JP5380344B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a color printer or a color copier.

2. Description of the Related Art Conventionally, an image forming apparatus such as a color printer or a color copier has a drive mechanism (unit) that rotationally drives each photosensitive drum on which a toner image of black toner, yellow toner, magenta toner, or cyan toner is developed.
In this image forming apparatus, for example, a “four motor system” in which each of the four photosensitive drums is rotated by one motor (see, for example, Patent Document 1), or “four motor drums are rotated by one motor”. The “1-motor system” (see, for example, Patent Document 2) is employed.

JP 2003-208024 A JP 2004-205688 A

Here, even if any of the above-described methods is employed, the drive mechanism (unit) needs to have a configuration corresponding to each method. In particular, since the required configuration is greatly different between the “4-motor system” and the “1-motor system”, the manufacturer has to manufacture completely separate drive mechanisms corresponding to the respective systems.
That is, the manufacturer needed to combine different parts in different modes for different models.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus having a photosensitive drum driving mechanism that can be used for a plurality of models.

  The present invention provides a plurality of photosensitive drums rotatable about a first rotation shaft, a plurality of first shaft members disposed on one end side of each of the plurality of photosensitive drums, and a plurality disposed on the other end side. The second shaft member, the plurality of drive gears coupled to the plurality of first shaft members and arranged to be rotatable about the first rotation shaft, and the plurality of drive gears adjacent to each other. One or a plurality of idle gears that are arranged to mesh with both of the drive gears and transmit the rotational driving force from one drive gear to the other drive gear, and formed corresponding to each of the plurality of drive gears. The present invention relates to an image forming apparatus comprising: a rotation drive unit having an output unit that outputs a driving force; and a plurality of installation units that can be installed so that the output unit comes into contact with the drive gear so that the rotation driving force can be transmitted.

  Moreover, it is preferable to provide the 1 or several rotation drive part installed in the 1 or several installation part among the said several installation parts.

  In addition, it is preferable that the plurality of installation units include an existing installation unit in which the rotation driving unit is installed and a non-installation unit in which the rotation driving unit is not installed.

  In addition, when the rotation drive unit is installed in any one of the plurality of installation units, all the drive gears of the plurality of drive gears are rotationally driven in the same rotation direction. It is preferable.

  A case member that accommodates the plurality of drive gears and the one or more idle gears, and is disposed on the outer side in the first rotation axis direction of the plurality of drive gears and the one or more idle gears. And a case member having a plate member attached to the case main body and pivotally supporting each of the plurality of first shaft members, and the installation portion includes an opening formed in the plate member; Preferably, the plate member includes the plurality of drive gears and a region around the opening on the surface opposite to the one or more idle gears.

  The plurality of photosensitive drums are provided with a yellow photosensitive drum on which yellow toner development is formed, a cyan photosensitive drum on which cyan toner development is formed, and magenta toner development. It is preferable that the rotation driving unit is installed in an installation unit corresponding to the cyan photosensitive drum or the magenta photosensitive drum.

  According to the present invention, it is possible to provide an image forming apparatus having a photosensitive drum driving mechanism capable of supporting a plurality of models.

FIG. 2 is a front view for explaining the arrangement of each component in the printer 1 as the first embodiment of the invention. It is the perspective view which looked at the plate member in the photosensitive drum drive mechanism equipped in the one end side of several photosensitive drums from the opposite side to the photosensitive drum. It is the perspective view which looked at the state by which the motor which is a rotational drive part is arrange | positioned in one of the some installation parts on the board member in a photoconductive drum drive mechanism from the opposite side to a photoconductive drum. FIG. 5 is a perspective view of a meshed state of a plurality of drive gears and a plurality of idle gears in the photosensitive drum driving mechanism as viewed from the side opposite to the photosensitive drum. FIG. 6 is a perspective view of a meshed state of a plurality of drive gears and a plurality of idle gears in the photosensitive drum driving mechanism as viewed from the photosensitive drum side. As a second embodiment of the present invention, a perspective view of a state in which a motor as a rotational drive unit is disposed in each of a plurality of installation units on a plate member in a photoconductive drum drive mechanism as viewed from the side opposite to the photoconductive drum. is there.

Hereinafter, embodiments of an image forming apparatus of the present invention will be described with reference to the drawings.
The overall structure of the printer 1 as the image forming apparatus of the first embodiment will be described with reference to FIG. FIG. 1 is a front view for explaining the arrangement of each component in the printer 1 as the first embodiment of the present invention.

  In the following description, the left-right direction is the direction of arrow X and the up-down direction is the direction of arrow Z as viewed from the user standing on the front side of the printer 1. Further, when viewed from the user standing on the front side of the printer 1, the front-rear (depth) direction is a direction orthogonal to both the arrow X and the arrow Z. The front-rear (depth) direction of the printer 1 is the axial direction of a photoconductor drum described later (the direction of the arrow Y shown in FIG. 4).

