JP2020101826A - Image forming apparatus - Google Patents

Abstract

To provide a driving device and an image forming apparatus that can selectively switch between two-system drive transmission paths while preventing an increase in cost.SOLUTION: A driving device 30 comprises: a driving source 1 that is capable of normal rotation and reverse rotation; a rotatable input-side rotation member 1a that receives input of a rotation driving force from the driving source; a rotatable output-side rotation member 8 that outputs the rotation driving force to a body to be driven 181a; two-system drive transmission paths for transmitting the rotation driving force from the input-side rotation member to the output-side rotation member; and drive transmission path switching means that switches the drive transmission path from the input-side rotation member to the output-side rotation member. The drive transmission path switching means has a rotatable moving rotation member 2 that, during normal rotation and reverse rotation of the driving source, moves in different directions in a thrust direction between the two-system drive transmission paths to transmit the rotation driving force from the driving source to one drive transmission path or the other drive transmission path, of the two-system drive transmission paths.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image forming apparatus.

An image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine thereof includes many driving devices for image forming operation.

Patent Document 1 describes such a drive device that rotates a discharge roller, which is a driven body, in a forward direction and a reverse direction. This drive device is provided with an input shaft to which a rotational drive force is input from a drive motor that is a drive source capable of normal rotation and a reverse rotation, and an output shaft that outputs the rotational drive force to a paper discharge roller. There are two drive transmission paths from the input shaft to the output shaft, and it meshes with the gear for transmitting the rotational driving force of the drive motor to the two drive transmission paths to selectively switch between the two drive transmission paths. Is equipped with a one-way clutch. During normal rotation of the drive motor, the one-way clutch is locked, and the rotational drive force from the drive motor is transmitted to one of the drive transmission paths of the two systems via the gear. On the other hand, when the drive motor rotates in the reverse direction, the one-way clutch idles, and the rotational drive force from the drive motor is transmitted to the other drive transmission path of the two systems via the gear.

However, in the drive device described in Patent Document 1, since the one-way clutch is provided to selectively switch the drive transmission paths of the two systems, there is a problem in that the cost increases accordingly.

In order to solve the above problems, the present invention provides a drive source capable of normal rotation and reverse rotation, and an image forming apparatus that drives a fixing roller and a paper discharge roller by the drive source, wherein the drive force of the drive source is The fixing roller drive transmission means for transmitting to the fixing roller and the discharge roller drive transmission means for transmitting the driving force of the drive source to the discharge roller are provided, and the fixing roller drive transmission means and the discharge roller drive transmission are provided. The means each include a drive transmission path of two systems for transmitting the driving force, and a drive transmission path switching means for switching the drive transmission paths of the two systems. The drive transmission path of is composed of a plurality of pulleys and a belt member stretched around the pulleys, and the other drive transmission path is composed of a plurality of gear members. When the source is rotating in the normal direction and when rotating in the reverse direction, it moves in different thrust directions between the drive transmission paths of the two systems to drive one drive transmission path or the other drive transmission path of the two drive transmission paths. The path has a rotatable moving rotary member that transmits the driving force from the drive source, and the deceleration ratio of the fixing roller and the paper discharge roller is different between the forward rotation and the reverse rotation of the drive source. It is characterized by

As described above, according to the present invention, there is an excellent effect that the drive transmission paths of the two systems can be selectively switched while suppressing the cost increase.

FIG. 3 is a schematic cross-sectional view of a drive device that drives a paper discharge roller according to Configuration Example 1. 1 is a schematic configuration diagram of a printer according to an embodiment. FIG. 2 is a schematic cross-sectional view of the drive device at the time of motor reverse rotation in which the motor is rotated in the direction opposite to that of FIG. 1. FIG. 3 is a schematic cross-sectional view of a drive device when a worm gear is provided on the output shaft of a motor. 3 is a schematic cross-sectional view of a drive device according to configuration example 2. FIG. FIG. 6 is a schematic cross-sectional view of the drive device at the time of motor reverse rotation in which the motor is rotated in the direction opposite to that of FIG. 5. FIG. 6 is a schematic cross-sectional view of a drive device according to configuration example 3. FIG. 6 is a schematic cross-sectional view of a drive device according to configuration example 4. FIG. 6 is a diagram showing a drive transmission configuration of a drive device according to configuration example 5; FIG. 9 is a diagram showing a drive transmission configuration of a drive device according to configuration example 6; FIG. 8 is a diagram showing a drive transmission configuration of a drive device according to configuration example 7.

[Embodiment 1]
An embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described below as an image forming apparatus to which the present invention is applied. First, the basic configuration of the printer will be described. FIG. 2 is a schematic configuration diagram of the printer according to the embodiment. In the figure, this printer is provided with four process units 160Y, 160C, 160M and 160K for forming toner images of yellow, cyan, magenta and black (hereinafter referred to as Y, C, M and K). There is. These use Y, C, M, and K toners of different colors as image forming substances, but have the same configuration except that they are replaced at the end of their life. Taking the process unit 160K for forming a K toner image as an example, it is provided with a drum-shaped photosensitive member 161K that is a latent image carrier, a developing device 162K, a charging device 163K, a drum cleaning device 164K, a charge eliminating device, and the like. The process unit 160K, which is an image forming unit, can be attached to and detached from the printer body, and consumable parts can be replaced at once.

The charging device 163K uniformly charges the surface of the photoconductor 161K that is rotated clockwise in the drawing by the driving unit. The uniformly charged surface of the photoconductor 161K is exposed and scanned by the laser beam L and carries an electrostatic latent image for K. The electrostatic latent image for K is developed into a Y toner image by the developing device 162K that uses K toner. Then, the intermediate transfer is performed on the intermediate transfer belt 179 described later. The drum cleaning device 164K removes the transfer residual toner adhering to the surface of the photoconductor 161K after the intermediate transfer process. Further, the charge eliminating device eliminates the residual electric charge of the photoconductor 161K after cleaning. By this charge removal, the surface of the photoconductor 161K is initialized and prepared for the next image formation. In the process units 160Y, 160C and 160M of other colors, Y, C and M toner images are similarly formed on the photoconductors 161Y, 161C and 161M and are intermediately transferred onto the intermediate transfer belt 179 described later. The cylindrical drum portion of the photoconductor 161K is a hollow aluminum tube whose front surface is covered with an organic photosensitive layer. Flange having a drum shaft is attached to both ends of the drum portion in the axial direction to form a photoconductor 161K. In the developing device 162K, the K toner stored in the developing device 162K is formed on the surface of the photoconductor 161K in a developing region, which is a region where the developing roller 162aK and the photoconductor 161K face each other, as the developing roller 162aK rotates. It is attached to the electrostatic latent image for development and developed into a K toner image.

Although the process unit 160K for K has been described with reference to FIG. 2, in the process units 160Y, 160C, 160M for Y, C, M as well, Y, C, and 161M on the surface of the photoconductors 161Y, 161C, 161M are subjected to the same process. C and M toner images are formed.

2, the optical writing unit 165 is disposed above the process units 160Y, 160C, 160M and 160K in the vertical direction. The optical writing unit 165, which is a latent image writing device, optically scans the photoconductors 161Y, 161C, 161M, 161K in the process units 160Y, 160C, 160M, 160K with the laser light L emitted from the laser diode based on the image information. To do. By this optical scanning, electrostatic latent images for Y, C, M, and K are formed on the photoconductors 161Y, 161C, 161M, and 161K. In such a configuration, the optical writing unit 165 and the process units 160Y, 160C, 160M, and 160K make Y, C, M, and K toners that are visible images of different colors on three or more latent image carriers, respectively. It functions as an image forming means for forming an image.

The optical writing unit 165 irradiates a laser beam emitted from a light source onto a photoconductor through a plurality of optical lenses and mirrors while polarizing the laser beam with a polygon mirror rotated by a polygon motor in the main scanning direction. is there. A device that performs optical writing by LED light emitted from a plurality of LEDs of the LED array may be adopted.

Below the process units 160Y, 160C, 160M and 160K in the vertical direction, there is provided a transfer unit 175 which is a belt device for endlessly moving the endless intermediate transfer belt 179 in a counterclockwise direction in the drawing. .. The transfer unit 175 also includes a drive roller 176, a tension roller 177, primary transfer rollers 174Y, 174C, 174M, 174K, a secondary transfer roller 178, a belt cleaning device 171, and a cleaning backup roller 172. The intermediate transfer belt 179 is stretched around a driving roller 176, a tension roller 177, a cleaning backup roller 172 and four primary transfer rollers 174Y, 174C, 174M and 174K arranged inside the loop. Then, by the rotational force of the drive roller 176 which is rotationally driven in the counterclockwise direction in the drawing by the drive means, it is endlessly moved in the same direction.

The four primary transfer rollers 174Y, 174C, 174M, and 174K sandwich the intermediate transfer belt 179, which is thus endlessly moved, between the photoconductors 161Y, 161C, 161M, and 161K. Due to this sandwiching, a primary transfer nip for Y, C, M, K where the front surface of the intermediate transfer belt 179 and the photoconductors 161Y, 161C, 161M, 161K contact is formed. A primary transfer bias is applied to each of the primary transfer rollers 174Y, 174C, 174M, and 174K by a transfer bias power source. As a result, a transfer electric field is formed between the electrostatic latent images of the photoconductors 161Y, 161C, 161M, 161K and the primary transfer rollers 174Y, 174C, 174M, 174K. A transfer charger or a transfer brush may be used instead of the primary transfer rollers 174Y, 174C, 174M and 174K.

When the Y toner formed on the surface of the photoconductor 161Y of the Y process unit 160Y enters the above-mentioned Y primary transfer nip as the photoconductor 161Y rotates, the photoconductor is caused by the action of the transfer electric field and the nip pressure. Primary transfer is performed from 161Y onto the intermediate transfer belt 179. The intermediate transfer belt 179 onto which the Y toner image is primarily transferred in this manner passes over the primary transfer nips for M, C, and K along with its endless movement, and then on the photoconductors 161M, 161C, and 161K. The M, C, and K toner images are primarily transferred onto the Y toner image in such a manner that they are sequentially superposed on each other. By this primary transfer of superposition, a four-color toner image is formed on the intermediate transfer belt 179.

The secondary transfer roller 178 of the transfer unit 175 is arranged outside the loop of the intermediate transfer belt 179, and the intermediate transfer belt 179 is sandwiched between the secondary transfer roller 178 and the tension roller 177 inside the loop. Due to this sandwiching, a secondary transfer nip where the front surface of the intermediate transfer belt 179 and the secondary transfer roller 178 contact each other is formed. A secondary transfer bias is applied to the secondary transfer roller 178 by a transfer bias power source. By this application, a secondary transfer electric field is formed between the secondary transfer roller 178 and the tension roller 177 which is grounded.

