser light L emitted from the optical writing device 3, whereby a predetermined electrostatic latent image is formed on the surface of the image bearing drum. This electrostatic latent image is visualized as a toner image by the toner when it passes through the developing device 4.

On the other hand, a recording medium P made of transfer paper or a resin sheet is fed from a paper feeding device (not shown),
The recording medium P is sent to the transfer position 6 at a predetermined timing by the pair of registration rollers 5, where the toner image on the image carrying drum 25 is transferred onto the recording medium. At the transfer position 6, a transfer belt 7 driven while being in contact with the surface of the image bearing drum 25 is arranged.
The recording medium P is sent to the transfer position 6 between the transfer belt 7 and the image carrying drum 25.
And the image bearing drum 25
The upper toner image is transferred onto the recording medium P.

The recording medium P on which the toner image has been transferred is sent to a fixing device (not shown) by the transfer belt 7, where the toner image is fixed on the recording medium. After the toner image is fixed, the recording medium is discharged out of the apparatus and stacked on a discharge tray (not shown).

The transfer residual toner adhering to the surface of the image bearing drum after the transfer of the toner image is removed by the cleaning blade 8A of the cleaning device 8, and the surface of the image bearing drum is cleaned. The cleaning blade 8A presses against the surface of the image bearing drum 25 to scrape off and remove transfer residual toner on the surface. Thereafter, the surface of the image bearing drum is subjected to a charge removing operation by light from the charge removing lamp 9.

FIG. 2 is a partial sectional plan view showing an example of a drive motor 10 for rotating the above-described image carrier 1 and a transmission for transmitting the rotation to the image carrier 1. FIG. It is a front view explaining arrangement state of each element.

The drive motor 10 is fixedly supported by a bracket 12 fixed to a frame 11 of the image forming apparatus main body. An output gear 13 of the drive motor 10 meshes with a first reduction gear 14. The gear 14 is rotatably supported by a shaft 15 fixed to the bracket 12 and meshes with a second gear 16. The second gear 16 is fixed to a shaft 17 rotatably supported on the bracket 12 via a bearing. A timing pulley 18 concentric with the second gear 16 is provided at one end of the shaft 17. Fixed. An endless timing belt 21 is wound around the timing pulley 18 and another timing pulley 19,
The other timing pulley 19 is fixed to a drive shaft 22 that supports one end of the image carrier 1 as described later. The image carrier 1, its driving shaft 22 and the timing pulley 19 are arranged concentrically with each other.

The drive shaft 22 is rotatably supported by an image carrier holder 24 via two bearings 23, and the holder 24 is fixed to the frame 11 of the image forming apparatus main body. One of these bearings has a drive shaft 22
Is formed as a current-carrying bearing for grounding the image bearing drum 25 through the contact. The other end of the image carrier 1 is also rotatably supported by the frame of the image forming apparatus main body via a support member (not shown).

The drive motor 10 is operated and its output gear 1
3 rotates, the rotation of the first and second gears 14,
The rotation is transmitted to a timing pulley 18 via a shaft 16 and a shaft 17, and the rotation thereof is transmitted to the image carrier 1 via a timing belt 21, a timing pulley 19 and a drive shaft 22, and the image carrier 1 is a clock in FIG. Rotate in the direction
The image forming operation is performed as described above.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.
FIG. 5 is a partial cross-sectional view taken in the direction of arrow V in FIG. 4 in a state in which the image carrier 1 is driven. As shown in these figures, the axial direction of the image carrier drum 25 formed in a cylindrical shape is shown in FIG. At each end, a flange 26 shown briefly above is fixedly provided (only one flange is shown in FIG. 4). The flange portion 26 is formed in a disk shape concentric with the image carrying drum 25, and is fitted and fixed to an end of the image carrying drum 25.
A center hole 27 is formed in the center of the disk-shaped flange portion 26 in the axial direction of the image bearing drum 25 so as to penetrate the flange portion 26. The center hole 27 is rotatable in the image forming apparatus main body. The aforementioned drive shaft 22 supported by
It is inserted concentrically with the image carrying drum 25 and detachably.

