JP6041194B2 - Drive transmission mechanism and image forming apparatus - Google Patents

Description

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

  An image provided with a drive transmission mechanism for transmitting a rotational driving force of a drive motor as a drive source to a photoreceptor as a latent image carrier for carrying a latent image and a rotating body arranged around the photoreceptor and rotating. Forming devices are known.

  For example, Patent Document 1 discloses a cleaning brush roller and a transfer residual toner which are rotating bodies that rotate while abutting on the surface of a photoconductor through a flange gear provided on the photoconductor to remove transfer residual toner on the surface of the photoconductor. An image forming apparatus including a drive transmission mechanism that transmits a rotational driving force of a drive motor to a lubricant application brush roller that is a rotating body that rotates while abutting on the surface of the photoreceptor after removal and applies lubricant to the surface of the photoreceptor. Have been described.

FIG. 10 is a perspective view showing a drive transmission mechanism that transmits a rotational driving force to the cleaning brush roller 162 and the lubricant application brush roller 163 in the image forming apparatus described in Patent Document 1.
As shown in the figure, the photosensitive member flange gear 180a meshes with the lubricant application brush roller drive gear 163b, and the lubricant application brush roller drive gear 163b and the cleaning brush roller drive gear 162b are connected via two idler gears 167. I'm engaged. A driving force is transmitted from a driving motor (not shown) from the photosensitive member shaft, and the photosensitive member 180 is rotationally driven. Further, the photosensitive member flange gear 180a rotates together with the photosensitive member 180, the driving force of a driving motor (not shown) is transmitted to the lubricant application brush roller drive gear 163b, and the lubricant application brush roller 163 is rotated. Further, the driving force of a driving motor (not shown) is transmitted to the cleaning brush roller driving gear 162b via the two idler gears 167, and the cleaning brush roller 162 is rotated.

  Further, Patent Document 2 has a photosensitive member gear that meshes with a driving gear of a driving motor and transmits a driving force of the driving motor to the photosensitive member, and an input gear that meshes with the driving gear of the driving motor. An image forming apparatus including a drive transmission mechanism including a developing gear train that transmits a driving force of a driving motor to a developing roller, which is a rotating body, via the gears of the image forming apparatus is described.

  However, in the drive transmission mechanism described in Patent Document 1, the lubricant application brush roller drive gear 163b fixed to the rotating shaft 163a of the lubricant application brush roller 163 is directly meshed with the photoreceptor flange gear 180a. For this reason, when a rotational load fluctuation occurs in the application brush roller 163, the rotational load fluctuation is directly transmitted from the lubricant application brush roller drive gear 163b to the photoconductor flange 180a, and the speed fluctuation occurs in the photoconductor 180. As a result, an abnormal image such as banding may occur.

  On the other hand, in the configuration described in Patent Document 2, when a load fluctuation occurs in the developing roller as a rotating body, the load fluctuation of the developing roller is transmitted to the photosensitive member gear via a plurality of gears and a driving gear of the developing gear train. As a result, the speed of the photoreceptor is affected. When momentary load fluctuations occur on the developing roller and the developing roller speed decreases, the teeth of each gear of the developing gear train elastically deform at the meshing position. The effect is attenuated. Further, high torque is applied to the driving gear that directly receives the driving force of the driving motor. Therefore, the driving gear rotates at a constant speed against the load fluctuation of the developing roller. As a result, the photoconductor gear can be rotated at a predetermined speed, which is affected by fluctuations in the rotational load of the developing roller.

  However, in the drive transmission mechanism described in Patent Document 2, when the drive motor is disposed on the opposite side of the developing roller with the photosensitive member interposed therebetween due to the layout of the apparatus, the rotational driving force is applied to the rotating body such as the developing roller. The number of gears for transmission increases. If the number of gears increases, gear tooth shape accuracy and backlash backlash accumulates, causing a problem that the start of rotation of the rotating body is delayed relative to the start of rotation of the photosensitive member. As in the image forming apparatus described in Patent Document 2, if the rotating body is a developing roller and is not in contact with the photoconductor, the rotation of the rotating body is slightly started relative to the start of rotation of the photoconductor. Even if it is delayed, there is no particular problem. However, in the case of a rotating body such as a lubricant application brush roller that rotates while being in contact with the photoconductor, the surface of the photoconductor and the rotating body rub against each other if the start of rotation is delayed with respect to the start of rotation of the photoconductor. This may damage the surface of the photoreceptor. For this reason, the drive transmission mechanism described in Patent Document 2 cannot be employed for the rotational drive of a rotating body that comes into contact with a photosensitive member such as a lubricant application brush roller.

  The present invention has been made in view of the above problems, and an object of the present invention is to suppress the load fluctuation of the rotating body from being transmitted to the latent image carrier and to rotate with respect to the start of rotation of the latent image carrier. It is an object of the present invention to provide a drive transmission mechanism and an image forming apparatus that can suppress a delay in the start of the body.

In order to achieve the above object, the invention according to claim 1 transmits the rotational driving force of the drive source to the latent image carrier that carries the latent image and the rotating body that rotates in contact with the latent image carrier. A latent image carrier gear which is provided coaxially with the latent image carrier, meshes with a driving gear of a drive source, and transmits a rotational driving force to the latent image carrier, and the latent image carrier. A first gear provided so as to rotate integrally with the latent image carrier gear on the same axis as the gear, and a plurality of gears meshed with the first gear, and the rotation source is connected with the drive source. The driving force is transmitted, and the diameter of the first gear is larger than the diameter of the gear meshing with the first gear and larger than the outer diameter of the latent image carrier. It is what.

