JP2006078907A - Rotating body driving apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating body driving apparatus capable of attaining a highly accurate control corresponding to a feedback control by reducing the elongation of a belt between a driving pulley and a driven pulley. <P>SOLUTION: Regarding the rotating body driving apparatus having a driving source for rotary-driving the rotating body, the driven pulley fixed to the rotating body, and a driving pulley arranged in the driving source, for transmitting the driving force to the rotating shaft of the rotating body through the belt put over the driving pulley and the driven pulley, a roller fixed in the belt stretching direction is arranged between the driving pulley and the driven pulley, and the roller is rotated in contact with the belt for driving the driven pulley in the belt moving direction by the rotating force of the driving pulley. Thus, the contact area of the belt driving becomes large, then, the controllability is improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotator driving device, and more particularly to a rotator driving device for transmitting a driving force to a rotating shaft of an image carrier such as a copying machine, a printer, and a FAX, and an image forming apparatus using the same.

In an electrophotographic image forming apparatus using a photoconductor as an electrostatic latent image carrier, fluctuations in the rotation of the photoconductor and fluctuations in the paper conveyance speed affect image formation, resulting in uneven density of the output image. There is a method of feedback control of the drive motor so that the photosensitive drum and the paper transport roller rotate at a constant rotation by the output pulse from the position detection member fixed to the body drum shaft and the position detection member attached to the paper transport unit. Are known.
In addition, in an image forming apparatus using an ink jet, a method is known in which a drive motor is feedback-controlled so that a paper transport roller rotates at a constant speed by an output pulse from a position detection member attached to a paper transport unit.
When the drive motor is feedback-controlled using a reduction mechanism, the gear drive mechanism is required to have a mechanism that always rotates while the gear is in pressure contact because the feedback controllability is impaired by backlash (gear meshing backlash).
Further, in the belt drive mechanism, the backlash does not cause a lot of backlash, but due to the belt elongation, the driven pulley generates speed fluctuations even when the drive motor rotates at a constant speed.

When feedback control is performed by detecting rotational fluctuations of a rotating body, a drive mechanism that eliminates uncontrollable factors due to gear backlash and belt elongation is required. However, in order to improve the accuracy of feedback control with the gear drive mechanism, it is necessary to increase the pressure contact force so that the gear always rotates in pressure contact even in a wide frequency range. Wear occurs.
Further, in order to improve the accuracy of feedback control by the belt drive mechanism, it is necessary to widen the belt width or shorten the belt length. However, if the width of the belt is increased, the inertia of the driven pulley is increased, so that the controllability is deteriorated and the drive mechanism is also increased.
Further, if the belt length is shortened, it becomes difficult to increase the reduction ratio, and a pulley having a large diameter is required to eliminate tooth skipping due to the small number of meshing engagements of the drive pulley.
The present invention has been made in consideration of the above-described circumstances. A roller is provided on the belt tension side of the driving pulley and the driven pulley, and the roller contacts the belt while rotating by the rotational force of the driving pulley. Since the number of meshes is increased and the drive pulley diameter is reduced and the reduction ratio can be increased while reducing the elongation, a rotating body driving device capable of high-precision control corresponding to feedback control and the rotating body driving device are used. An object is to provide an image forming apparatus.

In order to solve the above-described problems, the invention described in claim 1 includes a rotating body, a driving source, a driving pulley that is rotationally driven by the driving source, and a transport roller pulley that is fixed to a rotating shaft of the rotating body. A rotating body driving device that transmits a driving force to the rotating shaft of the rotating body via the belt, the driving pulley and the transporting roller pulley. A roller is provided between the roller and the roller, and the roller rotates in the moving direction of the belt while being in contact with the belt.
According to a second aspect of the present invention, in the rotating body driving device according to the first aspect, the belt contact surface linear velocity of the roller is equal to or slower than the belt linear velocity.
According to a third aspect of the present invention, in the rotating body drive device according to the first aspect, the roller is fixed in a belt tension direction between the driving pulley and the driven pulley.
According to a fourth aspect of the present invention, in the rotating body drive device according to the first aspect of the present invention, the inner side of the belt is a toothed belt and the outer side is a toothless belt.
According to a fifth aspect of the present invention, in the rotating body driving device according to the first aspect, the roller is rotated by a gear provided in a driving source.
According to a sixth aspect of the present invention, in the rotating body drive device according to the fifth aspect, the gear is a helical gear.
According to a seventh aspect of the present invention, there is provided an image forming apparatus wherein the conveyance of the printing paper is driven and controlled by the rotating body driving device according to any one of the first to sixth aspects.

