JP6697710B2 - Speed switching device, drive device and image forming device - Google Patents

Description

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

  Some conventional image forming apparatuses include a speed switching device that switches the rotation speed of an output target rotating body such as a fixing roller.

  In Patent Document 1, as the speed switching device, a common gear that is driven by a driving force of a drive motor to rotate and is movable along an axial direction, and a common gear that is arranged in parallel with the shaft of the common gear are provided on a fixing roller. It has a plurality of speed change gears mounted on an output shaft that outputs a driving force. The plurality of speed change gears are provided at positions axially different from each other within the axial movement range of the common gear. Further, the plurality of speed change gears have the same outer diameter and are configured to have different numbers of teeth. The rotational speed of the fixing roller is switched by moving the common gear in the axial direction and changing the speed change gear with which the common gear meshes.

  However, it is possible to finely adjust the speed of the output target rotating body such as the fixing roller (for example, 1% or less) only by making the number of teeth of the speed change gear different from each other as in the speed switching device described in Patent Document 1. Then, there is a problem that the device becomes large.

In order to solve the above problems, the present invention provides a speed switching device for switching the rotational speed of the output target rotating body has a plurality of speed switching unit comprising a plurality of different drive transmission path velocity transmission ratio to each other, a plurality of At least one of the speed switching units is a first speed switching unit that rotates the output target rotating body in the same direction and includes a plurality of drive transmission paths having different speed transmission ratios. The section is provided with an input drive transmission member to which a driving force is first input in the drive transmission path and an output drive transmission member to which a driving force is finally input in each of the plurality of drive transmission paths, and a plurality of drive transmission paths. having thereon a drive transmission switching unit capable of switching between a state for blocking the transmission of the state and the driving force for transmitting driving force to each transmission path, the speed switching unit, a plurality stages, the speed of the plurality of stages One of the switching units includes a two-system drive transmission path, and moves in different thrust directions between the two-system drive transmission paths during forward rotation and reverse rotation of the drive source. A thrust speed switching unit having a rotatable moving rotary member that transmits the rotational driving force from the drive source to one of the two drive transmission paths or the other drive transmission path. The two-system flow drive transmission paths of the speed switching unit include a drive transmission path in which the rotation direction of the output drive transmission member is the same as the rotation direction of the drive source, and a rotation direction of the output drive transmission member is the drive source. And a drive transmission path that is opposite to the rotation direction of .

  According to the present invention, the size of the device can be reduced.

1 is a schematic configuration diagram of a printer according to an embodiment. 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. FIG. 3 is a schematic cross-sectional view showing a fixing roller, a secondary transfer roller, a registration roller pair, and a drive device that drives these. The control flow diagram which shows an example of control of a drive device. FIG. 6 is a schematic cross-sectional view of a drive device according to a second embodiment. FIG. 6 is a schematic cross-sectional view of a drive device according to a third embodiment. FIG. 6 is a schematic cross-sectional view of a drive device according to a fourth embodiment. 5 is a schematic cross-sectional view of a drive device according to a fifth embodiment. 7 is a schematic cross-sectional view of a drive device according to a sixth embodiment. 7 is a schematic cross-sectional view of a drive device according to a seventh embodiment. 8 is a schematic cross-sectional view of a drive device according to an eighth embodiment.

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

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

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

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

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

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

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

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

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

  A registration roller pair 143 composed of a registration driving roller 143a and a registration driven roller 143b is arranged near the end of the sheet feeding path. The registration roller pair 143 stops the rotation of both rollers as soon as the recording paper, which is a recording member sent out from the paper feed cassette 141, is sandwiched between the rollers. Then, the recording paper sandwiched is restarted in the secondary transfer nip at a timing at which it can be synchronized with the four-color toner image on the intermediate transfer belt 179, and the recording paper P is sent toward the secondary transfer nip. ..

  The four-color toner image on the intermediate transfer belt 179, which is brought into close contact with the recording paper at the secondary transfer nip, is secondarily transferred onto the recording paper P all at once under the influence of the secondary transfer electric field and the nip pressure. In combination with the white color, a full color toner image is formed. Note that the transfer residual toner that has not been transferred to the recording paper adheres to the intermediate transfer belt 179 after passing through the secondary transfer nip. This is cleaned from the belt surface by the belt cleaning device 171 that is in contact with the front surface of the intermediate transfer belt 179. The cleaning backup roller 172 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 the full-color toner image formed on its surface passes through the secondary transfer nip, and is separated from the secondary transfer roller 178 and the intermediate transfer belt 179 by curvature. Then, it is sent to the fixing device 140 as a fixing unit via the post-transfer conveyance path. The fixing device 140 is provided with a fixing roller 145 including a heat source 145a such as a halogen lamp, and a pressure roller 147 that rotates while contacting the fixing roller 145 with a predetermined pressure. The pressure roller 147 forms a fixing nip. The recording paper fed into the fixing device 140 is sandwiched in the fixing nip so that the unfixed toner image bearing surface of the recording paper is in close contact with the fixing roller 145. Then, the toner in the toner image is softened by the influence of heating and pressurization, and the full-color image is fixed.

  When the single-sided print mode is set by an input operation 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 a pair of discharge rollers that rotates in the normal direction. It is discharged to the outside of the machine as it is by 181. Then, it is stacked on the stack portion 150 which is the upper surface of the upper cover of the housing.

  Further, the paper discharge roller pair 181 discharges the recording paper P conveyed from the fixing device 140 to the stack unit 150, and when the double-sided print mode is set, the paper discharge roller pair 181 is reversed. The recording paper P is switched back to the re-feed path 170 side. That is, the paper discharge roller pair 181 includes a pair of paper discharge rollers 181a and 181b, and when the paper discharge sensor 182 detects a nip state in which the end portion of the recording paper P is sandwiched between the paper discharge rollers 181a and 181b, the paper discharge roller 181 is discharged. The paper rollers 181a and 181b are reversed. As a result, the recording paper P is conveyed by the double-sided roller 183, passes through the re-feeding path 170, and is conveyed again to the secondary transfer nip in a state where the front side and the back side are reversed so that it can be transferred to the back side thereof. Then, after passing through the secondary transfer nip and a toner image is formed on the back surface of the recording paper P, the toner image is fixed on the recording paper P by the fixing device 140 and is discharged to the stack portion 150 by the paper discharge roller pair 181. It

  Next, an example of a driving device included in the 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 and the registration driving roller 143a.
The motor 1 which is a drive source for driving the fixing roller 145 and the registration driving roller 143a is fixed to the surface of the bracket 31 opposite to the roller side surface. The motor shaft of the motor 1 penetrates the bracket 31, and teeth are formed on the outer periphery of the motor shaft to form the motor gear 1a.

  Between the bracket 31 and the side plate 32 facing the roller-side surface of the bracket 31, a fixing drive transmission mechanism 301 for transmitting drive to the fixing roller 145 and a registration drive transmission mechanism for transmitting drive to the registration drive roller 143a. 302 are provided.

  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 a bracket 31 and a side plate 32, and has a first external gear 2a meshing with the motor gear 1a and a second external gear meshing with the fixing gear 3. It has a gear 2b. The fixing gear 3 is attached so as to rotate integrally with a fixing shaft 145b of a fixing roller 145 rotatably supported by the side plate 32 via a bearing 32a.

  The registration drive transmission mechanism 302 has a registration idler gear 4, a registration input gear 5, and a speed switching mechanism D as a speed switching device. The resist idler gear 4 is rotatably supported by a second fixed shaft t fixed to the bracket 31 and the side plate 32. The registration input gear 5 is rotatably supported by a third fixed shaft u fixed to the bracket 31 and the side plate 32.

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

  The first input gear 6a, the second input gear 6b, and the registration input gear 5 are integrally formed, and the registration drive transmission member 102, which is an integrated body thereof, is fixed to the bracket 31 and the side plate 32 by a third fixing. It is rotatably supported by the shaft u.

  The first output gear 10, the first electromagnetic clutch 8, the second output gear 11, and the second electromagnetic clutch 9 are the registration shaft 7 of the registration driving roller 143a rotatably supported by the side plate 32 via the bearing 32b. It is provided in. The first output gear 10 and the second output gear 11 are rotatably supported by the registration shaft 7. The first electromagnetic clutch 8 and the second electromagnetic clutch 9 are fixed to the registration 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.

FIG. 3 is a schematic configuration diagram 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 insertion hole has a D-shaped cross section. The registration shaft 7 has a D-shaped cross section so as to be fitted in the D-shape. The cross-section D-shaped portion of the resist shaft 7 extends to a position where the second electromagnetic clutch 9 is attached. By fitting the D-shaped section of the shaft fixing portion 9e with the D-shaped section of the resist shaft 7, the shaft fixing portion 9e is fixed so as to rotate together with the resist shaft 7.