A suitable number of drive pins 28 projecting in the radial direction are fixed to the drive shaft 22. In the illustrated example, two drive pins 28 are connected to the drive shaft 22 as shown in FIG. It protrudes and extends linearly outward from the outer peripheral surface in the radial direction. On the other hand, when the space defined by the image bearing drum 25 and the flanges fixed to each end thereof is referred to as an internal space S, the inner surface of the flange 26 shown in FIG. A mounting groove 29 into which the drive pin 28 is fitted is formed on the outer surface 26B opposite to 26A. In the illustrated example, the four mounting grooves 29 are formed in a radially
Extending in the radial direction of which two extend linearly with each other
As shown in FIG. 5, two drive pins 28 are
Are fitted respectively.

When the drive shaft 22 is driven to rotate as described above, the drive pin 28 fixed thereto also rotates, whereby the rotation of the drive shaft 22 is transmitted to the image carrier 1 via the drive pin 28. , The image carrier 1 rotates about its central axis. As described above, a toner image is formed on the outer surface of the rotating image carrier 1 that rotates, and the toner image is transferred to a recording medium.

In the above-mentioned internal space S, an appropriate number of current-carrying members including conductive current-carrying leaf springs 30 are arranged. Are fixed to the inner side surface 26A of the image carrier drum by, for example, caulking, and the respective free end portions thereof are pressed against the inner peripheral surface of the base of the image bearing drum 25 made of a conductor and the drive shaft 22 also made of a conductor. In the illustrated example, two energizing leaf springs 30 that are opposed to each other in the radial direction of the image carrier 1 are provided. In this way, the base of the image carrier 1 is grounded via the energizing leaf spring 30, the drive shaft 22, and the aforementioned energizing bearing 23 (FIG. 2), and the electric charge of the image carrier drum 25 is transferred to the image forming apparatus main body. The potential of the base of the image bearing drum 25 is maintained at 0 V. In the illustrated example, the flange portion 26 is made of an insulating material, but it may be made of a conductive material.

When replacing the image carrier 1, the image carrier 1
Is stopped, and the image carrier 1 is pulled out in a direction away from the drive shaft 22 as shown by an arrow A in FIG. Thereby, as shown in FIG. 6, the drive shaft 22 on the image forming apparatus main body side is pulled out from the center hole 27, and the image carrier 1 can be detached from the image forming apparatus main body. vice versa,
When the image carrier is pushed in as shown by the arrow B in FIG. 6, the center hole 27 and the drive shaft 22 are fitted to each other, and at this time, the drive pin 28 is fitted to any two mounting grooves 29 so that the image carrier is The body can be attached to the image forming apparatus main body.

As described above, when the image carrier is attached to and detached from the image forming apparatus main body, the width W of the mounting groove 29 is larger than the diameter D of the driving pin 28 so that the driving pin 28 can easily enter the mounting groove 29. Is also set large. The driving pin 28 fits into the mounting groove 29, and a slight gap G (FIG. 5) in the rotation direction of the image carrier 1 is formed between the mounting groove 29 and the driving pin 28. Therefore, when the drive pin 28 is attached to and detached from the mounting groove 29, a large frictional force does not act between them, and the operator can attach and detach the image carrier 1 with a small operation force.

As described above, the image forming apparatus shown in FIG.
The image carrier 1 having a cylindrical image carrier drum 25 and a flange portion 26 fixed to an axial end of the image carrier drum 25, and is detachable from a center hole 27 formed in the flange portion 26. And a drive shaft 22 fixed to the drive shaft 22 and an outer surface 26 of the flange portion 26.
B, and a driving pin 28 which fits into a mounting groove 29 formed in the mounting member B. The rotation of the driving shaft 22 is transmitted to the image carrier 1 via the driving pin 28, and the image carrier 1 is rotationally driven. A toner image is formed on the outer surface of the image carrying drum 25, and the toner image is transferred to the recording medium P.