According to the present invention, since the roller provided between the driving pulley and the driven pulley rotates in the forward direction by the driving force of the driving pulley while contacting the belt, the contact area of the belt driving is widened and the controllability is improved.
Further, since the roller provided between the driving pulley and the driven pulley bites into and comes into contact with the belt, the distance that the belt wraps around the driving pulley increases, so that controllability is improved.
Further, since the driving roller is interposed between the driving pulley and the driven pulley, the distance that does not contact the driving pulley and the driven pulley is shortened, and the speed fluctuation due to the elongation and runout of the belt is reduced, so that the controllability is improved.
In addition, by making the linear velocity of the roller outer peripheral surface equal to or slower than the linear velocity of the roller contact surface of the belt, the belt conveys between the drive pulley and the roller with a constant tension, so that highly accurate drive control with little fluctuation is possible. it can.
Also, when the drive pulley rotates, the belt is pulled and lifts the roller, but by fixing the roller in the belt tension direction between the drive pulley and the driven pulley, the distance between the pulleys is always constant, Controllability is improved.
In addition, the inside of the belt that drives the driving pulley and the driven pulley is a toothed belt, so that the rotation amount of the driving pulley is accurately transmitted to the driven pulley, and the outside of the belt that the roller contacts is free of teeth, so that the outer circumference of the roller Even if the surface linear velocity is different from the linear velocity of the belt, it is possible to drive without affecting the rotation amount of the driven pulley due to the sliding of the roller.
Further, the roller can be rotated by a gear provided coaxially with the drive pulley, whereby a low-cost drive mechanism with a simple structure can be provided.
Further, by using a helical gear as the gear that transmits the driving force to the roller, it is possible to drive the belt with little fluctuation in the rotation of the roller.
In addition, the rotating body driving device is used in an image forming apparatus that drives and controls the conveyance of printing paper, so that the rotation of the photosensitive drum and transfer belt that requires rotational position accuracy, and the conveyance of the paper are driven with less belt stretching and vibration. By performing feedback control with the mechanism, high-precision drive control is possible, and a high-quality image forming apparatus with less printing positional deviation and color deviation can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic perspective view of a mechanism part of the ink jet recording apparatus, and FIG. 2 is a side view of the mechanism part of the ink jet recording apparatus.
In FIG. 1, an ink jet recording apparatus includes a carriage 2 that can move in the main scanning direction inside a recording apparatus main body 1, a recording head 3 (see FIG. 2) mounted on the carriage 2, and an ink cartridge that supplies ink to the recording head 3. 4. A carriage drive motor 6 that drives the carriage 2 in the main scanning direction by rotating the belt 5 fixed to the carriage 2, a paper transport roller 7 that transports the recording paper under the recording head 3, and the paper transport roller 7 It includes a conveyance drive motor 8 that rotates and a recovery device 9 that recovers ink adhering to the recording head 3 and cleaning ink.
In FIG. 2, a lower portion of the apparatus main body 1 has a paper feed tray 11 on which a large number of sheets 10 can be stacked, and the paper 10 on the paper feed tray 11 is taken into the recording head 3 side by a paper feed roller 12.
The paper 10 transported from the paper feed roller 12 is transported to the recording head 3 by the transport roller 13, and the transported paper 10 is recorded by the recording head 3 and then discharged to the paper discharge tray 14.
The carriage 2 is slidably held in the main scanning direction (vertical direction in FIG. 2) by a main guide rod 15 and a sub guide rod 16 fixed to the left and right side plates of the recording apparatus main body 1. A recording head 3 composed of an ink jet head that ejects ink droplets of each color (Y), cyan (C), magenta (M), and black (Bk) is arranged in a direction crossing a plurality of ink ejection ports with the main scanning direction. The ink droplet ejection direction is directed downward.
In addition, each ink cartridge 4 for supplying ink of each color to the recording head 3 is replaceably mounted on the carriage 2.

