JP2018180186A - Driving device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving device that can change the speed ratio between two rotating bodies and a rotating body different from these rotating bodies without changing the speed ratio between the two rotating bodies, and an image forming apparatus.SOLUTION: A driving device 30 comprises: a registration paper feed drive transmission mechanism 302 being a first drive transmission part that transmits a driving force of a motor 1 being a driving source to a registration driving roller 143a and a paper feed roller 142; and the first drive transmission part such as a fixing drive transmission mechanism 301 that transmits a driving force of the motor 1 of a fixing roller 145. The registration paper feed drive transmission mechanism 302 is provided with a speed switching mechanism D being a speed switching device.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a drive device and an image forming apparatus.

  DESCRIPTION OF RELATED ART Conventionally, the drive device which rotationally drives three or more rotary bodies by one drive source is known.

  Patent Document 1 describes a drive device in which a single drive source rotationally drives a feed roller, a development roller, a registration roller, a transfer roller, a photosensitive member, a fixing roller, and a discharge roller as a rotating body. It is done.

  However, in the drive device described in Patent Document 1, changing the speed ratio between the two rotating bodies and the other rotating body without changing the speed ratio between the two rotating bodies. could not.

  In order to solve the above problems, the present invention relates to a first drive transmission unit for transmitting the driving force of the drive source to two rotating bodies, in a driving device which rotationally drives three or more rotating bodies by one driving source. And a second drive transmission unit for transmitting the driving force of the drive source to a rotating body different from the two rotating bodies, and the speed switching device is provided to the first drive transmission unit or the second drive transmission unit. Is provided.

  According to the present invention, it is possible to change the speed ratio between the two rotating bodies and the other rotating body without changing the speed ratio between the two rotating bodies.

FIG. 1 is a schematic configuration diagram of a printer according to an embodiment. FIG. 1 is a schematic cross-sectional view of a drive device according to a first embodiment. The schematic block diagram of a 2nd electromagnetic clutch. The control flow figure showing an example of control of a drive. The schematic sectional drawing of the conventional drive device. FIG. 5 is a schematic configuration diagram of a drive device according to a second embodiment. The schematic block diagram of the drive device of Example 2 which removed the bracket. FIG. 8 is a schematic configuration diagram of a drive device of a third embodiment. The schematic block diagram of the drive device of Example 3 which removed each bearing from the bracket. FIG. 14 is a schematic cross-sectional view of a drive device according to a fourth embodiment. FIG. 14 is a schematic cross-sectional view of a drive device according to a fifth embodiment. FIG. 16 is a schematic cross-sectional view of a drive device according to a sixth embodiment. FIG. 18 is a schematic cross-sectional view of a drive device according to a seventh embodiment. FIG. 18 is a schematic cross-sectional view of a drive unit according to an eighth embodiment.

Hereinafter, an 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. First, the basic configuration of the printer will be described.
FIG. 1 is a schematic configuration diagram of a printer according to the embodiment.
In the figure, this printer includes 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 an image forming material, but other than that, they have the same configuration and are replaced when their lifetime is reached. Taking a process unit 160K for forming a K toner image as an example, a drum-shaped photosensitive member 161K as a latent image carrier, a developing device 162K, a charging device 163K, a drum cleaning device 164K, a charge removing device, etc. are provided. The process unit 160K, which is an image forming unit, is detachable from the printer main body, and consumable parts can be replaced at one time.

  The charging device 163K uniformly charges the surface of the photosensitive member 161K which is rotated clockwise in FIG. The surface of the uniformly charged photosensitive member 161K is exposed and scanned by a laser beam L to carry an electrostatic latent image for K. The K electrostatic latent image is developed into a Y toner image by a developing device 162K using K toner. Then, intermediate transfer is performed on an intermediate transfer belt 179 described later. The drum cleaning device 164K removes the transfer residual toner adhering to the surface of the photosensitive member 161K after the intermediate transfer process. Further, the charge removing device removes the residual charge of the photosensitive member 161K after the cleaning. By this charge removal, the surface of the photosensitive member 161K is initialized and prepared for the next image formation. Similarly, in the process units 160Y, 160C, and 160M of other colors, Y, C, and M toner images are formed on the photosensitive members 161Y, 161C, and 161M, and intermediately transferred onto an intermediate transfer belt 179 described later. The cylindrical drum portion of the photosensitive member 161K is obtained by coating an organic photosensitive layer on the front surface of a hollow aluminum pipe. A flange having a drum shaft is attached to each end of the drum portion in the axial direction to constitute a photosensitive member 161K. In the developing device 162K, the K toner contained inside is formed on the surface of the photosensitive member 161K in the developing region which is the opposing region of the developing roller 162aK and the photosensitive member 161K as the developing roller 162aK rotates. The toner image is attached to an 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. 1, the process units 160Y, 160C, and 160M for Y, C, and M also use Y, Y, and C on the surfaces of the photosensitive members 161Y, 161C, and 161M by the same process. C, M toner images are formed.

  In FIG. 1 described above, the optical writing unit 165 is disposed vertically above the process units 160Y, 160C, 160M, and 160K. The optical writing unit 165, which is a latent image writing device, optically scans the photosensitive members 161Y, 161C, 161M, and 161K in the process units 160Y, 160C, 160M, and 160K with a laser beam L emitted from a laser diode based on image information. Do. By this light scanning, electrostatic latent images for Y, C, M and K are formed on the photosensitive members 161Y, 161C, 161M and 161K. In such a configuration, Y, C, M, and K toners of different colors are respectively displayed on three or more latent image carriers by the optical writing unit 165 and the process units 160Y, 160C, 160M, and 160K. It functions as an imaging means for imaging an image.

  The optical writing unit 165 irradiates the photosensitive member via a plurality of optical lenses and mirrors while polarizing the laser light emitted from the light source in the main scanning direction by the polygon mirror rotationally driven by the polygon motor. is there. It is also possible to employ one that performs optical writing by LED light emitted from a plurality of LEDs of the LED array.

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

  The four primary transfer rollers 174Y, 174C, 174M and 174K sandwich the intermediate transfer belt 179 thus endlessly moved between the photosensitive members 161Y, 161C, 161M and 161K. By this sandwiching, a primary transfer nip for Y, C, M, K where the front surface of the intermediate transfer belt 179 and the photosensitive members 161Y, 161C, 161M, 161K are in contact is formed. A primary transfer bias is applied to the primary transfer rollers 174Y, 174C, 174M, and 174K, respectively, by a transfer bias power supply. As a result, a transfer electric field is formed between the electrostatic latent images of the photosensitive members 161Y, 161C, 161M and 161K and the primary transfer rollers 174Y, 174C, 174M and 174K. A transfer charger, a transfer brush or the like may be employed instead of the primary transfer rollers 174Y, 174C, 174M, 174K.

  When the Y toner formed on the surface of the photosensitive member 161Y of the process unit 160Y for Y enters the above-described primary transfer nip for Y as the photosensitive member 161Y rotates, the photosensitive member is obtained by the action of the transfer electric field and the nip pressure. The image is primarily transferred onto the intermediate transfer belt 179 from above 161Y. The intermediate transfer belt 179 to which the Y toner image is primarily transferred in this manner passes the primary transfer nips for M, C, and K along with the endless movement, and the intermediate transfer belt 179 is on the photosensitive members 161M, 161C, and 161K. The M, C, and K toner images are sequentially superimposed on the Y toner image and primarily transferred. A four-color toner image is formed on the intermediate transfer belt 179 by the overlapping primary transfer.

  The secondary transfer roller 178 of the transfer unit 175 is disposed outside the loop of the intermediate transfer belt 179 and sandwiches the intermediate transfer belt 179 with the tension roller 177 inside the loop. By this pinching, a secondary transfer nip is formed where the front surface of the intermediate transfer belt 179 and the secondary transfer roller 178 abut. A secondary transfer bias is applied to the secondary transfer roller 178 by a transfer bias power supply. By this application, a secondary transfer electric field is formed between the secondary transfer roller 178 and the tension roller 177 connected to ground.

  Below the transfer unit 175 in the vertical direction, a sheet feeding cassette 141 that accommodates a plurality of recording sheets P in a bundle of stacked sheets is slidably provided in a printer housing. In the sheet feeding cassette 141, the sheet feeding roller 142 is brought into contact with the top recording sheet P of the sheet bundle, and the recording sheet P is rotated by rotating the sheet feeding roller 142 in a counterclockwise direction in the drawing at a predetermined timing. Send P toward the paper feed path.

  In the vicinity of the end of the paper feed path, a registration roller pair 143 including a registration driving roller 143a and a registration driven roller 143b is disposed. The pair of registration rollers 143 stops the rotation of both rollers as soon as the recording sheet as the recording member delivered from the sheet feeding cassette 141 is sandwiched between the rollers. Then, the rotational drive is resumed at a timing at which the recording sheet pinched can be synchronized with the four-color toner image on the intermediate transfer belt 179 in the above-described secondary transfer nip, and the recording sheet P is sent out toward the secondary transfer nip. .