When the image carrier 1 is rotated to perform an image forming operation, the image carrier is in contact with the outer surface of the image carrier drum 25. From external force. In the example shown in FIG. 1, the cleaning blade 8A, the charging roller 2, and the transfer belt 7 are in contact with the peripheral surface of the image bearing drum 25. The cleaning blade 8A exerts a frictional force on the rotating image carrier 1 in a direction opposite to the rotating direction, and the outer peripheral linear velocity of the charging roller 2 and the transfer belt 7 is the same as the outer peripheral linear velocity of the image carrying drum 25. Instead, there is usually a slight relative speed difference between the two. For this reason, a frictional force for decelerating or increasing the speed of the image carrying drum 25 from the charging roller 2 and the transfer belt 7 always acts on the outer peripheral surface of the image carrying drum 25. At this time, between the drive pin 28 and the mounting groove 29 as described above,
If there is a gap G in the rotation direction (circumferential direction) of the image carrier 1, the rotational speed of the image carrier 1 may fluctuate due to the frictional force acting on the outer surface of the image carrier drum 25. Assuming that such a change in the rotation speed is left, the beam spot of the laser beam L emitted from the optical writing device 3 shown in FIG. The toner image formed on the surface of the image carrying drum expands and contracts, thereby causing an abnormality.

In order to eliminate the above-mentioned inconvenience, a projection 31 is provided on the drive pin 28 as shown by a chain line in FIG.
Attempts have been made to eliminate backlash between the drive pin 28 and the mounting groove 29. However, if such a protrusion 31 is provided, the drive pin 28 is fitted into or removed from the mounting groove 29. At this time, a large operation force is required, and the workability when attaching and detaching the image carrier 1 is reduced. Also, if the protrusion 31 wears over time, rattling occurs between the drive pin 28 and the mounting groove 29,
The function of the protrusion 31 will be lost.

Further, the diameter D of the drive pin 28 is increased,
Alternatively, a method of reducing the width W of the mounting groove 29 to eliminate the backlash between the two has been attempted. However, even with this configuration, a large operation force is required at the time of attaching and detaching the image carrier, and the working efficiency is reduced.

Therefore, in the image forming apparatus of this embodiment,
As shown in FIGS. 4, 6 and 7, an elastic member composed of a leaf spring 32 is provided in an internal space S of the image carrier 1 defined by the image carrier drum 25 and the flange portion 26. The base 32A of the play-back leaf spring 32 is fixed to the inner surface 26A of the flange 26 by, for example, caulking. Although the number of the play leaf springs 32 may be one or plural, in the illustrated example, two rattles are arranged linearly in the radial direction of the image carrier 1. A leaf spring 32 is provided.
Numerals 2 are provided in the spaces between the respective energizing leaf springs 30 and the drive shaft 22. In order to avoid complication of the drawing, FIG. 7 shows only one play leaf spring 32.

On the other hand, on the outer peripheral surface of the drive shaft 22, there is formed a locking groove 33 with which the above-mentioned play leaf spring 32 is engaged. In the illustrated example, as shown in FIG. 7, four locking grooves 33 arranged in a cross shape at an angle of 90 ° in the circumferential direction of the drive shaft 22 are formed, and each of the locking grooves 33 is It extends in the axial direction of the drive shaft. At this time, as can be seen from FIGS. 4 and 7, two locking grooves 33 that are linearly arranged in the radial direction of the drive shaft 22 and that are positioned opposite to each other coincide with the center axis C of the drive pin 28. The other two locking grooves 33 occupy an angular position shifted by 90 ° with respect to the center axis C of the drive pin 28. The cross-sectional shape of each locking groove 33 is formed in a tapered shape whose width is expanded from the bottom toward the opening.

