JP3293718B2 - Driving force transmission device to image carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for transmitting a driving force to an image carrier for driving a plurality of image carriers.
You .

[0002]

2. Description of the Related Art As a conventional structure for rotating a plurality of rotating members, for example, Japanese Unexamined Utility Model Publication No.
-95345 has four worms and worm wheels.
There has been proposed a configuration in which rotation is performed by a combination with a motor. However, in such a configuration, if the precision of the parts (the precision of the tooth profile between the worm wheel and the worm wheel, especially the runout) is poor, a rotation error occurs. In particular, the rotation of the fourth rotating member (drum) farthest from the driving motor is accumulated. In addition, an attempt to improve the precision of the parts increases the cost, the mounting members and the like become complicated, and this leads to an increase in the cost of the apparatus.

[0003] For example, Japanese Utility Model Laid-Open No. 2-129666 proposes a configuration using a belt and a gear. However, even in such a configuration, accurate components and the like are required, which leads to an increase in the cost of the apparatus. In addition, when a belt (timing belt) is used, a meshing error with the belt pulley, a belt vibration, and the like also occur, so that it becomes difficult to transmit a good rotation.

Further, for example, Japanese Patent Application Laid-Open No. HEI 2-15786
No. 8 also proposes a configuration using a belt and a gear, but such a configuration causes a problem that vibration generated in the belt or the gear is transmitted as it is. Especially in the case of belt transmission, one
The rotation is transmitted from the step and driven pulleys to each of the pulleys via the respective pulleys, and to the pulley of the rotating member (drum) via three stages of pulleys. In this case, the vibration generated in each pulley and the belt becomes very large and further accumulates, so that a serious problem occurs.

[0005] When a plurality of rotating members are driven, each rotating member has a rotation fluctuation component, causing variations. In particular, when the rotating member is a photosensitive drum, if the variation is large, that is, if there is a large variation in the rotation of each photosensitive drum (variation in the amount of fluctuation of the worm oil, phase difference, etc.), the color shift is caused. Leads to In addition, when vibration or the like at the time of gear engagement is transmitted, fine feeding unevenness occurs on an image, which leads to a reduction in resolution.

[0006]

As described above, the configuration proposed to rotate a plurality of rotating members proposed in the prior art has the drawbacks that the cost of the apparatus is increased and that a large amount of vibration is generated.

[0007] The present invention has been made in view of the above, and an object of the present invention is to provide an apparatus that suppresses an increase in apparatus cost and generation of vibration.

[0008]

According to the present invention , a drive motor is provided at a substantially central portion to achieve the above object.
The drive is performed on the axes of the left and right image carriers that are close to the moving motor.
Each driven member to which the driving force from the moving motor is transmitted
Left and right images close to the drive motor
One end of the first rotation support member is fixed to the shaft of the carrier.
And each of the first rotation support members
Independent link means are connected to the other end of the
And the outer left side which is not close to the drive motor.
One end of the second rotation support member is provided on the shaft of each image carrier on the right.
And each of the second rotations
Each of the link means is connected to the other end of the support member.
A driving force transmitting device for transferring the image to the image carrier,
The length of the holding member was set to half the length of the first rotation support member.
It is another object of the present invention to provide a device for transmitting a driving force to an image carrier .

According to another aspect of the present invention, there is provided an image forming apparatus , comprising:
And the outermost left and right image carriers of the plurality of image carriers.
Separated from the body axis by a distance equal to the pitch between each image carrier
To hold one end of the link means rotatably.
2. A fixing portion provided for each of the first and second members.
The present invention proposes a device for transmitting a driving force to an image carrier as described in the above item .