The rear side of the carriage 2 (downstream side in the paper conveyance direction) is slidably fitted on the main guide rod 15, and the front side (upstream side in the paper conveyance direction) is slidably mounted on the sub guide rod 16. . In order to move and scan the carriage 2 in the main scanning direction, a timing belt 5 is stretched between a driving pulley 17 and a driven pulley 18 that are rotationally driven by a carriage driving motor 6. The carriage 2 is reciprocally driven by forward and reverse rotation of the carriage drive motor 6.
On the other hand, in order to convey the paper 10 set in the paper feed cassette 11 to the lower side of the recording head 3, the paper feed roller 12 and the friction pad 19 for separately feeding the paper 10 from the paper feed tray 11 and the paper 10 are guided. Guide members 20, 21, and 22, a conveying roller 23 that presses the fed paper 10 against the peripheral surface of the conveying roller 13, and a leading end roller 24 that defines a sheet feeding angle from the conveying roller 13 are provided.
The conveyance roller 13 is rotationally driven by a rotation of the conveyance drive motor 8 via a belt 27 wound around a drive pulley 25 and a conveyance roller pulley 26. Below the recording head 3 of the carriage 2, there is provided a printing receiving member 28 which is a paper guide member for guiding the paper 10 fed from the transport roller 13. A paper discharge roller 29 and a spur 30 that are rotationally driven to send the paper 10 to the paper discharge tray 14 in the paper discharge direction are disposed downstream of the printing receiving member 28 in the paper transport direction.
A recovery device 9 for recovering the ejection failure of the recording head 3 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 2. The recovery device 9 includes a cap unit, a suction unit, and a cleaning unit. The carriage 2 is moved to the recovery device 9 side during printing standby, and the recording head 3 is capped by the capping means, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying.
Further, by ejecting ink that is not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant and stable ejection performance is maintained. When a discharge failure occurs, the discharge port of the recording head 3 is sealed with a capping unit, and bubbles and the like are sucked from the discharge port with a suction unit through a tube not shown, and then adhered to the discharge port surface. Ink and dust are removed by a cleaning means to recover ejection failure.
The sucked ink is discharged into a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.

FIG. 3 is a schematic configuration diagram of a general belt drive mechanism. In the figure, when a belt 27 is wound around the driving pulley 25 and the conveying roller pulley 26 and the driving pulley 25 rotates in the arrow A direction, the conveying roller pulley 26 rotates in the arrow B direction. In order to correct the deviation of the length of the belt 27 wound around the driving pulley 25 and the conveying roller pulley 26, the belt 27 is pressed against the belt 27 between the driving pulley 25 and the conveying roller pulley 26 by a tension roller 31.
FIG. 4 is a schematic configuration diagram of a belt driving mechanism according to the present invention, and FIG. 5 is a detailed plan view of the belt driving mechanism according to the present invention.
When the belt 27 is wound around the driving pulley 25 and the conveying roller pulley 26 and the driving pulley 25 rotates in the direction of arrow A, the conveying roller pulley 26 rotates in the direction of arrow B.
Flanges 26 a and 26 b are provided on both sides of the pulley portion of the conveyance roller pulley 26 so that the belt 27 does not come off the conveyance roller pulley 26 and the drive pulley 25. A belt driving roller 32 that also adjusts the length of the belt 27 is disposed on the tension side of the belt 27 wound around the driving pulley 25 and the conveying roller pulley 26.
The transport roller pulley 26 is fixed to the rotating shaft 7a of the paper transport roller 7, and the paper transport roller 7 is fixed to the side plate 34 by a bearing 33 inserted into the rotary shaft 7a.
A bearing (not shown) is inserted into the shaft opposite to the paper carrying roller 7 of the carrying roller pulley 26, and this bearing is rotatably fixed to a side plate (not shown).
The conveyance drive motor 8 is fixed to the side plate 34, and the drive pulley 25 is fixed to the drive shaft 8 a of the conveyance drive motor 8. The drive pulley 25 is integrally formed with a drive gear 25 a and meshes with a driven gear 32 a formed integrally with the belt drive roller 32.
Here, when the driving pulley 25 rotates, the belt 27 is pulled and the belt driving roller 32 is lifted, so the belt driving roller 32 is fixed in the tensioning direction of the belt 27 between the driving pulley 25 and the conveying roller pulley 26. By doing so, the distance between these pulleys is always constant, and the controllability is improved.

When the drive pulley 25 rotates in the direction of arrow A, the driving force is transmitted from the drive gear 25a formed integrally with the drive pulley 25 to the driven gear 32a, and the belt drive roller 32 rotates. Thereby, the belt drive roller 32 is rotated by a gear provided coaxially with the drive pulley 25, and a low-cost drive mechanism with a simple structure can be provided.
The number of teeth of the driven gear 32a is the same as that of the drive gear 25a, and the outer shape of the belt drive roller 32 is the same as or smaller than the pitch diameter of the drive pulley 25.
As a result, the belt 27 is transported between the drive pulley 25 and the transport roller pulley 26 with a constant tension force (the belt drive roller 32 rotates while sliding), so that highly accurate drive control with little fluctuation can be performed. (If the linear velocity of the belt driving roller 32 is faster than the belt 27, the belt 27 is bent and the driving pulley 25 and the conveying roller pulley 26 become unstable.)
Further, the inner side of the belt 27 that drives the driving pulley 25 and the conveying roller pulley 26 is a toothed belt, so that the rotation amount of the driving pulley 25 is accurately transmitted to the conveying roller pulley 26 and the belt 37 that the belt driving roller 32 contacts. Since the outer peripheral surface of the belt driving roller 32 has no teeth, even if the linear speed of the outer peripheral surface of the belt driving roller 32 is different from the linear speed of the belt 27, the belt driving roller 32 can be driven without affecting the rotation amount of the conveying roller pulley 26 due to slippage. become.
As a result, the belt contact surface linear velocity of the belt drive roller 32 becomes equal to or less than the linear velocity of the belt 27, and the belt 27 between the drive pulley 25 and the belt drive roller 32 moves without being bent. A plate 37 that is rotatable by bearings 35 and 36 is inserted into the drive shaft 8 a of the conveyance drive motor 8, and the belt drive roller 32 is rotatable by bearings 38 and 39 fixed to the shaft 37 a of the plate 37. . The plate 37 b is integrated with the plate 37, and the plate 37 is fixed to the rear side plate 34 while being pressed against the belt 27.
In addition, by using a helical gear as the gear that transmits driving to the belt driving roller 32, belt driving with little fluctuation in the rotation of the belt driving roller 32 can be performed.