  According to the present invention, since the driving force of the driving source is transmitted to the rotating body through the meshing of the plurality of gears from the first gear, when a load change occurs in the rotating body, the plurality of gears Speed reduction due to load fluctuations of the rotating body can be attenuated by elastic deformation of the teeth. As a result, compared to the configuration in which the first gear described in Patent Document 1 is directly provided on the shaft of the rotating body and meshes with the gear, the influence of the load variation of the rotating body transmitted from the first gear to the latent image carrier is affected. Can be suppressed.

Further, according to the present invention, when the drive source is disposed on the opposite side of the rotating body with the latent image carrier interposed therebetween, the latent image carrier of the rotating body is compared with the drive transmission mechanism described in Patent Document 2. The delay of the rotation start with respect to can be suppressed. In the drive transmission mechanism described in Patent Document 2, an input gear different from the latent image carrier gear is meshed with a driving gear, and drive transmission is transmitted from the input gear to a rotating body through a plurality of gears. The drive transmission path from the driving gear to the latent image carrier and the drive transmission path from the driving gear to the rotating body are completely separated. Therefore, in the configuration described in Patent Document 2, all the gears on the drive transmission path from the driving gear to the rotating body are the factors that cause a delay in the rotation start of the rotating body relative to the latent image carrier. In the case where the drive source is disposed on the opposite side of the rotating body with the latent image carrier interposed therebetween, the drive transmission mechanism described in Patent Document 2 has the rotating body on the drive source side with the shaft of the latent image carrier interposed therebetween. A gear that causes a delay in starting rotation with respect to the latent image carrier is arranged.
On the other hand, according to the present invention, a driving force is transmitted from a first gear provided coaxially with the latent image carrier gear and rotating integrally with the latent image carrier gear to the rotating body via a plurality of gears. ing. As a result, from the driving gear to the first gear, the same drive transmission path as the drive transmission path for transmitting drive to the latent image carrier is taken, and the drive transmission path from the first gear to the rotating body branches. Therefore, the gear that causes a delay in the start of rotation of the rotator relative to the latent image carrier is a gear subsequent to the first gear. Therefore, even when the drive source is disposed on the opposite side of the rotating body with the photoconductor interposed therebetween, the gear that causes a delay in the start of rotation of the rotating body with respect to the latent image carrier is placed with the axis of the latent image carrier interposed therebetween. Only the gear arranged on the rotating body side can be used. Thus, as described above, when the drive source is disposed on the opposite side of the rotating body with the latent image carrier interposed therebetween, the latent image of the rotating body is also disposed on the drive source side with the axis of the latent image carrier interposed therebetween. Compared to the configuration described in Patent Document 2 in which a gear that causes a delay in starting rotation with respect to the carrier is required, the number of gears that cause a delay in starting rotation of the rotor relative to the latent image carrier is reduced. I can do it. Thereby, the rotation start delay of a rotating body can be suppressed with respect to the rotation start of a latent image carrier as compared with the aspect described in Patent Document 2. As a result, rubbing between the latent image carrier and the rotating body can be suppressed, and scratches on the surface of the latent image carrier can be suppressed.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment. The schematic sectional drawing which expands and shows one of four image forming units. The perspective view which shows the state which open | released the side cover provided in the main body case. The perspective view which shows a 1st drive transmission mechanism. The perspective view which shows the structure by the side of the apparatus main body of a 1st drive transmission mechanism. The perspective view which shows the structure by the side of the process cartridge of a 1st drive transmission mechanism. FIG. 4 is a view showing a back side surface of the process cartridge with the developing device removed. FIG. 3 is a front view illustrating a configuration of the developing drive transmission mechanism on the apparatus main body side and a configuration of the first drive transmission mechanism on the apparatus main body side. FIG. 3 is a plan view showing the configuration of the developing drive transmission mechanism on the apparatus main body side and the configuration of the first drive transmission mechanism on the apparatus main body side together with the process cartridge from which the developing device is removed. The figure which shows the conventional drive transmission mechanism.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the present embodiment.
As shown in FIG. 1, in a main body case 2 of the image forming apparatus 1, a printer engine 3, an optical writing device 4 that emits a light beam, and a recording medium storage unit that stores a recording medium P that is a transfer target. A paper feed cassette 5, a fixing device 6 for fixing the recording medium P on which the toner image is transferred, a waste toner collecting container 7 for collecting waste toner generated after the toner image is transferred, and the like are provided.

  The printer engine 3 forms a toner image and transfers the formed toner image to the recording medium P. The printer engine 3 supports yellow (Y), magenta (M), cyan (C), and black (K) toners. The four image forming units 23Y, 23C, 23M, and 23K are arranged side by side.

FIG. 2 is an enlarged schematic sectional view showing one of the four image forming units 23 described above. The basic configuration of the image forming unit 23 shown in FIG. 2 is the same as the known image forming unit 23, and the image forming unit 23 can be attached to and detached from the main body case 2 as a process cartridge. .
Since all the image forming units of the four image forming units 23 (Y, M, C, K) have the same configuration, the display of Y, M, C, and K indicating the distinction of colors is omitted in FIG. To do.

