JPH08101549A - Driving force transmission device and image forming apparatus - Google Patents

Abstract

PURPOSE: To obtain a device which is suppressed in the increase of the cost of the device and the generation of vibration by forming plural groups of linking means to a similar shape. CONSTITUTION: In a linking mechanism on the left which consists of a first link a-part, 12, a first link b-part, 14, etc., and a linking mechanism on the right which consists of a second link a-part 13, a second link b-part 15, etc., a rotary supporting member is rotated with the same phase of both the left and right mechanisms, so that in the state shown by the figure, an angle formed by the first link a-part 12 and the first link b-part 14 of the linking mechanism on the left is small and an angle formed by the second link a-part 13 and the second link b-part 15 of the linking mechanism on the right is large. In other words, both linking mechanisms are formed to the similar shape, but when the rotary supporting member is in a horizontal state, both linking mechanisms have a different form. On the other hand, when the rotary supporting member is in a vertical state, both linking mechanisms have the same form. Thus, driving force from a driving motor can be smoothly transmitted to four photoreceptor drums.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for driving a plurality of rotating members and an image forming apparatus for driving a plurality of image carriers.

[0002]

2. Description of the Related Art As a conventional structure for rotationally driving a plurality of rotating members, for example, Japanese Utility Model Publication No. 2-95344 and Japanese Utility Model Publication No.
-95345 has four worms and worm wheels.
It has been proposed to rotate and drive it in combination with a cable. However, in such a configuration, if the accuracy of the parts (the accuracy of the tooth profile between the worm and the worm wheel, especially the runout) is poor, a rotation error will occur. In particular, the rotation error of the fourth rotating member (drum) located farthest from the drive motor is accumulated. In addition, it is costly to improve the accuracy of the parts, and the mounting member and the like are complicated, which leads to an increase in the cost of the device.

For example, Japanese Utility Model Laid-Open No. 2-129666 proposes a structure using a belt and a gear. However, even with such a configuration, highly accurate parts and the like are required, which increases the cost of the apparatus. Further, when a belt (timing belt) is used, an error in meshing with the belt pulley, vibration of the belt, and the like occur, which makes it difficult to transmit good rotation.

Furthermore, for example, Japanese Patent Laid-Open No. 2-15786.
No. 8 also proposes a structure using a belt and a gear, but such a structure causes a problem that the vibration generated by the belt or the gear is transmitted as it is. Especially for belt transmission, 1 from the drive motor
Rotation is transmitted from one stage, the driven pulley to one stage further via each pulley, and to the pulley of the rotating member (drum) via three stages of pulleys. Then, the vibrations generated in each pulley and the belt become very large, and the vibrations are further accumulated, which causes a big problem.

When a plurality of rotating members are driven, each rotating member has a rotation fluctuation component, which causes variations. Especially when the rotating member is a photoconductor drum, if the variation is large, that is, if there is a large difference in rotation variation between the photoconductor drums (ie, variation in the amount of wobble of the warm oil, phase difference, etc.), the color shift occurs. Will lead to. Further, if vibrations or the like generated when the gears are meshed with each other are transmitted, fine feed unevenness occurs on the image, leading to a reduction in resolution.

[0006]

As described above, the structure proposed in the related art for rotationally driving a plurality of rotating members has drawbacks such as an increase in device cost and a large amount of vibration.

The present invention has been made in view of the above, and an object of the present invention is to provide an apparatus in which the cost of the apparatus is increased and the occurrence of vibration is suppressed.

[0008]

In order to achieve the above object, the present invention provides a plurality of rotating members, a driving source for applying a rotating force to the rotating members, and a plurality of driving forces from the driving sources. And a plurality of sets of linking means for transmitting to the rotating member, and the plurality of sets of linking means are configured in a similar shape.

In order to achieve the above-mentioned object, the present invention has a plurality of image carriers and driving means for driving the plurality of image carriers, and conveys a recording medium along the image carriers. At this time, in the image forming apparatus for recording by transferring the electrostatic latent image formed on the recording medium onto the recording medium, the driving force from the driving source is transmitted to the plurality of image carriers. The present invention proposes a device that includes a plurality of sets of linking means, and the plurality of sets of linking means are configured in a similar shape.

Further, a drive motor is arranged at the substantially central portion, and the drive force from the drive motor is transmitted to the shafts of the left and right image carriers which are close to the drive motor. A driven member is provided, and one end side of the first rotation support member is fixedly provided on the shafts of the left and right image carriers that are close to the drive motor. Link means is connected to the other end side of the support member, and one end side of the second rotation support member is fixedly attached to the shafts of the left and right image carriers outside the drive motor. While being provided, the respective link means are connected to the other end side of each of the second rotation support members, and the length of the second rotation support member is 1/2 of that of the first rotation support member. A longer length is more effective.