Further, the present invention achieves the above object.
For this reason, a driving motor is disposed at a substantially central portion, and a driven member in which a driving force from the driving motor is transmitted to shafts of the left and right image carriers that are close to the driving motor. Are provided, respectively .
The drive motor - motor - with one end of the first rotary support member to a shaft of the left and right image bearing member in proximity are provided respectively fixedly to the other end of the respective first rotary support member mutually independent linkage means are connected respectively to the drive motor - motor - is the axis of the image carriers of the left and right outer unapproximated to one end each solid <br/> second rotary support member together provided the Joteki, each link means is connected each of the other end side of each of the second rotary support member Zo担
A driving force transmission device for a holding body, comprising :
The shape and the shape of the second rotation support member are the same,
The drive between a plurality of image carriers located on the left side of the moving motor and the drive
Between a plurality of image carriers located on the right side of the moving motor,
It is noted that each is connected by one link
It proposes a driving force transmission device to the image carrier
There is .

[0011]

[0012]

[0013]

According to the present invention, a plurality of sets of link means having a similar shape are provided to transmit the driving force from the driving means. It can be driven.

[0014]

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

1 to 4 show an embodiment (first embodiment) of the present invention. FIG. 1 is a plan view, FIG. 2 is a front view, FIG. 3 is a perspective view, and FIG. FIG. 2 shows a partially enlarged view of FIG. 1. 1 is a first photosensitive drum, 2 is a second photosensitive drum, 3 is a third photosensitive drum, 4 is a fourth photosensitive drum, 5 and 6 are driven gears, 7 is a driving gear, and 8 to 11 are rotationally supported. Member, 12 is a first link a portion, 13 is a second link a portion, 14 is a first link b portion, 15 is a second link b
Parts, 16 and 17 are fixed parts, 18 and 19 are link connecting parts, 20 is a fixed part supporting member, 21 is a bearing, 22
Represents an E-ring.

FIG. 1 shows a color image forming apparatus. In the figure, for example, four photosensitive drums as image carriers are arranged in a straight line. If the first to fourth photosensitive drums are referred to in order from the leftmost photosensitive drum in FIG. 1, a recording medium such as a recording paper (not shown)
Is transported right below each photoconductor drum from the first photoconductor drum toward the fourth photoconductor drum, and during the conveyance, the electrostatic latent image on each photoconductor drum is transferred to recording paper. Thus, a color image is formed.

In FIG. 2, a driving motor (not shown) is
A drive gear 7 is provided at the center of the drive motor, which is arranged at a central portion equidistant from the second and third photosensitive drums. A driven gear 5 is fixed to the shaft of the second photosensitive drum 2, and a driven gear 6 is fixed to the shaft of the third photosensitive drum 3 so as to mesh with the driving gear 7. Further, one end of the rotation support member 9 is fixed to the shaft of the second photosensitive drum 2, and one end of the rotation support member 10 is fixed to the shaft of the third photosensitive drum 3. One end of the rotation support member 8 is fixed to the shaft of the first photosensitive drum 1, and one end of the rotation support member 11 is fixed to the shaft of the fourth photosensitive drum 4. Driving motor
The length (rotation radius) of the rotary support members 8 and 11 located far from the motor is 1/2 of the length (rotation radius) of the rotary support members 9 and 10 located near the drive motor. I have.

Fixed portions 16 and 17 for attaching one end of a link are provided on a line connecting the axes of the photosensitive drums. The fixing parts 16 and 17 are
The distance between the first photosensitive drum 1 and the axis of the first photosensitive drum 1 is equal to the pitch between the axes of the respective photosensitive drums.
And the distance to the axis of the fourth photoconductor drum 4 is equal to the pitch between the axes of the respective photoconductor drums.

The other end of the rotation support member 9 and the fixed portion 16 are attached to both ends of the first link a portion 12, respectively, and the middle portion of the first link a portion 12 is connected by a connecting portion 18. ing. Similarly, both ends of the second link a portion 13 are attached to the other end side of the rotation support member 10 and the fixed portion 17, respectively, and the middle portion of the second link a portion 13 is connected by the connection portion 19. ing.

Both ends of the first link b section 14 are connected to the first link a section 12, and the center of the first link b section 14 is connected to the other end of the rotation support member 8. I have.
Similarly, both ends of the second link b section 15 are connected to the second link a section 13, and the center of the second link b section 15 is connected to the other end of the rotation support member 11. .