Below the transfer unit 175 in the vertical direction, a paper feed cassette 141 that accommodates a plurality of recording papers P in a stack of papers is slidably attached to the housing of the printer. In this paper feed cassette 141, a paper feed roller 142 is brought into contact with the uppermost recording paper P in a bundle of paper, and the recording paper P is rotated by rotating the paper feed roller 142 counterclockwise in the drawing at a predetermined timing. Send P toward the paper feed path.

A registration roller pair 143 composed of registration rollers 143a and 143b is arranged near the end of the sheet feeding path. This pair of registration rollers 143 stops the rotation of both rollers as soon as the recording paper, which is the recording member sent out from the paper feed cassette 141, is sandwiched between the rollers. Then, the recording paper that has been sandwiched is restarted to rotate at a timing that can synchronize the four-color toner image on the intermediate transfer belt 179 in the above-mentioned secondary transfer nip, and the recording paper P is sent toward the secondary transfer nip. ..

The four-color toner image on the intermediate transfer belt 179, which is brought into close contact with the recording paper at the secondary transfer nip, is secondarily transferred onto the recording paper P all at once under the influence of the secondary transfer electric field and the nip pressure. In combination with the white color, a full-color toner image is formed. It should be noted that the transfer residual toner that has not been transferred to the recording paper adheres to the intermediate transfer belt 179 after passing through the secondary transfer nip. This is cleaned from the belt surface by the belt cleaning device 171 that is in contact with the front surface of the intermediate transfer belt 179. The cleaning backup roller 172 arranged inside the loop of the intermediate transfer belt 179 backs up the cleaning of the belt by the belt cleaning device 171 from the inside of the loop.

The recording paper P on which the full-color toner image is formed passes through the secondary transfer nip, and is separated from the secondary transfer roller 178 and the intermediate transfer belt 179 by curvature. Then, it is sent to the fixing device 140 as a fixing unit via the post-transfer conveyance path. The fixing device 140 is provided with a fixing roller 145 including a heat source 145a such as a halogen lamp, and a pressure roller 147 that rotates while contacting the fixing roller 145 with a predetermined pressure. A fixing nip is formed by the pressure roller 147. The recording paper fed into the fixing device 140 is sandwiched in the fixing nip so that the unfixed toner image bearing surface of the recording paper is in close contact with the fixing roller 145. Then, the toner in the toner image is softened by the influence of heating and pressurization, and the full-color image is fixed.

When the single-sided print mode is set by an input operation on the operation unit or a control signal sent from a personal computer or the like, the recording paper P discharged from the inside of the fixing device 140 is a pair of paper discharge rollers that rotates in the normal direction. It is discharged to the outside of the machine as it is by 181. Then, it is stacked on the stack portion 150 which is the upper surface of the upper cover of the housing.

Further, the paper discharge roller pair 181 discharges the recording paper P conveyed from the fixing device 140 to the stack unit 150, and reverses the paper discharge roller pair 181 when the double-sided print mode is set. The recording paper P is switched back to the re-feed path 170 side. That is, the paper discharge roller pair 181 includes a pair of paper discharge rollers 181a and 181b, and when the paper discharge sensor 182 detects the nip state in which the end portion of the recording paper P is sandwiched between the paper discharge rollers 181a and 181b, the paper discharge roller 181 is discharged. The paper rollers 181a and 181b are reversed. As a result, the recording paper P is conveyed by the double-sided roller 183, passes through the re-feeding path 170, and is conveyed again to the secondary transfer nip in a state where the front side and the back side are reversed so that the back side can be transferred. Then, after the toner image is formed on the back surface of the recording paper P through the secondary transfer nip, the toner image is fixed on the recording paper P by the fixing device 140, and is discharged to the stack section 150 by the paper discharge roller pair 181. It In the present embodiment, the paper discharge rollers 181a of the paper discharge roller pair 181 are rotationally driven by the drive device 30 described later, but at least one paper discharge roller of the paper discharge roller pair 181 is rotationally driven by the drive device 30. It may be configured as follows.

[Configuration example 1]
FIG. 1 is a schematic cross-sectional view of a drive device 30 that drives a paper discharge roller 181a according to Configuration Example 1. As shown in FIG. 1, the drive device 30 includes a motor 1 which is a drive source capable of forward and reverse rotations, and the motor 1 is attached to a side plate 131. The output shaft of the motor 1 is provided with a helical gear 1a, and the helical gear 1a and an idler gear 2 which is a helical gear mesh with each other. The idler gear 2 is rotatably supported by a fixed shaft S1 fixed to a side plate 131 and a side plate 132, and a plurality of drive connecting claws 2a and a plurality of drive connecting claws 2b are provided on both axial side surfaces. On the side surface of the external gear 9 rotatably supported by the fixed shaft S1 facing the idler gear 2, a plurality of drive connection holes 9a into which a plurality of drive connection claws 2a are fitted are provided on the rotation path of the drive connection claws 2a. Has been formed. Then, the idler gear 2 moves toward the external gear 9 in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 2a is fitted into the drive connection hole 9a, whereby the idler gear 2 and the external gear 9 are engaged. It is possible. In addition, a plurality of drive connection holes 3a into which a plurality of drive connection claws 2b are fitted are formed on the side surface of the pulley 3 rotatably supported by the fixed shaft S1 facing the idler gear 2 on the rotation path of the drive connection claws 2b. Has been formed. The idler gear 2 moves toward the pulley 3 in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 2b is fitted into the drive connection hole 9a, so that the idler gear 2 and the pulley 3 can be engaged with each other. There is.

The fixed shaft S2 is fixed to the side plate 131 and the side plate 132 at a position radially displaced from the fixed shaft S1 toward the paper discharge roller 181a side, and the rotation shaft 7 of the paper discharge roller 181a is provided on the side plate 132. It is rotatably supported by a bearing 132a. A pulley 5 which stretches a timing belt 4 together with the pulley 3 is rotatably supported on the fixed shaft S2. Further, the external gear 10 that meshes with the external gear 9 coaxially with the pulley 5 and the drive gear 6 that meshes with the external gear 8 fixed by the fixing pin 7a to the rotary shaft 7 of the paper discharge roller 181a are freely rotatable. Supported by.

The drive device 30 shown in FIG. 1 has a first drive transmission path R1 and a second drive transmission path R2, which are two types of drive transmission paths for transmitting the driving force of the motor 1 to the paper discharge roller 181a. ing. The first drive transmission path R1 is composed of a pulley 3 which is a drive transmission member, a timing belt 4 and a pulley 5, and the second drive transmission path R2 is an external gear 9 and an external gear which are drive transmission members. 10 and 10.

The direction of the thrust force acting on the idler gear 2 from the helical gear 1a is determined by the rotation direction of the motor 1 and the twisting direction of the helical gear 1a. In FIG. 1, since the rotation direction of the motor 1 is the clockwise direction (CW) and the helical direction of the helical gear 1a is left, thrust force acts on the idler gear 2 from the helical gear 1a to the pulley 3 side. Therefore, the idler gear 2 moves to the pulley 3 side in the thrust direction, the drive connection claw 2b is fitted into the drive connection hole 3a, and the idler gear 2 and the pulley 3 are engaged with each other, so that the idler gear 2 drives the pulley 3. The pulley 3 drives a pulley 5 rotatably attached to the fixed shaft S2 via a timing belt 4. Then, the drive gear 6 arranged coaxially with the pulley 5 drives the external gear 8 provided on the rotary shaft 7 of the paper discharge roller 181a. As a result, the paper discharge roller 181a provided on the rotation shaft 7 rotates in the same direction as the rotation direction of the motor 1 by the driving force transmitted from the first drive transmission path R1.

FIG. 3 is a schematic cross-sectional view of the drive device 30 when the motor 1 is rotated in the reverse direction to that shown in FIG. In the drive device 30 shown in FIG. 3, since the motor 1 is driven in the counterclockwise direction (CCW), thrust force acts on the idler gear 2 from the helical gear 1a to the external gear 9 side. Therefore, the idler gear 2 moves toward the external gear 9 side in the thrust direction, the drive coupling claw 2a is fitted into the drive coupling hole 9a, and the idler gear 2 and the external gear 9 are engaged with each other. The gear 9 is driven. The external gear 9 drives an external gear 10 arranged coaxially with the pulley 5. Then, the drive gear 6 arranged coaxially with the external gear 10 drives the external gear 8 provided on the rotary shaft 7 of the paper discharge roller 181a. As a result, the discharge roller 181a provided on the rotation shaft 7 is in the opposite direction to the rotation direction of the motor 1 due to the driving force transmitted from the second drive transmission path R2, and the pulley 3/pulley 5 is decelerated. It is driven at a speed different from the ratio.

In the drive device 30 according to the present configuration example, the idler gear 2 is moved between the two system drive transmission paths in different thrust directions between the forward rotation and the reverse rotation of the motor 1 to drive the idler gear 1a. The drive transmission path to the gear 6 can be switched. That is, the idler gear 2 having a function of transmitting the rotational driving force from the motor 1 to each drive transmission path is also used as a member for selectively switching the drive transmission paths of the two systems. Therefore, in addition to the gear for transmitting the rotational driving force from the motor 1 to each drive transmission path, the one-way clutch is not provided as compared with the configuration in which the one-way clutch for selectively switching the drive transmission paths of the two systems is provided. Therefore, the cost increase can be suppressed.

Here, in the configuration in which the idler gear 2 is moved in the radial direction and meshes with the external gear 9 in order to switch the drive transmission path, a loud noise may be generated when the idler gear 2 and the external gear 9 mesh with each other. On the other hand, in a configuration in which the idler gear 2 is moved in the thrust direction and the drive connection claw 2a provided on the side surface of the idler gear 2 and the drive connection hole 9a formed on the side surface of the external gear 9 are fitted together, the gears are engaged with each other. Since it is not present, the generation of the loud noise can be suppressed. Therefore, as in the drive device 30 of the present configuration example, by adopting the configuration in which the idler gear 2 is moved in the thrust direction to selectively switch the drive transmission paths of the two systems, noise reduction at the time of switching the drive transmission paths is achieved. be able to.

Further, by setting the number of drive transmission members in the first drive transmission path R1 and the second drive transmission path R2 between the two fixed shafts S1 and S2 to be an odd number and an even number, the rotation direction of the motor 1 is changed. Even if it is changed, only the reduction ratio can be changed without changing the rotation direction of the paper discharge roller 181a.