As shown in FIG. 1, a printer 1 as an image forming apparatus includes an apparatus main body M, an image forming unit GK that forms a toner image on a sheet T as a sheet-like transfer material based on predetermined image information, A paper supply / discharge unit KH that supplies the paper T to the image forming unit GK and discharges the paper T on which the toner image is formed.
The outer shape of the apparatus main body M is configured by a case body BD as a casing.

  As shown in FIG. 1, the image forming unit GK includes photosensitive drums 2a, 2b, 2c, and 2d as image carriers (photosensitive members), charging units 10a, 10b, 10c, and 10d, and a laser as an exposure unit. Scanner units 4a, 4b, 4c, 4d, developing devices 16a, 16b, 16c, 16d, toner cartridges 5a, 5b, 5c, 5d, toner supply units 6a, 6b, 6c, 6d, drum cleaning unit 11a, 11b, 11c, 11d, static eliminators 12a, 12b, 12c, 12d, intermediate transfer belt 7, primary transfer rollers 37a, 37b, 37c, 37d, secondary transfer roller 8, counter roller 18, fixing Part 9.

  As shown in FIG. 1, the paper feed / discharge unit KH includes a paper feed cassette 52, a manual paper feed unit 64, a conveyance path L for paper T, a registration roller pair 80, a plurality of rollers or roller pairs, A paper unit 50. As will be described later, the transport path L is an aggregate of a first transport path L1, a second transport path L2, a third transport path L3, a manual transport path La, and a return transport path Lb.

Hereinafter, each configuration of the image forming unit GK and the paper supply / discharge unit KH will be described in detail.
First, the image forming unit GK will be described.
In the image forming unit GK, the charging units 10a, 10b, 10c, and 10d are sequentially applied to the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d in order as the photosensitive drums 2a, 2b, 2c, and 2d rotate during image formation. Charging by 10d, exposure by laser scanner units 4a, 4b, 4c and 4d, development by developing devices 16a, 16b, 16c and 16d, primary transfer by intermediate transfer belt 7 and primary transfer rollers 37a, 37b, 37c and 37d, Static elimination by the static eliminators 12a, 12b, 12c, and 12d and cleaning by the drum cleaning units 11a, 11b, 11c, and 11d are performed.
Further, in the image forming unit GK, secondary transfer by the intermediate transfer belt 7, the secondary transfer roller 8 and the counter roller 18, and fixing by the fixing unit 9 are performed.

Each of the photosensitive drums 2a, 2b, 2c, and 2d is formed of a cylindrical member and functions as a photosensitive member or an image carrier. Each of the photosensitive drums 2a, 2b, 2c, and 2d rotates in the direction of the arrow shown in FIG. 1 about a rotation axis (first rotation axis) extending in a direction orthogonal to the traveling direction of the intermediate transfer belt 7. Arranged to be possible. An electrostatic latent image can be formed on the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d.
Each of the photosensitive drums 2a, 2b, 2c, and 2d is rotationally driven by a drum drive mechanism (unit) (not shown). Details of the drum drive mechanism will be described later.

  Each of the charging units 10a, 10b, 10c, and 10d is disposed to face the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the charging units 10a, 10b, 10c, and 10d uniformly charges the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d to be positive (plus polarity).

  The laser scanner units 4a, 4b, 4c, and 4d function as exposure units, and are spaced apart from the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the laser scanner units 4a, 4b, 4c, and 4d includes a laser light source (not shown), a polygon mirror, a polygon mirror driving motor, and the like.

  Each of the laser scanner units 4a, 4b, 4c, and 4d scans and exposes the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d based on image information input from an external device such as a PC (personal computer). The scanning exposure is performed by each of the laser scanner units 4a, 4b, 4c, and 4d, thereby removing the charges on the exposed portions of the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Thereby, electrostatic latent images are formed on the respective surfaces of the photosensitive drums 2a, 2b, 2c, and 2d.

  The developing units 16a, 16b, 16c, and 16d are provided corresponding to the photosensitive drums 2a, 2b, 2c, and 2d, respectively, and are disposed to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. . Each of the developing units 16a, 16b, 16c, and 16d attaches toner of each color to a portion where the electrostatic charge image formed on the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d is removed, Color toner images are formed on the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the developing devices 16a, 16b, 16c, and 16d corresponds to four colors of yellow, cyan, magenta, and black. Each of the developing devices 16a, 16b, 16c, and 16d includes a developing roller disposed opposite to the surface of the photosensitive drums 2a, 2b, 2c, and 2d, a stirring roller for stirring the toner, and the like.