Further, the first link a portion 12 and the second link a portion 13 are formed by members having only one kind of length.
The link b portion 14 and the second link b portion 15 are formed only by members having a half length thereof, and have quadrilaterals having equal sides facing each other. Therefore, the number of parts can be reduced, and cost reduction can be achieved.

Referring to FIG. 2, the left link mechanism formed by the first link a section 12 and the first link b section 14 and the like, and the second link a section 13 and the second link b section 15 are formed by the second link a section 13 and the second link b section 15 and the like. In the right link mechanism, since the rotation support member rotates in phase, the angle formed by the first link a portion 12 and the first link b portion 14 of the left link mechanism is small in the state shown in FIG. The angle formed by the second link a portion 13 and the second link b portion 15 of the right link mechanism is large. That is, the left and right link mechanisms have a similar configuration, but when the rotation support member is in a horizontal state as shown in FIG. 2, the left and right link mechanisms are different in form.
On the other hand, when the rotation support member is in a vertical state, the forms of the left and right link mechanisms are the same.

FIG. 4 is an enlarged view of the fixing portion 16 in FIG. 1. The first link a portion 12 is attached to the fixing portion support member 20 via a bearing 21. Further, the first link a portion 12 is
An E-ring 22 is provided so as not to come off. The fixing portion 17 has the same configuration. The bearing 21 and the E-ring 22
Are provided so that smooth rotation can be performed.

By using such two sets of link mechanisms, the driving force from the driving motor can be smoothly transmitted to the four photosensitive drums.

FIG. 5 shows another embodiment of the present invention (second embodiment).
FIG. 1-11, 16, 17
Is similar to the configuration of the first embodiment shown in FIGS. 23 is a first link a portion, 24 is a second link a portion, 25 is a first link b portion, 26 is a second link b portion, 27 is a first link c portion, and 28 is a second link c.
Sections 29 to 36 are connection sections.

1 to 11, 16 and 17 are shown in FIGS.
The configuration is the same as that of the first embodiment shown in FIG.

As in the first embodiment, one end of the rotation support member 8 is fixed to the shaft of the first photosensitive drum 1.
The other end is connected to the first link a portion 23 at an intersection portion in the middle of the first link a portion 23 formed by two intersecting members. Further, two left ends of the first link a portion 23 in FIG. 5 are connected to both ends of the first link b portion 25 at connecting portions 29 and 30. The middle part of the first link b part 25 is rotatably connected to the fixed part 16.

As in the first embodiment, the rotation supporting member 9
Is fixed to the shaft of the second photosensitive drum 2, while the other end is connected to the first link c portion 27 at the center of the first link c portion 27. Further, right end portions of the first link a portion 23, which exist in two places in FIG. 5, are connected to both end portions of the first link c portion 27 at connecting portions 31 and 32.

The link mechanism of the left half in FIG. 5 has been described above. Like the link mechanism of the left half, the link mechanism of the left half is the second link a portion 24 formed of two intersecting members. , The second link b portion 26, the second link c portion 28, the connecting portions 33 to 36, and the like.

Also, in the embodiment shown in FIG. 5, as in the embodiment shown in FIG. 2, the link mechanism is formed by members having two different lengths, so that the number of parts is reduced and the cost is reduced. it can.

FIGS. 6 to 8 show schematic diagrams of another embodiment (third embodiment) of the present invention . FIG. 6 is a plan view, FIG. 7 is a front view, and FIG. 8 is a perspective view. It represents.
1 to 11 are substantially the same as those of the first embodiment shown in FIGS. 37 is the first link A
Section, 38 is the second link A section, 39 is the first link B section, 4
0 is a second link B portion, 41 is a first link C portion, 42 is a second link C portion, 43 is a first link D portion, 44 is a second link D portion, 45 to 48 are fixed portions, 49 to 52. Is a connecting portion.

Structures 1 to 11 are substantially the same as those of the first embodiment shown in FIGS. 1 to 4, and parts different from those in FIGS. 1 to 4 will be described below.