Further, the drive transmission path can be quieter by using the timing belt like the first drive transmission path R1 than by using only the external gear like the second drive transmission path R2. it can. On the other hand, when the second drive transmission path R2 is composed of only the external gear, the durability can be improved more than when the first drive transmission path R1 is composed of the timing belt. Therefore, for example, when the first drive transmission path R1 and the second drive transmission path R2 are configured such that the rotation direction and the speed reduction ratio of the paper discharge roller 181a are the same, either quietness or durability is achieved. The drive transmission path may be switchable depending on whether to take it.

As shown in FIG. 4, the motor 1 is arranged so that the axial direction of the motor 1 is orthogonal to the axial direction of the fixed shaft S1 with respect to the drive device 30, and the output shaft of the motor 1 is provided with a helical gear. A configuration in which the worm gear 1b is used instead of 1a can also be adopted. Even with this configuration, the direction of the thrust force that acts on the idler gear 2 that is the helical gear from the worm gear 1b is changed between the forward rotation and the reverse rotation of the motor 1 in the same manner as described above, and the idler gear 2 is axially moved. The drive transmission path can be switched by moving in different directions.

Further, in the present configuration example, even if the rotation speed of the motor 1 is the same as that of the forward rotation and the reverse rotation thereof, the rotation of the motor 1 is controlled by one control constant and the rotation speed of the discharge roller 181a is controlled. Can be increased.

[Configuration example 2]
FIG. 5 is a schematic cross-sectional view of the drive device 30 according to the second configuration example. As shown in FIG. 3, the drive device 30 includes a motor 1 which is a drive source capable of forward and reverse rotations, and the motor 11 is attached to the side plate 131. The output shaft of the motor 1 is provided with a helical gear 11a, and the helical gear 11a and the idler gear 12 mesh with each other. The idler gear 12 is rotatably supported by a fixed shaft S1 fixed to a side plate 131 and a side plate 132, and a plurality of drive connection claws 12a and a plurality of drive connection claws 12b are provided on both axial side surfaces. On the side surface of the external gear 18 rotatably supported by the fixed shaft S1 facing the idler gear 12, a plurality of drive connection holes 18a into which a plurality of drive connection claws 12a are fitted are provided on the rotation path of the drive connection claws 12a. Has been formed. Then, the idler gear 12 moves toward the external gear 18 side in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 12a is fitted into the drive connection hole 18a so that the idler gear 12 and the external gear 18 are engaged with each other. It is possible. Further, a plurality of drive connection holes 13a into which a plurality of drive connection claws 12b are fitted are formed on the side surface of the external gear 13 rotatably supported by the fixed shaft S1 facing the idler gear 12, and a plurality of drive connection holes 13a are inserted into the rotation path of the drive connection claws 12b. Formed on. Then, the idler gear 12 moves toward the external gear 13 side in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 12b is fitted into the drive connection hole 13a, so that the idler gear 12 and the external gear 13 are engaged with each other. It is possible.

The fixed shaft S2 is fixed to the side plate 131 and the side plate 132 at a position radially displaced from the fixed shaft S1 toward the paper discharge roller 181a side, and the rotation shaft 7 of the paper discharge roller 181a is provided on the side plate 132. It is rotatably supported by a bearing 132a. An external gear 14 that meshes with the external gear 13 is rotatably supported on the fixed shaft S2. Further, an external gear 20 that meshes with the external gear 18 coaxially with the external gear 14, and a drive gear 15 that meshes with the external gear 17 fixed to the rotary shaft 7 of the paper discharge roller 181a with a fixing pin 7a, It is rotatably supported.

In the drive device 30 shown in FIG. 5, the first drive transmission path R1 that is one of the two drive transmission paths for transmitting the drive force of the motor 11 to the paper discharge roller 181a is an external tooth that is a drive transmission member. It is composed of a gear 13 and an external gear 14. Further, the second drive transmission path R2, which is the other of the two systems of drive transmission paths, is configured by the external gear 18, the external gear 19, and the external gear 20 that are drive transmission members.

The direction F of the thrust force acting on the idler gear 12 from the helical gear 11a is determined by the rotating direction of the motor 11 and the twisting direction of the helical gear 11a. In FIG. 5, since the rotation direction of the motor 11 is the clockwise direction (CW) and the helical direction of the helical gear 11a is left, thrust force acts on the idler gear 12 from the helical gear 11a to the external gear 13 side. Therefore, the idler gear 12 moves toward the external gear 13 side in the thrust direction, the drive connecting claw 12b is fitted into the drive connecting hole 13a, and the idler gear 12 and the external tooth gear 13 are engaged with each other, so that the idler gear 12 is externally toothed. The gear 13 is driven. The external gear 13 drives the external gear 14 rotatably attached to the fixed shaft S2. Then, the drive gear 15 arranged coaxially with the external gear 14 drives the external gear 17 provided on the rotary shaft 7 of the paper discharge roller 181a. As a result, the discharge roller 181a provided on the rotation shaft 7 rotates in the same direction as the rotation direction of the motor 11 by the driving force transmitted from the first drive transmission path R1.

FIG. 6 is a schematic cross-sectional view of the driving device 30 when the motor 11 is rotated in the reverse direction to that shown in FIG. In the drive device 30 shown in FIG. 3, since the motor 11 is driven in the counterclockwise rotation direction, thrust force acts on the idler gear 12 from the helical gear 11a to the external gear 18 side. Therefore, the idler gear 12 moves toward the external gear 18 side in the thrust direction, the drive coupling claw 12a is fitted into the drive coupling hole 18a, and the idler gear 12 and the external gear 18 engage with each other. The gear 18 is driven. The external gear 18 drives an external gear 20 arranged coaxially with the fixed shaft S2 via an external gear 19 rotatably supported by the fixed shaft S3. Then, the drive gear 15 arranged coaxially with the external gear 20 drives the external gear 17 provided on the rotation shaft 7 of the paper discharge roller 181a. As a result, the discharge roller 181a provided on the rotation shaft 7 is driven by the driving force transmitted from the second drive transmission path R2 so that the discharge roller 181a is in the opposite direction to the rotation direction of the motor 11 It is driven at a rotational speed different from the reduction ratio of the gear 13/external gear 14.

Further, by setting the number of drive transmission members in the first drive transmission path R1 and the second drive transmission path R2 between the two fixed shafts S1 and S2 to be an odd number and an even number, the rotation direction of the motor 11 is changed. Even if changed, only the reduction ratio can be changed without changing the rotation direction of the paper discharge roller 181a.

Further, like the drive device 30 according to the present configuration example, by configuring both the first drive transmission path R1 and the second drive transmission path R2 with only the external gear, drive transmission of two systems with high durability is achieved. The drive can be transmitted through the path, and the life of the drive device 30 can be extended.

[Configuration example 3]
FIG. 7 is a schematic cross-sectional view of the drive device 30 according to the configuration example 3. As shown in FIG. 7, the drive device 30 includes a motor 21 that is a drive source capable of forward and reverse rotations, and the motor 21 is attached to the side plate 131. The output shaft of the motor 21 is provided with a helical gear 21a, and the helical gear 21a and the idler gear 22 mesh with each other. The idler gear 22 is rotatably supported by a fixed shaft S1 fixed to a side plate 131 and a side plate 132, and a plurality of drive connection claws 22a and a plurality of drive connection claws 22b are provided on both axial side surfaces thereof. On the side surface of the internal gear 23 rotatably supported by the fixed shaft S1 facing the idler gear 22, a plurality of drive connection holes 23a into which a plurality of drive connection claws 22a are fitted are provided on the rotation track of the drive connection claws 22a. Has been formed. Then, the idler gear 22 moves toward the internal gear 23 side in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 22a is fitted into the drive connection hole 23a, whereby the idler gear 22 and the internal gear 23 are engaged. It is possible. Further, a plurality of drive connection holes 27a into which a plurality of drive connection claws 22b are fitted are formed on a side surface of the external gear 27 rotatably supported by the fixed shaft S1 opposed to the idler gear 22, and a rotation trajectory of the drive connection claws 22b. Formed on. Then, the idler gear 22 moves toward the external gear 27 side in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 22b is fitted into the drive connection hole 27a, whereby the idler gear 22 and the external gear 27 are engaged. It is possible.

The fixed shaft S2 is fixed to the side plate 131 at a position displaced radially toward the paper discharge roller 181a with respect to the fixed shaft S1, and the rotary shaft 7 of the paper discharge roller 181a is attached to the bearing 132a provided on the side plate 132. It is rotatably supported. An external gear 28, which meshes with the external gear 27, is rotatably supported on the fixed shaft S2. Further, an external gear 24 that meshes with the internal gear 23 coaxially with the external gear 28, and a drive gear 25 that meshes with an external gear 26 that is fixed to the rotary shaft 7 of the paper discharge roller 181a with a fixing pin 7a, It is rotatably supported.

In the drive device 30 shown in FIG. 7, the first drive transmission path R1 that is one of the two drive transmission paths for transmitting the drive force of the motor 21 to the paper discharge roller 181a is an external tooth that is a drive transmission member. It is composed of a gear 27 and an external gear 28. Further, the second drive transmission path R2, which is the other of the two systems of drive transmission paths, is configured by the internal gear 23 and the external gear 24 that are drive transmission members.

The direction of the thrust force acting on the idler gear 22 from the helical gear 21a is determined by the rotation direction of the motor 21 and the twisting direction of the helical gear 21a. In FIG. 7, since the helical direction of the helical gear 11a is left, the thrust force acts on the idler gear 22 from the helical gear 21a to the external gear 27 side by driving the motor 21 in the clockwise direction (CW). Therefore, the idler gear 22 moves toward the external gear 27 side in the thrust direction, the drive connecting claw 22b is fitted into the drive connecting hole 27a, and the idler gear 22 and the external gear 27 are engaged with each other. The gear 27 is driven. The external gear 27 drives the external gear 28 rotatably attached to the fixed shaft S2. Then, the drive gear 25 arranged coaxially with the external gear 28 drives the external gear 26 provided on the rotation shaft 7 of the paper discharge roller 181a. As a result, the paper discharge roller 181a provided on the rotation shaft 7 rotates in the same direction as the rotation direction of the motor 21 by the driving force transmitted from the first drive transmission path R1.