Of the above-mentioned four locking grooves 33, two locking grooves 33 which are opposed to each other and are linearly arranged in the radial direction of the drive shaft 22 are fitted with the above-mentioned rattling leaf springs. 32, the free end side portion 32B of the image carrier 1 is detachably engaged with the image carrier 1 in a rotational direction, as shown in FIG. Integrated into Therefore, when the image carrier 1 is rotationally driven by the rotation of the drive shaft 22 as described above, the drive pins 2
A gap G (FIG. 5) is formed between the image bearing member 25 and the mounting groove 29 in the rotation direction of the image carrier, and a frictional force is applied to the outer peripheral surface of the image carrier drum 25 by an image forming element such as the cleaning blade 8A. However, the image carrier 1 and the drive shaft 22 do not rattle, they rotate at the same speed, and the speed fluctuation occurring in the image carrier 1 can be effectively suppressed. This can effectively prevent an abnormal toner image from being formed on the surface of the image bearing drum.

As described above, when the image carrier 1 is detached from the image forming apparatus main body, the leaf spring 32, which constitutes an example of an elastic member, engages the locking groove 33 with the drive shaft 22.
While sliding in the direction of the axis of FIG. In order to mount the image carrier 1 on the image forming apparatus main body, when the center hole 27 is fitted to the drive shaft 22 and the image carrier 1 is pushed in, the drive pin 28 fits into the mounting groove 29 and The rattling leaf spring 32 also fits into the locking groove 33.

When the image carrier is attached to and detached from the image forming apparatus main body as described above, since the play-back leaf spring 32 can be elastically deformed, the image carrier 1 is pulled out or pushed in. No large operation force is required, and the image carrier can be easily attached and detached. Further, since the width of the locking groove 33 of the present example is widened toward the opening, the leaf spring 32 for backlash enters the locking groove 33 by its own elasticity, and is smoothly locked. The groove 33 is engaged. Thereby, the operation force at the time of attaching and detaching the image carrier 1 can be effectively reduced.

As described above, in the image forming apparatus of this embodiment, the image caused by the gap G in the rotation direction of the image carrier formed between the mounting groove 29 formed in the flange portion 26 and the drive pin 28. An elastic member for suppressing speed fluctuation of the carrier is fixed to the image carrier 1, and the elastic member is detachably engaged with the drive shaft 22. This configuration is common to each embodiment described later, and prevents the operation force at the time of attaching / detaching the image carrier from becoming excessively large, and prevents the speed fluctuation occurring when the image carrier rotates. Can be effectively suppressed. Moreover, since the elastic member is fixed to the image carrier 1, when the image carrier is replaced, the elastic member is also replaced. Therefore, when the elastic member is used for a long period of time, there is no fear that the elastic member is permanently deformed and its function is deteriorated.

Further, in the first embodiment shown in FIGS. 4 to 7, the elastic member is constituted by a rattling leaf spring 32, which is formed on the drive shaft 22. The engaging groove 33 is detachably engaged with the locking groove 33 without rattling in the rotation direction of the image carrier 1. Thus, the above-described operation and effect can be achieved with a simple configuration.

FIGS. 8 to 10 show the second embodiment and correspond to FIGS. 4, 6 and 7. FIG. This second
In the embodiment, the removing leaf spring 32, which is an example of an elastic member, also serves as an energizing member of the image carrier 1, and the energizing leaf spring 30 shown in FIGS. Not provided. That is, the ratchet leaf spring 32 shown in FIGS. 8 to 10 is made of a conductor, the base 32A of which is fixed to the inner surface 26A of the flange portion 26, and the free end portion 32B of one of the ends. As in the previous embodiment, the locking groove 33 formed in the drive shaft 22 made of a conductor
The other free side portion 32C of the play leaf spring 32 is in pressure contact with the inner surface of the base made of the conductor of the image bearing drum 25. Thereby, the image carrier 1
Can be released to the main body of the image forming apparatus via the play-out leaf spring 32, the drive shaft 22, and the above-described energizing bearing 23. FIG. 10 also shows only one play leaf spring 32.