  The electromagnetic coil portion 9d is rotatably attached to the shaft fixing portion 9e with respect to 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 side. A pair of drive coupling holes 11a is formed on the surface of the second output gear 11 facing the second electromagnetic clutch 9, and the drive claws 9a of the drive coupling member 9f are fitted into these drive coupling holes 11a. .. As a result, the second electromagnetic clutch 9 and the second output gear 11 can rotate integrally.

  When the second electromagnetic clutch 9 is OFF, the drive connecting member 9f is in a free state, and is in a state in which it can idle around the shaft fixing portion 9e. As a result, the drive transmission from the second output gear 11 to the registration shaft 7 is cut off, and the drive connecting member 9f and the second output gear 11 idle around the registration shaft 7.

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

  In the second electromagnetic clutch 9 of the present embodiment, the drive connecting member 9f may be slidably provided in the axial direction, and the second output gear 11 may be rotatable with respect to the registration shaft 7. The gap between the output gear 11 and the registration shaft 7 can be made smaller than in the case where the output gear 11 is configured to be slidable in the axial direction. This can prevent the second output gear 11 from tilting with respect to the registration shaft 7.

  The configuration of the first electromagnetic clutch 8 is the same as that of the second electromagnetic clutch 9.

FIG. 4 is a schematic cross-sectional view showing the fixing roller 145, the secondary transfer roller 178, the registration roller pair 143, and a drive device for driving these.
As shown in FIG. 4, the fixing roller 145 and the registration driving roller 143a are driven by the driving device 30 described above, and the secondary transfer roller is driven by the secondary transfer driving device 70.

  In the present embodiment, the image forming speed is changed according to the type of the recording paper P so that 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 rotation speed of the secondary transfer roller 178 and the rotation speed of the fixing roller 145 are made slower than those of plain paper so that the speed of the recording paper passing through the secondary transfer nip and the fixing nip is reduced. I'm dropping it. Further, in order to prevent the paper from being pulled or fed too much between the registration roller pair and the secondary transfer roller, the speed ratio of the registration drive roller 143a to the rotation speed of the secondary transfer roller is that of the plain paper. The rotation speed is changed so as to maintain the same speed ratio as at the time.

  The relationship between the rotation speeds of the rollers is as follows, based on the rotation speed of the secondary transfer roller 178. That is, when the linear velocity of the secondary transfer roller 178 for plain paper is Vf, the linear velocity of the registration driving roller 143a is Vf×(1+α), and the linear velocity of the fixing roller is Vf×(1+β). Is becoming For thick paper, the linear velocity of the secondary transfer roller 178 is changed from Vf to Vt (Vf>Vt), the linear velocity of the registration driving roller 143a is Vf×(1+α), and the linear velocity of the fixing roller is Vt×. The relationship is (1+β+γ). For example, when α=0.004, β=−0.006, γ=0.006, and when the linear velocity Vf of the secondary transfer roller 178 for plain paper is Vf=178 [mm/s], the line of the fixing roller 145. The speed is 176.932 [mm/s], and the linear speed of the registration driving roller 143a is 178.712 [mm/s]. Therefore, the relative speed ratio of the registration driving roller 143a and the fixing roller 145 at this time is about 1%.

  When the linear velocity Vt of the secondary transfer roller 178 for thick paper is set to 89 [mm/s], which is half the linear velocity for plain paper, the linear velocity of the fixing roller 145 is 89 [mm. /S], and the linear velocity of the registration driving roller 143a becomes 89.36 [mm/s]. Therefore, the relative speed ratio between the registration 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 ratios of the registration driving roller 143a and the fixing roller 145 are different between the plain paper and the thick paper. Therefore, only by changing the rotation speed of the motor, the fixing roller 145 and the registration roller 145 are not changed. Only one of the drive rollers 143a can be set to the specified rotation speed. Therefore, in the present embodiment, the registration drive transmission mechanism 301 of the drive device 30 is provided with the speed switching mechanism D including two drive transmission paths having different speed transmission ratios. Thus, with respect to the fixing roller, by adjusting the rotation speed of the motor, the fixing roller 145 is set to a specified rotation speed for the plain paper and the thick paper, and for the registration drive roller 143a, the drive transmission path is changed by the speed switching mechanism D. By switching, the relative speed ratio with the secondary transfer roller for thick paper is set to the same speed ratio as for plain paper.

  The linear velocity of the secondary transfer roller 178 and the registration driving roller 143a for thick paper is set to 89 [mm/s], which is half the linear velocity for plain paper. The linear velocity of is +γ (0.6%) faster than half the speed of plain paper. Therefore, the rotation speed of the motor 1 is made to be 0.6% faster than half the rotation speed of plain paper. Therefore, in order to make the linear velocity of the registration drive roller 143a for thick paper half that of plain paper, the relative speed ratio between the first drive transmission path D1 and the second drive transmission path D2 should be set to 0. It is necessary to set to 6%, and it is necessary to set the relative speed ratio to less than 1%.

  In the speed switching device described in Patent Document 1, as described above, the speed shift device slides in the rotation axis direction to be placed in either the speed change gear of the first drive transmission path or the speed change gear of the second drive transmission path. Up to a common gear that meshes, the first and second drive transmission paths are common, and the only difference between the first and second drive transmission paths is the transmission gear. Therefore, in the speed switching device described in Patent Document 1, the speed transmission ratio can be made different between the first drive transmission path and the second drive transmission path only by the number of teeth of the transmission gear. As a result, in order to reduce the speed ratio between the first drive transmission path and the second drive transmission path to less than 1%, the number of teeth of the speed change gear needs to be 100 or more, and the diameter of each speed change gear is large. The diameter becomes large and the device becomes large.

On the other hand, in the first embodiment, the number of teeth of the motor gear 1a is Z1, the number of teeth of the registration idler gear 4 is Z2, the number of teeth of the registration input gear 5 is Z3, and the number of teeth of the first input gear 6a is Z4. When the number of teeth of the output gear 10 is Z5, the speed transmission ratio V1 when drive transmission is performed using the first drive transmission path D1 is as follows.
V1=(Z2/Z1)×(Z3/Z2)×(Z5/Z4)
=(Z3/Z1)×(Z5/Z4)... (1)

When 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)×(Z7/Z6)
=(Z3/Z1)×(Z7/Z6)... (2)

  The relative speed ratio (V1/V2) between when the first drive transmission path is used and when the second drive transmission path is used is (Z5/Z4)×(Z6/Z7), and the relative speed ratio is It is determined by the speed transmission ratio (Z5/Z4) of the first drive transmission path and the speed transmission ratio (Z7/Z6) of the second drive transmission path D2. As described above, in the present embodiment, the two gears of the first drive transmission path D1 (the first input gear 6a and the first output gear 10) and the two gears of the second drive transmission path (the second input gear 6b and the second input gear 6b The relative speed ratio can be adjusted by the second output gear 11). With this, unlike the speed switching device described in Patent Document 1, even if the number of teeth of the gears forming each drive transmission path is less than 100, the relative speed ratio can be less than 1%. As a result, it is possible to suppress an increase in the diameter of the gear of each drive transmission path, and it is possible to suppress an increase in the size of the device.

  Specifically, a module of gears (first input gear 6a and first output gear 10) forming the first drive transmission path, and a gear (second input gear 6b and second output) forming the second drive transmission path. Different gear 11) modules. As an example, the module 0.5 of the first input gear 6a and the first output gear 10 that configure the first drive transmission path D1, the number of teeth Z4 of the first input gear 6a is 60 teeth, and the module of the first output gear 10 is The number of teeth Z5 is 61 teeth. Further, the module 0.6 of the second input gear 6b and the second output gear 11 forming the second drive transmission path D2, the number of teeth Z6 of the second input gear 6b is 50 teeth, and the number of teeth Z7 of the second output gear 11 is Z7. Is 51 teeth. The relative speed ratio (V1/V2) between when the first drive transmission path of this example is used and when the second drive transmission path is used is 0.3%.

  Further, the relative speed ratio (V1/V2) can be set to 1% or less by making the twist angles of the gears forming the respective drive transmission paths different from each other. For example, the first input gear 6a of the first drive transmission path D1 and the module 0.5 of the first output gear 10 have a twist angle of 0° (flat teeth), and the number of teeth Z4 of the first input gear 6a is 60 teeth. The number of teeth Z5 of one output gear 10 is 61 teeth. The module 0.5 of the second input gear 6b and the second output gear 11 which constitute the second drive transmission path D2, the twist angle is 8° (a helical tooth), the number of teeth Z6 of the second input gear 6b is 59 teeth, The number of teeth Z7 of the second output gear 11 is 60 teeth. The relative speed ratio (V1/V2) between when the first drive transmission path of this example is used and when the second drive transmission path is used is 0.03%.