  The four-color toner image on the intermediate transfer belt 179 brought into close contact with the recording sheet at the secondary transfer nip is secondarily transferred collectively onto the recording sheet P under the influence of the secondary transfer electric field and the nip pressure. Together with the white color, it becomes a full color toner image. Note that transfer residual toner that has not been transferred to the recording paper is attached to the intermediate transfer belt 179 after passing through the secondary transfer nip. This is cleaned from the belt surface by a belt cleaning device 171 in contact with the front surface of the intermediate transfer belt 179. The cleaning backup roller 172 disposed 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 having a full color toner image formed on its surface separates from the secondary transfer roller 178 and the intermediate transfer belt 179 as it passes through the secondary transfer nip. Then, after transfer, the sheet is sent to the fixing device 140 serving as the fixing unit via the conveyance path. The fixing device 140 is provided with a fixing roller 145 containing a heat source 145a such as a halogen lamp, and a pressure roller 147 rotating while being in contact with 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 nipped by the fixing nip so that the unfixed toner image bearing surface is in close contact with the fixing roller 145. Then, the toner in the toner image is softened by the influence of heat and pressure, and a full color image is fixed.

  When the single-sided printing mode is set by an input operation to 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 subjected to a pair of discharge rollers for rotating forwardly. By 181, it is discharged out of the machine as it is. Then, it is stacked on the stack unit 150 which is the upper surface of the upper cover of the housing.

  Further, the discharge roller pair 181 discharges the recording sheet P conveyed from the fixing device 140 to the stack unit 150, and reverses the discharge roller pair 181 when the duplex printing mode is set. The recording paper P is switched back to the paper refeeding path 170 side. That is, when the sheet discharge roller pair 181 includes a pair of sheet discharge rollers 181a and 181b and the sheet discharge sensor 182 detects a nip state in which the recording sheet P is pinched by the sheet discharge rollers 181a and 181b, the sheet discharge is performed. The paper rollers 181a and 181b are reversely rotated. As a result, the recording sheet P is conveyed by the double-sided roller 183, passes through the sheet re-feed path 170, and is conveyed again to the secondary transfer nip in a state in which the front and back are reversed in the transferable direction on the back. 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 discharged to the stack unit 150 by the discharge roller pair 181 Ru.

  Next, an example of a drive device provided in the present printer will be described.

Example 1
FIG. 2 is a schematic cross-sectional view of the drive device 30 according to the first embodiment.
The driving device 30 according to the first embodiment drives the fixing roller 145, the registration driving roller 143a, and the paper feeding roller 142, and is located on one end side of the fixing roller 145, the registration driving roller 143a, and the paper feeding roller 142 in the axial direction. It is provided.
A motor 1 serving as a driving source for driving the fixing roller 145, the registration driving roller 143a, and the sheet feeding roller 142 is fixed to the surface of the bracket 31 opposite to the surface on the roller side. The motor shaft of the motor 1 passes through the bracket 31, and teeth are formed on the outer periphery of the motor shaft to form a motor gear 1a.

  Between the bracket 31 and the side plate 32 facing the roller-side surface of the bracket 31, drive transmission is performed to the fixing drive transmission mechanism 301 that transmits drive to the fixing roller 145, and to the registration drive roller 143a and the paper feed roller 142. A resist sheet feeding drive transmission mechanism 302 is disposed.

  The fixing drive transmission mechanism 301 includes a fixing idler gear 2 and a fixing gear 3. The fixing idler gear 2 is rotatably supported by a first fixed shaft S fixed to the bracket 31 and the side plate 32, and a first external gear 2a meshing with the motor gear 1a and a second external gear meshing to the fixing gear 3 And a gear 2b. The fixing gear 3 is attached so as to rotate integrally with a fixing shaft 145 b of the fixing roller 145 rotatably supported by the side plate 32 via a bearing 32 a.

  The resist sheet feeding drive transmission mechanism 302 has a resist sheet feeding idler gear 4, a speed switching mechanism D as a speed switching device, a branch gear 12, a sheet feeding idler gear 16, a sheet feeding clutch gear 14, and a sheet feeding electromagnetic clutch 13. . The resist feed idler gear 4 is rotatably supported by a second fixed shaft t fixed to the bracket 31 and the side plate 32.

  The speed switching mechanism D has two drive transmission paths having different reduction ratios. The first drive transmission path D1 has a first input gear 6a as an input drive transmission member, a first output gear 10 as an output drive transmission member, and a first electromagnetic clutch 8 as a drive transmission switching means. The second drive transmission path D2 has a second input gear 6b as an input drive transmission member, a second output gear 11 as an output drive transmission member, and a second electromagnetic clutch 9 as a drive transmission switching means.

  The first input gear 6a and the second input gear 6b are integrally configured, and the resist sheet feeding drive transmitting member 102 which is an integral body thereof rotates about a third fixed shaft u fixed to the bracket 31 and the side plate 32. It is freely supported.

  The resist drive in which the first output gear 10, the first electromagnetic clutch 8, the second output gear 11, and the second electromagnetic clutch 9 are rotatably supported by the side plate 32 and the bracket 31 via the bearings 32b and 31a. It is provided on the resist shaft 7 of the roller 143a. The first output gear 10 and the second output gear 11 are rotatably supported by the resist shaft 7. The first electromagnetic clutch 8 and the second electromagnetic clutch 9 are fixed to the resist shaft 7. The first electromagnetic clutch 8 is engaged with the first output gear 10 in the axial direction, and the second electromagnetic clutch 9 is engaged with the second output gear 11 in the axial direction.

  The speed switching mechanism D controls ON / OFF of the first electromagnetic clutch 8 and the second electromagnetic clutch 9 to switch the drive transmission path between the first drive transmission path D1 and the second drive transmission path D2. , You can switch the speed.

  Further, a branch gear 12 is attached to the resist shaft 7 so as to rotate integrally with the resist shaft 7, and a sheet feed idler gear 16 meshes with the branch gear 12. The paper feed idler gear 16 is rotatably supported by a fourth fixed shaft v fixed to the bracket 31 and the side plate 32. The sheet feeding clutch gear 14 meshes with the sheet feeding idler gear 16. The sheet feeding clutch gear 14 and the sheet feeding electromagnetic clutch 13 are provided on the sheet feeding shaft 15 of the sheet feeding roller 142 rotatably supported by the side plate 32 and the bracket 31 via the bearings 32 c and 31 b.

FIG. 3 is a schematic configuration view of the second electromagnetic clutch 9.
The second electromagnetic clutch 9 includes a shaft fixing portion 9e, an electromagnetic coil portion 9d, a rotor portion 9c, an armature 9b, a drive connecting member 9f, and the like. The shaft fixing portion 9e has an insertion hole into which the resist shaft 7 is inserted, and the cross section of the insertion hole is substantially in the form of a square with a part of a circular shape cut away. The resist shaft 7 has a substantially square-round cross-sectional shape similar to the insertion hole so as to be fitted into the insertion hole. The substantially square-round section of the resist shaft 7 extends to a point where the second electromagnetic clutch 9 is attached. The shaft fixing portion 9 e is fixed so as to rotate with the resist shaft 7 by fitting the cross section of the shaft fixing portion 9 e with the cross section of the resist shaft 7. There is.

  An electromagnetic coil portion 9d is rotatably attached to the shaft fixing portion 9e at the shaft fixing portion 9e. On the other hand, the rotor portion 9c is fixed to the shaft fixing portion 9e so as to rotate integrally with the shaft fixing portion 9e. The armature 9b is attached to a drive connecting member 9f having a pair of drive claws 9a extending toward the second resist output gear. A pair of drive connection holes 11a are formed on the surface of the second output gear 11 facing the second electromagnetic clutch 9, and drive claws 9a of the drive connection member 9f are fitted in these drive connection holes 11a. . Thereby, the second electromagnetic clutch 9 and the second output gear 11 are integrally rotatable.

  When the second electromagnetic clutch 9 is turned off, the drive connecting member 9 f is in a free state, and can freely rotate with respect to the shaft fixing portion 9 e. Thereby, the drive transmission from the second output gear 11 to the resist shaft 7 is interrupted, and the drive connecting member 9 f and the second output gear 11 idle with respect to the resist shaft 7.

  When the clutch is turned on, a current flows through the electromagnetic coil unit 9d to generate an electromagnetic force. When an electromagnetic force is generated, the armature 9b of the metal disk is attracted to the electromagnetic coil portion 9d by the electromagnetic force, and the drive connecting member 9f integral with the armature 9b slides toward the rotor portion 9c. Then, the armature 9 b is attracted to the rotor portion 9 c, and the driving force transmitted to the second output gear 11 is transmitted to the resist shaft 7 via the second electromagnetic clutch 9. Thereby, the registration drive roller 143a is rotationally driven.

  In the second electromagnetic clutch 9 of the present embodiment, the drive connecting member 9 f may be provided so as to slide in the axial direction, and the second output gear 11 may be made rotatable relative to the resist shaft 7, The gap with the resist shaft 7 can be made smaller than when the output gear 11 is configured to be slidable in the axial direction. Thereby, the second output gear 11 can be prevented from being inclined with respect to the resist shaft 7.

  The configurations of the first electromagnetic clutch 8 and the sheet feeding electromagnetic clutch 13 are the same as those of the second electromagnetic clutch 9.

  In the present embodiment, the image forming speed is changed according to the type of the recording paper P, and the recording paper passes through the secondary transfer nip and the fixing nip at a conveyance speed suitable for obtaining high image quality. For example, in the case of thick paper, the rotational speed of the secondary transfer roller 178 and the rotational speed of the fixing roller 145 are slower than in the case of plain paper, and the speed of recording paper passing through the secondary transfer nip and the fixing nip is It has dropped. Also, for the resist drive roller 143a, the speed ratio to the rotational speed of the secondary transfer roller 178 is that of the plain paper so that the paper is not pulled or fed excessively between the registration roller pair 143 and the secondary transfer roller 178. The rotational speed is changed so as to maintain the same speed ratio as when. Further, for the same reason, the rotational speed is changed so that the speed ratio between the sheet feeding roller 142 and the registration driving roller 143a is also maintained at the same speed ratio as that of the plain paper.