According to the above configuration, the dedicated energizing leaf spring 3
0 (FIGS. 4 and 6) can be omitted, the number of parts can be reduced, the structure of the image carrier can be simplified, the cost can be reduced, and as is clear from FIG. The length of one of the free ends 32, that is, the free end on the side that contacts the drive shaft 22, can be increased, and this portion can be configured to be more easily elastically deformed. For this reason, the operating force required when attaching and detaching the image carrier 1 is reduced.
It is possible to make it even smaller than in the case of the first embodiment described above. At this time, the rigidity in the image carrier rotation direction at one free end side of the long flat play removing spring 32 is reduced, so that when the drive shaft 22 rotates,
As shown in FIG. 10, in order to prevent one of the free ends from being greatly elastically deformed, as shown in FIG. 10, the width of one of the free ends of the play-back leaf spring 32, particularly the portion close to its base 32A (FIG. 8). It is desirable to increase the width of the wire to prevent the rigidity from being reduced.

Other configurations of the second embodiment shown in FIGS. 8 to 10 are the same as those of the embodiment shown in FIGS. 1 to 7, and therefore, the description of the same portions will be omitted.

FIGS. 11, 13 and 14 show a third embodiment, corresponding to FIGS. 4, 6 and 7, and FIG. 12 is a view taken in the direction of arrow XII in FIG. It is. The drive shaft 22 shown in FIG. 13 is shown in a state where the drive shaft 22 shown in FIG. 4 is rotated by 90 °. In the third embodiment, the locking groove 33 formed in the drive shaft 22 of each of the above-described embodiments is not provided. Instead, the drive shaft 22 is provided in the radial direction thereof. The protruding locking pin 34 is fixed by, for example, press fitting. Although the number of the locking pins 34 can be set as appropriate, in the illustrated example, two locking pins 34 are provided, and one of the locking pins 34 is
The one driving pin 28 is arranged at the same angular position, and the other locking pin 34 is provided at an angular position shifted by 90 ° from the one locking pin 34. These locking pins 34 are arranged closer to the tip of the drive shaft 22 than the pair of drive pins 28.

On the other hand, inside the image carrier 1, an appropriate number of elastic members, in the example shown in the figure, comprising two play leaf springs 32, are arranged. Only the leaf spring 32 is shown. One play leaf spring 32 is arranged at the same angular position as one mounting groove 29 formed in the flange portion 26, and the other play leaf spring 32 is
It is arranged at the same angular position as the adjacent mounting groove 29 which is positioned at an angle of 90 ° with respect to one mounting groove 29.

As in the case of the second embodiment shown in FIGS. 8 to 10, the rattling leaf spring 32 is made of a conductive material, and as shown in FIG. 26, one of its free end portions 32B is pressed against the drive shaft 22 made of a conductor, and the other free end portion 32C of the base made of the conductor of the image bearing drum 25 is pressed. It is pressed against the inner surface. As a result, the play leaf spring 32 also serves as a current-carrying member.

Notches 35 each formed of a through hole are formed in each of the rattling leaf springs 32. As shown in FIG. Are detachably engaged without rattling in the rotation direction. The flange portion 26 has a through hole 36 through which the locking pin 34 passes when the image carrier 1 is attached or detached. The other configuration is the same as the configuration of the embodiment described above with reference to FIGS. 1 to 7, and thus the description of the same portions will be omitted.

As described above, in the third embodiment, the elastic member is composed of the play-back leaf spring 32 and is fixed to the drive shaft 22 in the notch 35 formed in the leaf spring 32. The locking pin 34 is detachably engaged with the rotating direction of the image carrier 1 without rattling. Therefore, in this example as well, the drive shaft 22 and the image carrier 1 are integrated in the rotating direction. The image carrier 1 is prevented from rattling with respect to the drive shaft 22 in the circumferential direction when the image carrier 1 is rotated, and the fluctuation of the rotation speed of the image carrier 1 is effectively suppressed. Is done. This can prevent an abnormal image from being formed on the surface of the image bearing drum 25.