  As shown in FIG. 2, the image forming unit 23 includes a unit frame 100 integrally with a photoconductor 8 and a charging roller 9, a developing device 10, a photoconductor cleaning device 11 and the like as process means as a process cartridge. The main body case 2 is detachable. Since the photosensitive member 8, the developing device 10, and the photosensitive member cleaning device 11 are unitized as a process cartridge, replacement and maintenance work can be facilitated, and the positional accuracy between the members can be maintained with high accuracy. And the quality of the formed image can be improved. In this embodiment, the image forming unit 23 itself as a process cartridge is replaced. However, there are various process cartridge configurations. For example, the charging roller 9, the developing device 10, and the photosensitive member. A configuration in which at least one of the cleaning devices 11 and the photosensitive member 8 are housed in a case and unitized may be employed. Alternatively, the image forming unit 23 may be removed from the main body case 2 and replaced with a new one in units such as the photoconductor 8, the charging roller 9, the developing device 10, and the photoconductor cleaning device 11.

Next, the image forming process will be described. The photoconductor 8 is formed in a cylindrical shape and connected to a drive motor (not shown), and rotates around the center line by the drive force from the drive motor. A photosensitive layer on which an electrostatic latent image is formed is provided on the outer peripheral surface of the photoreceptor 8. The charging roller 9 is disposed on the outer peripheral surface of the photoconductor 8. When a voltage is applied to the charging roller 9 from a power supply unit (not shown), the outer peripheral surface of the photoconductor 8 is uniformly charged.

  The optical writing device 4 emits a light beam corresponding to the image data, and exposes the outer peripheral surface of the uniformly charged photoreceptor 8. By this exposure, an electrostatic latent image corresponding to the image data is formed on the outer peripheral surface of the photoreceptor 8. The developing device 10 supplies toner to the photoreceptor 8. The supplied toner adheres to the electrostatic latent image formed on the outer peripheral surface of the photoconductor 8, and the electrostatic latent image on the outer peripheral surface of the photoconductor 8 is visualized as a toner image.

  The intermediate transfer belt 13 is a loop-shaped belt formed of a resin film or rubber as a base, and is wound around a drive roller 16, an entrance roller 17, and a tension roller 18, and is driven by a drive motor (not shown). When the connected driving roller 16 is driven to rotate, it rotates in the direction of arrow A. The entrance roller 17 and the tension roller 18 are driven to rotate by the frictional force with the intermediate transfer belt 13 as the intermediate transfer belt 13 rotates in the direction of arrow A.

  The primary transfer roller 12 is disposed on the inner peripheral surface side (inside the loop) of the intermediate transfer belt 13, and a toner image on each photoconductor 8 is formed by applying a transfer voltage to the primary transfer roller 12. The image is transferred onto the intermediate transfer belt 13. The toner images formed on the respective photoreceptors 8 are sequentially transferred and superimposed on the intermediate transfer belt 13, and a color toner image is formed on the intermediate transfer belt 13.

  The photoconductor cleaning device 11 cleans the outer peripheral surface of the photoconductor 8 after the toner image is transferred to the intermediate transfer belt 13. By this cleaning, toner, paper dust, and the like remaining on the outer peripheral surface of the photoreceptor 8 after the toner image is transferred to the intermediate transfer belt 13 are collected as waste toner.

  The color toner image formed on the intermediate transfer belt 13 is transferred to the secondary transfer roller 14 at the timing when the recording medium P is sent to the transfer position where the intermediate transfer belt 13 and the secondary transfer roller 14 are in contact with each other. When the working voltage is applied, it is transferred to the recording medium P. The recording medium P is fed from the sheet feeding cassette 5 and is conveyed by the conveyance roller 19 and the registration roller 20, and is transferred to the fixing device 6 after the toner image is transferred. The recording medium P to which the toner image has been transferred is subjected to fixing processing by applying heat and pressure in the fixing device 6, and the toner image melted by this fixing processing is fixed to the recording medium P. The recording medium P for which the fixing process has been completed is discharged onto a discharge tray 21 formed on the upper surface of the main body case 2.

  The intermediate transfer cleaning device 15 cleans the outer peripheral surface of the intermediate transfer belt 13 after the color toner image is transferred to the recording medium P. By this cleaning, toner, paper dust, and the like remaining on the outer peripheral surface of the intermediate transfer belt 13 after the toner image is transferred are collected as waste toner.

  The waste toner collection container 7 is a portion in which waste toner collected by the photoconductor cleaning device 11 and the intermediate transfer cleaning device 15 is input from the cleaning devices 11 and 15 and the input waste toner is stored. The waste toner collection container 7 is detachably attached to the main body case 2, and is removed from the main body case 2 when the waste toner in the waste toner collection container 7 is almost full, and an empty waste toner collection container. 7 is attached.

FIG. 3 is a perspective view showing a state in which the side cover 24 provided in the main body case 2 is opened.
By opening the side cover 24, the printer engine 3 and the waste toner collection container 7 appear, and the process cartridge 23, the intermediate transfer belt 13 and the waste toner collection container 7 can be replaced and other maintenance can be performed. The intermediate transfer belt 13, the rollers 16, 17, 18 and the intermediate transfer cleaning device 15 are housed in a belt case 13a and unitized.

