JPH11101308A - Drive device for rotary body and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the light, compact drive device and image forming device of a photosensitive body drum (rotary body) with a low cost, hard to receive the influence from an external disturbance which can achieve a precise rotation reduced in a speed unevenness and reduce the gain of a transfer function. SOLUTION: The connection means of the drive device of a rotary body is composed of a drive connection member and driven connection member. An elastic body member 35 having an elastically deformable flexible beam shape part 351 and a fluid sealed type vibration prevention means 37 face contacted and fixed to one surface of the flexible beam shape part 351 are provided in the drive connection member. The driven connection member is composed of a projection member for connection 36 and the rotation drive force of a drive source is transmitted to the rotary body 10 through the connection means by contacting and connecting the projection member for connection 36 to the flexible beam shape part 351.

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 a rotating body for driving and rotating a rotating body such as a photosensitive body, and an image forming apparatus for forming an image on a rotating photosensitive body by a digital method.

[0002]

2. Description of the Related Art In an electrophotographic copying machine, a printer, or the like, an electrostatic latent image is formed on the surface of a rotating cylindrical photoconductor or a belt-shaped photoconductor, and the formed electrostatic latent image is formed. The toner is attached to the latent image and developed, and the toner image is transferred and fixed on a recording paper to obtain an image.

Here, a cylindrical photosensitive member of an image forming apparatus,
That is, the photoconductor drum and the driving roller for driving the belt-shaped photoconductor are referred to as a rotating body.

[0004] When a speed fluctuation (rotation unevenness) occurs in a photosensitive member to be rotated at a uniform speed, a phenomenon of small pitch banding occurs, and an output image has jitter and image unevenness. This is particularly noticeable in a digital electrophotographic technique in which writing on a photoconductor is performed by scanning a semiconductor laser. Fluctuations in the rotation speed of the photoconductor cause fluctuations in the sub-scanning direction of the writing system, resulting in a writing line. Causes a slight shift in the distance between the images, causing a significant reduction in image quality.

There have been many proposals for a technique for improving the accuracy of driving a rotating body that should rotate at a uniform rotation speed, but the following two main flows are seen.

[0006] One flow is to incorporate a flywheel into a drive system. Conventionally, a flywheel that facilitates the attachment and detachment of a flywheel is disclosed in JP-A-7-281500 and JP-A-8-2022.
No. 05 is disclosed in each publication. Japanese Patent Application Laid-Open No. Hei 6-1308 discloses that a flywheel is provided in a rotating body.
No. 72, No. 6-130874, No. 7-302020
And JP-A-8-202206. Further, Japanese Patent Application Laid-Open Nos. 8-63041 and 8-111504 disclose a method of detecting a frequency characteristic of a rotating body and optimizing a moment of inertia of a flywheel in relation to an excitation frequency.
Nos. 1 and 8-220966.

As another major flow, the use of a gear or a timing belt / pulley incorporating an elastic member in the middle of a rotating body drive system absorbs vibration in the rotational direction of the drive transmission system. Specifically, JP-A-6-249321 and JP-A-6-294453.
No. 7,325,445, No. 7-325446, and No. 8-54047.

As described above, in the prior art, the use of a flywheel is the most effective technical means for improving the driving accuracy of a rotating body. However, the size of the apparatus is increased, and a large torque is required at the start of rotation. Is a fundamental problem. In addition, since the flywheel itself reduces rotational vibration by the kinetic energy of rotation, when rotating the rotating body at a low speed, a flywheel having a diameter larger than that of the rotating body is required to be effective. It is necessary to adopt wheels. Therefore, in order to avoid an increase in the size of the apparatus, a functional limit must be recognized even when a flywheel is provided in the rotating body.

In recent years, the natural frequency of the drive system of the rotating body has been determined, the drive system has been designed in consideration of the relationship with the excitation frequency, and the frequency response of the rotary system centered on the natural frequency has been determined. It has been generalized that the shape of the frequency characteristic, that is, the shape of the transfer function is changed by designing the amount of inertia, the peak position is changed, and the drive system is optimized. The biggest problem in this case is that in consideration of shifting the natural frequency to the low frequency region in one rotating body drive system, the flywheel diameter is inevitably increased or its weight is increased. This means that the natural frequency f of the fundamental frequency is

[0010]

(Equation 1)

[0011] In this case, increasing the inertia moment I corresponds to decreasing the value of the natural frequency f.

On the other hand, improving the driving accuracy by providing an elastic member in the middle of the drive system involves converting a rotational vibration component generated in the drive system into heat in the elastic member and dissipating the heat. is there. Since the concept such as the frequency characteristic and the transfer function of the drive system is not included here, the effect cannot be predicted depending on the excitation frequency of the generated vibration and the configuration of the drive system, and the level of the effect varies.

In the specification of Japanese Patent Application No. 9-74849, the natural frequency and the transmission gain can be easily controlled. However, when the loss coefficient of the viscoelastic member is increased and the resonance gain is reduced, the vibration damping range is reduced. However, there is a problem that the gain increases and the image stabilization characteristics decrease. Furthermore, when the load condition or the line speed changes, the excitation frequency or the natural frequency changes, and the optimum vibration-proof characteristics may not be obtained.

[0014]

In the development of a digital type image forming apparatus, as the performance is improved, the reproducibility of one dot line by laser writing is strictly required, and the accuracy required for the drive system is also rapidly increasing. It became tough. The accuracy required here is a level at which the uniformity of the writing by the laser in the sub-scanning direction is guaranteed in relation to the visible sensitivity of the visual system, and the recording density is from 600 dpi to 24 dpi.
With high-density recording such as 00 dpi, there is a demand for high-precision driving of a rotating body without rotation unevenness that satisfies a high level in which small pitch banding cannot be recognized by humans.

For this reason, in the range of the prior art, high-precision gears, dedicated driving, and a large flywheel are generally used to increase the precision of driving of the rotating body. However, the adoption of the flywheel inevitably increases the weight and the device as described above. Furthermore, in order to provide an electrophotographic printer, the gear driving force is applied to a rotating body such as a photosensitive drum via an elastic member due to the demand for lightweight, compact, low-cost and highly accurate driving. A transmission structure and the like have been proposed. However, in this technology, the elastic member alone has a large effect of reducing the speed unevenness at a natural frequency or higher, but the gain in the resonance region increases, and the banding is greatly affected by speed unevenness near the resonance region and load fluctuation. There was a problem that got worse.

The present invention achieves high-quality image output by achieving a high-precision drive with a lightweight, compact, low-cost, less susceptible to disturbances, etc., by a new structure that solves these problems. And an image forming apparatus.

In the specification of Japanese Patent Application No. 9-74849, proposals have been made to solve these problems. However, when the loss coefficient of the viscoelastic member is increased to reduce the resonance gain, the gain in the vibration damping region increases. In addition, there is a problem that the anti-vibration characteristics are reduced. Furthermore, when the load condition or the line speed changes, the excitation frequency or the natural frequency changes, and the optimum vibration-proof characteristics may not be obtained. The present invention has a novel structure that solves these problems, and is lightweight, compact, low-cost, hardly affected by disturbances, etc., and drives the photosensitive drum and belt photosensitive drive roller with high precision. It is another object of the present invention to provide an image forming apparatus that outputs a high-quality image.