  The relationship between the rotational speeds of the registration drive roller 143 a and the fixing roller 145 is as follows, based on the rotational speed of the secondary transfer roller 178. That is, assuming that the rotational speed of the secondary transfer roller 178 in the case of plain paper is Vf, the rotational speed of the registration drive roller 143a is Vf × (1 + α), and the rotational speed of the fixing roller 145 is Vf × (1 + β). It has become. In the case of thick paper, the rotational speed of the secondary transfer roller 178 is changed from Vf to Vt (Vf> Vt), the rotational speed of the registration drive roller 143a is Vf × (1 + α), and the rotational speed of the fixing roller 145 is Vt. It has a relation of × (1 + β + γ). For example, when α = 0.004, β = −0.006, γ = 0.006, and the rotational speed of the secondary transfer roller 178 in the case of plain paper Vf = 178 [mm / s], the rotation of the fixing roller 145 The speed is 176.932 [mm / s]. The rotational speed of the registration drive roller 143a is 178.712 [mm / s]. Therefore, the relative speed ratio between the resist driving roller 143a and the fixing roller 145 at this time is about 1%.

  When the rotational speed Vt of the secondary transfer roller 178 for thick paper is set to a half speed 89 [mm / s] with respect to the rotational speed for plain paper, the rotational speed of the fixing roller 145 is 89 [mm] / S]. Also, the rotational speed of the registration drive roller 143a is 89.36 [mm / s]. Therefore, the relative speed ratio between the resist driving roller 143a and the fixing roller 145 at this time is about 0.4%.

  As described above, in the present embodiment, the relative speed ratio between the resist driving roller 143a and the fixing roller 145 is different between plain paper and thick paper. Therefore, only by changing the rotational speed of the motor 1, only one of the fixing roller 145 and the registration driving roller 143a can be set to the specified rotational speed. Therefore, in the present embodiment, the resist sheet feeding drive transmission mechanism 302 of the drive device 30 is provided with the speed switching mechanism D provided with drive transmission paths of two systems having different speed transmission ratios. As a result, with regard to the fixing roller 145, by adjusting the rotational speed of the motor 1, the fixing roller 145 can be made to have a specified rotational speed between plain paper and thick paper. On the other hand, for the registration drive roller 143a, by switching the drive transmission path by the speed switching mechanism D, the relative speed ratio with the secondary transfer roller 178 in the case of thick paper can be made the same speed ratio as in the case of plain paper.

In the first embodiment, assuming that the number of teeth of the motor gear 1a is Z1, the number of teeth of the resist feed idler gear 4 is Z2, the number of teeth of the first input gear 6a is Z3, and the number of teeth of the first output gear 10 is Z4. The speed transmission ratio V1 when performing drive transmission using the first drive transmission path D1 is as follows.
V1 = (Z2 / Z1) × (Z3 / Z2) × (Z4 / Z3)
= (Z4 / Z1) ... (1)

Further, assuming that the number of teeth of the second input gear 6b is Z6 and the number of teeth of the second output gear 11 is Z7, the speed transmission ratio V2 when performing drive transmission using the second drive transmission path D2 is as follows: become.
V2 = (Z2 / Z1) × (Z3 / Z2) × (Z6 / Z5)
= (Z3 / Z1) x (Z6 / Z5) ... (2)

  The relative velocity ratio (V1 / V2) between the time when the first drive transmission path D1 is used and the time when the second drive transmission path D2 is used is (Z4 / Z3) × (Z5 / Z6). Thus, the relative speed ratio is determined by the speed transmission ratio (Z4 / Z3) of the first drive transmission path D1 and the speed transmission ratio (Z5 / Z6) of the second drive transmission path D2. Thus, in the present embodiment, the two gears (first input gear 6a and the first output gear 10) of the first drive transmission path D1 and the two gears (second input gear 6b) of the second drive transmission path D2 And the second output gear 11) can adjust the relative speed ratio.

  Specifically, a module of the gears (the first input gear 6a and the first output gear 10) constituting the first drive transmission path D1 and the gear (the second input gear 6b and the second) constituting the second drive transmission path D2 Different modules of the 2 output gear 11). As an example, the first input gear 6a and the module 0.5 of the first output gear 10 constituting the first drive transmission path D1, the number of teeth Z3 of the first input gear 6a of 60, and the first output gear 10 The number of teeth Z4 is 61. In addition, the second input gear 6b and the second output gear 11 module 0.6 constituting the second drive transmission path D2, the number of teeth Z5 of the second input gear 6b is 50, and the number of teeth of the second output gear 11 Z6 With 51 teeth. The relative velocity ratio (V1 / V2) between the time when the first drive transmission path D1 of this example is used and the time when the second drive transmission path D2 is used is 0.3%.

  Further, the relative speed ratio (V1 / V2) can be reduced to 1% or less by making the twist angles of the gears constituting each drive transmission path different from each other. For example, the module 0.5 of the first input gear 6a of the first drive transmission path D1 and the first output gear 10, the twist angle 0 ° (spur teeth), the number of teeth Z3 of the first input gear 6a is 60, The number of teeth Z4 of one output gear 10 is 61. Module 0.5 of the second input gear 6b and the second output gear 11 constituting the second drive transmission path D2, the twist angle is 8 ° (helical teeth), the number of teeth Z5 of the second input gear 6b is 59, The number of teeth Z6 of the second output gear 11 is 60. The relative velocity ratio (V1 / V2) between the time when the first drive transmission path D1 of this example is used and the time when the second drive transmission path D2 is used is 0.03%.

  As described above, in the first embodiment, the relative speed ratio can be 1% or less with less than 100 teeth of the gears constituting each drive transmission path. As a result, the relative speed ratio can be reduced to 1% or less by reducing the diameter of the gears of the drive transmission paths, and the apparatus can be miniaturized. This is because the drive force is transmitted to each drive transmission path by providing an electromagnetic clutch as a drive transmission switching means capable of switching between the state for transmitting the drive force and the state for blocking the transmission of the drive force. In each drive transmission path, it can be selected whether or not to output the driving force. Thus, gears (a first input gear 6a and a second input gear 6b according to the first embodiment) for inputting a driving force to the drive transmission path, and a gear (a first output according to the first embodiment) for outputting a drive This is because the gear 10 and the second output gear 11) can be provided for each drive transmission path.

FIG. 4 is a control flowchart showing an example of control of the drive device 30. As shown in FIG.
First, the control unit of the printer checks whether the recording sheet P being conveyed is a thick sheet (S1). For example, when the recording sheet is set in the sheet feeding cassette, the sheet thickness information of the recording sheet set by the user is input by operating the operation display unit. It can be grasped. Alternatively, a sheet thickness detection sensor may be provided upstream of the registration roller pair 143 in the conveying direction, and the sheet thickness of the recording sheet P being conveyed may be grasped by detecting the sheet thickness by the sheet thickness detection sensor.

  When the recording sheet being conveyed is not a thick sheet (No in S1), the first electromagnetic clutch 8 is turned off, the second electromagnetic clutch 9 is turned on (S4), and the resist is transmitted using the second drive transmission path D2 The driving force is set to be transmitted to the driving roller 143a. Then, the motor 1 is driven at the second rotational speed Vb (S5). Thus, the image forming apparatus is driven to rotate at a predetermined speed ratio with respect to the rotational speeds Vf of the fixing roller 145, the registration driving roller 143a, and the secondary transfer roller 178.

  On the other hand, when the recording paper being conveyed is thick paper (Yes in S1), the first electromagnetic clutch 8 is turned ON, the second electromagnetic clutch 9 is turned OFF (S2), and the first drive transmission path D1 is used. The driving force is set to be transmitted to the registration driving roller 143a. Then, the motor 1 is driven at the first rotation speed Va which is slower than the second rotation speed Vb (S3).

  By driving the motor 1 at a first rotation speed Va lower than the second rotation speed Vb, the fixing roller 145 is rotationally driven at a low rotation speed. As a result, even in the case of thick paper, the toner image on the recording paper can be sufficiently heated in the fixing nip, and the toner image can be favorably melted, and good fixing performance can be obtained. In the present embodiment, the first rotational speed Va is reduced by 0.3% to 0.6% with respect to the second rotational speed Vb.

  On the other hand, in the case of thick paper, the registration drive roller 143a is rotationally driven by transmitting the driving force via the first drive transmission path D1. In the first drive transmission path D1, when the motor 1 is driven at the first rotational speed Va, the rotational speed of the resist drive roller 143a is plain paper with respect to the rotational speed vt of the secondary transfer roller 178 when the thick paper is used. It is set to have the same speed ratio as in. Thus, even when the rotational speed of the motor 1 is reduced to reduce the rotational speed of the fixing roller 145 when the sheet is thick, the speed ratio between the registration roller pair 143 and the secondary transfer roller 178 can be maintained. As a result, even in the case of thick paper, the recording paper can be favorably transported to the secondary transfer nip, and the toner image on the intermediate transfer belt 179 can be secondarily transferred onto the recording paper.