On the other hand, by driving the motor 21 in the counterclockwise direction (CCW), a thrust force acts on the idler gear 22 from the helical gear 21a to the axial internal gear 23 side. Therefore, the idler gear 22 moves toward the internal gear 23 side in the thrust direction, the drive coupling claw 22a is fitted into the drive coupling hole 23a, and the idler gear 22 and the internal gear 23 are engaged with each other, so that the idler gear 22 moves to the internal gear. Drive the gear 23. The internal gear 23 drives the external gear 24 rotatably supported by the fixed shaft S2. Then, the drive gear 25 arranged coaxially with the external gear 24 drives the external gear 26 provided on the rotary shaft 7 of the paper discharge roller 181a. As a result, the paper discharge roller 181a provided on the rotary shaft 7 is in a direction opposite to the rotation direction of the motor 21 due to the driving force transmitted from the second drive transmission path R2, and the external gear 27/external tooth The gear 28 is driven at a rotation speed different from the reduction ratio.

As in the drive device 30 according to the present configuration example, by configuring the drive transmission path using the internal gear, the meshing part with the external gear can be covered with the internal gear, and the meshing part The generated noise can be shielded by the internal gear. Further, the meshing ratio of the external gear and the internal gear can be higher than the meshing of the external gears, and the generation of noise and vibration can be suppressed. Thereby, the quietness of the drive device 30 can be improved. For this reason, it is preferable that the drive transmission path using the internal gear is used for drive transmission that is used frequently and has a long use time.

[Configuration example 4]
FIG. 8 is a schematic cross-sectional view of the drive device 30 according to the configuration example 4. As shown in FIG. 8, in the drive device 30, a motor 31 that is a drive source capable of forward and reverse rotation is attached to the side plate 133. The output shaft of the motor 31 is provided with a helical gear 31a, and an internal tooth helical gear portion 32a of an idler gear 32 rotatably supported by a fixed shaft S3 fixed to the side plates 131 and 133 and a helical gear 31a. Are in mesh. The idler gear 32 is concentrically provided with an external tooth helical gear part 32b, and is an idler gear 33 which is a helical gear rotatably supported by a fixed shaft S1 fixed to the side plates 131 and 132, and an external tooth helical gear. It engages with the portion 32b. The idler gear 33 is rotatably supported by a fixed shaft S1 fixed to the side plate 131 and the side plate 132, and a plurality of drive connection claws 33a and a plurality of drive connection claws 33b are provided on both axial side surfaces. On the side surface of the external gear 37 rotatably supported by the fixed shaft S1 facing the idler gear 33, a plurality of drive connection holes 37a into which a plurality of drive connection claws 33a are fitted are provided on the rotation orbit of the drive connection claws 33a. Has been formed. Then, the idler gear 33 moves toward the external gear 37 side in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 33a is fitted into the drive connection hole 37a, whereby the idler gear 33 and the external gear 37 are engaged. It is possible. Further, a plurality of drive connection holes 34a into which a plurality of drive connection claws 33b are fitted are formed on the side surface of the pulley 34 rotatably supported by the fixed shaft S1 facing the idler gear 33, on the rotation track of the drive connection claws 33b. Has been formed. Then, the idler gear 33 moves to the pulley 34 side in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 33b is fitted into the drive connection hole 34a, so that the idler gear 33 and the pulley 34 can be engaged with each other. There is.

The fixed shaft S2 is fixed to the side plate 131 and the side plate 132 at a position radially displaced from the fixed shaft S1 toward the paper discharge roller 181a side, and the rotation shaft 7 of the paper discharge roller 181a is provided on the side plate 132. It is rotatably supported by a bearing 132a. A pulley 36 that stretches a timing belt 35 is rotatably supported together with the pulley 34 on the fixed shaft S2. Further, an external gear 38 that meshes with the external gear 37 coaxially with the pulley 36, and a drive gear 39 that meshes with an external gear 40 that is fixed to the rotation shaft 7 of the paper discharge roller 181a by a fixing pin 7a are freely rotatable. Supported by.

In the drive device 30 shown in FIG. 8, the first drive transmission path R1 which is one of the two drive transmission paths for transmitting the drive force of the motor 31 to the paper discharge roller 181a is the pulley 34 which is a drive transmission member. And the timing belt 35 and the pulley 36. The second drive transmission path R2, which is the other of the two systems of drive transmission paths, is configured by the external gear 37 and the external gear 38, which are drive transmission members.

The motor 31 drives the idler gear 33 via the inner toothed helical gear portion 32a and the outer toothed helical gear portion 32b of the idler gear 32. Here, the direction of the thrust force acting on the idler gear 33 from the external tooth helical gear portion 32b is determined by the rotation direction of the idler gear 32 and the twisting direction of the external tooth helical gear portion 32b. In FIG. 8, by driving the motor 31 in the counterclockwise direction (CCW), the idler gear 32 is rotated in the counterclockwise direction via the helical gear 31a, and the idler gear 33 is rotated in the axial direction from the external toothed helical gear portion 32b. Thrust force acts toward the tooth gear 37 side. Therefore, the idler gear 33 moves to the external gear 37 side in the thrust direction, the drive coupling claw 33a is fitted into the drive coupling hole 37a, and the idler gear 33 and the external gear 37 are engaged with each other, so that the idler gear 33 is externally toothed. The gear 37 is driven. The external gear 37 drives an external gear 38 rotatably attached to the fixed shaft S2. Then, the drive gear 39 arranged coaxially with the external gear 38 drives the external gear 40 provided on the rotary shaft 7 of the paper discharge roller 181a. As a result, the discharge roller 181a provided on the rotation shaft 7 rotates in the direction opposite to the rotation direction of the motor 31 by the driving force transmitted from the second drive transmission path R2.

On the other hand, in FIG. 8, by driving the motor 31 in the clockwise direction (CW), the idler gear 32 is rotated in the clockwise direction via the helical gear 31a, and the idler gear 33 is rotated from the external tooth helical gear portion 32b to the axial pulley. Thrust force acts on the 34 side. Therefore, the idler gear 33 moves toward the pulley 34 in the thrust direction, the drive connecting claw 33b is fitted into the drive connecting hole 34a, and the idler gear 33 and the pulley 34 are engaged with each other, so that the idler gear 33 drives the pulley 34. The pulley 34 drives a pulley 36 rotatably attached to the fixed shaft S2 via a timing belt 35. Then, the drive gear 39 arranged coaxially with the pulley 36 drives the external gear 40 provided on the rotary shaft 7 of the paper discharge roller 181a. As a result, the paper discharge roller 181a provided on the rotation shaft 7 is driven by the driving force transmitted from the first drive transmission path R1 so that the paper discharge roller 181a is in the same direction as the rotation direction of the motor 31 and the external gear It is driven at a rotational speed different from the reduction ratio of 37/external gear 38.

Further, between the fixed shaft S1 and the fixed shaft S2, the rotation direction of the motor 31 is changed by setting the number of drive transmission members in the first drive transmission route R1 and the second drive transmission route R2 to odd and even. Also, only the reduction ratio can be changed without changing the rotation direction of the paper discharge roller 181a.

Further, the helical gear 31a of the motor 31 does not directly mesh with the idler gear 33, which is an external gear, but meshes with the internal tooth helical gear portion 32a of the idler gear 32, and through the internal tooth helical gear portion 32a and the external tooth helical gear portion 32b. The drive is transmitted to the idler gear 33. Accordingly, the root of the helical gear 31a can be meshed with the internal tooth helical gear portion 32a, and the rotational accuracy can be improved and the noise can be reduced.

As described above, in the present embodiment, the configuration in which the discharge roller 181a as the driven body is rotationally driven by the drive device 30 has been described, but the driven body is not limited to the discharge roller 181a. For example, in order to form an image on both sides of the recording paper P, the double-sided roller 183 that reverses the front and back of the recording paper P and conveys the re-feeding path 170 is used as the driven body, and the drive device of each of the above-described configurations It is also possible to employ a configuration in which it is rotationally driven by 30.

[Embodiment 2]
Hereinafter, another embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described as an image forming apparatus to which the present invention is applied. The basic configuration of the printer according to the present embodiment is the same as the configuration of the printer according to the first embodiment, and the description thereof will be omitted.

Although the image forming apparatus conveys the paper by a plurality of rollers, the paper feed speed of the rollers is associated with the paper so that the paper is not pulled or fed too much between the rollers. An image forming apparatus corresponding to various paper thicknesses finely adjusts the paper feed speed ratio between rollers depending on the paper type because the transferability/fixability of the image changes depending on the paper thickness. Therefore, conventionally, the driving sources are separately provided for the rollers whose paper feed speed ratios are desired to be changed. However, fine adjustment of the speed between the rollers can be easily changed by changing the speed of the motor, but the increase in the number of motors raises the problems of cost increase, drive noise increase, space, and power consumption. Therefore, in a drive device having a drive train of at least two systems from one motor and a plurality of rollers, a "drive train for forward rotation" and a "drive train for reverse rotation" of the motor are provided, and deceleration of each drive train is performed. The paper feed speed ratio between the rollers is changed by finely adjusting the ratio. As a result, it is possible to solve the problems of cost increase, driving sound increase, space, and power consumption that may occur due to the increase in the number of motors as described above.

Specifically, the motor output gear is a helical gear, and the idler gear that meshes with the motor output gear is movable in the axial direction. By changing the rotation direction of the motor, the direction of the thrust force that acts on the idler gear from the motor output gear, which is a helical gear, changes, so that the idler gear shaft coupling (coupling) can be selected. Since the rotation direction of the motor is changed, the rotation direction from the shaft coupling to the roller is different, such as "changing the number of gears", "gear and belt" or "external gear and internal gear". Two drive transmission paths are provided. Moreover, by changing the speed reduction ratio, the rotation direction of the rollers can be made the same and the speed can be finely adjusted.

[Configuration example 5]
FIG. 9 is a diagram showing a drive transmission configuration of the drive device 30 according to the configuration example 5. The drive device 30 according to the fifth configuration example includes the motor 1 that is a drive source capable of rotating in the forward and reverse directions, and the motor 1 is attached to the side plate 131. The output shaft of the motor 41 is provided with a helical gear left left helical gear 41a, and the helical gear 41a and the idler gear 42 mesh with each other. The idler gear 42 is rotatably supported by a fixed shaft S1 fixed to the side plate 131 and the side plate 132, and a plurality of drive connection claws 42a and a plurality of drive connection claws 42b are provided on both axial side surfaces. On the side surface of the external gear 48 rotatably supported by the fixed shaft S1 facing the idler gear 42, a plurality of drive connection holes 48a into which a plurality of drive connection claws 42a are fitted are provided on the rotation path of the drive connection claws 42a. Has been formed. Then, the idler gear 42 moves toward the external gear 48 side in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 42a is fitted into the drive connection hole 48a, whereby the idler gear 42 and the external gear 48 are engaged. It is possible. Further, a plurality of drive connection holes 43a into which a plurality of drive connection claws 42b are fitted are formed on the side surface of the pulley 43 rotatably supported by the fixed shaft S1 facing the idler gear 42, on the rotation path of the drive connection claws 42b. Has been formed. Then, the idler gear 42 moves toward the pulley 43 side in the axial direction while rotating on the fixed shaft S1, and the drive connection claw 42b is fitted into the drive connection hole 43a, whereby the idler gear 42 and the pulley 43 can be engaged with each other. There is.