  As described above, in the first embodiment, the relative speed ratio can be set to 1% or less when the number of gear teeth of each drive transmission path is less than 100. As a result, the gears in each drive transmission path can be made small in diameter, and the relative speed ratio can be set to 1% or less, and the size of the device can be reduced. This is because by providing an electromagnetic clutch, which is a drive transmission switching means, capable of switching between a state in which the driving force is transmitted and a state in which the transmission of the driving force is interrupted, in each drive transmission path, the drive force is transmitted to each drive transmission path. It is possible to select whether or not to output the driving force in each drive transmission path. This is because it is possible to provide gears (first input gear 6a and second input gear 6b of the first embodiment) for inputting the driving force to the drive transmission paths for each drive transmission path.

FIG. 5 is a control flow chart showing an example of control of the drive device 30.
First, the control unit of the printer checks whether or not the recording paper P being conveyed is thick paper (S1). The information on the thickness of the recording paper P to be conveyed is, for example, when the recording paper is set in the paper feed cassette and the paper thickness information of the recording paper set by the user is input by operating the operation display unit. You can figure it out. Alternatively, a paper thickness detection sensor may be provided on the upstream side of the registration roller pair 143 in the conveyance direction, and the paper thickness of the recording paper P to be conveyed may be grasped by detecting the paper thickness with the paper thickness detection sensor.

  When the conveyed recording paper is not thick paper (No in S1), the first electromagnetic clutch 8 is turned off and the second electromagnetic clutch 9 is turned on (S4), and the second drive transmission path D2 is used for registration. The driving force is set to be transmitted to the driving roller 143a. Then, the motor 1 is driven at the second rotation speed Vb (S5). As a result, the fixing roller 145, the registration driving roller 143a, and the secondary transfer roller are rotationally driven at a predetermined speed ratio with respect to the rotational speed Vf.

  On the other hand, when the conveyed recording paper is thick paper (Yes in S1), the first electromagnetic clutch 8 is turned on and the second electromagnetic clutch 9 is turned off (S2), and the first drive transmission path D1 is used. It is set so that the driving force is 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 the first rotation speed Va which is slower than the second rotation speed Vb, the fixing roller 145 is rotationally driven at the slow rotation speed. As a result, even with thick paper, the toner image on the recording paper can be sufficiently heated in the fixing nip, the toner image can be melted well, and good fixability can be obtained. In the present embodiment, the first rotation speed Va is 0.3% to 0.6% lower than the second rotation speed Vb.

  On the other hand, in the case of thick paper, the registration driving roller 143a is rotationally driven by the driving force transmitted through the first drive transmission path D1. When the motor 1 is driven at the first rotation speed Va, the first drive transmission path D1 is when the rotation speed of the registration drive roller is plain paper as compared with the rotation speed vt of the secondary transfer roller when thick paper is used. It is set to have the same speed ratio as. As a result, even when the rotation speed of the motor 1 is decreased to decrease the rotation speed of the fixing roller 145 in the case of thick paper, the speed ratio between the registration roller pair 143 and the secondary transfer roller can be maintained. As a result, the recording paper can be satisfactorily conveyed to the secondary transfer nip even with thick paper, and the toner image on the intermediate transfer belt 176 can be satisfactorily secondarily transferred to the recording paper.

  In the first embodiment, the registration drive transmission mechanism 302 that transmits drive to the registration drive roller 143a is provided with the speed switching mechanism D that is a speed switching device, but the speed is transmitted to the fixing drive transmission mechanism 301 that transmits drive to the fixing roller 145. A switching mechanism D may be provided. When the fixing drive transmission mechanism 301 is provided with the speed switching mechanism D, the rotation speed of the registration drive roller is adjusted by the rotation speed of the motor, and the rotation speed of the fixing roller is switched between the drive transmission paths of the speed switching mechanism D. Is adjusted by. As a result, the registration drive roller 143a can maintain the prescribed relationship with the rotation speed of the secondary transfer roller between the thick paper and the other thick paper, and the fixing roller 145 can obtain good fixing properties between the thick paper and the other. It is possible to switch to the rotation speed that can be obtained.

  Generally, the electromagnetic clutch has a shorter life than drive transmission members such as gears and pulleys, and needs to be replaced regularly. When replacing the electromagnetic clutch, it is necessary to access the shaft to which the electromagnetic clutch is attached, remove the life-long electromagnetic clutch from the shaft, and attach a new electromagnetic clutch to the shaft. When the first electromagnetic clutch 8 and the second electromagnetic clutch 9 are provided on different shafts, it is necessary to allow the worker to access the respective shafts, and it is necessary to provide a space for that purpose in the image forming apparatus. .. As a result, there is a problem that the size of the printer is increased.

  On the other hand, in the first embodiment, since the first electromagnetic clutch 8 and the second electromagnetic clutch 9 are provided on the registration shaft 7, it suffices that the operator can access the registration shaft 7. Therefore, the size of the printer can be reduced as compared with the configuration in which the electromagnetic clutches are attached to different shafts.

  Further, in the first embodiment, the first and second electromagnetic clutches 8 and 9 are provided on the registration shaft 7 which is the rotation shaft of the registration driving roller 143a which is the output target rotation body. The shafts to which the first and second electromagnetic clutches 8 and 9 are attached must be rotatably supported by the side plates. Therefore, when the first and second electromagnetic clutches are provided coaxially with the first input gear 6a and the second input gear 6b, the shaft that supports the first input gear 6a and the second input gear 6b (the third fixed shaft u ) Must be rotatably attached to the side plate via a bearing, which increases the number of parts and increases the cost of the device. On the other hand, the registration shaft 7, which is the shaft of the registration driving roller as the output target rotating body, is rotatably supported by the side plate through a bearing for rotating the registration driving roller 143a. Therefore, by providing the first and second electromagnetic clutches 8 and 9 on the registration shaft 7, compared with the case where the first and second electromagnetic clutches are provided coaxially with the first input gear a and the second input gear 6b. The increase in the number of parts can be suppressed, and the cost increase of the device can be suppressed.

  By providing the first and second electromagnetic clutches 8 and 9 on the registration shaft 7, the first input gear 6a, the second input gear 6b and the registration input gear 5 can be integrated. As a result, the number of parts can be reduced and the number of assembling steps can be reduced as compared with the case where the first input gear 6a, the second input gear 6b, and the resist input gear 5 are separately provided and attached to the shaft. be able to.

[Example 2]
FIG. 6 is a schematic cross-sectional view of the drive device 30A according to the second embodiment.
The drive device 30A of the second embodiment is a modification of the first embodiment, in which the first drive transmission path D1 of the speed switching mechanism D is configured by a gear train including a plurality of external gears, and the second drive transmission path D2 is formed. A belt member is used to perform drive transmission. In the following description, the same points as those in the first embodiment will be omitted.

  The first drive transmission path D1 includes a first input gear 6a, a first idler gear 13, a first output gear 10, and a first electromagnetic clutch 8. The second drive transmission path D2 includes a second input pulley 15, a second output pulley 17, a second timing belt 16 that is a toothed belt, and a second electromagnetic clutch 9.

  The first input gear 6a and the second input pulley 15 are an integral body, and the integral body is rotatably supported by the second fixed shaft t. The first input gear 6a meshes with the motor gear 1a. The first idler gear 13 is rotatably supported by the third fixed shaft u, and meshes with the first input gear 6 a and the first output gear 10. The first output gear 10, the first electromagnetic clutch 8, the second output pulley 17, and the second electromagnetic clutch 9 are provided on the rotating shaft X rotatably supported by the side plate 32 and the bracket 31 via bearings 32c and 31a. Has been. The first output gear 10 and the second output pulley 17 are rotatably supported on the rotary shaft X. The first electromagnetic clutch 8 is fixed to the rotary shaft X, and the first output gear 10 and the axial direction are Engaged. The second electromagnetic clutch 9 is fixed to the rotating shaft and is engaged with the second output pulley 17 in the axial direction. The second timing belt 16 is stretched around the second input pulley 15 and the second output pulley 17.

  A first registration gear 12a is attached to the roller-side end of the rotary shaft X, and the first registration gear 12a meshes with a second registration gear 12b fixed to the registration shaft 7.