Next, the common configuration of each image forming unit 23 (K, M, C, Y) will be described in more detail with reference to FIG.
Each image forming unit 23 includes a photoconductor 8 that is a latent image carrier and a charging roller 9 that is a charging unit that charges the surface of the photoconductor 8. The image forming unit 23 applies toner to the latent image formed on the photoconductor 8 by irradiating the surface of the photoconductor 8 charged by the charging roller 9 with the laser light L from the optical writing device 4. A developing device 10 is provided as developing means for supplying and developing. Further, the image forming unit 23 includes a photoconductor cleaning device 11 that removes residual toner remaining on the surface of the photoconductor 8 after the toner image formed by the developing device 10 is transferred to the intermediate transfer belt 13.
The photoconductor cleaning device 11 includes a cleaning blade 61, a coating brush roller 62 that is a rotating body, and a leveling blade 66 in order from the upstream side of the surface movement direction of the photoconductor 8. In the photoconductor cleaning device 11, the toner is removed by the cleaning blade 61. The application brush roller 62 and the configuration in which the solid lubricant 64 held by the bracket is pressed against the application brush roller 62 by the lubricant pressurizing spring 68 constitute a lubricant supply mechanism.

  The cleaning blade 61 is fixed to a holder (not shown) that is rotatably held, and is supported so as to contact the surface of the photoconductor 8 in the counter direction with respect to the surface movement direction of the photoconductor 8. Further, the cleaning blade 61 comes into contact with the photoconductor 8 by a pressurizing spring (not shown) to remove toner.

  The residual transfer toner remaining on the surface of the photoreceptor 8 after the toner image is transferred to the intermediate transfer belt 13 at the primary transfer portion is removed by the cleaning blade 61. The toner removed by the cleaning blade 61 is transported out of the photoconductor cleaning device 11 by the transport screw 67.

  The surface of the photosensitive member 8 from which the toner has been removed by the cleaning blade 61 is coated with a lubricant by an application brush roller 62 that is a rotating member that contacts the surface of the photosensitive member. The lubricant used here is a mixture of zinc stearate, boron nitride, and alumina, and solidified by compression molding to obtain a solid lubricant 64. In applying the lubricant, the solid lubricant 64 held by the bracket is pressed against the application brush roller 62 by the lubricant pressurizing spring 68, and the application brush roller 62 scrapes the solid lubricant 64 on the surface of the photoreceptor 8. It is applied to.

  The application brush roller 62 rotates in the counter direction with respect to the surface movement direction of the photoconductor 8. The lubricant scraped from the solid lubricant 64 by the application brush roller 62 and adhered to the surface of the photoconductor 8 in powder form comes into contact with the surface of the photoconductor 8 in the counter direction with respect to the surface movement direction of the photoconductor 8. It is leveled on the photoconductor 8 by the fixed pressure type leveling blade 66 supported in this manner.

  In each image forming unit 23, the transfer residual toner on the photoconductor 8 is removed in this way, and a lubricant is applied to prepare for the next image formation starting from uniform charging by the charging roller 9.

  The application brush roller 62 and the conveying screw 67 are connected to a photoconductor drive motor M1 that is a drive source of the photoconductor 8, and are driven to rotate as the photoconductor drive motor M1 rotates. Further, the developing roller 10a of the developing device 10 and the two agitating / conveying screws 10b and 10c are connected to the developing drive motor M2, and are driven to rotate as the developing drive motor M2 rotates.

  FIG. 4 is a perspective view showing a first drive transmission mechanism 120 that transmits the driving force of the photosensitive member driving motor M1 to the photosensitive member 8, the conveying screw 67, and the application brush roller 62, and FIG. 5 shows the first driving transmission. FIG. 6 is a perspective view showing a configuration of the mechanism 120 on the apparatus main body side, FIG. 6 is a perspective view showing a configuration of the first drive transmission mechanism 120 on the process cartridge side, and FIG. 7 is a process cartridge with the developing device 10 removed. FIG.

As shown in FIGS. 4 and 5, a drive transmission member 122 and a cleaning female side joint member 123 are provided on the apparatus main body side of the first drive transmission mechanism 120.
The drive transmission member 122 includes a photoconductor gear 122a as a latent image carrier gear that meshes with the driving gear 121 of the photoconductor drive motor M1, and a first gear for transmitting drive to the conveying screw 67 and the application brush roller 62. Part 122b and a photoreceptor involute spline male part 122c for transmitting drive to the photoreceptor 8. These are integrally formed of the same material (for example, resin material). The photosensitive member gear 122a, the first gear 122b, and the photosensitive member involute spline male portion 122c are integrally formed, so that the eccentricity of the photosensitive member gear and the first gear with respect to the rotation shaft can be reduced. The eccentricity of attachment of the portion 122c to the rotating shaft does not occur. As a result, it is possible to eliminate the speed fluctuation of the photosensitive member 8 due to the mounting eccentricity between the photosensitive member gear 122a and the photosensitive member involute spline male portion 122c. Further, it is possible to eliminate fluctuations in the speed of the application brush roller 62 due to the eccentricity of attachment between the photoconductor gear 122a and the first gear 122b.

  The diameter of the photoconductor gear portion 122 a and the diameter of the first gear portion 122 b are larger than the diameter of the photoconductor 8. By increasing the diameter of the photoconductor gear portion 122a, the speed can be reduced by one step, and the pitch error on the surface of the photoconductor corresponding to the one-tooth engagement of the gear is reduced, so that the print density in the sub-scanning direction is reduced. The influence of unevenness (banding) can be reduced. Further, by reducing the number of speed reduction steps from the driving gear 121 to the photosensitive member 8 to reduce the number of parts and the cost, it is possible to reduce the cause of transmission errors due to meshing errors and eccentricity. The reduction ratio is determined based on the speed region where high efficiency and high rotation accuracy can be obtained from the relationship between the target speed of the photoconductor 8 and the motor characteristics. The drive transmission member 122 is made of a resin material having a relatively small friction coefficient, such as polyacetal resin.