[0018]

According to a first aspect of the present invention, there is provided a driving apparatus for a rotating body, wherein the rotating body is rotatably supported, a driving source drives the rotating body, and a rotation of the driving source. In a driving device for a rotating body having a driving member for transmitting a driving force to the rotating body, a driven member, and a connecting means, the connecting means includes a driving connecting member and a driven connecting member, and the driving connecting member An elastic member having an elastically deformable flexible beam-like portion, and a fluid-filled type vibration-proof device fixed in surface contact with one surface of the flexible beam-like portion. The connecting member has a connecting protruding member, the connecting protruding member is brought into contact with the flexible beam-shaped portion to be connected, and the rotational driving force of the driving source is applied to the rotating body via the connecting means. It is characterized by transmitting (claim 1).

In addition, a rotating body driving apparatus according to the present invention that achieves the above object includes a rotating body rotatably supported, a driving source for driving the rotating body, and a rotational driving force of the driving source. A driving member for transmitting to the rotating body, a driven member,
In a driving device for a rotating body having a transmission means comprising a connection means, the connection means comprises a drive connection member and a driven connection member, the drive connection member comprises a connection projection member, and the driven connection member includes An elastic member having an elastically deformable flexible beam portion; and a fluid-filled vibration isolator fixed in surface contact with one surface of the flexible beam portion. The connecting projection member is brought into contact with and connected to the flexible beam-like portion of the driven connecting member, and the rotational driving force of the driving source is transmitted to the rotating body via the connecting means. (Claim 2).

An image forming apparatus according to the present invention that achieves the above object includes an image carrier for carrying at least an image, image forming means for forming an image on the image carrier, the image carrier or the image carrier. Having a drive source for driving and rotating a rotating body for holding the image, a driving member for transmitting a rotational driving force of the driving source to the image carrier or the rotating body, a driven member, and a transmission unit including a coupling unit. In the forming apparatus, the connection means includes a drive connection member and a driven connection member, and the drive connection member or the driven connection member includes an elastic member having an elastically deformable flexible beam, Fluid-filled vibration-proof means fixed in surface contact with one surface of the flexible beam-shaped part, and the fluid-filled vibration-proof means is provided with a viscoelastic member on the side in contact with the flexible beam-shaped part. Having a box closed by the viscoelastic member, In the box, a partition plate having an orifice for fluid flow, a first fluid chamber and a second fluid chamber partitioned by the partition plate, and the second fluid chamber and the air chamber can be moved. A vibration-proof rubber film member for partitioning the fluid, the fluid contained in the first fluid chamber and the second fluid chamber of the fluid-filled type vibration-proof device is an electric fluid whose viscosity is reversibly changed by turning on and off an electric field. A viscous fluid or an electromagnetorheological fluid in which the shear stress of the fluid changes due to the simultaneous application of an electric field and a magnetic field.They must be controlled to obtain the optimal vibration isolation characteristics according to the load conditions of the drive system and changes in line speed. (Claim 7).

According to another aspect of the present invention, there is provided an image forming apparatus, comprising: a rotatably supported rotatable member; a driving source for driving the rotatable member; A driving unit for transmitting to the rotating body, the driving unit having a transmission unit including a driven member, a driven member, and a coupling unit, wherein the coupling unit includes a driving connection member and a driven coupling member; The member is provided with an elastic member having an elastically deformable flexible beam-like portion, and a fluid-filled type vibration damping means fixed in surface contact with one surface of the flexible beam-like portion, The fluid-filled type vibration damping means has a viscoelastic member on the side that contacts the flexible beam-like portion, and a box closed with the viscoelastic member. A plurality of orifices having a plurality of orifices; Fluid chamber, a second fluid chamber, an anti-vibration rubber membrane member that movably partitions the second fluid chamber and the air chamber, and a plurality of on-off valves that can open and close the plurality of orifices. The driven connecting member connected to the driving connecting member, or the driving connecting member connected to the driven connecting member, a projection member is fixedly provided, and the projection member is brought into contact with the flexible beam-shaped portion. A driving means for connecting the driving source to the rotating body via a connecting means comprising the driving connecting member and the driven connecting member to transmit the rotational driving force of the driving source, and operating the open / close valve to be able to open and close; A control means for controlling the means opens and closes a predetermined on-off valve, thereby making it possible to variably control the amount of fluid flowing through the orifice, and optimal vibration damping characteristics according to the load conditions of the drive system and changes in line speed. Control to get Those characterized (claim 8).

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of an embodiment of the present invention, the structure and operation of a color printer as an example of an image forming apparatus equipped with a rotating body (photosensitive drum) of the present invention will be described with reference to FIG. This will be described with reference to a sectional configuration diagram.

In this color printer, after each color toner image sequentially formed on the photosensitive drum is superimposed, the color image is formed on the recording paper by a transfer unit once, and then the image is formed by a separation unit. This is a color image forming apparatus of a method of peeling off from a surface of a carrier.

In FIG. 1, reference numeral 10 denotes a cylindrical photoconductor drum having a diameter of 120 mm, which is formed by coating an OPC photoconductor (organic photoconductor) on a drum base, and is grounded and has a linear velocity in the clockwise direction shown in the figure. It is driven and rotated at 100 mm / sec. Reference numeral 11 denotes a scorotron charger, and the photosensitive drum 10
It is given by a corona discharge by a grid and the corona discharge wire held potential grid potential V _G uniform charging of the high voltage V _H to the peripheral surface. This scorotron charger 1
Prior to the charging by 1, in order to eliminate the history of the photoreceptor up to the previous printing, exposure is performed by a pre-charging static eliminator (PCL) 12 using a light emitting diode or the like to eliminate the peripheral surface of the photoreceptor. The history of the photoreceptor refers to an image pattern remaining on the photoreceptor formed by charging and image exposure during preceding image formation, and is also referred to as a photoreceptor memory.

After the photosensitive drum 10 is uniformly charged, the image exposure means 13 performs image exposure based on the image signal. The image exposing means 13 scans the optical path by using a laser diode (not shown) as a light emitting light source, and the optical path is bent by a reflecting mirror via a rotating polygon mirror, fθ lens, and cylindrical lens, and a latent image is formed by rotation of the photosensitive drum 10. Is done. In the present embodiment performs exposure on a character portion, towards the exposed portion potential V _L to form an inverted latent image as a lower potential than the charge potential V _H.

Around the periphery of the photosensitive drum 10, a developing device 14Y containing a two-component developer including a toner such as yellow (Y), magenta (M), cyan (C), and black (K) and a carrier. , 14M, 14C, and 14K are provided.

First, development of the first color yellow is performed by a developer carrier (hereinafter referred to as a developing sleeve) 141 which rotates while holding a developer with a built-in magnet. The developer consists of a carrier with ferrite as the core and an insulating resin coated around it, and a toner with polyester as the main material and a pigment according to the color, a charge control agent, silica, titanium oxide, etc. The developer is applied onto the developing sleeve 141 by a developer layer forming means described later.
The developer is conveyed to the development area while being regulated to a developer layer thickness of 00 to 600 μm.

The gap between the developing sleeve 141 and the photosensitive drum 10 in the developing area is larger than the developer layer thickness.
2 to 1.0 mm, during which the AC bias V _AC and D
C bias _VDC is applied in a superimposed manner. DC bias V
For _DC and the photosensitive member charge potential V _H, the charging of the toner the same polarity, the toner given the opportunity to leave from the carrier by the AC bias V _AC is positively charged at higher potential than the DC bias V _DC photoreceptor charging It does not adhere to the portion of the potential V _H , but adheres to the portion of the exposed portion potential _VL lower than the DC bias _VDC to perform visualization (reversal development).