  Further, as described above, with respect to the sheet feeding roller 142 to which the driving force is transmitted via the resist sheet feeding drive transmitting mechanism 302, the relative speed ratio with the resist driving roller 143a is the same for plain paper and thick sheet. It is necessary to change the rotational speed so that the relative speed ratio is maintained.

FIG. 5 is a schematic cross-sectional view of a conventional drive device 30 '.
As shown in FIG. 5, in the conventional drive device 30 ′, the sheet feed idler gear 16 is meshed with the first output gear 10 serving as the output drive transmission member of the first drive transmission path D1 of the speed switching mechanism D. The driving force is transmitted from one output gear 10.

  In this configuration, the drive transmission path to the sheet feed roller 142 is motor gear 1a → resist sheet feed idler gear 4 → first input gear 6a → first output gear 10 → sheet feed idler gear 16 → sheet feed clutch gear 14. In this configuration, even if the drive transmission path is switched between the first drive transmission path D1 and the second drive transmission path D2 by the ON / OFF control of the first electromagnetic clutch 8 and the second electromagnetic clutch 9, sheet feeding is performed. The drive transmission path to the roller 142 is not switched, and the driving force is transmitted to the paper feed roller 142 through the above-mentioned drive path. As a result, in the related art, the speed ratio between the registration drive roller 143a and the paper feed roller 142 changes between the thick paper and the plain paper. Therefore, during plain paper conveyance or thick paper conveyance, there is a possibility that paper buckling or the like may occur between the paper feed roller 142 and the registration roller pair 143 due to pulling of the paper or excessive feeding.

  On the other hand, in the first embodiment, as shown in FIG. 2 described above, the branch gear 12 is provided on the resist shaft 7 which is an output target member to which the speed switching mechanism D outputs the driving force. The driving force is transmitted to the sheet feed roller 142. Thus, when the first electromagnetic clutch 8 is ON, the driving force is transmitted to the paper feeding roller 142 via the first drive transmission path D1 as in the case of the registration driving roller 143a. On the other hand, when the second electromagnetic clutch 9 is ON, the driving force is transmitted to the sheet feeding roller 142 via the second drive transmission path D2. As a result, the paper feed roller 142 is changed in speed by the speed switching mechanism D in the same manner as the registration drive roller 143a, and the relative speed ratio between the paper feed roller 142 and the registration drive roller 143a From time to time, the same relative speed ratio can be maintained.

  As described above, the driving device 30 according to the first embodiment does not change the relative speed ratio between the sheet feeding roller 142 and the registration driving roller 143a, and the driving roller 30 of the fixing roller 145, the sheet feeding roller 142, and the registration driving roller 143a. The relative speed ratio can be changed.

Example 2
FIG. 6 is a schematic configuration view of a drive device 30A according to a second embodiment, (a) is a schematic cross-sectional view, and (b) is a schematic view seen from the bracket side.
The drive device 30A of the second embodiment is a modification of the first embodiment, and the first drive transmission path D1 of the speed switching mechanism D is configured to perform drive transmission using a belt member, and a second drive transmission path D2 is configured by a gear train composed of a plurality of external gears. In the following description, the same points as in the first embodiment will not be described.

  The first drive transmission path D1 is composed of a first input pulley 6c, a first output pulley 43, a first timing belt 42 which is a toothed belt, and a first electromagnetic clutch 8. The second drive transmission path D2 is configured by a second input gear 6b, a second relay gear 45, a second clutch gear 44, a second electromagnetic clutch 9, and a second output gear 11.

  The first input pulley 6c and the second input gear 6b are an integral body, and the integral body is rotatably supported by the second fixed shaft t. The first output pulley 43 is rotatably supported by the resist shaft 7. The first electromagnetic clutch 8 is fixed to the resist shaft 7 and engaged with the first output pulley 43 in the axial direction. The first timing belt 42 is stretched around the first input pulley 6 c and the first output pulley 43.

  The second input gear 6b meshes with the motor gear 1a. The second relay gear 45 is provided on the rotation axis x rotatably supported by the bracket 31 and the side plate 32 via the bearings 31 c and 32 d so as to rotate integrally with the rotation axis x. It meshes with the input gear 6b. Further, a second clutch gear 44 and a second electromagnetic clutch 9 are provided on the rotating shaft x. The second clutch gear 44 is rotatably supported with respect to the rotation axis x, and the second electromagnetic clutch 9 is fixed to the rotation axis x and engaged with the second clutch gear 44 from the axial direction. There is. The second output gear 11 attached to the resist shaft 7 is engaged with the second clutch gear 44 so as to rotate integrally with the resist shaft 7.

Assuming that the number of teeth of the motor gear 1a is Z1, the number of teeth of the second input gear 6b is Z2, the number of teeth of the first input pulley 6c is Z3, and the number of teeth of the first output pulley 43 is Z4, the first drive transmission path D1 is The velocity transmission ratio V1 used is as follows.
V1 = (Z2 / Z1) × (Z4 / Z3) ··· (Equation 3)

Assuming that the number of teeth of the second relay gear 45 is Z5, the number of teeth of the second clutch gear 44 is Z6, and the number of teeth of the second output gear 11 is Z7, the speed transmission ratio V1 using the second drive transmission path D2 Is the following equation.
V2 = (Z2 / Z1) × (Z5 / Z2) × (Z7 / Z6)
= (Z5 / Z1) x (Z7 / Z6) ... (Equation 4)

From Equation 3 and Equation 4, the relative speed ratio (V1 / V2) between the time when the first drive transmission path D1 is used and the time when the second drive transmission path D2 is used is as follows.
(V1 / V2) = (Z2 / Z1) × (Z4 / Z3)
X (Z1 / Z5) x (Z6 / Z7)
= (Z4 / Z3) x {(Z2 / Z5) x (Z6 / Z7)} (Equation 5)

  As described above, also in the second embodiment, the relative speed ratio is the same as in the first embodiment, and the speed transmission ratio (Z4 / Z3) of the first drive transmission path D1 and the speed transmission ratio of the second drive transmission path D2 ((Z5 It is determined by / Z2) x (Z7 / Z6)). Thus, also in the second embodiment, the plurality of drive transmission members (the first input pulley 6c and the first output pulley 43) of the first drive transmission path D1 and the plurality of drive transmission members of the second drive transmission path D2 ( The relative speed ratio can be adjusted by the second input gear 6b, the second relay gear 45, the second clutch gear 44 and the second output gear 11. Thereby, even if the number of teeth of the gears and pulleys constituting each drive transmission path is less than 100, the relative speed ratio can be made less than 1%.

  Therefore, also in the second embodiment, as in the first embodiment, the number of teeth of each drive transmission path can be 100 or less, and the relative speed ratio can be 1% or less, thereby suppressing the increase in diameter of gears and pulleys. It is possible to reduce the size of the device.

  In addition, the first drive transmission path D1 configured using a timing belt is used as the drive transmission path for thick paper, and the second drive transmission path D2 is used as the drive transmission path for other than thick paper such as plain paper. preferable. As a drive transmission path, it is more resistant to wear and the like when configured with only an external gear than with a configuration using a timing belt, and durability for repeated use is high. On the other hand, in the case where the drive transmission path is configured by only the external gear, when a large load fluctuation occurs, the teeth abut each other, and there is a possibility that the teeth may be damaged or noise may be generated. On the other hand, when the timing belt is used, the timing belt can be elastically deformed to absorb the load fluctuation, and the durability against the load fluctuation is high and the noise reduction is also high.

  Therefore, when the sheet has a large load fluctuation when entering the pair of registration rollers 143 or when passing through the pair of registration rollers 143, the first drive transmission path D1 configured using the timing belt is used. Then, except for thick paper such as plain paper which is generally used frequently, the second drive transmission path D2 constituted only by the external gear is used. As a result, it is possible to achieve both durability against repeated use and durability against load fluctuation, and to improve the quietness of the device.

  Further, in the second embodiment, the first electromagnetic clutch 8 is provided on the resist shaft 7 and the second electromagnetic clutch 9 is provided on the rotating shaft x, and the electromagnetic clutches 8 and 9 are provided on mutually different shafts. Further, the first electromagnetic clutch 8, the second electromagnetic clutch 9, and the sheet feeding electromagnetic clutch 13 do not overlap any drive transmission member of the drive device 30 when viewed from the bracket side which is one end side in the axial direction. Configured. Specifically, the drive transmission member provided coaxially is disposed closest to the bracket 31 side. That is, the first electromagnetic clutch 8 is disposed closer to the bracket 31 than the branch gear 12, the second output gear 11, and the first output pulley 43. The second electromagnetic clutch 9 is disposed closer to the bracket 31 than the second relay gear 45 and the second clutch gear 44. Further, the sheet feeding electromagnetic clutch 13 is disposed closer to the bracket 31 than the sheet feeding clutch gear 14. In addition, the first timing belt 42 disposed closer to the bracket than the second electromagnetic clutch 9 is disposed offset from the second electromagnetic clutch 9 in the direction perpendicular to the paper surface, and the first timing belt 42 is disposed on the bracket side. When viewed from the side, the second electromagnetic clutch 9 is not overlapped (see FIG. 7 (b)).

  The side plate 32 is provided with a stud 35 for fixing the bracket 31, and the bracket 31 is fixed to the stud 35 by a screw 33 at its four corners.