The fixed shaft S2 is fixed to the side plate 131 and the side plate 132 at a position radially offset from the fixed shaft S1 toward the registration roller 143a, and the rotation shaft of the registration roller 143a is a bearing 132a provided on the side plate 132. It is rotatably supported by. A pulley 45, which stretches a timing belt 44 together with a pulley 43, is rotatably supported on the fixed shaft S2, and a drive gear 46 that meshes with an external gear 48 coaxially with the pulley 45 is rotatably supported. There is. The drive gear 46 meshes with an external gear 47 fixed to a rotary shaft 49 of the registration roller 143a with a fixing pin 49a.

In the drive device 30 shown in FIG. 9, the first drive transmission path Rs1 which is one of the two drive transmission paths for transmitting the drive force of the motor 41 to the registration roller 143a and the pulley 43 which is a drive transmission member. It is composed of a timing belt 44 and a pulley 45. The second drive transmission path Rs2, which is the other of the two drive transmission paths, is configured by the external gear 48 and the drive gear 46 that are drive transmission members.

Further, the helical gear 41 a meshes with the idler gear 52. The idler gear 52 is rotatably supported by a fixed shaft t1 fixed to the side plate 131 and the side plate 132, and a plurality of drive connection claws 52a and a plurality of drive connection claws 52b are provided on both axial side surfaces. On the side surface of the external gear 58 rotatably supported by the fixed shaft t1 facing the idler gear 52, a plurality of drive connection holes 58a into which a plurality of drive connection claws 52a are fitted are provided on the rotation track of the drive connection claws 52a. Has been formed. Then, the idler gear 52 moves toward the external gear 58 side in the axial direction while rotating on the fixed shaft t1, and the drive connection claw 52a is fitted into the drive connection hole 58a, whereby the idler gear 52 and the external gear 58 are engaged. It is possible. Further, a plurality of drive connection holes 53a into which a plurality of drive connection claws 52b are fitted are formed on the side surface of the pulley 53 rotatably supported by the fixed shaft t1 opposite to the idler gear 52, on the rotation track of the drive connection claws 52b. Has been formed. Then, the idler gear 52 moves toward the pulley 53 side in the axial direction while rotating on the fixed shaft t1, and the drive connecting claw 52b is fitted into the drive connecting hole 53a, whereby the idler gear 52 and the pulley 53 can be engaged with each other. There is.

The fixed shaft t2 is fixed to the side plate 131 and the side plate 132 at a position radially displaced from the fixed shaft t1 toward the fixing roller 145 side, and the rotation shaft of the fixing roller 145 is a bearing 132b provided on the side plate 132. It is rotatably supported by. A pulley 55, which stretches a timing belt 54 together with the pulley 53, is rotatably supported on the fixed shaft t2, and a drive gear 56 meshing with the external gear 58 coaxially with the pulley 55 is rotatably supported. There is. The drive gear 56 meshes with the external gear 57 fixed to the rotating shaft 59 of the fixing roller 145 with a fixing pin 59a.

In the drive device 30 shown in FIG. 9, the first drive transmission path Rt1 which is one of the two drive transmission paths for transmitting the drive force of the motor 41 to the fixing roller 145 and the pulley 53 which is a drive transmission member. It is composed of a timing belt 54 and a pulley 55. Further, the second drive transmission path Rt2, which is the other of the two systems of drive transmission paths, is configured by the external gear 58 and the drive gear 56 that are drive transmission members.

In FIG. 9, by driving the motor 41 in the clockwise direction (CW), a thrust force acts on the idler gear 42 from the helical gear 41a to the axial pulley 43 side. Therefore, the idler gear 42 moves to the pulley 43 side in the thrust direction, the drive connecting claw 42b is fitted into the drive connecting hole 43a, and the idler gear 42 and the pulley 43 are engaged with each other, so that the idler gear 42 drives the pulley 43. The pulley 43 drives a pulley 45 rotatably attached to the fixed shaft S2 via a timing belt 44. Then, the drive gear 46 arranged coaxially with the pulley 45 drives the external gear 47 provided on the rotation shaft 49 of the registration roller 143a. As a result, the registration roller 143a provided on the rotation shaft 49 rotates in the same direction as the rotation direction of the motor 41 by the driving force transmitted from the first drive transmission path Rs1.

Further, by driving the motor 41 in the clockwise rotation direction, a thrust force acts on the idler gear 52 from the helical gear 41a to the axial pulley 53 side. Therefore, the idler gear 52 moves to the pulley 53 side in the thrust direction, the drive connecting claw 52b is fitted into the drive connecting hole 53a, and the idler gear 52 and the pulley 53 are engaged with each other, so that the idler gear 52 drives the pulley 53. The pulley 53 drives a pulley 55 rotatably attached to the fixed shaft t2 via a timing belt 54. Then, the drive gear 56 arranged coaxially with the pulley 55 drives the external gear 57 provided on the rotation shaft 59 of the fixing roller 145. As a result, the fixing roller 145 provided on the rotation shaft 59 rotates in the same direction as the rotation direction of the motor 41 by the driving force transmitted from the first drive transmission path Rt1.

On the other hand, in FIG. 9, by driving the motor 41 in the counterclockwise direction (CCW), a thrust force acts on the idler gear 42 from the helical gear 41a to the axial external gear 48 side. Therefore, the idler gear 42 moves toward the external gear 48 side in the thrust direction, the drive connecting claw 42a is fitted into the drive connecting hole 48a, and the idler gear 42 and the external tooth gear 48 engage with each other. The gear 48 is driven. Then, the external gear 48 drives the drive gear 46 arranged coaxially with the pulley 45, so that the external gear 47 provided on the rotation shaft 49 of the registration roller 143 a is driven by the drive gear 46. .. As a result, the registration roller 143a provided on the rotation shaft 49 is in the direction opposite to the rotation direction of the motor 41 due to the driving force transmitted from the second drive transmission path Rs2, and the reduction ratio of the pulley 43/the pulley 45. It is driven at a different rotation speed.

Further, by driving the motor 41 in the counterclockwise direction, thrust force acts on the idler gear 52 from the helical gear 41a toward the external gear 58 in the axial direction. Therefore, the idler gear 52 moves toward the external gear 58 side in the thrust direction, the drive connecting claw 52a is fitted into the drive connecting hole 58a, and the idler gear 52 and the external tooth gear 58 engage with each other, so that the idler gear 52 moves to the external tooth. The gear 58 is driven. Then, the external gear 58 drives the drive gear 56 arranged coaxially with the pulley 55, so that the external gear 57 provided on the rotation shaft 59 of the fixing roller 145 is driven by the drive gear 56. .. As a result, the fixing roller 145 provided on the rotation shaft 59 is in the opposite direction to the rotation direction of the motor 41 due to the driving force transmitted from the second drive transmission path Rt2, and the reduction ratio of the pulley 53/the pulley 55. It is driven at a different rotation speed.

In the drive device 30 according to the present configuration example, as described above, the reduction ratio is set between the drive transmission path when the rotation direction of the motor 41 is clockwise and the drive transmission path when the rotation direction is counterclockwise. Make them different. As a result, the ratio of the rotation speeds of the registration roller 143a and the fixing roller 145 can be changed depending on whether the rotation direction of the motor 41 is clockwise or counterclockwise. Therefore, the speed of the registration roller 143a and the fixing roller 145 can be finely adjusted with the single motor 41 without providing two motors corresponding to the registration roller 143a and the fixing roller 145, respectively, and the cost can be reduced. Can be planned. It is desirable that the difference in deceleration ratio between the registration roller 143a and the fixing roller 145 be 3% or less. As a result, fine adjustment of the speed between the two rollers can be performed at 3% or less.

[Configuration example 6]
FIG. 10 is a diagram showing a drive transmission configuration of the drive device 30 according to the configuration example 6. The drive device 30 according to the configuration example 6 includes a motor 61 that is a drive source capable of forward and reverse rotations, and the motor 61 is attached to the side plate 131. The output shaft of the motor 31 is provided with a helical gear 61a on the left side in the twisting direction, and the helical gear 61a and the idler gear 62 mesh with each other. The idler gear 62 is rotatably supported by a fixed shaft S1 fixed to the side plate 131 and the side plate 132, and a plurality of drive connection claws 62a and a plurality of drive connection claws 62b are provided on both axial side surfaces. A plurality of drive connection holes 68a, into which a plurality of drive connection claws 62a are fitted, are formed on the side surface of the pulley 68 rotatably supported by the fixed shaft S1 facing the idler gear 62, on the rotation path of the drive connection claws 62a. ing. Then, the idler gear 62 moves toward the pulley 68 side in the axial direction while rotating on the fixed shaft S1, and the drive connecting claw 62a is fitted into the drive connecting hole 68a, so that the idler gear 62 and the pulley 68 can be engaged with each other. There is. Further, a plurality of drive connecting holes 63a into which a plurality of drive connecting pawls 62b are fitted are formed on the side surface of the external gear 63 rotatably supported by the fixed shaft S1 facing the idler gear 62, and a rotational trajectory of the drive connecting pawls 62b. Formed on. Then, the idler gear 62 moves on the axial direction external tooth gear 63 side while rotating on the fixed shaft S1, and the drive connecting claw 62b is fitted into the drive connecting hole 63a, whereby the idler gear 62 and the external tooth gear 63 are engaged. It is possible.

The fixed shaft S2 and the fixed shaft S3 are fixed to the side plate 131 and the side plate 132 at a position radially displaced from the fixed shaft S1 toward the registration roller 143a side, and the rotation shaft of the registration roller 143a is fixed to the side plate 132. It is rotatably supported by a bearing 132a provided. A pulley 70, which stretches a timing belt 69 together with a pulley 68, is rotatably supported on the fixed shaft S2. Further, an external gear 64 that is coaxial with the pulley 70 and that meshes with the external gear 63, and an external gear 65 that is located between the pulley 70 and the external gear 64 in the axial direction are rotatable about the fixed shaft S2. Supported by. A drive gear 66 that meshes with the external gear 65 is rotatably supported on the fixed shaft S3. The drive gear 66 is further fixed to the rotary shaft 49 of the registration roller 143a by a fixed pin 49a. It is in mesh with 67.