After the visualization of the first color is completed, the magenta image forming process of the second color is started, and the scorotron charger 1 is again activated.
1 is performed, and a latent image based on the image data of the second color is formed by the image exposure unit 13. At this time 1
The charge elimination by the PCL 12 performed in the color image forming process is not performed because the toner attached to the image portion of the first color scatters due to a sharp drop in the surrounding potential.

[0030] Again among the photoreceptor drum 10 peripheral surface of the entire surface is charged to the photosensitive drum charge potential V _H across the photosensitive member, get the same latent image and a color for the portion having no first color image While being development is carried out, in part for re-development to part there is an image of the first color, the influence of the charge possessed by the shading of the toner itself by the toner adhering the first color, than the first color of the exposed portion potential V _L also a latent image of a slightly higher voltage V _M is formed, developed according to the potential difference between the DC bias V _DC and the potential V _M is performed.

For the third color cyan and the fourth color black, the same image forming process as that for the second color magenta is performed, and a visible image of four colors is formed on the peripheral surface of the photosensitive drum 10.

Each of the developing units 14Y, 14M, 14C, 1
A toner supply device for controlling and replenishing each new color toner in 4K includes a plurality of detachable toner cartridges 15.
(Y, M, C, K), toner storage means 16 (Y, M,
C, K) and toner transport means 161 (Y, M, C, K).

On the other hand, the half-moon roller 2
One transfer material (transfer paper or the like) P carried out through 1 is
The sheet is temporarily stopped near the registration sensor position via the intermediate sheet feeding roller pairs 22A and 22B, and is fed to the transfer area by the rotation operation of the registration roller pair 23 of the sheet feeding unit when the transfer timing is adjusted.

In the transfer area, transfer means 17 for applying a voltage for transferring a toner image to the peripheral surface of the photosensitive drum 10 is pressed against the peripheral surface of the photosensitive drum 10 in synchronization with the transfer timing, and the fed transfer material P is pinched. Then, the multicolor image is transferred at a time.

Next, the transfer material P is neutralized by a separating means 18 such as a sawtooth electrode, separated from the peripheral surface of the photosensitive drum 10 and transported to the fixing device 24, where it is heated by a heat roller (upper roller).
241 and a pressure roller (lower roller) 242, the toner is fused by heating and pressing, and then a pair of discharge rollers 25A, 25A
After passing through 5B and 25C, the sheet is discharged onto a sheet discharge tray 26 outside the apparatus. The transfer unit 17 is retracted from the peripheral surface of the photosensitive drum 10 after passing the transfer material P, and prepares for the formation of the next toner image.

On the other hand, the photosensitive drum 1 from which the transfer material P is separated
In the case of No. 0, the residual toner is removed and cleaned by the pressure contact of the blade 191 of the cleaning device 19, and the charge is removed by the PCL 12 and charged by the scorotron charger 11 again to start the next image forming process. The blade 191
Moves immediately after the cleaning of the surface of the photoconductor and retreats from the peripheral surface of the photoconductor drum 10. The waste toner scraped into the cleaning device 19 by the blade 191 is
After being discharged by the screw 192, it is stored in a waste toner collecting container (not shown).

FIG. 2A is a perspective view showing the photosensitive drum 10 and the driving mechanism 30. FIG. 2B shows the photosensitive drum 1.
FIG. 2 is a partial cross-sectional view of a drive mechanism 30 and a drive mechanism 30;

The driving mechanism 30 includes a driving motor (driving source) M1 such as a pulse motor and gear trains 31 to 33 connected thereto.
Consists of The final gear 33 of the gear trains 31 to 33 is meshed with a drive gear (drive transmission member) 34 that is rotatably provided coaxially with the photosensitive drum 10.

A shaft 103 is fitted to flanges (driven transmission members) 101 attached to both ends of the photosensitive drum 10. Therefore, the end face of one flange 101 and the side face of the drive gear 34 are located at a predetermined interval, and the connecting elastic body (drive connecting member) 35 provided on the drive gear 34 and the connection provided by the flange 101. The driving motor M1 is driven by the projection member (driven connection member) 36 for driving.
Is transmitted to the photosensitive drum 10.

In the illustrated embodiment, the shaft 103 is fixedly supported on the main body of the image forming apparatus, and the drive gear 34 is fitted to the shaft 103 via a bearing (not shown), for example, an oilless bearing. The flange 101 attached to the photosensitive drum 10 is fitted to a shaft 103 via a bearing 102. The shaft 103 is rotatably supported with respect to the image forming apparatus main body, and the photosensitive drum 1
0 may be fixed to the shaft 103.

FIG. 3A is a perspective view showing the photosensitive drum 10 and the connecting means.

FIG. 3B is a front view showing the structure of one embodiment of the connecting elastic body 35.

The connection means comprises a drive connection member and a driven connection member. The drive connecting member includes an elastic member 35 having elastically deformable both-end supporting beam portions (flexible beam portions) 351, and a fluid-filled type fixed in surface contact with one surface of the both-end supporting beam portions 351. An anti-vibration means 37 is provided.
The driven connecting member includes a connecting protrusion member 36, and the connecting protrusion member 36 is brought into contact with the both-end supporting beam portion 351 to be connected to each other, and the rotational driving force of the driving source M1 is formed by the driving connecting member and the driven connecting member. The elastic member 35 for transmitting the drive between the drive gear 34 transmitting the flange 101 of the photoconductor drum 10 and the flange 101 of the photoconductor drum 10 through the connection means has a connection beam 351 having both ends. An elastic body 351 is provided on the end face of the drive gear 34, and the both-ends support beam portion 351 is fixedly provided in a positional relationship substantially in the radial direction of the drive gear 34. On the end face of the flange 101, a rod-shaped rigid connecting projection member 36 is fixedly provided. Then, in the assembled state, as shown in FIG. 3B, the connecting projection member 36 is provided at both ends of the supporting elastic member 35 of the connecting elastic body 35.
When the drive gear 34 rotates, the connecting protrusion 36 is pushed in the direction indicated by the arrow through the support beam 351 at both ends, and the drive is transmitted to the photosensitive drum 10.

In the drive connecting member of the present embodiment, the fluid-filled type vibration damping means 37 which makes surface contact while deforming at a constant compression ratio on the opposite side of the contact projection member 36 of the both-ends support beam portion 351 to the contact point. Is provided. According to the present invention, the both ends support beam portion (first elastic member) 351 that determines the natural frequency of the drive system including the rotating body and the drive source by the elastic deformation behavior, and the elastic behavior of the both ends support beam portion 351 are described. A fluid-filled vibration isolator (second elastic member) that acts to increase its damping characteristics
37 in the drive transmission unit, which will be described in detail below.

The connecting elastic body 35 of the present embodiment is a resin molded member made of polyacetal (POM).
For example, it is firmly fixed to the drive gear 34 by three screws. The both ends support beam part 351 is a both-end fixed beam having a thickness of 1.8 mm and a length of 35 mm, and the natural frequency is determined by this. As the material of the elastic body 35 for connection, in addition to the above, an ABS resin, a SUS alloy, a galvanized steel plate (SECC-C-20 / 20), an industrial resin material having elastic properties such as an aluminum alloy or a metal material is selected. Can be used for Further, in the embodiment, the shape of the both-ends support beam portion 351 is used, but the shape of the cantilever support beam portion 352 as shown in FIG. 3C may be used.