  A second shaft portion 122e (see FIG. 9) is provided at the center of the back surface (the surface on the photoconductor drive motor M1 side) of the photoconductor gear portion 122a of the drive transmission member 122, and this second shaft portion 122e. The first shaft portion 122d and the first shaft portion 122d are rotatably attached to the two back side plates (not shown) by a bearing.

  The driving gear 121 is formed by forming gear teeth directly on the motor output shaft of the photosensitive member driving motor M1 by cutting.

  The cleaning female joint member 123 includes a second gear portion 123a that meshes with the first gear portion 122b, and a cleaning involute spline female portion 123b. The second gear portion 123a and the cleaning involute spline female portion 123b are integrally formed of the same material (for example, a resin material). By integrally molding them, the eccentricity of the attachment of the second gear 123a to the rotating shaft and the eccentricity of the cleaning involute spline female portion 123b to the rotating shaft do not occur. The diameter of the second gear part 123a is shorter than the diameter of the first gear part 122b.

  As shown in FIGS. 6 and 7, a photoreceptor involute spline female portion 128 that meshes with the photoreceptor involute spline male portion 122 c of the drive transmission member 122 is provided on the rear flange 8 a of the photoreceptor 8. The photoreceptor involute spline male part 122c and the photoreceptor involute spline female part 128 constitute an involute spline joint for photoreceptor.

  As shown in FIGS. 6 and 7, a cleaning male joint member 124 and an idler gear 126 are rotatably attached to the back side plate 100a of the process cartridge. The cleaning male side joint member 124 includes a cleaning involute spline male portion 124a that meshes with the cleaning involute spline female portion 123b, and a joint gear portion 124b. The cleaning involute spline male part 124a and the cleaning involute spline female part 123b constitute a cleaning involute spline joint. A brush gear 125 fixed to the shaft of the application brush roller 62 and an idler gear 126 are engaged with the joint gear portion 124b. The idler gear 126 meshes with a conveyance gear 127 fixed to the shaft of the conveyance screw 67.

  When the process cartridge 23 is inserted, the photosensitive member involute spline female portion 128 moves in the direction of arrow X shown in FIGS. 5 and 6, and the photosensitive member involute spline male portion 122 c moves to the photosensitive member involute spline female portion 128. The photoconductor involute spline male part 122c is inserted and meshed with the internal teeth of the photoconductor involute spline female part 128. As a result, the driving force of the photosensitive member driving motor M1 is transmitted to the photosensitive member 8 via the photosensitive member gear portion 122a and the photosensitive member involute spline joint, and the photosensitive member 8 is rotationally driven.

  Also, the cleaning involute spline male part 124a moves in the direction of the arrow Y shown in FIGS. 5 and 6, and the cleaning involute spline male part 124a is inserted into the cleaning involute spline female part 123b, and the cleaning involute spline male part 124a. However, it meshes with the internal teeth of the cleaning involute spline female portion 123b. As a result, the driving force of the photosensitive member driving motor M1 is applied to the application brush roller via the photosensitive member gear portion 122a, the first gear portion 122b, the second gear portion 123a, the cleaning involute spline joint, the joint gear 124b, and the brush gear 125. The application brush roller 62 is rotationally driven. Further, the driving force of the photosensitive member driving motor is transmitted from the joint gear 124b to the conveying screw 67 through the idler gear 126 and the conveying gear 127, and the conveying screw 67 is rotationally driven.

  In the present embodiment, drive transmission of the photosensitive member 8 is performed only by meshing of gears. When driving is transmitted to the photoconductor 8 using a belt or the like for driving transmission, when a load fluctuation occurs in the photoconductor 8, slippage occurs between the belt and the roller on which the belt is stretched, and the photoconductor. There is a problem that the drive transmission to 8 stops for a moment and the speed fluctuation of the photosensitive member 8 increases. On the other hand, as in the present embodiment, when drive transmission to the photoconductor 8 is performed only by meshing of the gear, when a load change occurs in the photoconductor 8, the teeth are elastically deformed. Although some speed fluctuation occurs, it can be suppressed as compared with the belt drive. In addition, by transmitting the drive to the application brush roller 62 only by meshing the gear, when the load fluctuation occurs in the application brush roller 62, the speed of the application brush roller 62 is higher than when the drive is transmitted via the belt. Variations can be suppressed, rubbing between the application brush roller 62 and the photoconductor 8 can be suppressed, and damage to the surface of the photoconductor 8 can be suppressed.

  In the present embodiment, the drive is transmitted from the first gear portion 122b to the application brush roller 62 through meshing of a plurality of gears. More specifically, the driving force is transmitted to the application brush roller 62 through meshing between the first gear part 122b and the second gear part 123a and meshing between the joint gear part 124b and the brush gear 163. When a rotational load fluctuation occurs in the application brush roller 62, the load fluctuation of the application brush roller 62 is attenuated by, for example, elastic deformation of the gear teeth. In other words, even if a load fluctuation occurs in the application brush roller 62, teeth such as the joint gear portion 124b, the brush gear 125, and the second gear portion 123a are elastically deformed to suppress the speed fluctuation on the upstream side in the drive transmission direction. It can be done. As a result, as described in Patent Document 1, it is possible to suppress the speed fluctuation of the photoconductor 8 due to the load fluctuation of the application brush roller 62 as compared with the configuration in which the brush gear is meshed with the photoconductor flange gear.