When the number of teeth of the motor gear 1a is Z1, the number of teeth of the first input gear 6a is Z2, the number of teeth of the first idler gear 13 is Z3, and the number of teeth of the first output gear 10 is Z4, the first drive transmission path D1 is The speed transmission ratio V1 used is given by the following formula.
V1=(Z2/Z1)×(Z3/Z2)×(Z4/Z3)
=(Z4/Z1)... (Equation 3)

When the number of teeth of the second input pulley 15 is Z5 and the number of teeth of the second output pulley 17 is Z6, the speed transmission ratio V2 using the second drive transmission path D2 is given by the following equation.
V2=(Z2/Z1)×(Z6/Z5)... (Equation 4)

From the above Expressions 3 and 4, the relative speed ratio (V1/V2) when the first drive transmission path D1 is used and when the second drive transmission path D2 is used is as follows.
(V1/V2)=(Z4/Z1)×(Z1/Z2)×(Z5/Z6)
=(Z4/Z2)×(Z5/Z6)... (Equation 5)

  Thus, also in the second embodiment, the relative speed ratio is the same as in the first embodiment, that is, the speed transmission ratio (Z4/Z2) of the first drive transmission path D1 and the speed transmission ratio (Z6 of the second drive transmission path D2. /Z5). As described above, also in the second embodiment, the two drive transmission members (the first input gear 6a and the first output gear 10) of the first drive transmission path and the two drive transmission members of the second drive transmission path (second The relative speed ratio can be adjusted by the input pulley 15 and the second output pulley 17). With this, unlike the speed switching device described in Patent Document 1, even if the number of teeth of the gears and pulleys forming each drive transmission path is less than 100, the relative speed ratio can be 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, and the increase in the diameter of the gear and the pulley can be suppressed. Therefore, it is possible to prevent the apparatus from increasing in size.

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

  Therefore, in the case of thick paper that has large load fluctuations when entering the pair of registration rollers or when exiting the pair of registration rollers, the second drive transmission path D2 configured by using the timing belt is used and generally used frequently. By using the first drive transmission path D1 configured only by the external gear when the card is not thick paper such as plain paper, it is possible to achieve both durability against repeated use and durability against load fluctuation, and The quietness of the device can be improved.

[Example 3]
FIG. 7 is a schematic cross-sectional view of the drive device 30B according to the third embodiment.
The drive device 30B according to the third embodiment is a modification of the first embodiment, in which the first electromagnetic clutch 8 and the second electromagnetic clutch 9 are provided on mutually different shafts. Specifically, the shaft that supports the first input gear 6a and the second input gear 6b is the rotation shaft X that is rotatably supported by the bracket 31 and the side plate 32 via the bearing, and the second electromagnetic clutch 9 is It was attached to the rotary shaft X and engaged with the second input gear 6b in the axial direction. On the other hand, with respect to the first electromagnetic clutch 8, the first output gear 10 and the second output gear 11 are attached to the registration shaft 7 rotatably supported, and are engaged with the first output gear 10 in the axial direction.

  Further, in the third embodiment, the registration input gear 5 of the first embodiment is eliminated, and the first input gear 6a of the first drive transmission path is meshed with the registration idler gear 4.

In the third embodiment, the number of teeth of the motor gear 1a is Z1, the number of teeth of the registration idler gear 4 is Z2, the number of teeth of the first input gear Z3, the number of teeth Z4 of the first output gear 10 and the number of teeth of the second input gear 6b. When Z5 and the number of teeth of the second output gear 11 are Z6, the speed transmission ratios V1 and V2 using the respective drive transmission paths are as follows.
V1=(Z2/Z1)×(Z3/Z2)×(Z4/Z3)
=(Z4/Z1)... (Equation 6)
V2=(Z2/Z1)×(Z3/Z2)×(Z6/Z5)
=(Z3/Z1)×(Z6/Z5)... (Formula 7)

From the above (Equation 6) and (Equation 7), the relative speed ratio (V1/V2) between when the first drive transmission path D1 is used and when the second drive transmission path D2 is used is as follows. Become.
(V1/V2)=(Z4/Z1)×(Z1/Z3)×(Z5/Z6)
=(Z4/Z3)×(Z5/Z6)... (Equation 8)

  Therefore, also in the third embodiment, the relative speed ratio is the same as in the first embodiment, the number of teeth Z3 of the first input gear 6a, which is the input transmission member of the first drive transmission path D1, and the output of the first drive transmission path D1. The ratio of the number of teeth Z4 of the first output gear 10 which is a transmission member, the number of teeth Z5 of the second input gear 6b which is an input transmission member of the second drive transmission path D2, and the output transmission member of the second drive transmission path D2. The ratio with the number of teeth Z6 of the second output gear 11 is Therefore, 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.

  In the third embodiment, the first electromagnetic clutch 8 and the second electromagnetic clutch 8 are provided on the different shafts by providing the first electromagnetic clutch 8 and the second electromagnetic clutch 9 which are longer in the axial direction than the gear and the pulley. As compared with the case where the clutch 9 and the clutch 9 are provided coaxially, the axial size can be reduced.

[Example 4]
FIG. 8 is a schematic sectional view of a driving device 30C according to the fourth embodiment.
In the fourth embodiment, both the first drive transmission path D1 and the second drive transmission path D2 of the speed switching mechanism are configured by using timing belts. The first drive transmission path D1 is stretched between the first input pulley 18 supported by the rotating shaft X, the first output pulley 19 attached to the registration shaft 7, and the first input pulley 18 and the first output pulley 19. It is provided with a first timing belt 20 which is a belt with teeth. The first electromagnetic clutch 8 is axially engaged with the first output pulley 19 and attached to the registration shaft.

  The second drive transmission path D2 is stretched between the second input pulley 15 supported by the rotating shaft X, the second output pulley 17 attached to the registration shaft 7, and the second input pulley 15 and the second output pulley 17. It is provided with the second timing belt 16 which is a toothed belt that is bridged. In addition, a second electromagnetic clutch 9 that is axially engaged with the second input pulley 15 and that is attached to the rotating shaft X is provided.

  A registration input gear 5 that meshes with the registration idler gear 4 is provided between the first input pulley 18 and the second input pulley 15 of the rotating shaft X, and the first input pulley 18 and the registration input gear 5 are connected to each other. Are integrally formed. Then, the integrated body is attached to the rotary shaft so as to rotate integrally with the rotary shaft X.

  Also in the fourth embodiment, the ratio of the number of teeth of the first input pulley 18 which is the input transmission member of the first drive transmission path D1 to the number of teeth of the first output pulley 19 which is the output transmission member of the first drive transmission path D1. And the ratio of the number of teeth of the second input pulley 15 which is the input transmission member of the second drive transmission path D2 to the number of teeth of the second output pulley 17 which is the output transmission member of the second drive transmission path D2. Therefore, when the first drive transmission path D1 is used depending on the number of teeth of the first input pulley 18, the number of teeth of the first output pulley 19, the number of teeth of the second input pulley 15, and the number of teeth of the second output pulley 17. And the relative speed ratio (V1/V2) between when the second drive transmission path D2 is used can be adjusted.

  For example, an S2M type timing belt is used as the timing belt of one drive transmission path, and an S3M type timing belt is used as the timing belt of the other drive transmission path. When the number of teeth is 100 or less, the relative speed ratio (V1/V2) can be 1% or less.

  Further, by configuring each drive transmission path using a timing belt, even if the registration drive roller 143a is arranged at a position away from the motor 1, each drive transmission path is formed by a gear train in which a plurality of gears mesh with each other. The number of parts can be reduced as compared with the case of (1) to drive the registration drive roller 143a. Thereby, the cost increase of the device can be suppressed.

[Example 5]
FIG. 9 is a schematic cross-sectional view of the drive device 30D according to the fifth embodiment.
The drive device according to the fifth embodiment is provided with an upper speed switching mechanism E such as a thrust speed switching unit 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 movement gear 28 mesh with the motor gear 1a. The fixing moving gear 21 is rotatably supported by a first fixing-side fixed shaft S1 fixed to a bracket 31 and a side plate 32, and a plurality of drive connecting claws 21a and 21b are provided on both axial side surfaces, respectively. There is. The registration moving gear 28 is rotatably supported by the first registration-side fixed shaft t1, and like the fixing moving gear 21, a plurality of drive connecting claws 28a and 28b are provided on both axial side surfaces, respectively.

  There are two drive transmission paths from the fixing movement gear to the fixing roller 145, that is, a first fixing drive transmission path R1 and a second fixing drive transmission path R2. The first fixing drive transmission path R1 is a fixing input pulley. 22, a fixing timing belt 23, and a fixing output pulley 24. The second fixing drive transmission path R2 includes a fixing input gear 25 and a 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 connecting claws 21b are fitted on the roller-side side surface facing the fixing moving gear 21. Drive connecting hole 22a is formed on the rotation orbit of the drive connecting claw 21b. A 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 a side surface of the fixing input gear 25 facing the fixing movement gear 21 on the motor side, on a rotation path of the drive connection claws 21a.