FIG. 7 is a schematic configuration view of the drive device 30A of the second embodiment with the bracket 31 removed, where (a) is a schematic cross-sectional view, and (b) is a schematic view seen from the bracket side.
In general, the life of the electromagnetic clutch is shorter than that of a drive transmission member such as a gear or a pulley, and it needs to be replaced regularly.
As described above, in the second embodiment, the electromagnetic clutches 8, 9 and 13 are provided on shafts different from each other, and are disposed on the bracket side which is one end side in the axial direction with respect to the drive transmission member provided coaxially. ing. Further, the rotation axis x is disposed such that the second electromagnetic clutch 9 disposed on the inner side of the first timing belt 42 does not overlap the first timing belt 42 in the axial direction. As a result, as shown in FIG. 7B, each of the electromagnetic clutches 8, 9, 13 does not overlap any drive transmission member of the drive device when viewed from the bracket side. Therefore, when the screw 33 is removed and the bracket 31 is removed together with the motor 1, the electromagnetic clutches 8, 9, 13 are exposed as shown in FIG. 7 (b). Thus, each electromagnetic clutch can be replaced without removing the drive transmission member coaxially arranged from the shaft, and the replacement operation of the electromagnetic clutch can be simplified.

[Example 3]
FIG. 8 is a schematic configuration view of a drive device 30B of the third embodiment, where (a) is a schematic cross-sectional view, and (b) is a schematic view as viewed from the bracket side.
The drive device 30B of the third embodiment is a modification of the second embodiment, and bearings 31a, 31b, 31c attached to a bracket 31 receiving the shafts x, 7, 15 to which the electromagnetic clutches 8, 9, 13 are fixed. The diameter of the magnetic clutch is equal to or greater than the outer diameter of each of the electromagnetic clutches 8, 9, 13. The bearings 31a, 31b, 31c are fixed to the bracket 31 by screws 311a, 311b, 311c.

FIG. 9 is a schematic configuration view of the drive device 30B of the third embodiment in which the bearings 31a, 31b, and 31c are removed from the bracket 31, (a) is a schematic cross sectional view, and (b) is from the bracket side. It is the schematic seen.
As shown in FIG. 9, when the bearing 31a for receiving the resist shaft 7 is removed from the bracket 31, the first electromagnetic clutch 8 fixed to the resist shaft 7 and disposed closer to the bracket than the branch gear 12 and the second output gear 11 Is exposed. Thus, the first electromagnetic clutch 8 can be accessed from the hole 131b in which the bearing 31a provided on the bracket 31 is fitted, and the first electromagnetic clutch 8 can be replaced.

  Further, when the bearing 31b for receiving the sheet feeding shaft 15 is removed from the bracket 31, the sheet feeding electromagnetic clutch 13 fixed to the sheet feeding shaft 15 and disposed closer to the bracket than the sheet feeding clutch gear 14 is exposed. Thus, the sheet feeding electromagnetic clutch 13 can be accessed from the hole 131c in which the bearing 31b provided in the bracket 31 is fitted, and the sheet feeding electromagnetic clutch 13 can be replaced.

  Further, when the bearing 31c receiving the rotation axis x is removed from the bracket 31, the second electromagnetic clutch 9 fixed to the rotation axis x and disposed closer to the bracket than the second relay gear 45 and the second clutch gear 44 is exposed. . As a result, the second electromagnetic clutch 9 can be accessed from the hole 131a in which the bearing 31c provided on the bracket 31 is fitted, and the second electromagnetic clutch 9 can be replaced.

  When replacing the electromagnetic clutch, the drive device 30B according to the third embodiment only needs to remove only the bearing, and the electromagnetic clutch can be replaced more easily than in the case where the large bracket 31 is removed together with the motor 1.

Example 4
FIG. 10 is a schematic cross-sectional view of a drive device 30C according to a fourth embodiment.
The fourth embodiment is a modification of the first embodiment, in which both the first drive transmission path D1 and the second drive transmission path D2 of the speed switching mechanism D are configured using a timing belt. The first drive transmission path D1 extends between the first input pulley 6c, the first output pulley 43 attached to the resist shaft 7, the first input pulley 6c and the first output pulley 43 as in the previous embodiment. A first timing belt 42, which is a bridged toothed belt, and a first electromagnetic clutch 8 engaged with the first output pulley 43 from the axial direction and attached to the resist shaft 7 are formed.

  The second drive transmission path D2 is stretched between the second input pulley 17 supported by the rotation axis x, the second output pulley 19 attached to the resist shaft 7, the second input pulley 17 and the second output pulley 19 A second timing belt 18 as a toothed belt and a second electromagnetic clutch 9 axially engaged with the second input pulley 17 and attached to the rotation axis x are provided.

  Further, between the first input pulley 6c and the second input pulley 17 of the rotation shaft x, a registration sheet feed input gear 41 meshing with the registration sheet feed idler gear 4 is provided, and the first input pulley 6c and the registration feed The paper input gear 41 is integrally formed. And the one-piece is attached to the rotation axis x so as to rotate integrally with the rotation axis x.

  Also in the fourth embodiment, the ratio of the number of teeth of the first input pulley 6c which is an input transmission member of the first drive transmission path D1 to the number of teeth of the first output pulley 43 which is an output transmission member of the first drive transmission path D1. And the ratio of the number of teeth of the second input pulley 17 which is an input transmission member of the second drive transmission path D2 to the number of teeth of the second output pulley 19 which is an output transmission member of the second drive transmission path D2. The speed ratio (V1 / V2) is determined. Therefore, when the first drive transmission path D1 is used according to the number of teeth of the first input pulley 6c, the number of teeth of the first output pulley 43, the number of teeth of the second input pulley 17, and the number of teeth of the second output pulley 19 The relative speed ratio (V1 / V2) of when the second drive transmission path D2 is used can be adjusted.

  For example, a timing belt of S2M type is used as the timing belt of one drive transmission path, and a timing belt of S3M type is used as the timing belt of the other drive transmission path, and the tooth shape of the timing belt is made different from each other. The relative speed ratio (V1 / V2) can be 1% or less when the number of teeth is 100 or less.

  Further, by configuring each drive transmission path using a timing belt, when the registration drive roller 143a and the paper feed roller 142 are disposed at a position away from the motor 1, a gear train in which a plurality of gears are engaged. Thus, the number of parts can be reduced and drive transmission can be performed to the registration drive roller 143a and the paper feed roller 142 as compared with the case where each drive transmission path is configured. Thereby, the cost increase of the device can be suppressed.

[Example 5]
FIG. 11 is a schematic cross-sectional view of a drive device 30D according to a fifth embodiment.
The driving device 30D according to the fifth embodiment is provided with an upper speed switching mechanism E on the upstream side of the speed switching mechanism D in the drive transmission direction.
In the drive device 30D according to the fifth embodiment, the motor gear 1a of the motor 1 is a helical gear. A fixing movement gear 21 as a helical gear and a registration sheet feeding movement gear 28 mesh with the motor gear 1a. The fixing movement gear 21 is rotatably supported by the first fixing side fixed shaft S1 fixed to the bracket 31 and the side plate 32, and a plurality of drive connection claws 21a and 21b are provided on both side surfaces in the axial direction. There is. The resist sheet feeding moving gear 28 is rotatably supported by the first resist side fixed shaft t1. Like the fixing moving gear 21, a plurality of drive connecting claws 28a and 28b are provided on both side surfaces in the axial direction.

  The drive transmission path from the fixing movement gear 21 to the fixing roller 145 has two systems of a first fixing drive transmission path R1 and a second fixing drive transmission path R2. The first fixing drive transmission path R1 is configured by the fixing input pulley 22, the fixing timing belt 23, and the fixing output pulley 24. The second fixing drive transmission path R2 is configured by the fixing input gear 25 and the fixing output gear 26.

  The fixing input pulley 22 is rotatably supported on the motor side of the first fixing side fixed shaft S1, and a plurality of drive connection claws 21b are fitted on the side surface of the roller facing the fixing movement gear 21. The drive connection hole 22a is formed on the rotation track of the drive connection claw 21b. Further, the fixing input gear 25 is rotatably supported on the roller side of the first fixing side fixed shaft S1. A plurality of drive connection holes 25a into which a plurality of drive connection claws 21a are fitted are formed on the rotation track of the drive connection claws 21a on the side of the fixing input gear 25 facing the fixing movement gear 21 on the motor side.

  A fixing drive transmission output member 101 provided with a fixing output pulley 24 and a fixing output gear 26 on a second fixing fixed shaft S2 fixed to the bracket 31 and the side plate 32 in parallel with the first fixing side fixed shaft S1. Is rotatably mounted. A fixing timing belt 23 is stretched around the fixing output pulley 24 of the fixing drive transmission output member 101 and the fixing input pulley 22. The fixing output gear 26 of the fixing drive transmission output member 101 meshes with the fixing input gear 25 and the fixing gear 3 provided at the motor side end of the fixing shaft 145 b of the fixing roller 145.

  The drive transmission members are configured such that the speed transmission ratio when using the first fixing drive transmission path R1 and the speed transmission ratio when using the second fixing drive transmission path R2 have the same value. . Therefore, as long as the rotational speed of the motor 1 is the same, the fixing roller 145 is configured to rotate at the same speed regardless of which drive transmission path.

  The drive transmission path from the registration sheet feed movement gear 28 to the speed switching mechanism D is divided into two systems of a first registration sheet feed drive transmission path E1 and a second resist sheet feed drive transmission path E2. Further, the speed transmission ratio of the first resist sheet feeding drive transmitting path E1 and the second resist sheet feeding driving transmitting path E2 are made different from each other, and the first resist sheet feeding drive transmitting path E1 and the second resist sheet feeding drive An upper speed switching mechanism E is configured by the transmission path E2 and the resist sheet feeding movement gear 28.