The dashed-dotted arrows in FIG. 3 indicate the direction in which the connecting projection 36 is inserted into the connecting elastic body 35 and the direction in which the drive gear 34 and the connecting elastic body 35 rotate. FIG.
Shows another embodiment of the connecting means. Note that FIG.
Portions having the same functions as those described above are denoted by the same reference numerals.

As shown in the perspective view of FIG. 4 (a), the connecting elastic body 35 having the both ends
01, and both ends of the support beam portion 351 are fixed to the flange 101 in a position substantially in the radial direction. The fluid-filled anti-vibration means 37 is press-fitted into the both-ends support beam 351 in a form in which the fluid-filled anti-vibration means 37 abuts. A rod-shaped rigid connecting projection 36 is fixed to the end face of the drive gear 34. In the assembled state, as shown in FIG. And the connecting protrusion 36 pushes the both-end supporting beam 351 in the direction of the arrow with the rotation of the driving gear 34, and the drive is transmitted to the photosensitive drum 10.

FIG. 5A is a cross-sectional view of the fluid-filled vibration damping means 37, and FIG. 5B is a cross-sectional view of the fluid-filled vibration damping means 37 taken along line AA.

The fluid-filled vibration damping means 37 includes a viscoelastic member 371 on the side of the connecting elastic body 35 which comes into contact with the flexible beam-like portion (both ends supporting beam portion 351 or cantilever supporting beam portion 352). And a box 370 closed by an elastic member 371. An orifice 3 for fluid flow is provided substantially at the center of the box 370.
A partition plate 372 having 72A is fixed. The inside of the box body 370 has an upper first fluid chamber 373 and a lower second fluid chamber 374 partitioned by a partition plate 372.
And an anti-vibration rubber film member 376 that movably partitions the second fluid chamber 374 and the lowermost air chamber 375.
The first fluid chamber 373 and the second fluid chamber 374 hermetically contain a viscous fluid, and the air chamber 375 is filled with air or gas.

The connecting elastic body 35 is made of resin such as polyacetal (POM) or ABS, or stainless steel (S
US), SECC, aluminum alloy and the like.
The vibration-proof rubber member 376 of the fluid-filled vibration-proof device 37 has high vibration absorption performance for ethylene propylene rubber (EPDM), silicone gel, oil-impregnated porous rubber, butyl rubber, chloroprene rubber, thermoplastic elastomer, and thermoplastic resin. The added high-functional material is used. As the viscous fluid, silicon oil, electrorheological fluid (ER fluid), electromagnetorheological fluid (EMR fluid), or the like is used.

The viscoelastic member 371 of this embodiment includes chloroprene rubber (CR) and ethylene propylene rubber (EP).
DM), silicone gel, oil-impregnated porous rubber, butyl rubber, thermoplastic elastomer, and a high-performance material obtained by adding high vibration absorption performance to a thermoplastic resin.

The fluid-filled vibration isolator 37 has a JIS rubber hardness of 20 to 100 degrees, preferably 40 to 8 degrees.
A viscoelastic body having a mechanical loss coefficient tan δ of 0.3 or more, preferably 0.5 or more, which is an elastic body between 0 degrees and represents the magnitude of internal friction in the fluid-filled type vibration damping means 37. Then, the natural vibration of the torsion is established by the spring constant and the damping coefficient of the drive transmission system including the rotating body 10 or the flywheel that rotates integrally with the rotating body 10, the connecting elastic body 35, and the fluid-filled vibration isolator 37. The number can be controlled to 5 to 60 Hz.

As shown in FIG. 3 (b), the fluid-filled type vibration damping means 37 having the above-mentioned characteristics can reduce the compression ratio from 1% to 15%.
In a pre-compressed state of%, the flexible beam portion 351 is in surface contact with a fixed area on the side opposite to the contact point of the connecting projection member 36.

The inventor has determined that the moment of inertia is 27000 g.
For the photoreceptor drum 10 of cm 2, a compression rate of 10% is used by using a fluid-sealed vibration isolator 37 having a JIS rubber hardness of 61 degrees.
And a fluid filled type vibration damping means for the flexible beam 351 having a loss coefficient tan δ of 1.9 and a natural frequency of torsion of 15 Hz. 37, the moment of inertia of the rotating body 10 is 10,000 g · cm ^{2 to} 30000 g · cm ^2.
With this, it was possible to reduce the gain of the transfer coefficient, and optimal vibration isolation characteristics were obtained.

FIG. 6 is a block diagram showing an embodiment in which the driving device for a rotating body according to the present invention is applied to the driving of a belt photoreceptor. In the figure, parts having the same functions as those in FIG. 2 are denoted by the same reference numerals. Further, points different from the above embodiment will be described.

The driving force of the driving motor (driving source) M1 is transmitted from the gear 31 to the driving gear 34, and the driving gear 34
Connecting elastic body 35 provided in the flywheel 1
The light is transmitted to the flywheel 104 via a connecting means consisting of the connecting projection member and the connecting projection member. Drive shaft 105 of flywheel 104 is flywheel 104
, But not connected to the drive gear 34. Therefore, the drive shaft 105 and the drive gear 34 rotate as a separate body, and the drive of the drive gear 34 is not transmitted through the drive shaft, but is transmitted through a connection means including a connection elastic body 35 and a connection protrusion 36. Is transmitted.

The speed unevenness transmitted to the flywheel 104 is reduced due to the inertia of the connecting means and the flywheel 104, and the driving rotation is performed by a connecting member (coupling) that makes the belt cartridge 106 detachable. The belt photoreceptor 110 transmitted to the driving roller 108 via the driving roller 107 and wound between the driving roller 108 and the driven roller 109 can be vibrated and driven with high precision.

FIG. 7A shows a connecting member (coupling) 1.
7 is a side view, and FIGS. 7B and 7B are cross-sectional views of the connecting member 107.

The connecting member 107 includes a connecting joint 107A on the photoconductor side and a connecting joint 10 on the flywheel 104 side.
7B. The coupling joint 107A is a male type having a plurality of convex portions, and the coupling joint 107B is a female type having a plurality of concave portions. The connecting joint 107A is connected to the connecting joint 10
The drive shaft on the photoreceptor side and the drive shaft on the flywheel 104 side are connected by fitting the drive shaft 7B in the axial direction.

FIG. 8 is a characteristic diagram showing the relationship between the excitation frequency and the gain of the transfer function (vibration transmissibility indicating the ratio of the output frequency to the input frequency).

The conventional solid type anti-vibration rubber has the characteristic that the resonance can be suppressed by increasing the loss coefficient, but the anti-vibration area goes in the direction of deterioration, whereas the viscous fluid, the orifice and the anti-vibration By combining with the rubber member, the loss coefficient can be increased in the resonance area and the loss coefficient can be reduced in the vibration proof area. Therefore, an ideal vibration characteristic as shown in FIG. 6 is exhibited.