  Each of the toner cartridges 5a, 5b, 5c, and 5d is provided corresponding to each of the developing devices 16a, 16b, 16c, and 16d, and each color toner supplied to each of the developing devices 16a, 16b, 16c, and 16d. To accommodate. Each of the toner cartridges 5a, 5b, 5c, and 5d accommodates yellow toner, cyan toner, magenta toner, and black toner.

  The toner supply units 6a, 6b, 6c, and 6d are provided corresponding to the toner cartridges 5a, 5b, 5c, and 5d and the developing devices 16a, 16b, 16c, and 16d, respectively. The toners of the respective colors accommodated in 5d are supplied to the developing devices 16a, 16b, 16c, and 16d, respectively. Each of the toner supply units 6a, 6b, 6c, and 6d is connected to each of the developing devices 16a, 16b, 16c, and 16d by a toner conveyance device (not shown).

  To the intermediate transfer belt 7, the toner images of the respective colors formed on the photosensitive drums 2a, 2b, 2c, and 2d are sequentially primary-transferred. The intermediate transfer belt 7 is stretched over a driven roller 35, a counter roller 18 that functions as a driving roller, a tension roller 36, and the like. Since the tension roller 36 biases the intermediate transfer belt 7 from the inside to the outside, a predetermined tension is applied to the intermediate transfer belt 7.

  Primary transfer rollers 37a, 37b, 37c, and 37d are arranged to face each other on the side opposite to the photosensitive drums 2a, 2b, 2c, and 2d with the intermediate transfer belt 7 interposed therebetween.

  The intermediate transfer belt 7 is sandwiched between the primary transfer rollers 37a, 37b, 37c, and 37d and the photosensitive drums 2a, 2b, 2c, and 2d, respectively. The sandwiched portion is pressed against the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d. Primary transfer nips N1a, N1b, N1c, and N1d are formed between the photosensitive drums 2a, 2b, 2c, and 2d and the primary transfer rollers 37a, 37b, 37c, and 37d, respectively. In the primary transfer nips N1a, N1b, N1c, and N1d, the toner images of the respective colors formed on the photoreceptor drums 2a, 2b, 2c, and 2d are sequentially primary-transferred onto the intermediate transfer belt 7, respectively. As a result, a full-color toner image is formed on the intermediate transfer belt 7.

  To the primary transfer rollers 37a, 37b, 37c, and 37d, toner images of the respective colors formed on the photosensitive drums 2a, 2b, 2c, and 2d are respectively transferred to the intermediate transfer belt 7 by a primary transfer bias applying unit (not shown). A primary transfer bias for transferring the toner image is applied.

  The static eliminators 12a, 12b, 12c, and 12d are arranged to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, respectively. The static eliminators 12a, 12b, 12c, and 12d respectively irradiate the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d to irradiate light, and the photosensitive drums 2a, 2b, and 2c after the primary transfer is performed. 2d, each surface is neutralized (charge is removed).

  Each of the drum cleaning units 11a, 11b, 11c, and 11d is disposed to face the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the drum cleaning units 11a, 11b, 11c, and 11d removes toner and adhering matter remaining after the primary transfer on the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, and removes the removed toner and the like to a predetermined level. It is transported to the collection mechanism and collected.

  The secondary transfer roller 8 secondarily transfers the full-color toner image primarily transferred to the intermediate transfer belt 7 onto the paper T. A secondary transfer bias for transferring the full color toner image formed on the intermediate transfer belt 7 to the paper T is applied to the secondary transfer roller 8 by a secondary transfer bias applying unit (not shown).

  The secondary transfer roller 8 contacts or separates from the intermediate transfer belt 7. Specifically, the secondary transfer roller 8 is configured to be movable between a contact position where the secondary transfer roller 8 is in contact with the intermediate transfer belt 7 and a spaced position where the secondary transfer roller 8 is separated from the intermediate transfer belt 7. Specifically, the secondary transfer roller 8 is disposed at a contact position when the full-color toner image primarily transferred onto the surface of the intermediate transfer belt 7 is secondarily transferred to the paper T, and in other cases. It is arranged at a separated position.

  A counter roller 18 is disposed on the opposite side of the intermediate transfer belt 7 from the secondary transfer roller 8. The intermediate transfer belt 7 is sandwiched between the secondary transfer roller 8 and the opposing roller 18. Then, the paper T is pressed against the outer surface of the intermediate transfer belt 7 (the surface on which the toner image is primarily transferred). A secondary transfer nip N <b> 2 is formed between the intermediate transfer belt 7 and the secondary transfer roller 8. At the secondary transfer nip N2, the full-color toner image primarily transferred to the intermediate transfer belt 7 is secondarily transferred to the paper T.