  The first resist sheet feeding drive transmission path E1 is configured by a first resist sheet feeding input pulley 61, a first resist sheet feeding timing belt 62, and a first resist sheet feeding output pulley 63. The second resist sheet feeding drive transmission path E2 is constituted by the second resist sheet feeding input gear 64 and the first input gear 6a of the speed switching mechanism D.

  The first resist feeding input pulley 61 of the first resist feeding drive transmission path E1 is rotatably supported on the motor side of the first resist side fixed shaft t1. A plurality of drive connection holes 61a in which a plurality of drive connection claws 28b are fitted are formed on the rotation track of the drive connection claws 28b on the side of the roller facing the registration sheet feed movement gear 28. A second registration sheet feeding input gear 64 is rotatably supported on the roller side of the first registration side fixed shaft t1. A plurality of drive connection holes 64a into which a plurality of drive connection claws 28a are fitted are provided on the side of the motor facing the registration paper feed movement gear 28 of the second registration paper feed input gear 64, and a rotation track of the drive connection claws 28a. It is formed on top.

  The second resist side fixed shaft t2 fixed to the bracket 31 and the side plate 32 in parallel with the first resist side fixed shaft t1 is a first input gear of the first resist paper feed output pulley 63 and the speed switching mechanism D. A resist sheet feeding drive transmitting member 102 having a 6a and a second input gear 6b is rotatably supported. A first registration sheet feeding timing belt 62 is stretched around a first registration sheet feeding output pulley 63 of the registration sheet feeding drive transmitting member 102 and a first registration sheet feeding input pulley 61. Further, the second resist sheet feeding input gear 64 meshes with the first input gear 6a.

  In FIG. 11, by driving the motor 1, a thrust force is exerted on the fixing movement gear 21 which is a helical gear and the registration sheet feeding movement gear. When the twist direction of the motor gear 1a which is a helical gear is left and the twist direction of the fixing movement gear 21 and the resist feeding movement gear 28 is right, the motor 1 is rotated clockwise (CW) as viewed from the roller side The fixing movement gear 21 and the registration sheet feeding movement gear 28 thrust move toward the motor. As a result, in the fixing moving gear 21, the drive connecting claw 21b is fitted into the drive connecting hole 22a of the fixing input pulley 22, and the fixing moving gear 21 and the fixing input pulley 22 are engaged to fix the fixing moving gear 21 and fixing. The input pulley 22 and the input pulley 22 rotate together. The fixing input pulley 22 is transmitted to the fixing output pulley 24 of the fixing drive transmission output member 101 via the fixing timing belt 23, and the fixing drive transmission output member 101 is driven. Then, the fixing gear 3 provided on the fixing shaft 145 b is driven via the fixing output gear 26 of the fixing drive transmission output member 101. Accordingly, the fixing roller 145 rotates in the same direction as the rotation direction of the motor 1 by the driving force transmitted from the first fixing drive transmission path R1.

  Further, by driving the motor 1 in the clockwise rotation direction, the registration sheet feeding movement gear 28 is moved to the motor side, and the drive coupling claw 28 b is fitted in the driving coupling hole 61 a of the first registration sheet input pulley 61. Incorporate. Thereby, the registration sheet feeding movement gear 28 and the first registration sheet feeding input pulley 61 are engaged, and the registration sheet feeding movement gear 28 and the first registration sheet feeding input pulley 61 are integrally rotationally driven. The resist feeding drive transmitting member rotatably attached to the second resist side fixed shaft t2 through the first resist feeding timing belt 62 when the first resist feeding input pulley 61 is rotationally driven. The first resist feed output pulley 63 is transmitted to the first resist feed output pulley 63. Thereby, the resist sheet feeding drive transmitting member 102 is rotationally driven. Next, the first output gear 10 is driven via the first input gear 6a of the resist sheet feeding drive transmitting member 102, and the second output gear 11 is driven via the second input gear 6b. Then, by turning on any one of the first electromagnetic clutch 8 and the second electromagnetic clutch 9, the drive is transmitted from the first output gear 10 or the second output gear 11 to the registration drive roller 143a and the sheet feeding roller 142. The resist driving roller 143 a and the sheet feeding roller 142 are rotationally driven in the same direction as the rotation direction of the motor 1.

  On the other hand, in FIG. 11, by driving the motor 1 in the counterclockwise direction (CCW), the fixing moving gear 21 moves to the roller side. As a result, the drive connection claw 21 a of the fixing movement gear 21 is fitted into the drive connection hole 25 a of the fixing input gear 25. Thereby, the fixing movement gear 21 and the fixing input gear 25 are engaged, and the fixing movement gear 21 and the fixing input gear 25 are integrally rotationally driven. Then, the fixing input gear 25 drives the fixing output gear 26, whereby the fixing gear 3 is driven by the fixing output gear 26. Thus, the fixing roller 145 is driven in the clockwise (CW) direction opposite to the rotation direction of the motor 1 by the driving force transmitted from the second fixing drive transmission path R2.

  Further, by driving the motor 1 in the counterclockwise (CCW) direction, the registration sheet feeding movement gear 28 is moved to the roller side, and the drive connecting claw 28a of the registration sheet feeding movement gear 28 performs the second registration sheet feeding input. The drive connection hole 64a of the gear 64 is fitted. Thereby, the registration sheet feeding movement gear 28 and the second registration sheet feeding input gear 64 are engaged, and the registration sheet feeding movement gear 28 and the second registration sheet feeding input gear 64 are integrally driven. Then, the driving force is transmitted to the first input gear 6a engaged with the second registration sheet feeding input gear 64, and the registration sheet feeding drive transmitting member 102 is rotationally driven. Next, the first output gear 10 is driven via the first input gear 6a of the resist sheet feeding drive transmitting member 102, and the second output gear 11 is driven via the second input gear 6b of the resist sheet feeding drive transmitting member 102. Drive to rotate. Then, by turning on any one of the first electromagnetic clutch 8 and the second electromagnetic clutch 9, the drive is transmitted from the first output gear 10 or the second output gear 11 to the registration drive roller 143a and the sheet feeding roller 142. The resist driving roller 143a and the sheet feeding roller 142 are rotationally driven in the direction opposite to the rotational direction of the motor 1 (CW direction).

  In the fifth embodiment, the drive transmission path to the resist drive roller 143a and the paper feed roller 142 is the drive transmission path passing through the first resist paper feed drive transmission path E1 and the first drive transmission path D1, and the second resist supply A drive transmission path passing through the paper drive transmission path E2 and the first drive transmission path D1, a drive transmission path passing through the first resist sheet feed drive transmission path E1 and the second drive transmission path D2, and a second resist sheet feed drive transmission path There are four drive transmission paths via E2 and the second drive transmission path D2. Therefore, if the speed transmission ratios of the first resist sheet feeding drive transmission path E1 and the second resist sheet feeding drive transmission path E2 are made different from each other, and the speed transmission ratios of the first drive transmission path D1 and the second drive transmission path D2 are different from each other By doing this, four types of speed switching can be performed. Thereby, the speed of the motor 1 is switched according to the paper thickness more finely to switch the speed of the fixing roller 145, and the registration roller pair 143, the secondary transfer roller 178, and the paper feeding roller 142 have a predetermined relationship. Can be rotated at a maintained rotational speed.

  As described above, by providing the speed switching mechanism in a plurality of stages, the drive transmission path can be reduced as compared with the case where the speed switching is performed by one speed switching mechanism. For example, when the drive transmission path of the upper stage speed switching mechanism E is 3 and the drive transmission path of the lower stage speed switching mechanism D is 3, 3 × 3 = 9 types of speed switching may be performed in six drive transmission paths. It is possible.

  In addition, switching between the first resist sheet feeding drive transmission path E1 and the second resist sheet feeding drive transmission path E2 of the upper speed switching mechanism E can be performed by the resist sheet feeding movement gear 28 which is a helical gear capable of thrust movement. The number of parts can be reduced compared to the case where a clutch or a one-way clutch is provided in each drive transmission path, and the cost of the apparatus can be reduced.

  Also in the upper speed switching mechanism E, in each drive transmission path, the input transmission members (the second registration sheet input gear 64 and the first registration sheet input pulley 61) and the output transmission member (the first input gear 6a) The first resist feeding output pulley 63) can be provided, and the speed transmission ratio can be adjusted by using two members. Therefore, also in the upper speed switching mechanism E, the relative speed ratio can be made 1% or less when the number of teeth of each drive transmission path is 100 teeth or less.

[Example 6]
FIG. 12 is a schematic cross-sectional view of a drive device 30E according to a sixth embodiment.
The driving device 30E according to the sixth embodiment includes a first registration sheet feeding drive transmission path E1 by a first registration sheet feeding input gear 51, a first registration sheet feeding idler gear 52, and a first registration sheet feeding output gear 53. It is what was constructed. In the following description, the description of the same configuration as that of the fifth embodiment is omitted.

  The first registration sheet feeding input gear 51 is rotatably supported on the motor side of the first registration side fixed shaft t1. A plurality of drive connection holes 51a in which a plurality of drive connection claws 28b are fitted on the side of the roller facing the registration sheet feed movement gear 28 of the first registration sheet feed input gear 51 is on the rotation track of the drive connection claws 28b. Is formed. The first registration sheet feeding output gear 53 includes a first input gear 6a and a second input gear 6b, and is provided to the registration sheet feeding drive transmitting member 102 rotatably supported by the second registration side fixed shaft t2. .