As in the first embodiment, one end of the rotary support member 8 is fixed to the shaft of the first photosensitive drum 1, and one end of the rotary support member 9 is fixed to the shaft of the second photosensitive drum 2. It is fixed to. However, unlike the first embodiment, the lengths of the rotation supporting member 8 and the rotation supporting member 9 are the same.

First photosensitive drum 1 and second photosensitive drum 2
Are connected by a first link A section 37. The other end of the rotation support member 8 is connected to an end of the first link C portion 41. The end of the first link C portion 41 not connected to the rotation support member 8 is rotatably connected to a fixing portion 45 provided on the main body side.

The other end of the rotation support member 9 is connected to an end of the first link D portion 43. Rotation support member 9
The end of the first link D portion 43 on the side not connected to the
It is rotatably connected at a fixing portion 47 provided on the main body side.

Further, a middle portion of the first link C portion 41,
The middle part of the first link D part 43 is the first link B part 39.
Are connected at both ends at the connecting portions 49 and 51, respectively.

The link mechanism in the left half in FIG. 7 has been described above. The link mechanism in the right half is also similar to the link mechanism in the left half in the rotation support member 10 and the rotation support member 1.
1 are the same length, the second link A portion 38, the second
The link B section 40, the second link C section 42, the second link D section 44, the fixing sections 46 and 48, the connecting sections 50 and 52, and the like are formed.

In the embodiment shown in FIG. 7, a part of the link C (lower half), a part of the link D (lower half),
A quadrilateral is formed by the link A portion and the link B portion having the same length as the link A portion, whereby the horizontally arranged link A portion and link B portion can always operate in parallel. Therefore, the rotation of the photosensitive drums of each set (the set including the first and second photosensitive drums and the set including the third and fourth photosensitive drums) can be completely synchronized, and the transfer with less color shift can be achieved. Can be performed.

Further, in the embodiment shown in FIG.
The upper half and the lower half of the link C portion sandwiching 9 and 50 are attached so as to always have an angle, and are not aligned. The same applies to the link D section. For this reason, the rotation is performed smoothly, and the rotation is stopped or intermittent because it tends to move in either direction when it is straight. Transfer becomes possible.

According to the mechanism for driving the photosensitive drum described above, one drive motor and one drive motor are provided.
The rotation of the photosensitive member is smoothly performed by one drive gear provided on the shaft of the motor, a driven gear provided on the shaft of two photosensitive drums, four rotation supporting members, and two sets of link mechanisms. Can be made.

FIGS. 9 and 10 show a driving force transmitting means from a driving motor applicable to the present invention.
Is a drive motor, 54 and 55 are worms, 56 and 5
7 is a worm wheel, 58 is a drive pulley, 59 and 60 are driven pulleys, and 61 is a timing belt.

In the conventional structure in which the driving force is transmitted by using the worm, four sets of the worm and four sets of the worm wheel are required. Gear 5
If worms and worm wheels are replaced with worms and worm wheels, only two sets are required as shown in FIG. Comparing other component costs, the configuration of FIG. 9 is clearly lower cost.

FIG. 10 shows a configuration using a timing belt as a configuration for transmitting the driving force. The conventional configuration in which the driving force is transmitted by using the timing belt has a disadvantage that noise is generated (the larger the noise, the more minute the rotation fluctuation). However, in the configuration of FIG. 3 Occurs only at the driven member portion of the photosensitive drum (basically does not occur at the link portion).
Also, it does not occur in the fourth photosensitive drum. Therefore,
The effect that noise and the occurrence of jitter due to rotation fluctuation can be significantly reduced can be obtained.

Although the embodiments of the present invention have been described with respect to the drive of the photosensitive drum, the present invention is applied to a device for driving a plurality of rollers at the same rotational speed, for example, a paper transport. This is a very effective configuration for driving a roller and driving a fixing roller.

[0045]

According to the driving force transmission device of the first aspect, the generation of vibration is prevented with a simple configuration, and the noise of the device is reduced. Further, the device is less susceptible to dust, dust, and the like, and as a result, the life of the device is extended. Further, since a plurality of similar link means are provided, the number of parts can be reduced.