  The fixing unit 9 melts and presses the toner of each color constituting the toner image secondarily transferred onto the paper T and fixes the toner on the paper T. The fixing unit 9 includes a heating rotator 9a heated by a heater and a pressure rotator 9b pressed against the heating rotator 9a. The heating rotator 9a and the pressure rotator 9b sandwich and pressurize the paper T onto which the toner image has been secondarily transferred, and convey the paper T. When the paper T is conveyed while being sandwiched between the heating rotator 9a and the pressure rotator 9b, the toner transferred to the paper T is fixed on the paper T by being melted and pressurized. Is done.

Next, the paper supply / discharge unit KH will be described.
As shown in FIG. 1, a paper feed cassette 52 that stores paper T is disposed below the apparatus main body M. The paper feed cassette 52 is configured to be able to be pulled out from the case body BD of the apparatus main body M in the horizontal direction. In the paper feed cassette 52, a placement plate 60 on which the paper T is placed is disposed. In the paper feed cassette 52, the paper T is stored in a state of being stacked on the placement plate 60. The paper T placed on the placement plate 60 is sent out to the transport path L by the cassette paper feed unit 51 disposed at the paper feed side end of the paper feed cassette 52 (the right end in FIG. 1). ing. The cassette paper feeding unit 51 includes a forward feed roller 61 for taking out the paper T on the placement plate 60 and a paper feed roller pair 81 for feeding the paper T one by one to the transport path L. Is provided.

  A manual paper feed unit 64 is provided on the right side surface (right side in FIG. 1) of the apparatus main body M. The manual paper feed unit 64 is provided mainly for supplying paper T having a size and type different from the paper T set in the paper feed cassette 52 to the apparatus main body M. The manual paper feed unit 64 includes a manual feed tray 65 that forms part of the right side surface of the apparatus main body M in the closed state, and a paper feed roller 66. The lower end of the manual feed tray 65 is attached to the vicinity of the paper feed roller 66 so as to be rotatable (openable and closable). The paper T is placed on the open manual feed tray 65. The paper feed roller 66 feeds the paper T placed on the open manual feed tray 65 to the manual feed path La.

  The conveyance path L for conveying the paper T includes a first conveyance path L1 from the cassette paper feeding unit 51 to the secondary transfer nip N2, a second conveyance path L2 from the secondary transfer nip N2 to the fixing unit 9, and a fixing unit. 9 to the paper discharge unit 50, the manual conveyance path La for joining the paper supplied from the manual paper feed unit 64 to the first conveyance path L1, and the third conveyance path L3 from the downstream side to the upstream side. And a return conveyance path Lb for reversing the sheet conveyed to the side and returning it to the first conveyance path L1.

Moreover, the 1st junction part P1 and the 2nd junction part P2 are provided in the middle of the 1st conveyance path L1. A first branch portion Q1 is provided in the middle of the third transport path L3.
The first joining part P1 is a joining part where the manual feed path La joins the first transport path L1. The second junction P2 is a junction where the return conveyance path Lb merges with the first conveyance path L1.
The first branch portion Q1 is a branch portion where the return transport path Lb branches from the third transport path L3.

  In the middle of the first conveyance path L1 (specifically, between the second joining portion P2 and the secondary transfer nip N2), a paper detection sensor (not shown) for detecting the paper T, A registration roller pair 80 is arranged for adjusting the timing with skew (oblique feeding) correction and toner image formation in the image forming unit GK. The paper detection sensor is disposed immediately before the registration roller pair 80 in the transport direction of the paper T (upstream in the transport direction). The registration roller pair 80 conveys the paper T by performing the above-described correction and timing adjustment based on detection signal information from the paper detection sensor.

  An intermediate roller pair 82 is disposed between the first joining portion P1 and the second joining portion P2 in the first transport path L1. The intermediate roller pair 82 is disposed on the downstream side in the paper transport direction with respect to the paper feed roller pair 81, sandwiches the paper T transported from the paper feed roller pair 81, and transports the paper T to the registration roller pair 80.

  The return conveyance path Lb is a conveyance path provided in order to make the opposite surface (unprinted surface) opposite to the already printed surface to the intermediate transfer belt 7 when performing duplex printing on the paper T. By the return conveyance path Lb, the paper T conveyed from the first branching section Q1 to the paper discharge section 50 side is reversed and returned to the first conveyance path L1, and is disposed on the upstream side of the secondary transfer roller 8. It can be conveyed to the upstream side of the roller pair 80. A toner image is transferred to the non-printed surface of the paper T that has been turned upside down by the return conveyance path Lb in the secondary transfer nip N2.

  A rectifying member 58 is provided in the first branch portion Q1. The rectifying member 58 rectifies the transport direction of the paper T that is carried out of the fixing unit 9 and transports the third transport path L3 from the upstream side toward the downstream side in a direction toward the paper discharge unit 50 and the paper discharge unit 50. The conveyance direction of the paper T that is conveyed from the downstream side toward the upstream side of the third conveyance path L3 is rectified in a direction toward the return conveyance path Lb.