With the above structure, the inertia moment of the inertial body (drive gear, flywheel, photosensitive drum, drive roller of the belt photosensitive body, etc.) and the natural frequency of the torsion by the elastic member are dominant, and the fluid-filled type is prevented. The damping coefficient can be controlled dominantly and freely by the vibration means 37, and the degree of freedom in design is significantly improved. The fact that the natural frequency and the damping coefficient of the photoconductor drive system can be set freely is, as a specific effect, in the region where the gain of the transfer function is originally reduced in the region higher in frequency than the natural frequency. In addition, the speed unevenness is reduced, and the effect of the damping member reduces the gain of the transfer function itself, which appears as an effect that the resonance level near the natural frequency decreases,
As a whole, it is possible to obtain an effect that speed unevenness relating to photoconductor driving is efficiently reduced, and as a result, photoconductor driving accuracy is significantly improved.

Further, by employing the viscoelastic member 371 of the fluid-filled vibration isolating means 37, if the resonance gain is about the same as that of the conventional solid-type viscoelastic member, the fluid-filled vibration isolating means can be used. Since the gain of the means 37 is reduced in the vibration damping region, the speed unevenness is further reduced (see FIG. 8).

Recently, a control-type vibration isolator capable of actively controlling dynamic characteristics has been developed so as to obtain ideal vibration insulation characteristics in response to changes in external force. This is a mechanical control type and an electrorheological fluid (E
(R fluid). The ER fluid is a fluid having a property that the viscosity changes according to the strength of the electric field when placed in an electric field, and has a characteristic that the reaction is reversible and the reaction time is short. In addition, electro-magnetic viscous fluid (EM
The R fluid is a fluid in which composite particles sensitive to an electric field and a magnetic field are dispersed in an electrically insulating solvent, and variably controls the shear stress of the EMR fluid by a synergistic effect of simultaneous application of an electric field and a magnetic field.

FIG. 9 is a block diagram showing another embodiment of the rotating body driving device.

The fluid-filled vibration isolator 37 is connected to the electric field generator and / or the magnetic field generator 111 and is variably controlled by the fluid controller 112. The driving motor M1 is controlled by the motor control unit 113.

When it is detected that the load on the rotating body of the photosensitive drum 10 or the line speed has changed, the process control unit 114 controls the fluid control unit 112 and the motor control unit 11.
3 is controlled to vary the viscosity of the ER fluid or the EMR fluid, so that optimal vibration-proof characteristics can be obtained with respect to changes in the excitation frequency and the natural frequency.

FIG. 10 is a characteristic diagram showing a change in a transfer function when control is performed using an ER fluid or an EMR fluid.

In a machine having two types of line speeds, the natural frequency and damping of the transfer function are controlled by controlling the viscosity of the fluid based on information on the number of rotations of the motor when the line speed changes from the motor control unit 113. The coefficient is changed so that the speed unevenness is reduced. That is, when the line speed is 1, the fluid viscosity is controlled to be small, and when the line speed is 2, the fluid viscosity is controlled to be large.

As a result, speed unevenness in the vicinity of the resonance region and speed unevenness at higher frequencies can be reduced efficiently, and furthermore, it is resistant to vibrations from the developing drive unit or disturbances such as load fluctuations of the cleaning blade and the transfer roller. And a stable drive system can be obtained. Further, even when the load condition or the line speed changes, the optimum vibration isolation characteristics can be obtained, and a stable drive system can be obtained.

FIG. 10 shows the change of the transfer function when the viscous fluid is controlled and the position of the speed unevenness component accompanying the change of the line speed. The transfer function is controlled so that these relationships do not resonate. .

FIG. 11A is a block diagram showing still another embodiment of the rotating body driving device, and FIG. 11B is a cross-sectional view of the fluid filled type vibration damping means 38. In FIG. 5, FIG.
Portions having the same functions as those in FIG. 9 are denoted by the same reference numerals.
Further, points different from the above embodiment will be described. This is an embodiment in which control is performed by applying a fluid filled type vibration damping means having a plurality of orifices 382A and 382B.

The partition plate 3 fixed in the box 370
82 has a first orifice 382A and a second orifice 382B. A movable plate 381 is slidably provided on the lower surface side of the partition plate 382. The movable plate 381 has an opening 381A. The movable plate 381 is moved by the drive motor M2. Partition plate 3
When the second orifice 382B of 82 and the opening 381A of the movable plate 381 coincide with each other, the fluid in the first fluid chamber 373 and the second fluid chamber 374 communicate with each other at this opening position. The opening 381A is used instead of the movable plate 381.
May be provided with an electromagnetic on-off valve. Further, the number of orifices is not limited to two, and three or more can be provided. FIG. 12 is a characteristic diagram showing a change of a transfer function when mechanical control is performed.

In a machine having two line speeds, the natural frequency and damping of the transfer function are controlled by controlling the viscosity of the fluid based on the information on the number of rotations of the motor when the line speed changes from the motor control section 113. The coefficient is changed so that the speed unevenness is reduced. That is, when the line speed is 1, the fluid viscosity is controlled to be small, and when the line speed is 2, the fluid viscosity is controlled to be large.

The main configuration is as shown in FIG. In a machine with two line speeds, the natural frequency and damping coefficient of the transfer function are controlled by controlling the number of orifices based on information on the motor rotation speed when the line speed changes from the motor control unit 113. The speed is controlled so as to reduce the speed unevenness.

FIG. 12 shows the change of the transfer function and the position of the speed unevenness component accompanying the change of the line speed in the case of controlling, and the transfer function is controlled so that these relations do not resonate. That is, when the line speed is 1, the number of orifices is controlled to two (382A, 382B), and when the line speed is 2, the number of orifices is controlled to one (382A).

FIG. 13 is a sectional view showing another embodiment of a color image forming apparatus to which the rotating body driving device of the present invention is applied.

Note that, in the reference numerals used in the drawings, parts having the same functions as those in FIG. 1 are given the same reference numerals. Further, points different from the above embodiment will be described.

Photosensitive drum 1 as drum-shaped image carrier
Reference numeral 0 denotes, for example, a cylindrical transparent resin substrate formed by a transparent member of a transparent acrylic resin provided inside, and a transparent conductive layer and an organic photoconductor layer (OPC) formed on the outer periphery of the substrate. It is rotated in the direction shown by the arrow in FIG. The flexible beam-shaped portion 35 is connected to the drive connecting means for transmitting the driving force from the drive source to the photosensitive drum 10.
The photosensitive drum 10 is driven with high accuracy by providing the connecting elastic body 35 having the number 1 and the fluid-filled type vibration damping means.

In the color image forming apparatus according to the present invention, a plurality of sets (four sets in the figure) of an image forming unit including a charging unit, an image exposing unit and a developing unit are arranged around the image carrier 10. .

Reference numerals 11Y, 11M, 11C, and 11K denote scorotron chargers (hereinafter referred to as chargers 11 (Y, M, C, and K)) which bring the organic photosensitive layer of the photosensitive drum 10 to a predetermined potential. The charging action is performed by the held grid and corona discharge by the discharge wire, and a uniform electric potential is given to the photosensitive drum 10.

Reference numerals 13Y, 13M, 13C, and 13K denote image exposure means (hereinafter, referred to as exposure optical systems 13 (Y, M, C, and K)) for performing image exposure based on image signals. An exposure optical system including an LED arrayed in the axial direction and a selfoc lens that is an equal-magnification image forming system. Image signals of respective colors read by a separate image reading device are sequentially taken out of a memory, and Each exposure optical system 13
(Y, M, C, K) are inputted as electric signals, respectively, and a latent image is formed by rotation (sub-scan) of the photosensitive drum 10. Each of the exposure optical systems 13 (Y, M, C, K) is attached to a support member 130 provided as an optical system support means, and is housed inside the base of the photosensitive drum 10.