In the drive device 30 shown in FIG. 10, the first drive transmission path Rs1, which is one of the two drive transmission paths for transmitting the drive force of the motor 61 to the registration roller 143a, is the external gear that is the drive transmission member. 63 and an external gear 64. In addition, the second drive transmission path Rs2, which is the other of the two drive transmission paths, is configured by the pulley 68, the timing belt 69, and the pulley 70 that are drive transmission members.

Further, the helical gear 61a and the idler gear 72 mesh with each other. The idler gear 72 is rotatably supported by a fixed shaft t1 fixed to the side plate 131 and the side plate 132, and is provided with a plurality of drive connection claws 72a and a plurality of drive connection claws 72b on both axial side surfaces. On the side surface of the external gear 78 rotatably supported by the fixed shaft t1 facing the idler gear 72, a plurality of drive connection holes 78a into which a plurality of drive connection claws 72a are fitted are provided on the rotation path of the drive connection claws 72a. Has been formed. Then, the idler gear 72 moves toward the pulley 78 side in the axial direction while rotating on the fixed shaft t1, and the drive connection claw 72a is fitted into the drive connection hole 78a, whereby the idler gear 72 and the external gear 78 can be engaged with each other. Has become. Further, a plurality of drive connection holes 73a into which a plurality of drive connection claws 72b are fitted are formed on the side surface of the external gear 73 rotatably supported by the fixed shaft t1 facing the idler gear 72, and a rotation path of the drive connection claws 72b. Formed on. Then, the idler gear 72 moves toward the external gear 73 side in the axial direction while rotating on the fixed shaft t1, and the drive connection claw 72b is fitted into the drive connection hole 73a, whereby the idler gear 72 and the external gear 73 are engaged. It is possible.

The fixed shaft t2 and the fixed shaft t3 are fixed to the side plate 131 and the side plate 132 at a position displaced in the radial direction toward the fixing roller 145 side with respect to the fixed shaft S1, and the rotation shaft of the fixing roller 145 corresponds to the side plate 132. It is rotatably supported by a bearing 132b provided. An external gear 74 that meshes with the external gear 73 is rotatably supported on the fixed shaft t3. An external gear 75 that meshes with the external gear 74 is rotatably supported on the fixed shaft t2, and a drive gear 76 that meshes with the external gear 78 is rotatably supported coaxially with the external gear 75. .. The drive gear 76 also meshes with an external gear 77 fixed to the rotary shaft 59 of the fixing roller 145 with a fixing pin 59a.

In the drive device 30 shown in FIG. 10, the first drive transmission path Rt1, which is one of the two drive transmission paths for transmitting the drive force of the motor 61 to the fixing roller 145, is the external gear that is the drive transmission member. 73, the external gear 74, and the external gear 75. A second drive transmission path Rt2, which is the other of the two systems of drive transmission paths, is configured by an external gear 78 and a drive gear 76 that are drive transmission members.

In FIG. 10, by driving the motor 61 in the clockwise direction (CW), a thrust force acts on the idler gear 62 from the helical gear 61a to the axial external gear 63 side. Therefore, the idler gear 62 moves toward the external gear 63 side in the thrust direction, the drive connecting claw 62b is fitted into the drive connecting hole 63a, and the idler gear 62 and the external tooth gear 63 are engaged with each other, so that the idler gear 62 is rotated. The gear 63 is driven. The pulley 43 drives a pulley 45 rotatably attached to the fixed shaft S2 via a timing belt 44. Then, the drive gear 46 arranged coaxially with the pulley 45 drives the external gear 47 provided on the rotation shaft 49 of the registration roller 143a. The external gear 63 drives an external gear 64 rotatably attached to the fixed shaft S2. Then, the drive gear 66 is driven via the external gear 65 arranged coaxially with the external gear 64, and the drive gear 66 drives the external gear 67 provided on the rotation shaft 49 of the registration roller 143a. .. As a result, the registration roller 143a provided on the rotation shaft 49 rotates in the same direction as the rotation direction of the motor 61 by the driving force transmitted from the first drive transmission path Rs1.

Further, by driving the motor 61 in the clockwise rotation direction, a thrust force acts on the idler gear 72 from the helical gear 61a toward the axial external gear 73 side. Therefore, the idler gear 72 moves toward the external gear 73 side in the thrust direction, the drive coupling claw 72b is fitted into the drive coupling hole 73a, and the idler gear 72 and the external gear 73 are engaged with each other. The gear 73 is driven. The pulley 53 drives a pulley 55 rotatably attached to the fixed shaft t2 via a timing belt 54. Then, the drive gear 56 arranged coaxially with the pulley 55 drives the external gear 57 provided on the rotation shaft 59 of the fixing roller 145. The idler gear 72 moves to the external gear 73 side, the drive connection claw 72b is fitted into the drive connection hole 73a, and the idler gear 72 and the external gear 73 are engaged with each other, so that the idler gear 72 drives the external gear 73. .. The external gear 73 drives the external gear 75 rotatably attached to the fixed shaft t2 via the external gear 74 rotatably attached to the fixed shaft t3. Then, the drive gear 76 arranged coaxially with the external gear 75 is driven, and the drive gear 76 drives the external gear 77 provided on the rotation shaft 59 of the fixing roller 145. As a result, the fixing roller 145 provided on the rotation shaft 59 rotates in the same direction as the rotation direction of the motor 61 by the driving force transmitted from the first drive transmission path Rt1.

On the other hand, in FIG. 10, by driving the motor 61 in the counterclockwise direction (CCW), thrust force acts on the idler gear 62 from the helical gear 61a to the axial pulley 68 side. Therefore, the idler gear 62 moves to the pulley 68 side in the thrust direction, the drive connecting claw 62a is fitted into the drive connecting hole 68a, and the idler gear 62 and the pulley 68 engage with each other, so that the idler gear 62 drives the pulley 68. The pulley 68 drives a pulley 70 rotatably attached to the fixed shaft S2 via a timing belt 69. Then, the drive gear 66 is driven via the external gear 65 arranged coaxially with the pulley 70, and the drive gear 66 drives the external gear 67 provided on the rotation shaft 49 of the registration roller 143a. As a result, the registration roller 143a provided on the rotation shaft 49 is in a direction opposite to the rotation direction of the motor 61 due to the driving force transmitted from the second drive transmission path Rs2, and thus the external gear 63/external gear. It is driven at a rotational speed different from the speed reduction ratio of 65.

Further, by driving the motor 61 in the counterclockwise direction, a thrust force acts on the idler gear 72 from the helical gear 61a to the axial external gear 78 side. Therefore, the idler gear 72 moves toward the external gear 78 side in the thrust direction, the drive coupling claw 72a is fitted into the drive coupling hole 78a, and the idler gear 72 and the external gear 78 are engaged with each other. The gear 78 is driven. The external gear 78 drives the drive gear 76 rotatably attached to the fixed shaft t2. Then, the drive gear 76 drives the external gear 77 provided on the rotating shaft 59 of the fixing roller 145. As a result, the fixing roller 145 provided on the rotation shaft 59 is in the direction opposite to the rotation direction of the motor 61 by the driving force transmitted from the second drive transmission path Rt2, and the external gear 73/the external gear It is driven at a rotational speed different from the reduction ratio of 75.

Between the fixed shaft S1 and the fixed shaft S2, the first drive transmission path Rs1 and the second drive transmission path Rs2 differ in the number of drive transmission members such as gears, pulleys, and timing belts even and odd. Therefore, even if the rotation direction of the motor 61 is changed, only the reduction ratio can be changed without changing the rotation direction of the paper discharge roller 181a. Further, between the fixed shaft t1 and the fixed shaft t2, the first drive transmission path Rt1 and the second drive transmission path Rt2 differ in the number of drive transmission members between odd and even. Therefore, even if the rotation direction of the motor 61 is changed, only the reduction ratio can be changed without changing the rotation direction of the fixing roller 145. Therefore, in the drive device 30 according to the present configuration example, even if the rotation direction of the motor 61 is changed, the rotation directions of the registration roller 143a and the fixing roller 145 do not change, and only the reduction ratio can be finely adjusted.

[Configuration example 7]
11: is a figure which shows the drive transmission structure of the drive device 30 which concerns on the example 7 of a structure. In the drive device 30 according to the configuration example 7, the motor 81, which is a drive source capable of forward and reverse rotation, is attached to the side plate 133. A motor gear 81a is provided on the output shaft of the motor 81, and an internal tooth helical gear portion 82a of an idler gear 82 rotatably supported on a fixed shaft S3 fixed to the side plates 131 and 133 and a motor gear 81a. Are in mesh. The idler gear 82 is concentrically provided with an external tooth helical gear 82b, and is an idler gear 83 that is a helical gear rotatably supported by a fixed shaft S1 fixed to the side plates 131 and 132, and an external tooth helical gear. The portion 82b meshes with it.

The idler gear 83 is provided with a plurality of drive connecting claws 83a and a plurality of drive connecting claws 83b on both side surfaces in the axial direction. A plurality of drive connection holes 84a into which a plurality of drive connection claws 83a are fitted are formed on the side surface of the external gear 84 rotatably supported by the fixed shaft S1 facing the idler gear 83, on the rotation path of the drive connection claws 83a. Has been formed. Then, the idler gear 83 moves on the axial direction external tooth gear 84 side while rotating on the fixed shaft S1, and the drive connecting claw 83a is fitted into the drive connecting hole 84a so that the idler gear 83 and the external tooth gear 84 are engaged. It is possible. Further, a plurality of drive connection holes 86a into which a plurality of drive connection claws 83b are fitted are formed on a side surface of the pulley 86 rotatably supported by the fixed shaft S1 opposed to the idler gear 83 on a rotation path of the drive connection claws 83b. Has been formed. Then, the idler gear 83 moves toward the pulley 86 side in the axial direction while rotating on the fixed shaft S1, and the drive connecting claw 83b fits into the drive connecting hole 86a, so that the idler gear 83 and the pulley 86 can be engaged with each other. There is.

The fixed shaft S2 is fixed to the side plate 131 and the side plate 132 at a position radially displaced from the fixed shaft S1 toward the paper discharge roller 181a side, and the rotation shaft 7 of the paper discharge roller 181a is provided on the side plate 132. It is rotatably supported by a bearing 132a. The fixed shaft S2 rotatably supports a pulley 88 which stretches a timing belt 87 together with the pulley 86, and a drive gear 85 which meshes with the external gear 84 coaxially with the pulley 88 is rotatably supported. There is. The drive gear 85 also meshes with an external gear 89 fixed to the rotary shaft 7 of the paper discharge roller 181a with a fixing pin 7a.