  A paper discharge unit 50 is formed at the end of the third transport path L3. The paper discharge unit 50 is disposed on the upper part of the apparatus main body M. The paper discharge unit 50 opens toward the left side of the apparatus main body M (left side in FIG. 1). The paper discharge unit 50 discharges the paper T to the outside of the apparatus main body M. The paper discharge unit 50 includes a discharge roller pair 53. The discharge roller pair 53 discharges the paper T conveyed from the upstream side to the downstream side in the third conveyance path L3 to the outside of the apparatus main body M, and reverses the conveyance direction of the paper T in the paper discharge unit 50. The paper T can be transported toward the upstream side of the third transport path L3.

On the opening side of the paper discharge unit 50, a paper discharge stacking unit M1 is formed. The paper discharge stacking unit M1 is formed on the upper surface (outer surface) of the apparatus main body M. The paper discharge stacking unit M1 is a part formed by the upper surface of the apparatus main body M being depressed downward. The bottom surface of the paper discharge stacking unit M1 constitutes a part of the top surface of the apparatus main body M. In the paper discharge stacking unit M1, sheets T formed with a predetermined toner image and discharged from the paper discharge unit 50 are stacked and stacked.
A paper detection sensor (not shown) is disposed at a predetermined position on each conveyance path.

Next, the operation of the printer 1 of the first embodiment will be briefly described with reference to FIG.
First, a case where single-sided printing is performed on the paper T stored in the paper feed cassette 52 will be described.
The paper T accommodated in the paper feed cassette 52 is sent out to the first transport path L1 by the forward feed roller 61 and the paper feed roller pair 81, and then intermediated via the first joining portion P1 and the first transport path L1. It is conveyed to the registration roller pair 80 by the roller pair 82.
In the registration roller pair 80, skew correction of the paper T and timing adjustment with toner image formation in the image forming unit GK are performed.

The paper T discharged from the registration roller pair 80 is introduced between the intermediate transfer belt 7 and the secondary transfer roller 8 (secondary transfer nip N2) via the first conveyance path L1. A toner image is transferred onto the paper T between the intermediate transfer belt 7 and the secondary transfer roller 8.
Thereafter, the paper T is discharged from between the intermediate transfer belt 7 and the secondary transfer roller 8, and is interposed between the heating rotator 9a and the pressure rotator 9b in the fixing unit 9 via the second conveyance path L2. Introduced into the fixing nip. Then, the toner melts in the fixing nip, and the toner is fixed on the paper T.

Next, the paper T is transported to the paper discharge unit 50 through the third transport path L3, and is discharged from the paper discharge unit 50 to the paper discharge stacking unit M1 by the discharge roller pair 53.
In this way, single-sided printing of the paper T stored in the paper feed cassette 52 is completed.

  When single-sided printing is performed on the paper T placed on the manual feed tray 65, the paper T placed on the manual feed tray 65 is sent out to the manual feed path La by the paper feed roller 66, and then the first joining portion. It is conveyed to the registration roller pair 80 via P1 and the first conveyance path L1. Subsequent operations are the same as the one-side printing operation of the paper T accommodated in the paper feed cassette 52 described above, and a description thereof will be omitted.

Next, the operation of the printer 1 when performing duplex printing will be described.
In the case of single-sided printing, as described above, the paper T on which single-sided printing has been performed is discharged from the paper discharge unit 50 to the paper discharge stacking unit M1, and the printing operation is completed.
On the other hand, when performing double-sided printing, the paper T on which single-sided printing has been performed is reversed from the time of single-sided printing and conveyed again to the registration roller pair 80 via the return conveyance path Lb. Then, double-sided printing is performed on the paper T.

  More specifically, the operation is the same as the above-described single-sided printing operation until the paper T on which single-sided printing has been performed is discharged from the paper discharge unit 50 by the discharge roller pair 53. Thus, in the case of double-sided printing, in a state where the paper T on which single-sided printing has been performed is held by the discharge roller pair 53, the rotation of the discharge roller pair 53 is stopped and rotated in the reverse direction. When the discharge roller pair 53 is thus rotated in the reverse direction, the paper T held by the discharge roller pair 53 moves in the reverse direction (the direction from the paper discharge unit 50 toward the first branching unit Q1) along the third conveyance path L3. ).

  As described above, when the paper T is transported in the reverse direction on the third transport path L3, the paper T is rectified to the return transport path Lb by the rectifying member 58, and then, via the second junction P2. Then, it joins the first transport path L1. Here, the paper T is turned upside down from the one-side printing.