At this time, in the image forming apparatus of this embodiment,
A locking pin 34 fixed to the drive shaft 22 is engaged with the leaf spring 32 near the base 32 </ b> A of the leaf spring 32. That is, the locking pin 34 is held by the ratchet leaf spring 32 near the bending origin 32D of the cantilever rattle leaf spring 32. For this reason, even if a sudden load change occurs in the image carrier 1 when the drive shaft 22 rotates, the deflection of the flat spring 32 is minimized, and the rotation of the drive shaft 22 is reliably performed. And the speed fluctuation of the image carrier can be suppressed more reliably.

When removing the image carrier 1 from the image forming apparatus main body, the image carrier 1 is pulled out as shown by an arrow A in FIG. As a result, the notch 35 formed in the play-back leaf spring 32 of the locking pin 34 is released, and then the locking pin 34 passes through the through-hole 36 formed in the flange portion 26 and passes through the image carrier 1.
Can be removed from the image forming apparatus main body without any trouble. When the image carrier 1 is pushed into the back of the image forming apparatus main body as shown by an arrow B in FIG. 13, the drive shaft 22 and the center hole 27 are fitted, and the drive pin 28 is fitted in the mounting groove 29. , The locking pin 34 passes through the through hole 36 of the flange portion 26, and then the notch 35 of the
And is retained here.

As described above, the rattling leaf spring 32 is
A center hole 2 formed in the flange portion 26 is provided in the internal space S of the image carrier 1 defined by the image bearing drum 25 and the flange portion 26.
When attaching / detaching the drive shaft 7 to / from the drive shaft 22, a through hole 36 through which the lock pin 34 passes is formed. 26 mounting groove 29 and flat leaf spring 3
By setting the relative mounting angle positions 2 as described above, the through hole 36 of the flange 26 can be formed at the bottom of the mounting groove 29 as shown in FIG. Thereby, it is not necessary to form the through hole 36 in the portion of the flange portion 26 sandwiched between the two mounting grooves 29,
The flange portion 26 can be easily processed at low cost.

The elastic member made of a play leaf spring can be provided outside the image carrier 1, but in each of the above-described embodiments, the elastic member is the image carrier drum 25 and the flange. Image carrier 1 partitioned by section 26
In the internal space S. For this reason, the image carrier 1
At the time of attachment and detachment, there is no risk that the elastic member will be in the way or other elements will hit the elastic member and break them,
The function of the elastic member can be maintained and maintained for a long time.

The present invention can be applied to various types of image forming apparatuses other than those shown in FIGS. 1 to 3. For example, the image carrier is primarily transferred with a toner image formed on a photoreceptor.
The present invention can be widely applied to an image forming apparatus including an intermediate transfer member for secondary transferring the toner image to a recording medium, an analog type image forming apparatus, and the like.

[0052]

According to the image forming apparatus of the first aspect, by engaging the elastic member with the drive shaft, the image carrier and the drive shaft are integrally formed in the rotation direction of the image carrier. The image carrier can be rotated at the same speed as the drive shaft even if an external force acts on the image carrier, thereby suppressing the speed fluctuation of the image carrier and forming the image carrier on the surface of the image carrier drum. The problem that an abnormality occurs in the toner image can be effectively suppressed.

Further, since the elastic member provided on the image carrier is engaged with the drive shaft, an excessively large operation force is not required when the image carrier is attached or detached. Further, since the elastic member is exchanged together with the image carrier, it is possible to prevent functional deterioration due to deterioration of the elastic member.

According to the image forming apparatus of the second aspect,
The above effects can be obtained with a simple configuration.

According to the image forming apparatus of the third aspect,
Since the elastic member also serves as a current-carrying member of the image carrier, an increase in the number of parts and an increase in cost can be suppressed.