Reference numerals 14Y, 14M, 14C, and 14K denote developers for accommodating yellow (Y), magenta (M), cyan (C), and black (K) developers, respectively. , A developing sleeve 140 that rotates while maintaining a predetermined gap, and a magnet roller 142 that has a stripped magnetic pole.

Each of the developing units 14 (Y, M, C, K)
Represents the electrostatic latent image on the photosensitive drum 10 formed by the charging by the charger 11 (Y, M, C, K) and the image exposure by the exposure optical system 13 (Y, M, C, K). By applying a developing bias voltage, reversal development is performed in a non-contact state.

The original image is temporarily stored in an image reading apparatus separate from the present apparatus in the form of an image read by an image sensor or an image edited by a computer as image signals for respective colors of Y, M, C and K. And stored.

At the start of image recording, the photosensitive drum driving motor starts to rotate the photosensitive drum 10 in a counterclockwise direction (the direction of the arrow in the figure), and at the same time, a potential is applied to the photosensitive drum 10 by the charging action of the charger 11Y. Be started.

After the potential is applied to the photosensitive drum 10, the exposure optical system 13Y starts exposure with an electric signal corresponding to a first color signal, that is, an image signal of yellow Y, and the surface of the photosensitive drum 10 is scanned by rotating the drum. An electrostatic latent image corresponding to the yellow (Y) image of the original image is formed on the photosensitive layer.

The latent image is reversal-developed by the developing device 14Y in a state where the developer on the developing sleeve 140 is not in contact, and a yellow (Y) toner image is formed in accordance with the rotation of the photosensitive drum 10.

Next, the photosensitive drum 10 is further provided with a potential on the yellow (Y) toner image by the charging action of the charger 11M, and a second color signal of the exposure optical system 13M, that is, an image of magenta (M) is provided. Exposure is performed by an electrical signal corresponding to the signal, and a magenta (M) toner image is sequentially superimposed on the yellow (Y) toner image by non-contact reversal development by the developing device 14M. .

By the same process, a cyan (C) toner image corresponding to the third color signal is further formed by the charger 11C, the exposure optical system 13C, and the developing device 14C.
1 (K), a black (K) toner image corresponding to the fourth color signal is sequentially formed by the exposure optical system 13K and the developing device 14K, and is formed on the peripheral surface within one rotation of the photosensitive drum 10. A color toner image is formed.

The photosensitive drum 1 of each of these exposure optical systems
The exposure of the organic photosensitive layer of No. 0 is performed from the inside of the drum through a substrate transparent to the above-mentioned exposure wavelength. Therefore, the exposure of the images corresponding to the second, third, and fourth color signals is performed without any influence from the previously formed toner image, and is equivalent to the image corresponding to the first color signal. It is possible to form an electrostatic latent image. Each developing unit 14
In the developing operation by (Y, M, C, K), a developing bias to which a direct current or a further alternating current is applied is applied to the developing sleeve 141, and the developing device 14 (Y, M, C, K) is applied.
Non-contact development is performed by a one-component or two-component developer contained in K), and non-contact reversal development is performed on the photosensitive drum 10 that grounds the transparent conductive layer.

The color toner image formed on the peripheral surface of the photosensitive drum 10 is temporarily transferred to the peripheral surface of the intermediate transfer belt 40 provided as intermediate transfer means. Intermediate transfer belt 4
Numeral 0 is stretched between the rollers 41, 42, 43 and the driving roller 44, and is circulated clockwise in synchronization with the peripheral speed of the photosensitive drum 10 by the power transmitted to the driving roller 44.

In the intermediate transfer belt 40, the belt surface between the drive roller 44 and the roller 42 is in contact with the peripheral surface of the photosensitive drum 10, and the outer peripheral belt surface of the drive roller 44 is in contact with the transfer roller 45 as a transfer member. A transfer area of the toner image is formed at each contact position.

The drive coupling means for transmitting the driving force from the drive source to the drive roller 44 is provided with the coupling elastic body 35 having the flexible beam-shaped portion 351 and the fluid-filled type vibration-proofing means. The body drum 10 is driven with high precision.

The color toner image composed of a plurality of colors adhered to the peripheral surface of the photosensitive drum 10 is first supplied with a bias voltage having a polarity opposite to that of the toner to the roller 42 at the contact position with the intermediate transfer belt 40. The transfer is sequentially performed on the peripheral surface side of the intermediate transfer belt 40 by the application. That is, the color toner image on the photosensitive drum 10 is conveyed to the transfer area without scattering the toner by the guidance of the grounded roller 41, and is applied to the intermediate transfer belt 40 by applying a bias voltage of 1 to 2 kV to the roller 42. It is transferred efficiently.

The cleaning device 5 is mounted on the photosensitive drum 10.
The reference numeral 0 indicates that the cleaning device 46 is in pressure contact with the intermediate transfer belt 40, and the blades of the respective devices are constantly in pressure contact with each other, and the remaining adhered toner is removed, and the peripheral surface is always kept in a clean state.

On the other hand, the transfer material P is carried out by the operation of the paper feed roller 22 B of the paper feed cassette (not shown) and fed to the timing roller 23, and synchronized with the transfer of the color toner image on the intermediate transfer belt 40. The paper is fed to the transfer area of the transfer roller 45.

The transfer roller 45 is rotated counterclockwise in synchronization with the peripheral speed of the intermediate transfer belt 40, and the fed transfer material P is
The transfer roller 45 is brought into close contact with the color toner image on the intermediate transfer belt 40 in the transfer area formed by the nip portion between the transfer rollers 45.
The color toner images are sequentially transferred onto the transfer material P by applying a bias voltage having a polarity opposite to that of the toner of 1 to 2 kV to the transfer material P.

The transfer material P to which the color toner image has been transferred is neutralized, conveyed to the fixing device 24 via the conveyance plate 27, and sandwiched and conveyed between the heat roller 241 and the pressure roller 242 to be heated. After the toner is fused and fixed, the toner is discharged to the outside of the apparatus via a discharge roller 25A.

The photosensitive drum 10 and the driving roller 44
By providing the connecting elastic body 35 having the flexible beam-shaped portion 351 and the fluid-filled type vibration damping means, the photosensitive drum 10
Further, the intermediate transfer belt 40 is driven with high accuracy, and can stably output a high-quality color image.

FIG. 14 is a sectional view of a color image forming apparatus using an intermediate transfer drum 60 as an image carrier. When the intermediate transfer drum 60 is used, the electrostatic latent image formed on the rotating photosensitive drum 10 is developed by a developing device 14Y having a developing sleeve 140 and a magnet roller 142 to form a yellow toner. An image is formed and this Y
The color toner image is transferred from the photosensitive drum 10 to the intermediate transfer drum 60.
Similarly, the electrostatic latent image formed on the photosensitive drum 10 is developed by the developing device 14M to form an M-color toner image, and the M-color toner image is transferred from the photosensitive drum 10 to the intermediate transfer. The toner image is transferred to the drum 60, and similarly, the C color toner image and the K color toner image are sequentially transferred from the photosensitive drum 10 to the intermediate transfer drum 60. Further, the intermediate transfer drum 60
In a transfer section where the transfer roller 17 and the transfer roller 17 are in contact, the multicolor toner images (Y, M, C, and K) are collectively electrostatically transferred onto the transfer material P, and then separated by the separating means 18 to form the fixing device 24.
To fix the image.