  Further, the paper T is subjected to the correction or the adjustment by the registration roller pair 80, and is introduced into the secondary transfer nip N2 through the first conveyance path L1. Since the unprinted surface of the sheet T passes through the return conveyance path Lb and faces the intermediate transfer belt 7, the toner image is transferred to the unprinted surface, and as a result, duplex printing is performed.

  Next, the details of the photosensitive drum driving mechanism 21 that rotationally drives the plurality of photosensitive drums 2a, 2b, 2c, and 2d in the printer 1 of the first embodiment will be described with reference to FIGS.

  FIG. 2 is a perspective view of a plate member in a photosensitive drum driving mechanism provided on one end side of a plurality of photosensitive drums as viewed from the side opposite to the photosensitive drum. FIG. 3 is a perspective view of a state in which a motor as a rotation driving unit is disposed in one of a plurality of installation units on a plate member in the photosensitive drum driving mechanism as viewed from the side opposite to the photosensitive drum. . FIG. 4 is a perspective view of the engagement state of the plurality of drive gears and the plurality of idle gears in the photosensitive drum driving mechanism as viewed from the side opposite to the photosensitive drum. FIG. 5 is a perspective view of the engagement state of the plurality of drive gears and the plurality of idle gears in the photosensitive drum driving mechanism as viewed from the photosensitive drum side.

  The photosensitive drum driving mechanism 21 of this embodiment is a driving unit that rotationally drives the three photosensitive drums 2a, 2b, and 2c for color. A photosensitive drum driving mechanism for rotating the photosensitive drum 2d for black is provided as a driving unit different from that for color.

First, before describing the photosensitive drum driving mechanism 21, a support structure for the plurality of photosensitive drums 2a, 2b, and 2c for color will be described.
Each of the plurality of photosensitive drums 2a, 2b, and 2c is supported so as to be rotatable about the first rotation shafts 23a, 23b, and 23c shown in FIGS.

  As shown in FIGS. 4 and 5, the first rotation shafts 23a, 23b, and 23c are center axes of the plurality of drum shafts 24a, 24b, and 24c to which the photosensitive drums 2a, 2b, and 2c are fixed, respectively. Each of the drum shafts 24a, 24b, and 24c is disposed along the front-rear direction of the printer 1 (the arrow Y direction in FIG. 4). In addition, each of the drum shafts 24a, 24b, and 24c has the first shaft members 25a, 25b, and 25c disposed on one end side, and the second shaft members 100a, 100b, and 100c disposed on the other end side. The first shaft members 25a, 25b, and 25c are rotatably supported by the photosensitive drum drive mechanism 21 of the present embodiment, and the second shaft members 100a, 100b, and 100c are the photosensitive drum drive mechanism 21 on the case body BD. It is rotatably supported by a shaft support member (shaft member support mechanism, shaft member support unit) (not shown) arranged on the opposite side to the (drive unit).

  In the present embodiment, the plurality of photosensitive drums 2a, 2b, and 2c are not shown, but are fixed to intermediate portions in the axial direction (arrow Y direction) of the respective drum shafts 24a, 24b, and 24c. That is, in each of the plurality of photosensitive drums 2a, 2b, and 2c in the present embodiment, the first shaft members 25a, 25b, and 25c are disposed on one end side, and the second shaft members 100a, 100b, and 100c are disposed on the other end side. Has been.

Next, the photosensitive drum drive mechanism 21 of the present embodiment will be described in detail.
As shown in FIGS. 2 to 5, the photosensitive drum driving mechanism 21 of the present embodiment includes a plurality of driving gears 26a, 26b, and 26c, a plurality of idle gears 27a and 27b, and a plurality of installation portions 28a and 28b. 28c, one motor 29 as a rotation drive unit, and a case member 41.

  As shown in FIGS. 4 and 5, the plurality of drive gears 26a, 26b, and 26c are coupled to the plurality of first shaft members 25a, 25b, and 25c, respectively, and rotate around the first rotation shafts 23a, 23b, and 23c. Arranged as possible.

  As shown in FIGS. 4 and 5, the idle gears 27a and 27b are disposed between the drive gears 26a, 26b, and 26c adjacent to each other. The idle gears 27a and 27b disposed between the drive gears 26a, 26b, and 26c adjacent to each other are disposed so as to mesh with both of the drive gears adjacent to each other, and the rotational drive force from one drive gear is obtained. Transmit to the other drive gear. Specifically, the idle gear 27a is disposed so as to mesh with the drive gear 26a and the drive gear 26b, and transmits, for example, a rotational driving force from the drive gear 26a to the drive gear 26b. Further, the idle gear 27b is arranged to mesh with the drive gear 26b and the drive gear 26c, and transmits, for example, the rotational driving force from the drive gear 26b to the drive gear 26c.