Further, at the left and right positions on the extension line connecting the shaft centers of the plurality of image carriers, and separated from the outermost left and right image carrier shaft centers by a distance equal to the pitch between the image carriers, It is even more effective if a fixing portion for rotatably holding one end of the link means is provided.

Further, a drive motor is arranged at a substantially central portion,
A driven member for transmitting the driving force from the driving motor is provided on the shafts of the left and right image carriers which are close to the driving motor, and the driven member is close to the driving motor. One end side of the first rotation support member is fixedly provided on the shafts of the left and right image bearing members, and link means is connected to the other end side of each of the first rotation support members. Motor
One end side of the second rotation support member is fixedly provided on the shafts of the left and right outer image carriers that are not close to each other, and the other end side of each of the second rotation support members is provided with Each link means is connected, and the shape of the first rotation support member and the shape of the second rotation support member are the same, and between the plurality of image carriers located on the left side of the drive motor. It is more effective if the plurality of image carriers located on the right side of the drive motor are connected by a single link.

[0013]

According to the present invention, since a plurality of sets of linking means having similar shapes are provided and the driving force from the driving means is transmitted, a plurality of rotating members and image bearing members can be accurately constructed with a simple structure. 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. It shows a partially enlarged view of FIG. 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 drive gear, and 8 to 11 are rotatably supported. Member, 12 is the first link a part, 13 is the second link a part, 14 is the first link b part, and 15 is the second link b.
Parts, 16 and 17 are fixed parts, 18 and 19 are link connecting parts, 20 is a fixed part support member, 21 is a bearing, 22
Represents an E-ring.

FIG. 1 shows a color image forming apparatus in which four photosensitive drums, which are image bearing members, are arranged in a straight line. When the first to fourth photoconductor drums are called in order from the leftmost photoconductor drum in FIG. 1, a recording medium such as a recording paper (not shown) is used.
Is conveyed right below each photoconductor drum toward the fourth photoconductor drum from the first photoconductor drum to the right, and the electrostatic latent image on each photoconductor drum is transferred onto the recording paper during the conveyance. By doing so, color image formation is performed.

In FIG. 2, a drive motor (not shown) is
A drive gear 7 is provided on the shaft of the drive motor, the drive gear 7 being arranged in the central portion equidistant from the second photoconductor drum and the third photoconductor drum. 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 drive gear 7. Further, one end side of the rotation support member 9 is fixed to the shaft of the second photosensitive drum 2, and one end side of the rotation support member 10 is fixed to the shaft of the third photosensitive drum 3. One end side of the rotation support member 8 is fixed to the shaft of the first photosensitive drum 1, and one end side of the rotation support member 11 is fixed to the shaft of the fourth photosensitive drum 4. Drive motor
The lengths (rotation radii) of the rotation support members 8 and 11 located farther from the position are ½ of the lengths (rotation radius) of the rotation support members 9 and 10 located near the drive motor. There is.

Fixing portions 16 and 17 for attaching one ends of the links are provided on a line connecting the shaft centers of the respective photosensitive drums. Further, the fixed portions 16 and 17 are
And the distance between the first photoconductor drum 1 and the axis of the first photoconductor drum 1 is equal to the pitch between the shafts of the respective photoconductor drums.
And the distance to the axis of the fourth photoconductor drum 4 is equal to the pitch between the shafts of the respective photoconductor drums.

Both ends of the first link a portion 12 are attached to the other end of the rotation support member 9 and the fixed portion 16, 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 connecting portion 19. ing.

Both ends of the first link b portion 14 are connected to the first link a portion 12, and the middle portion of the first link b portion 14 is connected to the other end side of the rotation support member 8. There is.
Similarly, both ends of the second link b portion 15 are connected to the second link a portion 13, and the middle portion of the second link b portion 15 is connected to the other end side of the rotation support member 11. .

Further, the first link a part 12 and the second link a part 13 are formed by members of one kind of length, and
Each of the link b portion 14 and the second link b portion 15 is formed of a member having a half length thereof, and a quadrangle having equal sides is formed. Therefore, the number of parts can be reduced and cost reduction can be achieved.

In FIG. 2, the left side link mechanism formed by the first link a portion 12 and the first link b portion 14 and the like, and the second link a portion 13 and the second link b portion 15 and the like are formed. In the link mechanism on the right side, the rotation support members rotate in the same phase, so in the state shown in FIG. 2, the angle formed by the first link a part 12 and the first link b part 14 of the left link mechanism is small, 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 similar configurations, but when the rotation support member is in a horizontal state as shown in FIG. 2, the left and right link mechanisms have different configurations.
On the other hand, when the rotation support member is in the vertical state, the left and right link mechanisms have the same form.