Also in this color image forming apparatus, the photosensitive drum 10 and the intermediate transfer drum 60 are provided with a connecting elastic body 35 having a flexible beam-shaped portion 351 and a fluid-sealed type vibration damping means. The body drum 10 and the intermediate transfer drum 60 are driven with high precision, and can stably output a high-quality color image.

FIG. 15 is a sectional view showing a still further embodiment of the color image forming apparatus to which the rotating body driving device of the present invention is applied.

In this color image forming apparatus, the charging means 11 (Y, M,
C, K), image exposure units 13 (Y, M, C, K), and developing units 14 (Y, M, C, K) are provided in plural sets (four in the drawing). is there. However, a flexible endless belt-shaped photoconductor (hereinafter, also referred to as a belt photoconductor) 110 is used as an image carrier, and the image exposure unit 14 (Y,
(M, C, K) using a laser beam scanning optical device.

The belt photoreceptor 110 is
And tensioned by the action of the tension roller 116, and rotated clockwise in the drawing while being locally abutted by the backup member 117 provided on the inner peripheral surface. The backup member 117 includes a developing sleeve 141 (Y, M, C, K).
And the image forming position of the image exposure means 13 (Y, M, C, K).

The four endless charging means 11 (Y, M, C,
K), image exposure means 13 (Y, M, C, K), developing means 1
4 (Y, M, C, K).

At the start of image recording, the drive motor rotates to drive the belt photoreceptor 110 via the drive roller 108.
Rotates clockwise as shown in FIG.
The application of the potential to the belt photoconductor 110 is started by the charging action of (Y). After a potential is applied to the belt photoreceptor 110, exposure by an electric signal corresponding to a first color signal, that is, an image signal of yellow (Y) is started in the image exposure unit 13 (Y), and rotation of the belt (sub-scanning) is performed. ), An electrostatic latent image corresponding to the yellow (Y) image of the developed image is formed on the photosensitive layer on the surface. This latent image is
By (Y), the developer adhered and conveyed onto the developing sleeve 141 (Y) is reversely developed in a non-contact state, and a yellow (Y) toner image is formed according to the rotation of the belt photoconductor 110.

Next, the belt photoreceptor 110 further applies a scorotron charger 11 on the yellow (Y) toner image.
A potential is applied by the charging action of (M), and the image exposure means 1
Exposure is performed with an electric signal corresponding to the second color signal of 3 (M), that is, the image signal of magenta (M), and the developing device 14
By the non-contact reversal development by (M), a magenta (M) toner image is superposed on the yellow (Y) toner image.

By the same process, the scorotron charger 11 (C), the image exposure means 13 (C) and the developing device 14
(C) further forms a cyan (C) toner image corresponding to the third color signal, and the scorotron charger 11
(K), a black (K) toner image corresponding to the fourth color signal is sequentially superimposed by the image exposure means 13 (K) and the developing device 14 (K), and is formed within one rotation of the belt photoconductor 110. Then, a color toner image is formed on the peripheral surface.

Developing units 14 (Y), 14 (M), 14
At the time of the developing action by (C) and 14 (K), the developing sleeves 141 (Y), 141 (M), 141
A developing bias to which a direct current or a further alternating current is applied to (C) and 141 (K) is applied, and non-contact development is performed by a one-component or two-component developer attached on the developing sleeve 141, and the conductive layer is grounded. Non-contact reversal development in which toner adheres to an exposed portion on the photoreceptor from the developing sleeve 141 to which a DC bias having the same polarity as the charging of the belt photoreceptor 110 is applied to the belt photoreceptor 110 thus performed.

Thus, the color toner image formed on the peripheral surface of the belt photoreceptor 110 is
After the potential of the adhered toner is made uniform by (F), static elimination is performed by the pre-transfer exposure device 12, and in the transfer section,
The sheet is fed out from the sheet feeding cassettes 20 (A), 20 (B) or a manual feed unit, and is conveyed to the pair of registration rollers 23. The image is transferred onto a transfer sheet fed in synchronization by a transfer roller 17 arranged opposite to a lower portion of a drive roller 108 for driving the belt photoconductor 110.

The transfer paper having received the transfer of the toner image is separated from the peripheral surface of the belt photoreceptor 110 along the curvature of the driving roller 108, and is conveyed to the fixing device 24, where it is fixed.
4, the toner is fused on the transfer paper by heating and pressing.
The sheet is fixed and discharged from the fixing device 24, and the discharge roller pair 2
The paper is conveyed by 5A, 25B, and 25C, and is discharged to a discharge tray 26 provided at an upper portion with the toner image surface on the transfer paper facing downward.

On the other hand, the belt photosensitive member 11 from which the transfer paper is separated
Reference numeral 0 indicates that the cleaning device 19 rubs the surface of the belt photoreceptor 110 with the cleaning blade 191 to remove and clean the residual toner, and then continues to form the toner image of the next original image or temporarily stops. stand by. When the formation of the toner image of the next original image is performed subsequently, the pre-charging static eliminator 12 exposes the photoconductor surface of the belt photoconductor 110 to remove the previous history.

Also in this embodiment, the driving roller 1
By providing the connecting elastic body 35 having a flexible beam portion 351 (not shown) and the fluid-filled type vibration damping means at 08, the drive roller 108 can be transferred at a constant speed without speed fluctuation. Therefore, the belt photoreceptor 110 is driven with high precision, can output a high-quality color image stably, and can significantly improve image quality.

In addition, the rotating body driving device of the present invention winds a photosensitive film around a drum-shaped rotating body, for example, while rotating the rotating body at a uniform speed while scanning with a polygon mirror or the like. Excellent effects can be obtained even when the present invention is applied to a recording apparatus for performing image recording.

According to the present invention, the natural frequency of torsion of the rotating body is dominantly controlled by the first elastic member (beam portion).
The damping coefficient can be controlled dominantly and freely by the second elastic member (viscoelastic body), and the degree of freedom in design is significantly improved. The fact that the natural frequency and damping coefficient of the rotating body drive system can be set freely is, as a specific effect, in the region where the gain of the transfer function is originally reduced in the region higher in frequency than the natural frequency. In addition, the speed unevenness is reduced, and the gain of the transfer function itself is reduced by the effect of the damping member, so that the resonance level in the vicinity of the natural frequency is reduced. The effect that the unevenness is efficiently reduced and the driving accuracy of the rotating body is remarkably improved can be obtained.

As a result, speed fluctuation near the resonance region, vibration in the image forming apparatus, or disturbance against load fluctuation of the blade, the transfer roller, etc., in the image forming apparatus,
A stable drive system can be obtained.

[0118]

According to the driving device for a rotating body according to the present invention,
Since the effects of load fluctuation and speed unevenness of the drive system can be extremely reduced, the rotating body and the photosensitive drum for forming an image can always rotate with high accuracy and stability. Further, even if the load condition or the line speed changes, the optimum vibration damping characteristics can be obtained, so that more accurate driving can be performed as compared with the conventional solid type.

The image forming apparatus provided with the driving device for the rotating body according to the present invention significantly reduces small pitch banding, which is a major image trouble caused by unevenness in the speed of the photosensitive member, and this level cannot be recognized by humans. And a high-quality image can be stably provided.
8).

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a color printer as an example of an image forming apparatus equipped with a rotating body driving device of the present invention.

FIG. 2 is a perspective view and a partial cross-sectional view showing a photosensitive drum and a driving mechanism.