  The first resist sheet feeding drive transmission path E1 is configured by the first resist sheet feeding input gear 51, the first resist sheet feeding idler gear 52, and the first resist sheet feeding output gear 53, and the number of gears is an odd number. Thereby, similarly to the fifth embodiment, the rotational direction of the registration drive roller 143a when the drive is transmitted via the first resist sheet feeding drive transmission path E1 can be rotationally driven in the reverse direction to the rotation direction of the motor 1. it can. Therefore, when the motor 1 is rotated clockwise as viewed from the roller side and the drive is transmitted through the second resist sheet feeding drive transmission path E2, the motor 1 is rotated counterclockwise as viewed from the roller side. When the drive is transmitted through the first resist sheet feeding drive transmission path E1, the rotational directions of the resist driving roller 143a and the sheet feeding roller 142 can be made the same.

  Further, one of the first fixing drive transmission path R1 and the second fixing drive transmission path R2 for transmitting drive to the fixing roller 145 may be configured by an even gear train, and the other may be configured by an odd gear train.

[Example 7]
FIG. 13 is a schematic cross-sectional view of a drive device 30F according to a seventh embodiment.
The driving device 30F according to the seventh embodiment configures the first resist sheet feeding drive transmission path E1 to perform drive transmission using an internal gear, and the second resist sheet feeding drive transmission path E2 includes a plurality of The drive transmission is performed by the gear train in which the external gear meshes. Specifically, the first resist sheet feeding drive transmission path E1 is configured by the internal gear 66 and the first resist sheet feeding output gear 53, and the second resist sheet feeding drive transmission path E2 is a second resist sheet feeding input A gear 64 and a second resist feed output gear 68 are provided.

  On the first registration side fixed shaft t1 rotatably supporting the registration sheet feeding movement gear 28, the internal gear 66 and the second registration sheet feeding input gear 64 face each other with the registration sheet feeding movement gear 28 interposed therebetween. It is rotatably supported. Drive coupling claws 28a and 28b are engaged with the side of the internal gear 66 facing the resist feeding movement gear 28 and the side of the second resist feeding input gear 64 facing the resist feeding movement gear 28. The connection holes 66a and 64a are formed on the rotation track of the drive connection claws 28a and 28b.

  The resist sheet feeding drive transmitting member 102 rotatably supported by the second resist side fixed shaft t2 includes a first resist sheet feeding output gear 53, a second resist sheet feeding output gear 68, a first input gear 6a and a second input. It has a gear 6b.

  Also in the seventh embodiment, as in the fifth and sixth embodiments, the rotation direction of the registration drive roller 143a and the paper feed roller 142 when the drive is transmitted through the first resist paper feed drive transmission path E1 is the same as the rotation of the motor 1. It can be rotationally driven in the direction opposite to the direction. On the other hand, it is possible to rotationally drive the registration drive roller 143a and the feed roller 142 in the same direction as the rotation direction of the motor 1 when the drive is transmitted via the second resist sheet feed drive transmission path E2. As a result, the motor 1 is rotated clockwise as seen from the roller side, and when the drive is transmitted via the second resist sheet feeding drive transmission path E2, the motor 1 is rotated counterclockwise as seen from the roller side. The rotational direction of the resist driving roller 143a can be made the same direction when the drive is transmitted through the first resist sheet feeding drive transmission path E1.

  Further, by forming the first resist sheet feeding drive transmission path E1 using the internal gear 66, the meshing portion with the first resist sheet feeding output gear 53 can be covered by the internal gear 66, and the meshing portion The internal gear 66 can shield the noise generated by Further, the meshing ratio between the external gear and the internal gear can be increased compared to the meshing of the external gears, and the generation of noise and vibration can be suppressed. Thereby, the quietness of the drive device can be enhanced. For this reason, as a drive transmission path using the internal gear 66, it is preferable to use it as a drive transmission path in the case of plain paper which is frequently used.

[Example 8]
FIG. 14 is a schematic cross-sectional view of a drive device 30G according to an eighth embodiment.
The driving device 30G according to the eighth embodiment is a modification of the fifth embodiment, and the motor 1 is attached to the roller side surface of the side plate 32. Further, a drive input member 65 is provided for transmitting the driving force from the motor gear 1 a and transmitting the driving force to the fixing movement gear 21 and the registration sheet feeding movement gear 28. The drive input member 65 has a tubular shape, an inner tooth 65a is formed on the inner circumferential surface, and an outer tooth 65b is formed on the outer circumferential surface. The drive input member 65 is rotatably supported by a fixed shaft u1 fixed to the bracket 31 and the side plate 32, and the motor gear 1a is engaged with the internal teeth 65a. The external teeth 65b are helical teeth, and the fixing movement gear 21 and the resist feeding movement gear 28 mesh with the external teeth 65b.

  In the eighth embodiment, by attaching the motor 1 to the side surface of the side plate 32 on the roller side, the motor noise can be blocked by the side plate 32 and the bracket 31. Therefore, compared to the case where the motor 1 is provided on the surface of the bracket 31 opposite to the roller side, the motor noise can be made less likely to leak to the outside. Thereby, noise reduction of the device can be achieved. Further, by attaching the motor 1 to the roller side surface of the side plate 32, the driving device can be shortened in the axial direction as compared with the case where the motor 1 is provided on the surface opposite to the roller side of the bracket 31. Thus, the device can be miniaturized.

  Further, by meshing the motor gear 1a with the internal teeth 65a of the drive input member 65, the meshing ratio with the motor gear 1a can be increased, and the occurrence of uneven rotation, noise and vibration can be suppressed.

  Further, the meshing with the motor gear 1a which is the meshing at the first stage has the highest noise application rate. As compared with the configuration in which the fixing movement gear 21 and the registration sheet feeding movement gear 28 mesh with the first-stage motor gear 1a, the meshing with the first-stage motor gear 1a having a high noise application rate is one of the inner teeth 65a. Noise can be suppressed.

  Although the resist feeding drive transmission mechanism 302 for transmitting the driving force of the motor 1 to the resist driving roller 143a is described as an example in which the speed switching device is provided in the above-described first to eighth embodiments, A speed switching device may be provided in the fixing drive transmission mechanism 301 that transmits the driving force of the above.

  In the fifth to eighth embodiments, the resist feeding movement gear 28 is provided to switch between the first resist feeding drive transmitting path E1 and the second resist feeding driving transfer path E2 of the upper speed switching mechanism E, Although this is performed by forward / reverse rotation of the motor 1, it is not limited to this. For example, drive transmission switching means such as a clutch is provided in the first resist sheet feeding drive transmission path E1 and the second resist sheet feeding drive transmission path E2, and the drive transmission switching means of each resist sheet feeding drive transmission path is controlled to drive The transmission path may be switched. In such a configuration, the fixing drive transmission mechanism 301 can be a drive transmission path of one system. In the fifth to eighth embodiments, the speed switching mechanism has two stages, but may have two or more stages. Further, in the first to eighth embodiments, the speed switching mechanism D is a drive transmission path of two systems, but three or more systems are provided with drive transmission paths, and from one of them, the resist drive roller 143a and the paper feed roller 142 are provided. It may be configured to transmit drive to the

  Alternatively, the driving force may be transmitted to the secondary transfer roller 178, the registration driving roller 143a, and the paper feeding roller 142 by the registration paper feeding drive transmission mechanism 302. Further, the driving force may be transmitted to the secondary transfer roller 178 and the registration driving roller 143a by the registration sheet feeding driving transmission mechanism 302.

The above-described one is an example, and the following effects can be obtained.
(Aspect 1)
In the drive device 30 that rotationally drives three or more rotating members (in the present embodiment, the fixing roller 145, the resist driving roller 143a, and the sheet feeding roller 142) by a driving source such as one motor 1, two rotating members In the embodiment, the first drive transmission unit such as the registration sheet feeding drive transmission mechanism 302 that transmits the driving force of the driving source to the registration driving roller 143a and the sheet feeding roller 142), and the rotation different from the two rotating bodies. And a second drive transmission unit such as the fixing drive transmission mechanism 301 for transmitting the driving force of the drive source to the body (in the present embodiment, the fixing roller 145), the first drive transmission unit or the second drive transmission The unit was provided with a speed switching device such as the speed switching mechanism D.
According to this, by switching the speeds of two rotating bodies or rotating bodies different from these by the speed switching device provided in the first drive transmitting unit or the second drive transmitting unit, The speed ratio can be maintained to change the speed ratio between the other rotating body and the two rotating bodies.