In the drive device 30 shown in FIG. 11, the first drive transmission path Rs1 which is one of the two drive transmission paths for transmitting the drive force of the motor 81 to the paper discharge roller 181a is the pulley 86 which is a drive transmission member. And a timing belt 87 and a pulley 88. Further, the second drive transmission path Rs2, which is the other of the two systems of drive transmission paths, is configured by the external gear 84 and the drive gear 85 that are drive transmission members.

The external tooth helical gear 82b of the idler gear 82 meshes with the idler gear 93 which is a helical gear. The idler gear 93 is provided with a plurality of drive connecting claws 93a and a plurality of drive connecting claws 93b on both side surfaces in the axial direction. On the side surface of the external gear 94, which is rotatably supported by the fixed shaft t1, facing the idler gear 93, a plurality of drive connection holes 94a into which a plurality of drive connection claws 93a are fitted are provided on the rotation path of the drive connection claws 93a. Has been formed. Then, the idler gear 93 moves toward the external gear 94 in the axial direction while rotating on the fixed shaft t1, and the drive connection claw 93a is fitted into the drive connection hole 94a, so that the idler gear 93 and the external gear 94 are engaged with each other. It is possible. Further, a plurality of drive connection holes 96a into which a plurality of drive connection claws 93b are fitted are formed on the side surface of the pulley 96 rotatably supported by the fixed shaft t1 opposite to the idler gear 93, on the rotation path of the drive connection claws 93b. Has been formed. Then, the idler gear 93 moves toward the pulley 96 side in the axial direction while rotating on the fixed shaft t1, and the drive connecting claw 93b fits into the drive connecting hole 96a, whereby the idler gear 93 and the pulley 96 can be engaged. There is.

The fixed shaft t2 is fixed to the side plate 131 and the side plate 132 at a position radially displaced from the fixed shaft t1 toward the fixing roller 145 side, and the rotation shaft of the fixing roller 145 is a bearing 132a provided on the side plate 132. It is rotatably supported by. A pulley 98 that stretches a timing belt 97 is rotatably supported together with the pulley 96 on the fixed shaft t2, and a drive gear 95 that meshes with the external gear 94 coaxially with the pulley 98 is rotatably supported. There is. The drive gear 95 also meshes with the external gear 99 fixed to the rotary shaft 59 of the fixing roller 145 with a fixing pin 59a.

In the drive device 30 shown in FIG. 11, the first drive transmission path Rt1 which is one of the two drive transmission paths for transmitting the drive force of the motor 81 to the fixing roller 145 and the pulley 96 which is a drive transmission member. It is composed of a timing belt 97 and a pulley 98. The second drive transmission path Rt2, which is the other of the two systems of drive transmission paths, is configured by the external gear 94 and the drive gear 95 that are drive transmission members.

The motor 81 drives the idler gear 83 via the inner toothed helical gear portion 82a and the outer toothed helical gear portion 82b of the idler gear 82. Here, the direction of the thrust force acting on the idler gear 83 from the external tooth helical gear 82b is determined by the rotation direction of the idler gear 82 and the twisting direction of the external tooth helical gear 82b. In FIG. 8, by driving the motor 81 in the clockwise direction (CW), the idler gear 82 rotates in the clockwise direction via the motor gear 81a, and the idler gear 83 includes the externally toothed helical gear 82b to the axial pulley 86 side. Thrust force works in the direction of. Therefore, the idler gear 83 moves to the pulley 86 side in the thrust direction, the drive connecting claw 83b is fitted into the drive connecting hole 86a, and the idler gear 83 and the pulley 86 are engaged with each other, so that the idler gear 83 drives the pulley 86. The pulley 86 drives a pulley 88 rotatably attached to the fixed shaft S2 via a timing belt 87. The drive gear 85 arranged coaxially with the pulley 88 drives the external gear 89 provided on the rotary shaft 7 of the paper discharge roller 181a. As a result, the paper discharge roller 181a provided on the rotation shaft 7 rotates in the same direction as the rotation direction of the motor 81 by the driving force transmitted from the first drive transmission path Rs1.

Further, the idler gear 82 meshes with the idler gear 93. By driving the motor 81 in the clockwise direction, the idler gear 82 rotates in the clockwise direction via the motor gear 81a, and a thrust force acts on the idler gear 93 from the external tooth helical gear 82b toward the axial pulley 96 side. .. Therefore, the idler gear 93 moves to the pulley 96 side in the thrust direction, the drive connecting claw 93b is fitted into the drive connecting hole 96a, and the idler gear 93 and the pulley 96 are engaged with each other, so that the idler gear 93 drives the pulley 96. The pulley 96 drives a pulley 98 rotatably attached to the fixed shaft t2 via a timing belt 97. Then, the drive gear 95 arranged coaxially with the pulley 98 drives the external gear 99 provided on the rotation shaft 59 of the fixing roller 145. As a result, the fixing roller 145 provided on the rotation shaft 59 rotates in the same direction as the rotation direction of the motor 81 by the driving force transmitted from the first drive transmission path Rt1.

On the other hand, in FIG. 11, by driving the motor 81 in the counterclockwise direction (CCW), the idler gear 82 rotates in the counterclockwise direction via the motor gear 81a, and the idler gear 83 rotates from the external toothed helical gear portion 82b to the shaft. Thrust force acts in the direction toward the direction external gear 84 side. Therefore, the idler gear 83 moves toward the external gear 84 side in the thrust direction, the drive connecting claw 83a is fitted into the drive connecting hole 84a, and the idler gear 83 and the external tooth gear 84 engage with each other, so that the idler gear 83 moves to the external tooth. The gear 84 is driven. Then, the external gear 84 drives the drive gear 85 arranged coaxially with the pulley 88, so that the external gear 89 provided on the rotary shaft 7 of the paper discharge roller 181 a is driven by the drive gear 85. It As a result, the discharge roller 181a provided on the rotation shaft 7 is in the opposite direction to the rotation direction of the motor 81 due to the driving force transmitted from the second drive transmission path Rs2, and the pulley 86/the pulley 88 is decelerated. It is driven at a speed different from the ratio.

Further, by rotating the idler gear 82 in the counterclockwise direction, a thrust force acts on the idler gear 93 from the external tooth helical gear 82b toward the axial external tooth gear 94 side. Therefore, the idler gear 93 moves toward the external gear 94 side in the thrust direction, the drive connecting claw 93a is fitted into the drive connecting hole 94a, and the idler gear 93 and the external tooth gear 94 engage with each other. The gear 94 is driven. Then, the external gear 94 drives the drive gear 95 arranged coaxially with the pulley 98, so that the external gear 99 provided on the rotation shaft 59 of the fixing roller 145 is driven by the drive gear 95. .. As a result, the fixing roller 145 provided on the rotation shaft 59 is in the opposite direction to the rotation direction of the motor 81 due to the driving force transmitted from the second drive transmission path Rt2 and the reduction ratio of the pulley 96/the pulley 98. It is driven at a different rotation speed.

In the drive device 30 according to the present configuration example, the motor gear 81a of the motor 81 does not directly mesh with the idler gears 83 and 93 that are external gears, but meshes with the internal tooth helical bar gear portion 82a of the idler gear 82. Then, the drive is transmitted from the motor gear 81a to the idler gears 83, 93 via the internal tooth helical gear portion 82a and the external tooth helical gear portion 82b. As a result, the root of the motor gear 81a can be meshed with the internal gear helical gear portion 82a, and the rotation accuracy can be improved and the noise can be reduced.