According to the image forming apparatus of the fourth aspect,
Even when a sudden change in the charge of the image carrier occurs, the deflection of the elastic member can be suppressed, and the speed fluctuation of the image carrier can be more effectively suppressed.

According to the image forming apparatus of the fifth aspect,
The image carrier can be easily manufactured, and its cost can be reduced.

According to the image forming apparatus of the sixth aspect,
The elastic member does not hinder the attachment and detachment of the image carrier and the like, and the elastic member can be prevented from hitting other objects to damage the elastic member.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view illustrating an example of an image forming apparatus.

FIG. 2 is a partial cross-sectional plan view showing a transmission used in the image forming apparatus shown in FIG.

FIG. 3 is a diagram illustrating an arrangement state of each element of the transmission illustrated in FIG. 2;

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 2, showing details of the first embodiment;

FIG. 5 is a view as seen in the direction of arrow V in FIG. 4;

FIG. 6 is a cross-sectional view similar to FIG. 4, showing a state when an image carrier is attached and detached.

FIG. 7 is a view seen in the direction of arrow VII on the left side of FIG. 4;

FIG. 8 is a sectional view similar to FIG. 4, showing details of the second embodiment.

9 is a cross-sectional view similar to FIG. 6, showing a state when the image carrier shown in FIG. 8 is attached and detached.

FIG. 10 is a view seen in the direction of arrow X, which is the left side of FIG. 8;

FIG. 11 is a sectional view similar to FIG. 4, showing details of the third embodiment.

12 is a view as seen in the direction of arrow XII in FIG.

FIG. 13 is a sectional view similar to FIG. 6, showing a state when the image carrier shown in FIG. 11 is attached and detached.

FIG. 14 is a diagram showing a state when viewed from the left side of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image carrier 22 Drive shaft 25 Image carrier drum 26 Flange part 27 Center hole 28 Drive pin 29 Mounting groove 32 Flat spring 33 Locking groove 35 Notch 36 Through hole G Gap S Internal space

Claims (6)

[Claims] 1. An image carrier having a cylindrical image carrier drum, an image carrier having a flange fixed to an axial end of the image carrier drum, and detachable from a center hole formed in the flange. A drive shaft fixed to the drive shaft, and a drive pin fixed to the drive shaft and fitted into a mounting groove formed in the flange portion, and the rotation of the drive shaft is transmitted to the image through the drive pin. The toner image is formed on the outer surface of the image bearing drum while the image carrier is rotated and driven,
An image forming apparatus for transferring the toner image to a recording medium, comprising: an elastic member for suppressing a speed variation of the image carrier due to a gap in the image carrier rotation direction formed between the mounting groove and the driving pin; An image forming apparatus fixed to a carrier, and the elastic member is detachably engaged with the drive shaft. 2. The image forming apparatus according to claim 1, wherein the elastic member comprises a rattling leaf spring, and the rattling leaf spring does not rattle in a locking groove formed in the drive shaft in a rotation direction of the image carrier. The image forming apparatus according to claim 1, wherein the image forming apparatus is detachably engaged. 3. The image forming apparatus according to claim 1, wherein the elastic member also serves as a current-carrying member of the image carrier. 4. The image bearing member according to claim 1, wherein the elastic member comprises a play leaf spring, and a notch formed in the play leaf spring has a locking pin fixed to the drive shaft. 2. A detachable engagement without rattling in a rotation direction.
An image forming apparatus according to claim 1. 5. The backlash spring is provided in an internal space of an image carrier defined by an image carrier drum and a flange, and a center formed in the flange is provided in the flange. The image forming apparatus according to claim 4, wherein a through hole through which the locking pin passes is formed when the hole and the drive shaft are attached and detached, and the through hole is formed at a bottom of the mounting groove. 6. The image forming apparatus according to claim 1, wherein said elastic member is provided in an internal space of an image carrier defined by an image carrier drum and a flange portion.