  In this embodiment, the load fluctuation of the application brush roller 62 is caused by the meshing between the joint gear portion 124b and the brush gear 1125, the meshing between the cleaning involute spline joint, the second gear portion 123a and the first gear portion 122b, and the photoconductor. 8 rotations are affected. Since there is backlash (play) at the meshing position of each gear portion, the teeth may not be in contact with each other when driving is stopped. Therefore, when driving is started, the rotation start of the application brush roller 62 may be delayed with respect to the rotation start of the photosensitive member 8 due to the backlash of each gear. However, in this embodiment, the meshing position of the gear from the first gear part 122b to the application brush roller 62 is the meshing of the first gear part 122b and the second gear part 123a, the joint gear part 124b and the brush gear 125. It is restrained to two places of meshing. Therefore, the synchronization deviation of the rotation start of the application brush roller 62 with respect to the photoconductor 8 can be minimized, and the friction between the application brush roller 62 and the photoconductor 8 is suppressed.

  Further, as described in Patent Document 2, a gear that meshes with the driving gear 121 is provided separately from the photoconductor gear 122a, and the driving force is transmitted from the gear to the application brush roller 62 via a plurality of gears. In this case, the load fluctuation of the coating brush roller 62 is transmitted to the photosensitive member 8 via the driving gear 121 that directly receives the driving force of the photosensitive member driving motor M1, and therefore the driving brush 121 is used by the driving gear 121. The influence of the load fluctuation 62 can be almost eliminated, and the speed fluctuation of the photoconductor 8 can be satisfactorily suppressed. However, in such a configuration, when the photosensitive member driving motor M1 is disposed on the opposite side with the application brush roller 62 and the photosensitive member 8 interposed therebetween, the driving force is transmitted to the application brush roller 62. The number of gears will increase. As a result, the rotation start of the application brush roller 62 is delayed with respect to the rotation start of the photoconductor 8, and the application brush roller 62 and the photoconductor 8 are rubbed, and the surface of the photoconductor may be damaged.

  On the other hand, in the present embodiment, the drive transmission to the application brush roller 62 is transmitted via the photoconductor gear portion 122a that drives and transmits the photoconductor 8. The application brush roller 62 provided so as to contact the surface of the photoconductor 8 is disposed around the photoconductor 8. In addition, the photoconductor gear portion 122 a is disposed coaxially with the photoconductor 8. Therefore, by configuring the configuration such that the drive is transmitted to the application brush roller 62 via the photoconductor gear portion 122a, the photoconductor drive motor M1 is positioned on the opposite side of the photoconductor 8 with respect to the application brush roller 62. Even when arranged, there are two meshing positions of the gears that cause a delay in the rotation start of the application brush roller 62 (meshing between the first gear part 122b and the second gear part 123a, joint gear part 124b and brush gear). (Meshing with 125). Thereby, the delay of the rotation start of the application brush roller 62 with respect to the rotation start of the photoconductor can be suppressed, and the rubbing between the application brush roller 62 and the photoconductor 8 can be suppressed. Further, the arrangement and number of gears for transmitting the driving force to the application brush roller 62 can be determined irrespective of the position of the photoconductor driving motor M1.

  In this embodiment, a spline joint is used for drive transmission from the apparatus main body side to the process cartridge side. The spline joint has a high meshing rate because the inner teeth formed on the inner circumferential surface of the cylindrical female portion and the outer teeth formed on the outer circumferential surface of the shaft mesh with each other. Therefore, by using a spline joint, meshing vibration at the joint portion can be suppressed. In particular, by using an involute spline joint, the meshing rate can be further increased, and meshing vibration at the joint can be further suppressed. Thereby, the speed fluctuation of the photosensitive member 8 and the speed fluctuation of the application brush roller 62 can be suppressed by the meshing vibration in the joint portion.

  Moreover, the following advantages can be obtained by using a spline joint for driving transmission between the apparatus main body side and the process cartridge side in the driving transmission path to the application brush roller 62. That is, since the spline joint is configured to mesh the external teeth and the internal teeth over one circumference in the circumferential direction, the external teeth and the internal teeth are always in contact at any position in the circumferential direction. Yes. Therefore, there is no backlash as in the case of gear meshing, so there is no drive transmission delay. As a result, a delay in the rotation start of the application brush roller 62 with respect to the rotation start of the photoconductor 8 can be suppressed, and rubbing between the application brush roller 62 and the surface of the photoconductor 8 can be suppressed.

  Moreover, in this embodiment, the diameter of the 1st gear part 122b is made larger than the diameter of the 2nd gear part 123a. Thus, even if the 2nd gear part 123a vibrates by enlarging the 1st gear part 122b and the vibration is transmitted to the 1st gear part 122b, the 1st gear part 122b and the 2nd gear part The influence of vibration per rotation of the photosensitive member can be reduced by the diameter ratio with respect to 123a. As a result, the influence of the vibration of the second gear portion 123a on the speed of the photosensitive member 8 can be reduced, and the influence of uneven printing density (banding) in the sub-scanning direction due to the vibration of the second gear portion 123a can be reduced. Can be reduced. In particular, in the present embodiment, the first gear portion 122b is made larger than the outer diameter of the photoconductor 8, and the diameter ratio between the second gear portion 123a and the first gear portion 122b is further increased. The influence of vibration of the two gear portion 123a is further reduced.