What has been described above is an example, and the following unique effects can be obtained.
(Aspect A)
A drive source such as a motor 1 capable of forward and reverse rotation, an input side rotating member such as a rotatable helical gear 1a to which a rotational drive force is input from the drive source, and a driven body such as a paper discharge roller 181a. An output side rotating member such as a rotatable external gear 8 that outputs a rotation driving force; two drive transmission paths for transmitting the rotation driving force from the input side rotating member to the output side rotating member; In a drive device such as a drive device 30 provided with a drive transmission path switching means for switching a drive transmission path from the input side rotation member to the output side rotation member, the drive transmission path switching means is provided when the drive source is in the normal rotation. And in reverse rotation, the drive transmission paths of the two systems are moved in different thrust directions to drive the drive system to one drive transmission path or the other drive transmission path of the two system drive transmission paths. It has a movable rotating member such as a rotatable idler gear 2 that transmits the rotational driving force from the source.
In (Aspect A), the input side rotation is performed by moving the moving rotation member between the drive transmission paths of the two systems in different thrust directions between the forward rotation and the reverse rotation of the drive source. The drive transmission path from the member to the output side rotating member can be switched. That is, the moving rotating body having a function of transmitting the rotational driving force from the drive source to each drive transmission path is also used as a member for selectively switching the drive transmission paths of the two systems. Therefore, in addition to the gear for transmitting the rotational driving force from the drive source to each drive transmission path, the one-way clutch is not provided as compared with the configuration in which the one-way clutch for selectively switching the drive transmission paths of the two systems is provided. Therefore, the cost increase can be suppressed.
(Aspect B)
In (Aspect A), the moving rotary member has a helical gear portion, and by rotating the drive source in the normal direction, the moving rotary member moves toward one end side in the thrust direction to transmit the one drive transmission. The rotary drive transmission member is engaged with a first drive transmission member such as a pulley 3 provided on the path to transmit the drive from the moving rotary member to the first drive transmission member, and reverse the drive source. Moves toward the other end in the thrust direction and engages with a second drive transmission member such as an external gear 9 provided on the other drive transmission path to move from the moving rotary member to the second drive transmission member. Drive is transmitted. According to this, as described in the above embodiment, by changing the rotation direction of the drive source, the direction of the force in the thrust direction acting on the moving rotary member changes, and the direction in which the moving rotary member moves in the thrust direction. Can be changed to switch the drive transmission path.
(Aspect C)
In (Aspect A) or (Aspect B), an internal gear such as an internal toothed helical gear part 32a meshing with an output gear member such as a helical gear 31a provided on the output shaft of the drive source, and an internal gear coaxially with the internal gear. And an external tooth helical gear, such as an external tooth helical gear portion 32b, which rotates integrally with the internal tooth gear, and the moving rotary member meshes with the external tooth helical gear. According to this, as described in the above embodiment, the quietness can be enhanced.
(Aspect D)
In any one of (Aspect A) to (Aspect C), the drive transmission paths of the two systems include a drive transmission path in which the input side rotation member and the output side rotation member have the same rotation direction, and the input side. And a drive transmission path in which the rotation directions of the rotation member and the output-side rotation member are opposite to each other. According to this, as described in the above embodiment, the rotation direction of the driven body can be the same regardless of the rotation direction of the drive source.
(Aspect E)
In (Aspect A) to (Aspect D), one of the two systems of drive transmission paths is configured to perform drive transmission using a belt member rotatably stretched by a plurality of pulleys, The other is configured so that drive transmission is performed by a gear train in which a plurality of gear members mesh. According to this, as described in the above embodiment, it is possible to make the rotational direction of the driven body the same regardless of the rotational direction of the drive source.
(Aspect F)
In (Aspect A) to (Aspect D), one of the two system drive transmission paths has an even number of drive transmission members, and the other has an odd number of drive transmission members. According to this, as described in the above embodiment, it is possible to make the rotational direction of the driven body the same regardless of the rotational direction of the drive source.
(Aspect G)
In (Aspect A) to (Aspect D), one of the two systems of drive transmission paths is configured to perform drive transmission using an internal gear, and the other is configured to transmit drive via only an external gear. Configured to do. According to this, as described in the above embodiment, it is possible to make the rotational direction of the driven body the same regardless of the rotational direction of the drive source.
(Aspect H)
In (Aspect A) to (Aspect G), the reduction ratios of the drive transmission paths of the two systems are different. According to this, the speed can be increased as described in the above embodiment.
(Aspect I)
In (Aspect A) to (Aspect H), the rotation speed is the same during forward rotation and during reverse rotation of the drive source. According to this, as described in the above embodiment, the rotation of the drive source can be controlled with one control constant.
(Aspect J)
In (Aspect A) to (Aspect I), among the drive transmission paths of the two systems, the drive transmission path located on the drive source side in the thrust direction is the drive located on the opposite side to the drive source in the thrust direction. Driving time is longer or more frequently used than the transmission path. According to this, durability can be improved.
(Aspect K)
In (Aspect A) to (Aspect J), the one having a smaller number of drive transmission members in the drive transmission paths of the two systems has a longer drive time or is used more frequently than the other. According to this, noise reduction can be achieved.
(Aspect L)
In (Aspect A) to (Aspect K), a plurality of the two-system drive transmission paths are provided corresponding to the plurality of driven bodies, and the two-system drive transmission is performed by the rotational drive force from the drive source. Each driven body is driven through the path, and the deceleration ratios of at least two driven bodies of the plurality of driven bodies differ between the forward rotation and the reverse rotation of the drive source. According to this, as described in the above embodiment, the rotational speeds of the two driven bodies can be finely adjusted by changing the rotational direction of the drive source.
(Aspect M)
In (Aspect L), the number of rotations is changed depending on whether the drive source is rotating normally or reversely. According to this, the rotational speeds of the two driven bodies can be significantly changed without significantly increasing the rotational speed of the drive source.
(Aspect N)
In (Aspect L) or (Aspect M), the difference between the deceleration ratios is 3% or less. According to this, the fine adjustment of the speed between the two driven bodies can be performed at 3% or less.
(Aspect O)
In an image forming apparatus including an image forming unit that forms an image and a driving unit that transmits a driving force to a driven body to drive the driven body, the driving unit may be any one of (Aspect A) to (Aspect N). The drive described was used. According to this, as described in the above embodiment, the rotation speed of the driven body can be changed without significantly increasing the rotation speed of the drive source.
(Aspect P)
In (Aspect O), a discharge roller such as a discharge roller 181a for discharging a recording medium such as the recording paper P to a discharge unit such as the stack unit 150 can be used as the driven body.
(Aspect Q)
In (Aspect O), as the driven body, a double-sided roller such as a double-sided roller 183 for reversing the front and back of the recording medium and conveying the same in order to form an image on both sides of the recording medium can be used.
(Aspect R)
In (Aspect O), a fixing roller such as the fixing roller 145 and a registration roller such as the registration roller 143a can be used as the plurality of driven bodies.
(Aspect S)
In (Aspect O), a fixing roller such as the fixing roller 145 and a sheet discharging roller such as the sheet discharging roller 181a can be used as the plurality of driven bodies.

DESCRIPTION OF SYMBOLS 1 motor 1a helical gear 1b worm gear 2 idler gear 2a drive connection claw 2b drive connection claw 3 pulley 3a drive connection hole 4 timing belt 5 pulley 6 drive gear 7 rotating shaft 7a fixed pin 8 external gear 9 external gear 9a drive connection hole 10 external Tooth gear 11 Motor 11a Helical gear 12 Idler gear 12a Drive connection claw 12b Drive connection claw 13 External tooth gear 13a Drive connection hole 14 External tooth gear 15 Drive gear 17 External tooth gear 18 External tooth gear 18a Drive connection hole 19 External tooth gear 20 External tooth Gear 21 Motor 21a Helical Gear 22 Idler Gear 22a Drive Connection Claw 22b Drive Connection Claw 23 Internal Gear 23a Drive Connection Hole 24 External Gear 25 Drive Gear 26 External Gear 27 External Gear 27a Drive Connection Hole 28 External Gear 30 Drive Device 31 Motor 31a Helical gear 32 Idler gear 32a Internal tooth helical gear part 32b External tooth helical gear part 33 Idler gear 33a Drive connecting pawl 33b Drive connecting pawl 34 Pulley 34a Drive connecting hole 35 Timing belt 36 Pulley 37 External gear 37a Drive connecting hole 38 External gear 39 drive gear 40 external gear 41a helical gear 41 motor 42 idler gear 42a drive connecting pawl 42b drive connecting pawl 43 pulley 43a drive connecting hole 44 timing belt 45 pulley 46 drive gear 47 external gear 48 external tooth gear 48a drive connecting hole 49 rotary shaft 49a Fixing pin 52 Idler gear 52a Drive connecting claw 52b Drive connecting claw 53 Pulley 53a Drive connecting hole 54 Timing belt 55 Pulley 56 Drive gear 57 External gear 58 External tooth gear 58a Drive connecting hole 59 Rotating shaft 59a Fixed pin 61 Motor 61a Hasp bar gear 62 Idler gear 62a Drive connecting claw 62b Drive connecting claw 63 External tooth gear 63a Drive connecting hole 64 External tooth gear 65 External tooth gear 66 Drive gear 67 External tooth gear 68 Pulley 68a Drive connecting hole 69 Timing belt 70 Pulley 72 Idler gear 72a Drive connecting claw 72b Drive connection claw 73 External gear 73a Drive connection hole 74 External gear 75 External gear 76 Drive gear 77 External gear 78 External gear 78a Drive connecting hole 81 Motor 81a Motor gear 82 Idler gear 82a Internal tooth helical gear 82b External tooth helical gear 83 Idler gear 83a Drive connecting pawl 83b Drive connecting pawl 84 External gear 84a Drive connecting hole 85 Drive gear 86 pulley 86a drive connecting hole 87 timing belt 88 pulley 89 external gear 93 idler gear 93a drive connecting pawl 93b drive connecting pawl 94 external tooth gear 94a drive connecting hole 95 drive gear 96 pulley 96a drive connecting hole 97 timing belt 98 pulley 99 external tooth Gear 131 Side plate 132 Side plate 132a Bearing 132b Bearing 133 Side plate 140 Fixing device 141 Paper feed cassette 142 Paper feed roller 143 Registration roller pair 143a Registration roller 143b Registration roller 145 Fixing roller 145a Heat source 147 Pressure roller 150 Stack section 160 Process unit 161 Body 162 Developing device 162a Developing roller 163 Charging device 164 Drum cleaning device 165 Optical writing unit 170 Re-feeding path 171 Belt cleaning device 172 Cleaning backup roller 174 Primary transfer roller 175 Transfer unit 176 Drive roller 177 Tension roller 178 Secondary transfer roller 179 Intermediate transfer belt 181 Paper discharge roller pair 181a Paper discharge roller 181b Paper discharge roller 182 Paper discharge sensor 183 Double-sided roller

Patent No. 5387704

Claims (9)

A drive source capable of normal rotation and reverse rotation,
In the image forming apparatus that drives the fixing roller and the discharge roller by the drive source,
A fixing roller drive transmission means for transmitting the driving force of the drive source to the fixing roller;
Discharge roller drive transmission means for transmitting the driving force of the drive source to the discharge roller,
The fixing roller drive transmission means and the discharge roller drive transmission means respectively include two systems of drive transmission paths for transmitting the drive force and drive transmission path switching means for switching the two systems of drive transmission paths. Equipped,
In the two systems of drive transmission paths, one drive transmission path is composed of a plurality of pulleys and a belt member stretched around the pulleys, and the other drive transmission path is composed of a plurality of gear members,
The drive transmission path switching means moves in different thrust directions between the drive transmission paths of the two systems during normal rotation and reverse rotation of the drive source, and the drive transmission path of the two systems is One of the drive transmission paths or the other drive transmission path has a rotatable moving rotary member that transmits the driving force from the drive source,
An image forming apparatus, wherein a deceleration ratio between the fixing roller and the paper discharge roller is different when the drive source is rotating forward and when rotating reversely. The image forming apparatus according to claim 1,
The moving rotary member has a helical gear part,
By rotating the drive source in the forward direction, the moving rotary member moves toward one end side in the thrust direction and engages with the first drive transmitting member provided in the one drive transmitting path to move from the moving rotating member. Drive is transmitted to the first drive transmission member,
By reversing the drive source, the moving rotary member moves toward the other end side in the thrust direction, engages with the second drive transmitting member provided in the other drive transmitting path, and moves from the moving rotary member. An image forming apparatus, wherein drive is transmitted to the second drive transmitting member. The image forming apparatus according to claim 1,
It has an internal gear that meshes with an output gear member provided on the output shaft of the drive source, and an external gear helical gear that is provided coaxially with the internal gear and that rotates integrally with the internal gear. An image forming apparatus, wherein the movable rotating member and the externally toothed helical gear mesh with each other. The image forming apparatus according to any one of claims 1 to 3,
An image forming apparatus, wherein the drive transmission paths of the two systems have different reduction ratios. The image forming apparatus according to any one of claims 1 to 4,
An image forming apparatus, wherein the number of rotations is the same when the drive source rotates in the normal direction and in the reverse direction. The image forming apparatus according to any one of claims 1 to 5,
Of the two drive transmission paths, the drive transmission path located on the drive source side in the thrust direction has a longer drive time or is used than the drive transmission path located on the opposite side to the drive source in the thrust direction. An image forming apparatus characterized by high frequency. The image forming apparatus according to any one of claims 1 to 6,
An image forming apparatus characterized in that one of the two systems of drive transmission paths, which has a smaller number of drive transmission members, has a longer drive time or is used more frequently than the other. The image forming apparatus according to any one of claims 1 to 7,
An image forming apparatus, wherein the number of revolutions is changed depending on whether the drive source is rotating forward or backward. The image forming apparatus according to any one of claims 1 to 8,
An image forming apparatus, wherein the difference between the deceleration ratios is 3% or less.

Images