  The second fixing fixing shaft S2 fixed to the bracket 31 and the side plate 32 in parallel with the first fixing fixing shaft S1 has a fixing drive transmission output member 101 having a fixing output pulley 24 and a fixing output gear 26. Is rotatably attached. 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 145b of the fixing roller 145.

  Each drive transmission member is 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. However, if the rotation speed of the motor 1 is the same, the fixing roller is configured to rotate at the same speed through any drive transmission path.

  Further, there are two drive transmission paths from the registration moving gear 28 to the speed switching mechanism D, that is, a first registration drive transmission path E1 and a second registration drive transmission path E2. The speed transmission ratios of the resist drive transmission path E2 are different from each other. That is, the first registration drive transmission path E1, the second registration drive transmission path E2, and the registration movement gear 28 constitute an upper speed switching mechanism E.

  The first registration drive transmission path E1 includes a first registration input pulley 41, a first registration timing belt 42, and a first registration output pulley 43. The second registration drive transmission path E2 is composed of the second registration input gear 44 and the first input gear 6a of the speed switching mechanism D.

  The first registration input pulley 41 of the first registration drive transmission path E1 is rotatably supported on the motor side of the first registration side fixed shaft t1, and a plurality of rollers are provided on the roller side surface facing the registration moving gear 28. A plurality of drive connection holes 41a into which the drive connection claws 28b are fitted are formed on the rotation path of the drive connection claws 28b. A second registration input gear 44 is rotatably supported on the roller side of the first registration side fixed shaft t1. On the side surface of the second registration input gear 44 facing the registration moving gear 28 on the motor side, a plurality of drive connection holes 44a into which a plurality of drive connection claws 28a are fitted are formed on the rotation path of the drive connection claws 28a. ing.

  The first resist output pulley 43, the first input gear 6a of the speed switching mechanism D, and the second resist fixed shaft t2 fixed to the bracket 31 and the side plate 32 are provided in parallel with the first resist side fixed shaft t1. A resist drive transmission member 102 having a two-input gear 6b is rotatably supported. A first registration timing belt 42 is stretched around the first registration output pulley 43 and the first registration input pulley 41 of the registration drive transmission member 102. Further, the second registration input gear 44 meshes with the first input gear 6a.

  In FIG. 9, by driving the motor 1, thrust force acts on the fixing moving gear 21 which is a helical gear and the registration moving gear 28. When the twisting direction of the motor gear 1a, which is a helical gear, is left and the twisting directions of the fixing moving gear 21 and the registration moving gear 28 are right, when the motor 1 is rotated in the clockwise (CW) direction as viewed from the roller side, the fixing is performed. The moving gear 21 and the resist moving gear 28 thrustly move to the motor side. As a result, in the fixing moving gear 21, the driving connecting claw 21b is fitted into the driving connecting hole 22a of the fixing input pulley 22, and the fixing moving gear 21 and the fixing input pulley 22 are engaged with each other, whereby the fixing moving gear 21 and the fixing moving gear 21 are fixed. 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 145b is driven via the fixing output gear 26 included in the fixing drive transmission output member 101. As a result, 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 moving gear 28 moves to the motor side, and the drive connection claw 28b fits into the drive connection hole 41a of the first registration input pulley 41. As a result, the registration moving gear 28 and the first registration input pulley 41 engage with each other, and the registration moving gear 28 and the first registration input pulley 41 rotate integrally. The first registration input pulley 41 is transmitted to the first registration output pulley 43 of the registration drive transmission member 102 rotatably attached to the second registration side fixed shaft t2 via the first registration timing belt 42, and the registration drive transmission member 43 is transmitted. 102 is driven. Next, the first output gear 10 is driven via the first input gear 6a of the registration drive transmission member 102, and the second output gear 11 is driven via the second input gear 6b. Then, by turning on 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 driving roller 143a, and the registration driving roller 143a. Are driven to rotate in the same direction as the rotation direction of the motor 1.

  On the other hand, in FIG. 9, by driving the motor 1 in the counterclockwise direction (CCW), the fixing movement gear 21 moves to the roller side. As a result, the drive connecting claw 21a of the fixing moving gear 21 fits into the drive connecting hole 25a of the fixing input gear 25. As a result, the fixing moving gear 21 and the fixing input gear 25 are engaged with each other, and the fixing moving gear 21 and the fixing input gear 25 are integrally driven to rotate. The fixing input gear 25 drives the fixing output gear 26, so that the fixing gear 3 is driven by the fixing output gear 26. As a result, 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 moving gear 28 moves to the roller side, and the drive connecting claw 28 a of the registration moving gear 28 moves into the drive connecting hole of the second registration input gear 44. It fits in 44a. As a result, the registration moving gear 28 and the second registration input gear 44 are engaged with each other, and the registration moving gear 28 and the second registration input gear 44 are integrally driven. Then, the registration drive transmission member 102 including the first registration output pulley 43, the first input gear 6a, and the second input gear 6b is driven. Next, the first output gear 10 is driven via the first input gear 6a of the registration drive transmission member 102, and the second output gear 11 is driven via the second input gear 6b of the registration drive transmission member 102. Then, by turning on 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 driving roller 143a, and the registration driving roller 143a. Is driven to rotate in the direction opposite to the rotation direction of the motor 1 (CW direction).

  In the fifth embodiment, the drive transmission path to the registration drive roller 143a is a drive transmission path that passes through the first registration drive transmission path E1 and the first drive transmission path D1, and the second registration drive transmission path E2 and the first drive. A drive transmission path passing through the transmission path D1, a drive transmission path passing through the first resist drive transmission path E1 and the second drive transmission path D2, and a drive transmission path passing through the second resist drive transmission path E2 and the second drive transmission path D2. There are 4 ways. Therefore, by making the speed transmission ratios of the first registration drive transmission path E1 and the second registration drive transmission path E2 different from each other, and by making the speed transmission ratios of the first drive transmission path D1 and the second drive transmission path D2 different from each other, Four types of speed switching can be performed. As a result, the speed of the motor 1 is switched more finely according to the paper thickness to switch the speed of the fixing roller 145, and the registration roller pair 143 is rotated at a rotation speed that maintains a predetermined relationship with the secondary transfer roller. Can be made

  As described above, by providing the speed switching mechanism in a plurality of stages, it is possible to reduce the drive transmission path 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 speed switching mechanism E is 3 and the drive transmission path of the lower speed switching mechanism D is 3, it is possible to perform 3×3=9 kinds of speed switching with 6 drive transmission paths. You can do it.

  Further, the switching between the first registration drive transmission path E1 and the first registration drive transmission path E2 of the upper stage speed changeover mechanism E can be performed by the registration movement gear which is a thrust-movable helical gear, and each electromagnetic clutch or one-way clutch is driven. The number of parts can be reduced and the cost of the device can be reduced as compared with the case where the transmission path is provided.

  Also in the upper speed switching mechanism E, the input transmission member (second registration input gear 44, first registration input pulley) and the output transmission member (first input gear 6a, second registration output) are respectively provided in each drive transmission path. Pulley) 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 number of teeth of each drive transmission path can be 100 teeth or less, and the relative speed ratio can be 1% or less.

[Example 6]
FIG. 10 is a schematic cross-sectional view of the drive device 30E according to the sixth embodiment.
In the drive device according to the sixth embodiment, the first resist drive transmission path E1 is composed of a first resist input gear 51, a first resist idler gear 52, and a first resist output gear 53. In the following description, the description of the same configuration as the fifth embodiment will be omitted.

  The first registration input gear 51 is rotatably supported on the motor side of the first registration side fixed shaft t1, and a plurality of drive connection claws 28b are fitted to the roller side surface facing the registration moving gear 28. A plurality of drive connection holes 51a are formed on the rotation path of the drive connection claw 28b. The registration drive transmission member 102 includes a first input gear 6a and a second input gear 6b, and is rotatably supported by the second registration side fixed shaft t2.

  The first resist drive transmission path E1 is composed of the first resist input gear 51, the first resist idler gear 52, and the first resist output gear 53, and the number of gears is an odd number. The rotation direction of the registration drive roller 143a when the drive transmission is performed via the first registration drive transmission path E1 can be rotationally driven in the direction opposite to the rotation direction of the motor 1. As a result, when the motor 1 is rotated clockwise when viewed from the roller side and the drive is transmitted through the second registration drive transmission path E2, when the motor 1 is rotated counterclockwise when viewed from the roller side, The rotation direction of the registration drive roller 143a can be the same direction as when the drive is transmitted via the first registration drive transmission path E1.