As shown in FIGS. 2 and 3, each of the plurality of installation portions 28 a, 28 b, 28 c is a part where the motor 29 can be installed. Each of the plurality of installation portions 28a, 28b, 28c is formed at three locations corresponding to each of the plurality of drive gears 26a, 26b, 26c.
More specifically, as shown in FIG. 5, the motor 29 installed in the installation units 28a, 28b, and 28c includes an output shaft 110 and an output gear 112 that constitute an output unit 29a that outputs a rotational driving force, and a control unit. Substrate 29b. The plurality of installation portions 28a, 28b, and 28c are in contact with each other so that the output gear 112 that is fixedly mounted on the distal end side of the output shaft 110 of the motor 29 can transmit the rotational driving force to the corresponding drive gears 26a, 26b, and 26c. As shown, each of the plurality of drive gears 26a, 26b, 26c is provided correspondingly.

The case member 41 accommodates a plurality of drive gears 26a, 26b, 26c and a plurality of idle gears 27a, 27b.
The case member 41 is disposed so that the first shaft members 25a, 25b, and 25c are inserted therethrough. The case member 41 includes a case main body 43 disposed at a position on one end side of the photosensitive drums 2a, 2b, and 2c, and a plate member 44 assembled to the case main body 43.

As shown in FIG. 4, the case main body 43 has a substantially box shape in which both surfaces in the direction of the first rotation shafts 23 a, 23 b, and 23 c are open surfaces. A plate member 44 is assembled on the surface of the case main body 43 that is far from the photosensitive drums 2a, 2b, and 2c.
The case member 41 has a concave space 45 formed by the case main body 43 and the plate member 44. The case member 41 accommodates a plurality of drive gears 26a, 26b, 26c and a plurality of idle gears 27a, 27b in a concave space 45.

As described above, the plate member 44 is disposed outside the first rotation shafts 23a, 23b, and 23c in the plurality of drive gears 26a, 26b, and 26c and the plurality of idle gears 27a and 27b so as to cover the open surface of the case body 43. Be placed.
As shown in FIG. 2, the plate member 44 includes a plurality of first shaft members by a plurality of first shaft insertion portions 45a, 45b, 45c provided corresponding to the plurality of first shaft members 25a, 25b, 25c, respectively. Each of 25a, 25b, and 25c is rotatably supported.
The plate member 44 rotatably supports the plurality of idle gears 27a and 27b by a plurality of second shaft insertion portions 46a and 46b provided corresponding to the arrangement of the plurality of idle gears 27a and 27b.

The plate member 44 includes a plurality of installation portions 28a, 28b, and 28c on which the motor 29 can be installed. Each of the installation portions 28 a, 28 b, 28 c has an opening group 47, 47, 47 formed through the plate member 44. The opening groups 47, 47, 47 include openings 47 a, 47 a, 47 a for inserting the output shaft 110 constituting the output part 29 a of the motor 29, and mounting holes 47 b, 47 b for preventing the motor 29 from rotating. 47b. Each of the installation portions 28a, 28b, 28c has surrounding regions 48, 48, 48 of the openings 47a, 47a, 47a.
The surrounding areas 48, 48, 48 are areas for securing an installation space for the motor 29. Specifically, the surrounding regions 48, 48, 48 are openings 47 a, 47 a, 47 a on the surface of the plate member 44 opposite to the plurality of drive gears 26 a, 26 b, 26 c and the plurality of idle gears 27 a, 27 b. It is the surrounding area.

In the photosensitive drum drive mechanism 21 of the present embodiment, the number of motors 29 provided on the plate member 44 is one, and the one motor 29 is provided with three installation portions 28 a and 28 b provided on the plate member 44. , 28c, which is one of the installation portions 28c.
That is, in the present embodiment, of the three installation portions 28a, 28b, 28c provided on the plate member 44, one installation portion 28c is an existing installation portion where the motor 29 is installed, and the other two installation portions. 28a and 28b are non-installed portions where the motor 29 is not installed.

As described above, the three photosensitive drums driven by the photosensitive drum driving mechanism 21 according to the present embodiment include the yellow photosensitive drum 2a on which toner development of yellow toner is formed, and toner development of cyan toner. The cyan photosensitive drum 2b is formed, and a magenta photosensitive drum 2c on which magenta toner development is formed.
The installation portion 28c where the motor 29 is installed is an installation portion corresponding to the drive gears 26a, 26b, and 26c on one end side of the magenta photosensitive drum 2c.

  Next, in the photosensitive drum driving mechanism 21 of the present embodiment, the operation when the driving gears 26a, 26b, 26c fixed to the photosensitive drums 2a, 2b, 2c are rotationally driven is based on FIG. explain.