  Further, the meshing vibration at the meshing position between the first gear part 122b and the second gear part 123 is suppressed by improving the meshing rate by using the teeth of the first gear part 122b and the second gear part 123a as a helical tooth. This is preferable.

FIG. 8 shows a configuration on the apparatus main body side of the developing drive transmission mechanism 110 that transmits driving to the developing roller 10a and the stirring and conveying screws 10b and 10c of the developing apparatus 10, and a configuration on the apparatus main body side of the first drive transmission mechanism 120. FIG. 9 is a plan view showing the configuration of the development drive transmission mechanism 110 on the apparatus main body side and the configuration of the first drive transmission mechanism 120 on the apparatus main body side together with the process cartridge 23 from which the development device 10 is removed. It is.
As shown in FIGS. 8 and 9, the apparatus main body side of the development drive transmission mechanism 110 includes a development drive transmission member 112, a development idler gear 113, and a development joint member 114. The development drive transmission member 112 has a development first gear portion 112a that meshes with the development driving gear 111 of the development drive motor M2, and a development second gear portion 112b that meshes with the development idler gear 113. The development joint member 114 includes a development third gear portion 114a that meshes with the development idler gear 113, and a development involute spline female portion 114b. When the process cartridge 23 is attached to the apparatus main body, a developing involute spline male part (not shown) provided on the back side surface of the developing apparatus 10 is inserted into the developing involute spline female part 114b and driven from the apparatus main body side to the developing apparatus. Power is transmitted.

  In the present embodiment, the present invention is applied to a mechanism that transmits driving to the application brush roller 62. For example, the present invention is applied to driving transmission of a cleaning roller that contacts the surface of the photosensitive member and cleans the toner on the surface of the photosensitive member. You may apply. In this case as well, fluctuations in the speed of the photosensitive member due to fluctuations in the load on the cleaning roller can be suppressed, and rubbing between the photosensitive member and the cleaning roller can be suppressed. In addition, the present invention can be applied to drive transmission of a charging roller that is in contact with the surface of the photoreceptor. Further, the present invention is not limited to this, and the present invention is applied to the drive transmission of the rotating member that contacts the photosensitive member, thereby suppressing the speed variation of the photosensitive member due to the load variation of the rotating member, and rubbing between the photosensitive member and the rotating member. Can be suppressed.

What has been described above is an example, and the present invention has a specific effect for each of the following aspects.
(Aspect 1)
The rotational driving force of the driving source such as the photosensitive member driving motor M1 is applied to the latent image bearing member such as the photosensitive member 8 that carries the latent image and the rotating member such as the application brush roller 62 that rotates in contact with the latent image carrier. In the drive transmission mechanism 120 that transmits the latent image, the latent image carrier such as the photosensitive gear 122a that is provided coaxially with the latent image carrier, meshes with the driving gear 121 of the drive source, and transmits the rotational driving force to the latent image carrier. A body gear and a first gear 122b that rotates coaxially with the latent image carrier gear on the same axis as the latent image carrier gear, and engages the plurality of gears from the first gear 122b. The driving force of the driving source is configured to be transmitted.
By providing such a configuration, as described in the embodiment, the photosensitive member due to the load fluctuation of the application brush roller is compared with that in which the drive is transmitted to the rotating body such as the application brush roller 62 via the first gear and one gear. The speed fluctuation of the latent image carrier such as the body can be suppressed. Further, it is possible to suppress a delay in the start of rotation of the rotating body relative to the latent image carrier, and to suppress friction between the rotating body and the latent image carrier.

(Aspect 2)
Further, in the drive transmission mechanism 120 described in (Aspect 1), the diameter of the first gear 123a is made larger than the diameter of the gear meshing with the first gear 123a (second gear portion 123a in the present embodiment).
By providing such a configuration, as described in the embodiment, it is possible to suppress fluctuations in the speed of the photosensitive member due to vibration of the second gear portion 123a.

(Aspect 3)
Further, in the drive transmission mechanism 120 described in (Aspect 1) or (Aspect 2), the drive transmission from the first gear 122b to the rotating body such as the application brush roller 62 is all gear engagement.
By providing such a configuration, as described in the embodiment, when a load fluctuation occurs in a rotating body such as the application brush roller 62, an increase in speed fluctuation of the rotating body can be suppressed.

(Aspect 4)
Further, in any of the drive transmission mechanisms 120 in (Aspect 1) to (Aspect 3), the drive transmission from the first gear 122b to the rotating body such as the application brush roller 62 is carried out twice (in this embodiment). , Meshing between the first gear 122b and the second gear 123a and meshing between the joint gear portion 124b and the brush gear 125).
By providing such a configuration, as described in the embodiment, it is possible to minimize the delay in the rotation start of the rotating body with respect to the rotation start of the latent image carrier such as the photoconductor 8.

(Aspect 5)
Further, in the drive transmission mechanism 120 according to any one of (Aspect 1) to (Aspect 4), the rotating body such as the application brush roller 62 is housed in a unit configured to be detachable from the apparatus main body. In the drive transmission path from the first gear 122b to the rotating body, a spline joint is used as the drive transmission from the drive side to the unit side.
By providing such a configuration, as described in the embodiment, it is possible to suppress the meshing vibration at the joint portion. In addition, it is possible to prevent the joint portion from causing a rotation start delay of the rotating body with respect to the rotation start of the photoconductor.