(Aspect 2)
In the aspect 1, the speed switching device such as the speed switching mechanism D rotates the output target member such as the resist shaft 7 in the same direction, and has a plurality of drive transmission paths different in speed transmission ratio (in this embodiment, A plurality of drive transmission members (a first input gear 6a and a first output gear 10, a second input gear 6b and a second drive transmission path D1 and a second drive transmission path D2) are provided in each of the plurality of drive transmission paths. There are provided two output gears 11) and drive transmission switching means (a first electromagnetic clutch 8 and a second electromagnetic clutch 9) capable of switching between a state for transmitting the driving force and a state for interrupting the transmission of the driving force.
According to this, the plurality of drive transmission members are individually provided in the plurality of drive transmission paths. Thus, the number of teeth of the plurality of non-common drive transmission members in each drive transmission path can be made different from each other, and the speed transmission ratio of each drive transmission path can be made different from each other. Therefore, even if the number of teeth of each drive transmission member of each drive transmission path is 100 or less, the ratio of the speed of the output target member by one drive transmission path to the speed of the output target member by the other drive transmission path is It can be 1% or less. Thus, the device can be miniaturized.
In the first aspect, by providing a plurality of drive transmission members individually with a plurality of drive transmission paths, one drive transmission path is a belt drive transmission, and the other drive transmission path is a gear train, etc. It is also possible to finely adjust the transmission ratio to 1% or less by making the transmission method different from one another for each drive transmission path.
Further, since drive transmission switching means such as an electromagnetic clutch is provided for each of the plurality of drive transmission paths, switching of the rotational speed of the output target member is performed by controlling the drive transmission switching means of each drive transmission path. Can.

(Aspect 3)
In the second aspect, the driving force is transmitted to the two rotating bodies (in the present embodiment, the resist driving roller 143a and the sheet feeding roller 142) through an output target member such as the resist shaft 7.
According to this, as described in the embodiment, the speeds of the two rotating bodies are changed by the speed switching device such as the speed switching mechanism D, and the speed ratio can be maintained.

(Aspect 4)
In the aspect 2 or 3, the drive device 30 is disposed at one end side in the axial direction of the three or more rotating bodies, and provided in each drive transmission path of the speed switching device such as the speed switching mechanism D. The drive transmission switching units such as the electromagnetic clutches 8 and 9 are provided on different shafts, and when viewed from the one end in the axial direction, each drive transmission switching unit is a first drive transmission such as the resist sheet feeding drive transmission mechanism 302 Drive transmission members (fixing idler gear) that constitute a second drive transmission unit such as a plurality of drive transmission members (branch gear 12, paper feed idler gear 16, paper feed clutch gear 14 etc.) 2. A plurality of drive transmission members (second input gear 6 b, first input pulley 6 c, second relay gear 4) of each drive transmission path of speed switching device such as fixing gear 3) and speed switching mechanism D , The second clutch gear 44, the second output gear 11, the first timing belt 42, and positioned so as not to overlap with any of the first output pulley 43, etc.).
According to this, as described in the second embodiment, the drive transmission switching means can be removed without removing the drive transmission member arranged coaxially with the drive transmission switching means, and the drive transmission switching means can be replaced. It can be done easily.

(Aspect 5)
In the fourth aspect, the shaft (rotational axis X, resist shaft 7) provided with drive transmission switching means such as the electromagnetic clutches 8 and 9 is received, and closer to the one end in the axial direction than the drive transmission switching means provided on this shaft The diameter of a bearing member such as the arranged bearings 31c, 31a is larger than the outer diameter of the drive transmission switching means, and with respect to a side plate such as a bracket 31 supporting the shaft via the bearing member. The bearing member is detachably provided.
According to this, as described in the third embodiment, by removing the bearing members such as the bearings 31c and 31a, the drive transmission switching means can be accessed from the holes into which the bearing members provided on the side plates such as the bracket 31 are fitted. The drive transmission switching means can be replaced. Thereby, it is possible to easily replace the drive transmission switching means as compared to the case where the drive transmission switching means is replaced by removing the side plate such as the bracket 31 or the like.

(Aspect 6)
In any one of the first to fifth aspects, the first drive transmission unit such as the registration sheet feed drive transmission mechanism 302 transmits the driving force to the registration roller such as the registration drive roller 143 a and the sheet feed roller 142, and the fixing drive transmission mechanism 301. And the like transmit the driving force to the fixing roller 145.
According to this, as described in the embodiment, the speed ratio between the fixing roller 145 and the registration roller is changed without changing the speed ratio between the registration roller such as the registration drive roller 143a and the sheet feeding roller 142. be able to.

(Aspect 7)
In an image forming apparatus including an image forming unit that forms an image and a driving unit that drives a plurality of output rotating bodies, any one of the driving devices according to any one of the aspects 1 to 6 is used as the driving unit.
According to this, it is possible to change the speed ratio of another rotating body and the speed ratio of the two rotating bodies without changing the speed ratio of the two rotating bodies with one drive source. As compared with an apparatus in which a drive source for driving two rotating bodies and a driving source for driving the other rotating body are separately provided, motor noise can be reduced, and noise reduction of the apparatus can be achieved. Further, the number of motors can be reduced, and the cost of the apparatus can be reduced and the apparatus can be miniaturized.

1: Motor 1a: Motor gear 2: Fixing idler gear 2a: First external gear 2b: Second external gear 3: Fixing gear 4: Registration paper feed idler gear 6a: First input gear 6b: Second input gear 6c: First Input pulley 7: Resist shaft 8: First electromagnetic clutch 9: Second electromagnetic clutch 9a: Drive claw 9b: Armature 9c: Rotor portion 9d: Magnet coil portion 9e: Shaft fixing portion 9f: Drive connecting member 10: First output gear 11: second output gear 11a: drive connecting hole 12: branch gear 13: sheet feeding electromagnetic clutch 14: sheet feeding clutch gear 15: sheet feeding shaft 16: sheet feeding idler gear 17: second input pulley 18: second timing belt 19 : Second output pulley 21: Fixing movement gear 21a, 21b: Drive connecting claw 22: Fixing input pulley 22a: Drive connecting hole 23: Fixing timing bell 24: Fixing output pulley 25: Fixing input gear 25a: Drive connecting hole 26: Fixing output gear 28: Resist feeding gear 28a, 28b: Drive connecting claw 30: Drive 31: Bracket 31a: Bearing 31b: Bearing 31c: Bearing 32: side plate 32a: bearing 32b: bearing 32c: bearing 32d: bearing 33: screw 35: stud 41: resist feed input gear 42: first timing belt 43: first output pulley 44: second clutch gear 45: second Relay gear 51: first resist feed input gear 51a: drive connecting hole 52: first resist feed idler gear 53: first resist feed output gear 61: first resist feed input pulley 61a: drive connect hole 62: first One resist feed timing belt 63: first resist feed output pulley 64: second resist feed input gear 64a: drive connection hole 65: drive input member 65a: internal teeth 65b: external gear 66: internal gear 66a: drive connection hole 68: second resist sheet feed output gear 101: fixing drive transmission output member 102: resist sheet feed drive Transmission member 140: fixing device 141: paper feeding cassette 142: paper feeding roller 143: registration roller pair 143a: registration driving roller 143b: registration driven roller 145: fixing roller 145a: heat source 145b: fixing shaft 147: pressure roller 150: Stacking unit 160: process unit 161: photosensitive member 162: developing device 162a: developing roller 163: charging device 164: drum cleaning device 165: optical writing unit 170: refeed 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 301: Fixing drive transmission mechanism 302: Registration sheet feed drive transmission mechanism 311a: Screw D: Speed switching mechanism D1: first drive transmission path D2: second drive transmission path E: upper stage speed switching mechanism E1: first resist sheet feeding drive Transmission path E2: second resist sheet feeding drive transmission path R1: first fixing drive transmission path R2: second fixing drive transmission path S: first fixed axis S1: first fixing side fixed axis S2: second fixing fixed Axis t: second fixed axis t1: first resist side fixed axis t2: second resist side fixed axis u: third fixed axis u1: fixed axis v: fourth fixed axis x: turn Axis

JP, 2000-221743, A

Claims (7)

In a drive device that rotationally drives three or more rotating bodies by one drive source,
A first drive transmission unit for transmitting the driving force of the drive source to two rotating bodies;
And a second drive transmission unit for transmitting the driving force of the drive source to a rotating body other than the two rotating bodies.
A driving device characterized in that a speed switching device is provided to the first drive transmission unit or the second drive transmission unit. In the drive device according to claim 1,
The speed switching device rotates the output target member in the same direction, and has a plurality of drive transmission paths having different speed transmission ratios from one another.
A drive device characterized in that each of a plurality of drive transmission paths is provided with a plurality of drive transmission members, and a drive transmission switching means capable of switching between a state for transmitting the driving force and a state for blocking the transmission of the driving force. . In the drive device according to claim 2,
A driving device according to any of the preceding claims, wherein a driving force is transmitted to the two rotating bodies via the output target member. In the drive device according to claim 2 or 3,
The drive device is disposed at one end side in the axial direction of the three or more rotating bodies,
The drive transmission switching means provided in each drive transmission path of the speed switching device are provided on mutually different axes,
When viewed from the one end side in the axial direction, each drive transmission switching means includes a plurality of drive transmission members constituting the first drive transmission unit, a plurality of drive transmission members constituting the second drive transmission unit, and A driving device characterized in that it is disposed so as not to overlap any of the plurality of drive transmission members of each drive transmission path of the speed switching device. In the drive device according to claim 4,
The diameter of the bearing member disposed on the one end side in the axial direction of the drive transmission switching means provided on the shaft is larger than the outer diameter of the drive transmission switching means. A driving device characterized in that the bearing member is detachably attached to a side plate which has a large diameter and supports the shaft via the bearing member. In the drive device according to any one of claims 1 to 5,
The first drive transmission unit transmits the driving force to the registration roller and the sheet feeding roller.
The second drive transmission unit transmits the driving force to a fixing roller. Image forming means for forming an image;
An image forming apparatus comprising driving means for driving three or more rotating bodies,
An image forming apparatus using the drive device according to any one of claims 1 to 6 as the drive means.

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