  Further, one of the first fixing drive transmission path R1 and the second fixing drive transmission path R2 that drive-transmits to the fixing roller 145 may be configured with an even gear train and the other may be configured with an odd gear train.

[Example 7]
FIG. 11 is a schematic cross-sectional view of the drive device 30F according to the seventh embodiment.
In the drive device according to the seventh embodiment, the first resist drive transmission path E1 is configured to perform drive transmission using the internal gear, and the second resist drive transmission path E2 is meshed with a plurality of external gears. The gear train is configured to perform drive transmission. Specifically, the first registration drive transmission path E1 is composed of the internal gear 61 and the first registration output gear 47, and the second registration drive transmission path E2 is the second registration input gear 44 and the second registration output gear. 48 and.

  On the first registration-side fixed shaft t1 that rotatably supports the registration moving gear 28, the internal gear 46 and the second registration input gear 44 are rotatably supported so as to face each other across the registration moving gear 28. Has been done. On the side surface of the internal gear 46 facing the registration moving gear 28 and the side surface of the second registration input gear 44 facing the registration moving gear 28, drive connecting holes 46a and 44a into which drive connecting claws are fitted are provided. It is formed on the rotation path of the nail.

  The registration drive transmission member 102 rotatably supported by the second registration fixed shaft t2 has a first registration output gear 47, a second registration output gear 48, a first input gear 6a and a second input gear 6b. ..

  Also in the seventh embodiment, similarly to the fifth and sixth embodiments, the rotation direction of the registration drive roller 143a when the drive transmission is performed via the first registration drive transmission path E1 is rotationally driven in the direction opposite to the rotation direction of the motor 1. Can be made. On the other hand, the rotation direction of the registration drive roller 143a when the drive is transmitted through the second registration drive transmission path E2 can be rotationally driven in the same direction as the rotation direction of the motor 1. As a result, when the motor 1 is rotated clockwise when viewed from the roller side and the drive is transmitted through the second registration drive transmission path E2, when the motor 1 is rotated counterclockwise when viewed from the roller side, The rotation direction of the registration drive roller 143a can be the same direction as when the drive is transmitted via the first registration drive transmission path E1.

  Further, by configuring the first registration drive transmission path E1 using the internal gear, the meshing portion with the first registration output gear 47 can be covered with the internal gear 46, and noise generated at the meshing portion can be reduced. It can be shielded by the internal gear 46. Further, the meshing ratio of the external gear and the internal gear can be increased as compared with 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 improved. Therefore, it is preferable to use the drive transmission path using the internal gear as the drive transmission path for plain paper which is frequently used.

[Example 8]
FIG. 12 is a schematic sectional view of a drive device 30G according to the eighth embodiment.
The drive device 30G according to the eighth embodiment is a modified example of the fifth embodiment, in which the motor 1 is attached to the side surface of the side plate 32 on the roller side, and the driving force is transmitted from the motor gear 1a and the fixing movement gear 21 and the registration movement gear. 28 is provided with a drive input member 45 for transmitting a drive force. The drive input member 45 has a tubular shape, and has inner teeth 45a formed on the inner peripheral surface and outer teeth 45b formed on the outer peripheral surface. The drive input member 45 is rotatably supported by a fixed shaft u1 fixed to the bracket 31 and the side plate 32, and the motor gear 1a meshes with the internal teeth 45a. The outer teeth 45b are helical teeth, and the fixing moving gear 21 and the resist moving gear 28 mesh with the outer teeth 45b.

  In the eighth embodiment, by mounting the motor 1 on the roller side surface of the side plate 32, the motor sound can be shielded by the side plate 32 and the bracket 31, and the motor 1 is provided on the surface of the bracket 31 opposite to the roller side. It is possible to prevent the motor noise from leaking to the outside as compared with the case where it is provided. This makes it possible to reduce the noise of the device. Further, by mounting the motor 1 on the roller side surface of the side plate 32, the drive device can be shortened in the axial direction as compared with the case where the motor 1 is provided on the surface of the bracket 31 opposite to the roller side. As a result, the size of the device can be reduced.

  Further, by engaging the motor gear 1a with the internal teeth 45a of the drive input member 45, the engagement rate with the motor gear 1a can be increased, and uneven rotation and noise/vibration can be suppressed.

  Further, the engagement with the motor gear 1a, which is the first-stage engagement, has the highest noise imparting rate. By making one of the internal teeth 45a mesh with the first-stage motor gear 1a having a high noise application rate, noise is reduced as compared with the configuration in which the fixing movement gear 21 and the registration movement gear 28 mesh with the first-stage motor gear 1a. Can be suppressed.

  In the above-described Embodiments 1 to 8, the registration drive transmission mechanism 302 for transmitting the driving force of the motor to the registration drive roller 143a is provided with the speed switching device, but the fixing roller 145 is provided with the motor drive force. A speed switching device may be provided in the fixing drive transmission mechanism 301 for transmission.

  Further, in the above fifth to eighth embodiments, the switching between the first registration drive transmission path E1 and the first registration drive transmission path E2 of the upper speed switching mechanism E is performed by providing the registration moving gear and rotating the motor forward/reversely. However, it is not limited to this. For example, even if drive transmission switching means such as a clutch is provided in the first registration drive transmission path E1 and the second registration drive transmission path E2 and the drive transmission switching means of each registration drive transmission path is controlled to switch the drive transmission path. Good. In the case of such a configuration, the fixing drive transmission mechanism 301 can be a single drive transmission path. Further, although the speed switching mechanism has two stages in the fifth to eighth embodiments, it may have two or more stages. Further, in the first to eighth embodiments, the speed switching mechanism D is a two-system drive transmission path, but three or more system drive transmission paths are provided, and one of them is configured to transmit drive to the registration roller. You may.

What has been described above is an example, and each of the following aspects has a unique effect.
(Aspect 1)
In a speed switching device such as a speed switching mechanism D that switches the rotation speed of an output target rotating body such as the registration drive roller 143a, a plurality of drive transmission paths that rotate the output target rotating body in the same direction and have different speed transmission ratios. (In this embodiment, the input drive transmission member (the first input gear 6a, the second input gear), which includes the first drive transmission path D1 and the second drive transmission path D2, in which the driving force is first input in the drive transmission path. 6b) and an output drive transmission member (first output gear 10, second output gear 11) to which the driving force is finally input are provided in each of the plurality of drive transmission paths, and each of the plurality of drive transmission paths is provided. A drive transmission switching means (first electromagnetic clutch 8 and second electromagnetic clutch 9) capable of switching between a state in which the driving force is transmitted and a state in which the transmission of the driving force is cut off is provided.
In the speed switching device described in Patent Document 1, the input drive transmission member that meshes with the transmission gear that is the output drive transmission member and determines the speed transmission ratio with the transmission gear is common to the plurality of transmission gears. It is a common gear. Therefore, by making the number of teeth of the one gear for shifting different from the number of teeth of the other gear for shifting, the speed of the output target rotor transmitted from one gear for shifting and the speed of the other gear can be changed. The difference from the speed of the output target rotating body which is drive-transmitted from the gear for use becomes the minimum. Therefore, the ratio of the speed of the output target rotating body that is drive-transmitted from one shift gear to the speed of the output target rotating body that is drive-transmitted from the other shift gear can be finely adjusted to, for example, 1% or less. In order to achieve this, it is necessary to set the number of teeth of each speed change gear to 100 or more, and the diameter of each speed change gear becomes large, resulting in an increase in size of the device.
On the other hand, in the aspect 1, the input drive transmission members such as the input gears are individually provided in the plurality of drive transmission paths. Accordingly, not only the output drive transmission member such as the output gear but also the input drive transmission member can be made different from each other, and the speed transmission ratios of the respective drive transmission paths can be made different from each other. Therefore, even if the number of teeth of the output drive transmission member is 100 or less, by adjusting the number of teeth of the input drive transmission member of each drive transmission path, the speed of the output target rotating body by one drive transmission path and the other drive The ratio of the speed of the transmission path to the output target rotating body can be 1% or less. This makes it possible to reduce the size of the device as compared with the device described in Patent Document 1.
Further, in the aspect 1, since the input drive transmission member such as the input gear can be individually provided in the plurality of drive transmission paths, one drive transmission path is the belt drive transmission and the other drive transmission path is the gear transmission. It is also possible to finely adjust the speed transmission ratio to 1% or less by making the drive transmission systems different from each other in each drive transmission path, such as forming a row.
Further, since each of the plurality of drive transmission paths has drive transmission switching means such as an electromagnetic clutch, the rotation speed of the output target rotating body is switched by controlling the drive transmission switching means of each drive transmission path. be able to.