FIG. 4 shows an enlarged view of the fixed portion 16 in FIG. 1, but the first link a portion 12 is attached to the fixed portion supporting member 20 via a bearing 21. Further, the first link a portion 12 is fixed to the fixed portion support member 20.
An E-ring 22 is provided so as not to come off. The fixed portion 17 has the same structure. Also, at each connecting portion, the bearing 21 and the E ring 22
Is provided, and the structure allows smooth rotation.

By using such two sets of link mechanisms, it becomes possible to smoothly transmit the driving force from the driving motor to the four photosensitive drums.

FIG. 5 shows another embodiment (second embodiment) of the present invention.
The schematic configuration diagram of is shown. 1-11, 16, 17
Is the same as that of the first embodiment shown in FIGS. Further, 23 is the first link a part, 24 is the second link a part, 25 is the first link b part, 26 is the second link b part, 27 is the first link c part, and 28 is the second link c.
The parts, 29 to 36, are connecting parts.

1 to 11, 16 and 17 are shown in FIG.
The structure is the same as that of the first embodiment shown in FIG. 4, and the parts different from those in FIGS. 1 to 4 will be described below.

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 side is connected to the first link a portion 23 at an intersection that is in the center of the first link a portion 23 formed by two intersecting members. Further, the left end portion of the first link a portion 23, which is present at two places in FIG. 5, is connected to both end portions of the first link b portion 25 at the connecting portions 29 and 30. The middle portion of the first link b portion 25 is rotatably connected to the fixed portion 16.

Further, similarly to the first embodiment, the rotation support member 9
One end side of is fixed to the shaft of the second photosensitive drum 2, but the other end side thereof is connected to the first link c portion 27 in the middle portion of the first link c portion 27. Further, the right end portion of the first link a portion 23, which is present at two places in FIG. 5, is connected to both end portions of the first link c portion 27 at the connecting portions 31 and 32.

The above is a description of the left half link mechanism in FIG. 5, but the right half link mechanism is also formed by two intersecting members a, like the left half link mechanism. , 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 of two different lengths, which reduces the number of parts and achieves cost reduction. it can.

FIGS. 6 to 8 show schematic configuration diagrams of another embodiment (third embodiment) of the present invention. FIG. 1 is a plan view, FIG. 2 is a front view, and FIG. 3 is a perspective view. Is represented.
1 to 11 have substantially the same configuration as that of the first embodiment described in FIGS. 1 to 4. 37 is the first link A
Part, 38 is the second link A part, 39 is the first link B part, 4
0 is the second link B section, 41 is the first link C section, 42 is the second link C section, 43 is the first link D section, 44 is the second link D section, 45 to 48 are fixed sections, and 49 to 52. Is a connecting part.

1 to 11 have substantially the same structure as that of the first embodiment shown in FIGS. 1 to 4, and the following description will be made on the parts different from those of FIGS. 1 to 4.

Similar to the first embodiment, one end side of the rotation support member 8 is fixed to the shaft of the first photosensitive drum 1, and one end side of the rotation support member 9 is the shaft of the second photosensitive drum 2. It is fixed to. However, unlike the first embodiment, the rotation support member 8 and the rotation support member 9 have the same length.

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

The other end of the rotation support member 9 is connected to the end of the first link D portion 43. Rotation support member 9
The end portion of the first link D portion 43 on the side not connected with
A fixed portion 47 provided on the main body side is rotatably connected.

Further, the 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 to both ends of each of the connecting portions 49 and 51, respectively.

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

In the embodiment shown in FIG. 7, part of the link C part (lower half), part of the link D part (lower half),
The link A portion and the link B portion having the same length as the link A portion form a quadrangle, so that the horizontally arranged link A portion and link B portion can always operate in parallel. For this reason, the rotations of the photoconductor drums of each set (the set including the first and second photoconductor drums and the set including the third and fourth photoconductor drums) can be perfectly synchronized, and the transfer with less color misregistration can be performed. Can be performed.

In the embodiment shown in FIG. 7, the connecting portion 4
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 smoothly performed, and when it is in a straight line, the rotation tends to move in either direction, so that the rotation operation is stopped or intermittent. Transfer is possible.

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

FIG. 9 and FIG. 10 show driving force transmitting means from the driving motor, which is 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 using the worm, four sets of worms and four worm wheels are required, but the drive gear 7 and the driven gear of the embodiment of the present invention are required. Gear 5
If 6 and 6 are replaced with a worm and a worm wheel, two sets are required as shown in FIG. Comparing the costs of other parts, the configuration of FIG. 9 clearly has a lower cost.