FIG. 6 is a schematic configuration diagram of another belt driving mechanism according to the present invention. A belt driving roller 32 is fixed on the pulling side of the belt 27 of the driving pulley 25 and the conveying roller pulley 26, and a conveying roller pulley 40 is fixed on the deflection side.
Although the detailed configuration diagram of the transport roller pulley 40 is the same as in FIG. 5, the transport roller pulley 40 is rotatably inserted into a plate (not shown) like the belt driving roller 32 provided on the pull side, and the transport roller pulley 40 A driven gear (not shown) integrally formed with 40 and a drive gear 25a mesh with each other, and the rotation of the transport drive motor 8 is transmitted. The belt 27 wound around the drive pulley 25 and the transport roller pulley 26 is transported while being in pressure contact with the transport roller pulley 26 and the transport roller pulley 40.

FIG. 2 is a schematic perspective explanatory view of a mechanism unit of an inkjet recording apparatus. Side surface explanatory drawing of the mechanism part of an inkjet recording device. The schematic block diagram of a general belt drive mechanism. The schematic block diagram of the belt drive mechanism which concerns on this invention. FIG. 3 is a detailed plan view of the belt driving mechanism according to the present invention. The schematic block diagram of the other belt drive mechanism which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording device main body, 2 Carriage, 3 Recording head, 4 Ink cartridge, 5 Timing belt, 6 Carriage drive motor, 7 Paper conveyance roller, 7a Rotation shaft of paper conveyance roller, 8 Conveyance drive motor, 8a Drive shaft of conveyance drive motor , 9 Recovery device, 10 paper, 11 paper feed tray, 12 paper feed roller, 13 transport roller, 14 paper discharge tray, 15 main guide rod, 16 sub guide rod, 17 driving pulley, 18 driven pulley, 19 friction pad, 20 , 21, 22 Guide member, 23 Conveying roller, 24 Tip roller, 25 Driving pulley, 25a Driving pulley gear, 26 Conveying roller pulley, 26a, 26b Flange, 27 Belt, 28 Printing receiving member, 29 Discharging roller, 30 Spur , 31 Tension roller, 32 Belt drive roller, 32a Belt drive Over la of the driven gear, 33 bearing, 34 the side plates, 35, 36 bearing, 37 plates, the axis of 37a plates, 37b plates, 38, 39 bearing, 40 conveying roller pulley

Claims (7)

  A rotating body, a driving source, a driving pulley that is rotationally driven by the driving source, a conveying roller pulley that is fixed to a rotating shaft of the rotating body, and a belt that spans between the driving pulley and the conveying roller pulley. A rotating body driving device that transmits a driving force to the rotating shaft of the rotating body via the belt, and a roller is provided between the driving pulley and the conveying roller pulley, and the roller is in contact with the belt while contacting the belt. Rotating body drive device characterized by rotating in the moving direction.   2. The rotating body drive device according to claim 1, wherein a linear speed of the belt contact surface of the roller is equal to or slower than a linear speed of the belt.   2. The rotating body driving apparatus according to claim 1, wherein the roller is fixed in a tension direction of a belt located between the driving pulley and the conveying roller pulley.   2. The rotating body drive device according to claim 1, wherein the inside of the belt is toothed and the outside of the belt is toothless.   2. The rotating body driving apparatus according to claim 1, wherein the roller is rotated by a gear provided in a driving source.   6. The rotating body drive device according to claim 5, wherein the gear is a helical gear. An image forming apparatus, wherein conveyance of printing paper is driven and controlled by the rotating body driving device according to any one of claims 1 to 6.

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