(Aspect 2)
In the first aspect, a gear drive transmission path that performs drive transmission by meshing gears and a belt drive transmission path that performs drive transmission using a belt are provided.
According to this, as described using the second embodiment, the number of teeth of the gear drive transmission path and the gear and the number of teeth of the pulley of the belt drive transmission path are 100 or less, and the gear drive transmission path and the belt drive transmission are set. The speed transmission ratio to the path can be set to 1% or less, the diameters of the gear and the pulley can be prevented from increasing, and the device can be prevented from increasing in size.

(Aspect 3)
In the first aspect, a plurality of gear drive transmission paths that perform drive transmission by meshing gears are provided, and the gear modules of the gear drive transmission paths are different from each other.
According to this, as described in the first embodiment, when the number of teeth of each gear is 100 teeth or less, the speed transmission ratio between one drive transmission path and the other drive transmission path can be set to 1% or less, An increase in the diameter of the gear can be suppressed, and an increase in the size of the device can be suppressed.

(Aspect 4)
In the first aspect, a plurality of gear drive transmission paths that perform drive transmission by meshing gears are provided, and the twist angles of the gear teeth of each gear drive transmission path are different from each other.
Even with such a configuration, as described in the first embodiment, when the number of teeth of each gear is 100 teeth or less, the relative speed ratio between one drive transmission path and the other drive transmission path can be set to 1% or less, An increase in the diameter of the gear can be suppressed, and an increase in the size of the device can be suppressed.

(Aspect 5)
In the first aspect, a plurality of belt drive transmission paths for performing drive transmission using a toothed belt such as a timing belt are provided, and the tooth profiles of the toothed belts of the belt drive transmission paths are different from each other.
According to this, as described in the fourth embodiment, when the number of teeth of each pulley is 100 teeth or less, the relative speed ratio between one drive transmission path and the other drive transmission path can be set to 1% or less, It is possible to suppress an increase in the diameter of the pulley and prevent an increase in the size of the device.

(Aspect 6)
In any one of modes 1 to 5, at least one of the plurality of drive transmission paths has a difference in speed transmission ratio with respect to a specific drive transmission path of 1% or less.
According to this, as described in the first embodiment, it is possible to reduce the difference in the speed transmission ratio to 1% or less by switching the drive transmission path.

(Aspect 7)
In any one of Modes 1 to 6, the plurality of drive transmission paths include two members, an input drive transmission member such as an input gear and an output drive transmission member such as an output gear to which the driving force is transmitted from the input drive transmission member. The plurality of drive transmission paths include an input drive transmission member, an output drive transmission member to which a driving force is transmitted from the input drive transmission member, and a drive transmission provided coaxially with the input drive transmission member or the output drive transmission member. It is composed only of switching means.
According to this, as described in the first embodiment, it is possible to configure a plurality of drive transmission paths between the first shaft such as the third fixed shaft u and the second shaft such as the resist shaft 7. Therefore, it is possible to prevent the speed switching device from increasing in size in the radial direction.

(Aspect 8)
In any one of modes 1 to 7, drive transmission switching means such as an electromagnetic clutch of each drive transmission path is provided coaxially.
According to this, as described in the first embodiment, it is possible to configure a device in which a speed switching device such as an image forming device is mounted so that an operator can access only the shaft to which the drive transmission switching means is attached. The drive transmission switching means of each drive transmission path can be replaced. As a result, it is possible to reduce the size of the device in which the drive device is mounted, as compared with the configuration in which the drive transmission switching means is attached to different rotating shafts.

(Aspect 9)
In the eighth aspect, drive transmission switching means such as an electromagnetic clutch of each drive transmission path is provided coaxially with the output target rotating body such as the registration drive roller 143a.
According to this, as described in the first embodiment, drive transmission switching means such as an electromagnetic clutch can be provided on the shaft that is originally rotatably supported, and when it is provided on a shaft different from the output target rotating body. Compared with this, it is possible to reduce the number of parts such as bearings, and it is possible to suppress an increase in the cost of the device.

(Aspect 10)
In any one of modes 1 to 7, at least one of the plurality of drive transmission switching means is provided on a shaft different from that of the other drive transmission switching means.
According to this, as described in the third embodiment, the device can be downsized in the axial direction as compared with the case where the drive transmission switching means such as the electromagnetic clutch of each drive transmission path is coaxially arranged.

(Aspect 11)
In any one of modes 1 to 10, a plurality of speed switching sections including a plurality of drive transmission paths having different speed transmission ratios are provided.
According to this, as described in the fifth embodiment, by providing the multi-stage speed switching unit, the number of drive transmission paths to be provided can be reduced as compared with the case where the speed switching is performed by one speed switching unit. You can As a result, it is possible to prevent the apparatus from increasing in size.

(Aspect 12)
In Aspect 11, one of the multiple speed switching units includes a drive transmission path of two systems (a first registration drive transmission path E1 and a second registration drive transmission path E2 in this embodiment), and drives the motor 1 or the like. When the source is rotating in the normal direction and when rotating in the reverse direction, it moves in different thrust directions between the drive transmission paths of the two systems to drive one of the drive transmission paths of the two systems or the drive of the other. A thrust speed switching unit such as an upper speed switching mechanism E having a rotatable rotating member such as a registration moving gear 28 that transmits the rotational driving force from the driving source to a transmission path.
According to this, as described in the fifth embodiment, the drive transmission paths of the two systems are switched between the drive transmission paths of the two systems during forward rotation and reverse rotation of the drive source such as the motor 1. This can be done by moving the moving and rotating member in different directions. As a result, the number of parts can be reduced and the cost of the device can be reduced compared to the case where an electromagnetic clutch or a one-way clutch is provided in each drive transmission path and the drive transmission path is switched.

(Aspect 13)
In the twelfth aspect, in the two-system drive transmission path of the thrust speed switching unit such as the upper speed switching mechanism E, the rotation direction of the output drive transmission member such as the registration drive transmission member 102 that outputs the driving force is the drive source such as the motor 1. Drive transmission paths such as a second registration drive transmission path E2 that is the same as the rotation direction of the first registration drive transmission path E2, and the first registration drive transmission path E2 in which the rotation direction of the output drive transmission rolling member is opposite to the rotation direction of the drive source. Drive transmission path.
According to this, as described in the fifth embodiment and the like, the output target rotary body such as the registration drive roller 143a can be rotated in one direction regardless of the rotation direction of the drive source such as the motor 1.

(Aspect 14)
In Mode 13, one of the two system drive transmission paths of the thrust speed switching unit such as the upper speed switching mechanism E is provided with a belt member such as a second registration timing belt 42 rotatably stretched by a plurality of pulleys. Drive transmission is performed by using the other, and the other is configured to perform drive transmission by a gear train in which a plurality of gear members mesh.
According to this, as described in the fifth embodiment, the output target rotating body such as the registration drive roller 143a can be rotated in one direction regardless of the rotation direction of the drive source such as the motor 1.

(Aspect 15)
In the aspect 13, among the drive transmission paths of the two systems of the thrust speed switching unit such as the upper speed switching mechanism E, one has an even number of drive transmission members and the other has an odd number of drive transmission members.
With the above configuration, as described in the sixth embodiment, the output target rotating body such as the registration driving roller 143a can be rotated in one direction regardless of the rotating direction of the drive source such as the motor 1. ..

(Aspect 16)
In Aspect 13, among the drive transmission paths of the two systems of the thrust speed switching unit such as the upper speed switching mechanism E, one is configured to perform drive transmission using an internal gear and the other is an external gear. It is configured to transmit the drive only by itself.
With the above configuration, as described in the seventh embodiment, the output target rotating body such as the registration driving roller 143a can be rotated in one direction regardless of the rotating direction of the drive source such as the motor 1. ..

(Aspect 17)
In a drive device that includes a drive source such as a motor 1 and transmits the drive force of the drive source to a plurality of output target rotating bodies (the fixing roller 145 and the registration drive roller 143a in this embodiment), each output target At least one of the plurality of drive transmission mechanisms provided corresponding to the rotating body is provided with speed switching means, and the speed switching device according to any one of aspects 1 to 16 is used as the speed switching means.
According to this, as described in the embodiment, it is possible to rotate a certain output target rotary body at a constant speed by the driving force of the drive source while switching the rotation speed of another output target rotary body.

(Aspect 18)
In mode 17, when the speed of the drive source such as the motor 1 is switched, the speed is switched by the speed switching means.
According to this, as described in the embodiment, it is possible to rotate a certain output target rotary body at a constant speed by the driving force of the drive source while switching the rotation speed of another output target rotary body.