According to the image forming apparatus of the second aspect, in addition to the same effects as those of the first aspect, a difference in rotation fluctuation of each image carrier is less likely to occur, and a decrease in resolution due to the difference in rotation fluctuation can be prevented. .

According to the image forming apparatus of the third aspect, the shorter the distance from the motor, the longer the length of the rotation supporting member, so that a sufficient driving torque with respect to the load torque can be obtained. (In the opposite case, the torque may be insufficient).
Therefore, the motor can be reduced in size, and the cost and the size of the device can be reduced.

According to the image forming apparatus of the fourth aspect, the processing accuracy for mounting the axis of the image carrier to the fixed portion can be easily obtained, and the color shift accuracy can be improved.

According to the image forming apparatus of the fifth aspect, since all the shapes of the rotation supporting members are the same, processing accuracy can be easily obtained, and the variation of the rotation radius between the image carriers, that is, the rotation error is small. Transfer with little color shift becomes possible.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a front view of FIG. 1;

FIG. 3 is a perspective view of FIG. 1;

FIG. 4 is a partially enlarged view of FIG. 1;

FIG. 5 shows a front view of another embodiment of the present invention.

FIG. 6 shows a plan view of yet another embodiment of the present invention.

FIG. 7 is a front view of FIG. 6;

FIG. 8 is a perspective view of FIG. 6;

FIG. 9 shows a driving force transmitting means from a driving motor applicable to the present invention.

FIG. 10 shows another driving force transmitting means from a driving motor applicable to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st photosensitive drum 2 2nd photosensitive drum 3 3rd photosensitive drum 4 4th photosensitive drum 5, 6 Follower gear 7 Drive gear 8-11 Rotation support member 12 1st link a part 13 2nd link a part 14 first link b part 15 second link b part 16, 17 fixing part 18, 19 link connecting part 20 fixing part supporting member 21 bearing 22 E-ring

Claims (3)

(57) [Claims] 1. A drive motor is disposed at a substantially central portion of the drive motor.
Driven by the axes of the left and right image carriers that are close to the motor
Each driven member to which the driving force from the motor is transmitted
Left and right image bearing members which are close to the driving motor.
One end of the first rotation support member is fixed to the shaft of the holder
And the first rotation support member.
Linking means independent from each other are connected to the other end.
Outer right and left sides not close to the drive motor
One end of the second rotation support member is located on the shaft of each image carrier of
And each of the second rotating supports is fixedly provided.
Each of the link means is connected to the other end of the holding member.
A driving force transmitting device for driving the image carrier,
The length of the member is set to half the length of the first rotation support member.
A driving force transmitting device for transmitting a driving force to an image carrier . 2. A left side on an extension line connecting axes of a plurality of image carriers.
The right position, the outermost left and right sides of the plurality of image carriers
Distance equal to the pitch between the image carriers from the image carrier axis of
And keep one end of the link means rotatable.
It is characterized by having fixed parts for holding each
The driving force transmission device for an image carrier according to claim 1 . 3. A driving motor is disposed at a substantially central portion, and a driving force from the driving motor is transmitted to shafts of left and right image carriers which are close to the driving motor. that each follower member is provided <br/>, the drive motor - with one end of the first rotary support member to a shaft of the left and right image bearing member in proximity to are provided respectively fixedly, - data Linking means independent of each other are connected to the other end of each of the first rotation supporting members, and a second rotation is provided on the axis of each of the left and right image carriers that are not close to the driving motor. one end of the support member it
Together provided Re fixedly respectively, wherein a driving force transmission device of each link means to each linked image bearing member wherein the other end of the second rotary support member, the first rotating support
The shape of the member and the shape of the second rotation support member are the same.
And a plurality of image carriers located on the left side with respect to the drive motor.
A plurality of image carriers located on the right side with respect to the drive motor
Are connected by a single link.
And a driving force transmitting device for transmitting the driving force to the image carrier .