FIG. 10 shows a structure using a timing belt as a structure for transmitting the driving force. In the conventional configuration in which the driving force is transmitted using the timing belt, there is a drawback that noise is generated (the louder the noise, the finer the rotational fluctuations are), but in the configuration of FIG. 3 It occurs only in the driven member portion of the photoconductor drum (basically it does not occur in the link portion).
And does not occur on the fourth photosensitive drum. Therefore,
It is possible to obtain the effect that the generation of noise and jitter due to rotation fluctuation can be significantly reduced.

Further, in the embodiment of the present invention, the driving of the photosensitive drum has been described, but the constitution of the present invention is a device for driving a plurality of rollers at the same rotation speed, for example, a sheet conveying device. This structure is also very effective for driving the rollers and fixing rollers.

[0045]

According to the driving force transmission device of the first aspect, the vibration is prevented with a simple structure, and the noise of the device is reduced. Further, it is less likely to be affected by dust, dust, etc., and as a result, the life of the device is extended. Moreover, since a plurality of sets of linking means having similar shapes are provided, the number of parts can be reduced.

According to the image forming apparatus of the second aspect, in addition to the effect similar to that of the first aspect, the difference in rotation variation of each image carrier is less likely to occur, and the reduction in resolution due to the difference in rotation variation can be prevented. .

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

According to the image forming apparatus of the fourth aspect, the processing accuracy for attaching the shaft center of the image bearing member and the fixed portion can be easily obtained, and the color misregistration accuracy is improved.

According to the image forming apparatus of the fifth aspect, since all the rotation supporting members have the same shape, it is easy to obtain the processing accuracy, and there is little variation in the radius of rotation between the image carriers, that is, there is little rotation error. Transfer with less color shift is possible.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a front view of FIG.

3 is a diagram showing a perspective view of FIG. 1. FIG.

FIG. 4 is a diagram showing a partially enlarged view of FIG.

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

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

7 is a diagram showing a front view of FIG.

8 is a diagram showing a perspective view of FIG. 6. FIG.

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]

 1 1st photoconductor drum 2 2nd photoconductor drum 3 3rd photoconductor drum 4 4th photoconductor drum 5, 6 Driven gear 7 Drive gear 8-11 Rotation support member 12 1st link a part 13 2nd link a part 14 1st link b part 15 2nd link b part 16 and 17 fixed part 18 and 19 link connection part 20 fixed part support member 21 bearing 22 E ring

Claims (5)

[Claims] 1. A plurality of rotary members, a drive source for applying a rotary force to the rotary members, and a plurality of sets of link means for transmitting the drive force from the drive sources to the plurality of rotary members. A driving force transmission device, comprising: the plurality of sets of link means having similar shapes. 2. A plurality of image carriers and drive means for driving the plurality of image carriers, and when the recording medium is conveyed along the image carrier, it is formed on the recording medium. An image forming apparatus for performing recording by transferring an electrostatic latent image on the recording medium, comprising a plurality of sets of link means for transmitting a driving force from the driving source to a plurality of image carriers, An image forming apparatus, wherein the plurality of sets of linking means have similar shapes. 3. A drive motor is arranged at a substantially central portion, and the drive force from the drive motor is transmitted to the shafts of the left and right image bearing members which are close to the drive motor. Provide a driven member that
One end side of each first rotation support member is fixedly provided on the shaft of each of the left and right image bearing members that are close to the drive motor, and the other end of each first rotation support member is fixed. Link means are connected to the respective sides, and one end side of the second rotation support member is fixedly provided on the shafts of the left and right image carriers outside which are not close to the drive motor. The link means are connected to the other end side of each of the second rotation support members, and the length of the second rotation support member is set to half the length of the first rotation support member. The image forming apparatus according to claim 2, wherein the image forming apparatus is an image forming apparatus. 4. A lateral position on an extension line connecting the axis centers of the plurality of image carriers, separated from the outermost left and right image carrier axis centers by a distance equal to the pitch between the image carriers. ,
The image forming apparatus according to claim 3, further comprising a fixing portion for rotatably holding one end portion of the link means. 5. A drive motor is arranged at a substantially central portion, and a drive force from the drive motor is transmitted to the shafts of the left and right image bearing bodies which are close to the drive motor. Provide a driven member that
One end side of each first rotation support member is fixedly provided on the shaft of each of the left and right image bearing members that are close to the drive motor, and the other end of each first rotation support member is fixed. Link means are connected to the respective sides, and one end side of the second rotation support member is fixedly provided on the shafts of the left and right image carriers outside which are not close to the drive motor. The link means are connected to the other end side of each of the second rotation support members, and the shape of the first rotation support member and the shape of the second rotation support member are the same. A plurality of image carriers located on the left side of the motor and a plurality of image carriers located on the right side of the drive motor are connected by a single link. The image forming apparatus according to claim 2.