(Aspect 6)
In the drive transmission mechanism 120 described in (Aspect 5), an involute spline joint is used as the spline joint.
By providing such a configuration, the meshing vibration of the joint portion can be further suppressed as described in the embodiment.

(Aspect 7)
Also, in the drive transmission mechanism 120 of any one of (Aspect 1) to (Aspect 6), the rotating body is charged with a charging member such as a charging roller that charges the surface of the latent image carrier, and the toner remaining on the surface of the latent image carrier. Either a cleaning member such as a cleaning roller to be removed, or a lubricant application member such as an application brush roller for applying a lubricant to the surface of the latent image carrier.
By providing such a configuration, it is possible to suppress the load fluctuation of the latent image carrier such as the photoconductor, and to suppress the scratch on the surface of the photoconductor.

(Aspect 8)
In addition, a latent image carrier such as a photosensitive member 8 that carries a latent image, a rotating member such as a coating brush roller 62 that rotates in contact with the latent image carrier, and a latent image carrier and a rotary member are driven by the photosensitive member. In the image forming apparatus 1 including the drive transmission mechanism 120 that transmits the driving force of a drive source such as the motor M1, the drive transmission mechanism of any one of the above (Aspect 1) to (Aspect 7) is used as the drive transmission mechanism. .
By providing such a configuration, as described in the embodiment, it is possible to suppress the occurrence of abnormal images such as banding, and to reduce the life of the photoreceptor.

(Aspect 9)
Further, in the image forming apparatus 1 described in (Aspect 8) above, a latent image carrier such as the photosensitive member 8 that carries a latent image, and a rotating body such as a coating brush roller 62 that rotates in contact with the latent image carrier. And a unit such as a process cartridge 23 detachable from the apparatus main body.
By providing such a configuration, as described in the embodiment, replacement and maintenance work can be easily performed.

1: Image forming device 8: Photoconductor 9: Charging roller 11: Photoconductor cleaning device 23: Process cartridge 62: Application brush roller 64: Solid lubricant 66: Leveling blade 67: Conveying screw 100: Unit frame 100a: Back Side plate 110: development drive transmission mechanism 111: development drive gear 112: development drive transmission member 112a: development first gear portion 112b: development second gear portion 113: development idler gear 114: development joint member 114a: development third gear portion 114b : Development involute spline female portion 120: First drive transmission mechanism 121: Driving gear 122: Drive transmission member 122 a: Photoconductor gear portion 122 b: First gear portion 122 c: Photoconductor involute spline male portion 122 d: First shaft portion 122 e: Second shaft portion 123: cleaning female joint member 123a Second gear part 123b: cleaning involute spline female part 124: cleaning male side joint member 124a: cleaning involute spline male part 124b: joint gear part 125: brush gear 126: idler gear 127: transport gear 128: photosensitive member involute spline female part M1: Photoconductor drive motor M2: Development drive motor

JP 2011-242467 A JP 2011-145423 A

Claims (8)

In a drive transmission mechanism that transmits a rotational driving force of a driving source to a latent image carrier that carries a latent image and a rotary body that rotates in contact with the latent image carrier,
A latent image carrier gear that is provided coaxially with the latent image carrier, meshes with a driving gear of a drive source, and transmits a rotational driving force to the latent image carrier;
A first gear provided coaxially with the latent image carrier gear and provided to rotate integrally with the latent image carrier gear;
The first power gear is configured to transmit the driving force of the driving source to the rotating body through meshing of a plurality of gears ,
A drive transmission mechanism characterized in that the diameter of the first gear is larger than the diameter of the gear meshing with the first gear and larger than the outer diameter of the latent image carrier . The drive transmission mechanism of claim 1 ,
A drive transmission mechanism characterized in that all of the drive transmission from the first gear to the rotating body is gear meshing. The drive transmission mechanism according to claim 1 or 2 ,
A drive transmission mechanism characterized in that the drive transmission from the first gear to the rotating body is performed by two engagements of gears. The drive transmission mechanism according to any one of claims 1 to 3 ,
The rotating body is housed in a unit configured to be detachable from the apparatus main body,
A drive transmission mechanism characterized in that a spline joint is used as a drive transmission from the drive side to the unit side in the drive transmission path from the first gear to the rotating body. The drive transmission mechanism according to claim 4 ,
An involute spline joint is used as the spline joint. The drive transmission mechanism according to any one of claims 1 to 5 ,
A charging member for charging the surface of the latent image carrier, a cleaning member for removing toner remaining on the surface of the latent image carrier, and a lubricant application member for applying a lubricant to the surface of the latent image carrier. A drive transmission mechanism characterized by being any one of the above. A latent image carrier for carrying a latent image;
A rotating body rotating in contact with the latent image carrier;
In the image forming apparatus comprising a drive transmission mechanism that transmits a driving force of a drive source to the latent image carrier and the rotating body,
As the drive transmission mechanism, an image forming apparatus characterized by using either of the drive transmission mechanism according to claim 1 to 6. The image forming apparatus according to claim 7 .
An image forming apparatus comprising: a latent image carrier that carries a latent image; and a rotating body that rotates in contact with the latent image carrier and is detachable from the apparatus main body.

Images