(Aspect 19)
In the seventeenth or eighteenth aspect, an internal gear is provided which meshes with an output gear member such as a motor gear 1a provided on the output shaft of a drive source such as the motor 1.
According to this, as described in the eighth embodiment, the meshing ratio with the output gear member can be increased, and the occurrence of uneven rotation and noise/vibration can be suppressed.

(Aspect 20)
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, the driving unit according to any one of Aspects 17 to 19 is used as the driving unit.
According to this, it is possible to drive the output target rotating body such as the registration driving roller 143a that rotates at a constant speed and the output target rotating body such as the fixing roller 145 that switches the speed depending on the paper thickness and the like with one drive source. .. As a result, the motor noise is reduced as compared with a device in which a drive source that drives an output target rotating body that rotates at a constant speed and a drive source that drives an output target rotating body that switches the speed depending on the paper thickness etc. are provided separately. It is possible to reduce the noise of the device. Further, the number of motors can be reduced, and the cost of the device can be reduced and the size of the device can be reduced.

(Aspect 21)
In the twentieth aspect, the rotation speed of at least one of the plurality of output target rotating bodies is switched according to the type of the recording medium on which the image is formed.
As a result, an image can be formed on the recording medium under the optimum image forming conditions according to the type of recording medium, and a good image can be formed on the recording medium.

DESCRIPTION OF SYMBOLS 1 motor 1a motor gear 2 fixing idler gear 2a first external tooth gear 2b second external tooth gear 3 fixing gear 4 registration idler gear 5 registration input gear 6a first input gear 6b second input gear 7 registration shaft 8 first electromagnetic clutch 9th 2 electromagnetic clutch 9a drive claw 9b armature 9c rotor part 9d electromagnetic coil part 9e shaft fixing part 9f drive connecting member 10 first output gear 11 second output gear 11a drive connecting hole 12a first resist gear 12b second resist gear 13 first idler gear 15 2nd input pulley 16 2nd timing belt 17 2nd output pulley 18 1st input pulley 19 1st output pulley 20 1st timing belt 21 fixing movement gears 21a and 21b drive connection nail 22 fixing input pulley 22a drive connection hole 23 fixing timing Belt 24 Fixing output pulley 25 Fixing input gear 25a Drive connecting hole 26 Fixing output gear 28 Registration moving gears 28a, 28b Drive connecting pawl 30 Drive device 31 Bracket 32 Side plate 41 First resist input pulley 41a Drive connecting hole 42 First resist timing belt 43 1st resist output pulley 44 2nd resist input gear 44a Drive connecting hole 45 Drive input member 45a Internal tooth 45b External tooth 46 Internal tooth gear 47 1st resist output gear 48 2nd resist output gear 51 1st resist input gear 52 One resist idler gear 53 First resist output gear 61 Internal gear 70 Secondary rotation drive device 71 Secondary rotation motor 101 Fixing drive transmission output member 102 Registration drive transmission member 140 Fixing device 143 Registration roller pair 143a Registration drive roller 143b Registration driven Roller 145 Fixing roller 145b Fixing shaft 178 Secondary transfer roller 179 Intermediate transfer belt 301 Fixing drive transmission mechanism 302 Registration drive transmission mechanism D Speed switching mechanism D1 First drive transmission path D2 Second drive transmission path E Upper speed switching mechanism E1 First Registration drive transmission path E2 Second registration drive transmission path P Recording paper R1 First fixing drive transmission path R2 Second fixing drive transmission path S First fixed shaft S1 First fixing side fixed shaft S2 Second fixing fixed shaft t Two fixed axes t1 First resist side fixed axis t2 Second resist fixed axis u Third fixed axis U1 Fixed axis

JP, 2005-69061, A

Claims (18)

In the speed switching device that switches the rotation speed of the output target rotating body ,
Has a plurality of speed switching unit velocity transmission ratio comprises a plurality of different drive transmission paths with each other,
At least one of the plurality of speed switching units is a first speed switching unit that rotates the output target rotating body in the same direction, and has a plurality of drive transmission paths having different speed transmission ratios,
The first speed switching unit has an input drive transmission member to which a driving force is first input in the drive transmission path and an output drive transmission member to which a driving force is finally input are provided in each of the plurality of drive transmission paths, And, a drive transmission switching means capable of switching between a state in which the driving force is transmitted and a state in which the transmission of the driving force is interrupted is provided to each of the plurality of drive transmission paths ,
The speed switching unit is provided in a plurality of stages,
One of the plurality of stages of the speed switching unit is provided with a drive transmission path of two systems, and the thrust directions are different between the drive transmission paths of the two systems during forward rotation and reverse rotation of the drive source. A thrust speed switching unit having a rotatable moving rotary member that moves and transmits the rotational driving force from the drive source to one of the two drive transmission paths or the other drive transmission path. And
The two-system flow drive transmission paths of the thrust speed switching unit include a drive transmission path in which the rotation direction of the output drive transmission member is the same as the rotation direction of the drive source, and a rotation direction of the output drive transmission member. A speed switching device having a drive transmission path that is opposite to a rotation direction of a drive source . The speed switching device according to claim 1,
The speed switching device is characterized in that the first speed switching unit includes a gear drive transmission path for transmitting drive by meshing gears and a belt drive transmission path for transmitting drive using a belt. The speed switching device according to claim 1,
The speed switching device according to claim 1, wherein the first speed switching unit includes a plurality of gear drive transmission paths that perform drive transmission by meshing gears, and the modules of the gears of the gear drive transmission paths are different from each other. The speed switching device according to claim 1,
The speed switching device according to claim 1, wherein the first speed switching unit includes a plurality of gear drive transmission paths that perform drive transmission by meshing gears, and twist angles of gear teeth of the gear drive transmission paths are different from each other. The speed switching device according to claim 1,
The first speed switching unit includes a plurality of belt drive transmission paths that perform drive transmission using a toothed belt,
A speed switching device characterized in that the toothed belts of each belt drive transmission path have different tooth profiles. The speed switching device according to any one of claims 1 to 5,
The first speed switching unit is characterized in that at least one of the plurality of drive transmission paths has a difference in speed transmission ratio with respect to a specific drive transmission path of 1% or less. The speed switching device according to any one of claims 1 to 6,
The first speed change unit, a plurality of drive transmission paths, the input drive transmission member, the speed switching device which is characterized by being configured only by the output drive transmission member and the drive transmission switching unit. The speed switching device according to any one of claims 1 to 7,
The speed switching device, wherein the first speed switching unit is provided coaxially with drive transmission switching means for each drive transmission path. The speed switching device according to claim 8,
A speed switching device, wherein an output drive transmission member of each drive transmission path and drive transmission switching means of each drive transmission path are provided coaxially with an output target rotating body. The speed switching device according to any one of claims 1 to 7,
The speed switching device, wherein the first speed switching unit is provided with at least one of the plurality of drive transmission switching units on a different axis from other drive transmission switching units. In speed switching device according to any 請 Motomeko 1 to 10,
Of the two systems of drive transmission paths of the thrust speed switching unit, one is configured to perform drive transmission using a belt member rotatably stretched by a plurality of pulleys, and the other is configured to have a plurality of gears. A speed switching device characterized in that drive transmission is performed by a gear train in which members are engaged with each other. The speed switching device according to any one of claims 1 to 11 ,
A speed switching device, wherein one of the two-system drive transmission paths of the thrust speed switching unit has an even number of drive transmission members, and the other has an odd number of drive transmission members. The speed switching device according to any one of claims 1 to 12 ,
Of the two systems of drive transmission paths of the thrust speed switching unit, one is configured to perform drive transmission using an internal gear, and the other is configured to perform drive transmission only by an external gear. A speed switching device characterized by the above. In a drive device that includes a drive source and transmits the drive force of the drive source to a plurality of output target rotating bodies,
At least one of the plurality of drive transmission mechanisms provided corresponding to each output target rotating body includes a speed switching unit,
Examples speed changing unit, drive device characterized by using the speed change device according to one of claims 1 to 13 had shifted. The drive device according to claim 14 ,
When the speed of the drive source is switched, the speed is switched by the speed switching means. The drive device according to claim 14 or 15 ,
A drive device comprising an internal gear that meshes with an output gear member provided on an output shaft of the drive source. An image forming means for forming an image,
In an image forming apparatus including a driving unit that drives a plurality of output rotating bodies,
An image forming apparatus comprising the driving device according to claim 14 as the driving unit. The image forming apparatus according to claim 17 ,
An image forming apparatus characterized in that at least one of a plurality of output target rotating bodies is switched in rotation speed in accordance with the type of a recording medium on which an image is formed.

Images