FIG. 3 is a perspective view showing a photosensitive drum and a connecting means, and a front view showing the structure of a connecting elastic body.

FIG. 4 is a perspective view showing another embodiment of the photosensitive drum and the connecting means, and a front view showing the structure of the connecting elastic body.

FIG. 5 is a cross-sectional view of the fluid-filled type vibration damping means and an AA cross-sectional view of the fluid-filled vibration damping means.

FIG. 6 is a configuration diagram showing an embodiment in which the rotating body driving device of the present invention is applied to belt photoconductor driving.

FIG. 7 is a side view and a cross-sectional view of a connecting member.

FIG. 8 is a characteristic diagram showing a relationship between an excitation frequency and a gain of a transfer function.

FIG. 9 is a block diagram showing another embodiment of the driving device for the rotating body.

FIG. 10 is a characteristic diagram showing a change in a transfer function when control is performed using an ER fluid or an EMR fluid.

FIG. 11 is a block diagram showing still another embodiment of a driving device for a rotating body, and a cross-sectional view of a fluid filled type vibration damping means.

FIG. 12 is a characteristic diagram illustrating a change in a transfer function when mechanical control is performed.

FIG. 13 is a cross-sectional configuration diagram illustrating another embodiment of a color image forming apparatus to which the rotating body driving device of the present invention is applied.

FIG. 14 is a cross-sectional configuration diagram illustrating an embodiment of a color image forming apparatus including an intermediate transfer drum to which the rotating body driving device according to the invention is applied.

FIG. 15 is a cross-sectional configuration diagram illustrating an embodiment of a color image forming apparatus including a belt photoconductor to which the rotating body driving device according to the invention is applied.

[Explanation of symbols]

 Reference Signs List 10 rotating body (photosensitive drum, image carrier) 101 flange 104 flywheel 108, 44 drive roller 110 belt photosensitive body 111 electric field magnetic field generating means 112 fluid control unit 113 motor control unit 114 process control unit 115 orifice control unit 30 drive mechanism 34 Drive gear (drive transmission member) 35 Elastic body for connection (elastic member, drive connection member) 351 Both-end support beam (flexible beam) 352 Cantilever support beam (flexible beam) 36 Connection projection member (following connection member) 37, 38 Fluid-sealed type vibration isolating means 371 Viscoelastic member 372 Partition plate 372A, 382A, 382B Orifice 373 First fluid chamber 374 Second fluid chamber 375 Air chamber 376 Vibration-proof rubber Member 381 Movable plate 381A Opening M1, M2 Drive motor (drive source)

Claims (8)

[Claims] A rotating member rotatably supported; a driving source for driving the rotating member; a driving member for transmitting a rotational driving force of the driving source to the rotating member; a driven member; Means, the connecting means comprises a driving connecting member and a driven connecting member, the driving connecting member has an elastic member having an elastically deformable flexible beam, Fluid-filled vibration isolating means fixed in surface contact with one surface of the flexible beam-shaped portion is provided, and the driven connection member has a connecting projection member, and the flexible beam-shaped portion has A driving device for a rotating body, wherein a connecting projection member is brought into contact with the rotating body, and the rotational driving force of the driving source is transmitted to the rotating body via the connecting means. A rotating member rotatably supported, a driving source for driving the rotating member, a driving member for transmitting a rotational driving force of the driving source to the rotating member, a driven member, and a connection. Means, the connection means comprises a drive connection member and a driven connection member, the drive connection member has a connection projection member, and the driven connection member is elastically deformable. An elastic member having a flexible beam portion; and a fluid-filled vibration isolator fixed in surface contact with one surface of the flexible beam portion. A driving force of the driving source is transmitted to the rotating body via the connecting means, by contacting the driven beam with the flexible beam-shaped portion of the driven connecting member. apparatus. 3. The fluid-filled type vibration damping means includes a viscoelastic member on a side that comes into contact with the flexible beam-like portion, and a box closed by the viscoelastic member. A partition plate having an orifice for fluid flow, a first fluid chamber and a second fluid chamber partitioned by the partition plate, and a partition for movably partitioning the second fluid chamber and the air chamber. The driving device for a rotating body according to claim 1 or 2, further comprising a vibration damping film member. 4. The driving device for a rotating body according to claim 1, wherein the JIS rubber hardness of the fluid-filled type vibration damping means is 20 degrees to 100 degrees. 5. A loss coefficient ta of the fluid-filled type vibration damping means.
3. The driving device for a rotating body according to claim 1, wherein nδ is 0.3 or more. 4. 6. The fluid filled type vibration damping means has a compression ratio of 1
3. The driving device for a rotating body according to claim 1, wherein the device is in contact with the elastic member in a pre-compressed state of% to 15%. 4. 7. An image carrier for carrying at least an image,
Image forming means for forming an image on the image carrier, a drive source for driving and rotating the image carrier or a rotator holding the image carrier, and a rotational driving force of the drive source for the image carrier or the rotation. In an image forming apparatus having a driving member for transmitting to a body, a driven member, and a transmitting unit including a connecting unit, the connecting unit includes a driving connecting member and a driven connecting member, and the driving connecting member or the driven connecting member. An elastic member having an elastically deformable flexible beam portion, and a fluid-filled vibration isolator fixed in surface contact with one surface of the flexible beam portion. The enclosing vibration isolator has a viscoelastic member on the side that comes into contact with the flexible beam-shaped portion, and a box closed by the viscoelastic member. A partition plate having an orifice, and a first fluid partitioned by the partition plate When a second fluid chamber, and a vibration isolating rubber film member which partitions the movable and said second fluid chamber and the air chamber, the first fluid chamber and a second of said fluid filled type vibration damping means
The fluid accommodated in the fluid chamber is an electrorheological fluid whose viscosity is reversibly changed by turning on and off an electric field, or an electromagnetorheological fluid whose shear stress is changed by simultaneous application of an electric field and a magnetic field. An image forming apparatus, wherein control is performed so as to obtain an optimum image stabilizing characteristic according to a change in a system load condition and a line speed. 8. A rotating body rotatably supported, a driving source for driving the rotating body, a driving member for transmitting a rotational driving force of the driving source to the rotating body, a driven member, and connecting means. And a transmission unit comprising: a transmission unit comprising: a drive connection member; and a driven connection member, wherein the drive connection member or the driven connection member includes an elastically deformable flexible beam. And a fluid-filled vibration isolator fixed in surface contact with one surface of the flexible beam-like portion, wherein the fluid-filled vibration isolator is A viscoelastic member on the side in contact with the portion, and a box closed by the viscoelastic member, a partition having a plurality of orifices for fluid flow inside the box, and the partition Partitioned first fluid chamber, second fluid chamber, and second fluid chamber and air A vibration-isolating rubber membrane member that movably partitions the chamber, and a plurality of on-off valves that can open and close the plurality of orifices, and a driven connection member connected to the drive connection member, or the driven connection member A protruding member is fixed to the driving connecting member to be connected, and the protruding member is connected to the flexible beam-shaped portion by being brought into contact with the protruding member. By transmitting to the rotating body through the connecting means consisting of and driving means for opening and closing the on-off valve, and control means for controlling the driving means, by opening and closing a predetermined on-off valve, the The amount of fluid flowing through the orifice can be variably controlled,
An image forming apparatus, wherein control is performed so as to obtain an optimum image stabilizing characteristic in accordance with a load condition of a drive system and a change in line speed.