  In FIG. 5, when the output shaft 110 (output unit 29a) of the motor 29 installed in one installation unit 28c rotates in the direction of arrow R1 in FIG. 5, the drive gear meshed with the output gear 112 (output unit 29a). 26c is rotationally driven in the direction of arrow R2. As a result, the first shaft member 25c (photosensitive drum 2c) is rotated in the direction of the arrow R2.

  Next, the rotation of the drive gear 26c is transmitted to the adjacent drive gear 26b via the meshed idle gear 27b. Specifically, when the drive gear 26c rotates in the arrow R2 direction, the meshed idle gear 27b is rotationally driven in the arrow R3 direction. Then, the other drive gear 26b meshing with the idle gear 27b is rotationally driven in the direction of arrow R4. Accordingly, the first shaft member 25b (photosensitive drum 2b) is rotated in the direction of the arrow R4.

  Subsequently, the rotation of the drive gear 26b is transmitted to the adjacent drive gear 26a via the meshed idle gear 27a. Specifically, when the drive gear 26b rotates in the direction of arrow R4, the engaged idle gear 27a is rotationally driven in the direction of arrow R5. The other drive gear 26a meshing with the idle gear 27a is rotationally driven in the direction of arrow R6. Thereby, the first shaft member 25a (photosensitive drum 2a) is rotated in the direction of the arrow R6.

  As described above, all the drive gears 26a, 26b, and 26c are rotationally driven in synchronization with the same rotational direction. That is, the three photosensitive drums 2a, 2b, and 2c coupled to the plurality of drive gears 26a, 26b, and 26c are rotationally driven in synchronization with the same rotational direction. In the photosensitive drum drive mechanism 21 of the present embodiment, all of the plurality of drive gears 26a, 26b, and 26c can be driven to rotate in synchronization in the same direction by a single motor 29.

  Further, in the photosensitive drum drive mechanism 21 of the present embodiment, one motor 29 is rotationally driven in the same direction for all three drive gears 26, regardless of which of the three installation portions 28 a, 28 b, 28 c is installed. Can be made. Further, even when the motor 29 is installed in any two of the three installation sections 28a, 28b, and 28c, or when the motor 29 is installed in all of the three installation sections 28a, 28b, and 28c, each motor By synchronizing the rotation of 29, all the three drive gears 26a, 26b, 26c can be rotationally driven in the same direction.

As shown in FIG. 5, when a plurality of drive gears 26 a, 26 b, and 26 c are rotationally driven by one motor 29, the drive gear that is rotationally driven from the motor 29 via another gear is separated from the motor 29. As a result, the shift due to the rotation error becomes large, and there is a risk of causing a shift of the image. On the other hand, image shift may be noticeable or not noticeable depending on the color. The colors that are not easily noticeable are yellow, cyan, and magenta in order, and the photosensitive drums that are easily noticeable are required to have higher rotation accuracy. Therefore, it is desirable that the motor 29 be installed in the installation section 28c corresponding to the magenta photosensitive drum 2c, or the installation section 28b corresponding to the cyan photosensitive drum 2b.
In the case of the present embodiment, the motor 29 is installed in the installation unit 28c corresponding to the magenta photosensitive drum 2c, in which the deviation is easily noticeable. Therefore, although it is a one-motor system in which a plurality of photosensitive drums are rotationally driven by a single motor, it is possible to suppress a decrease in image quality due to deviation.

According to the printer 1 of the present embodiment described above, for example, the following effects are exhibited.
The printer 1 according to this embodiment includes a plurality of photosensitive drums 2a, 2b, and 2c that can rotate around the first rotation shafts 23a, 23b, and 23c, and one end side of each of the plurality of photosensitive drums 2a, 2b, and 2c. The first shaft members 25a, 25b, and 25c that are disposed, the plurality of second shaft members 100a, 100b, and 100c disposed on the other end side, and the plurality of first shaft members 25a, 25b, and 25c, respectively, A plurality of drive gears 26a, 26b, 26c arranged so as to be rotatable around one rotation shaft 23a, 23b, 23c, and a plurality of drive gears 26a, 26b, 26c are engaged with both adjacent drive gears. One or a plurality of idle gears 27a, 27b and a plurality of drive gears 26a, 26b, 26c that transmit the rotational driving force from one drive gear to the drive gear. A motor 29 having an output portion 29a that outputs the rotational driving force can be installed so that the output portion 29a is disposed in contact with the drive gears 26a, 26b, and 26c so as to transmit the rotational driving force. A plurality of installation portions 28a, 28b, and 28c.
Therefore, when the motor 29 is installed in at least one of the plurality of installation portions 28a, 28b, and 28c, the printer 1 rotationally drives the plurality of drive gears 26a, 26b, and 26c, and performs a plurality of photosensitive operations. The body drums 2a, 2b, and 2c can be rotationally driven. Further, the printer 1 can rotate the plurality of photosensitive drums 2a, 2b, and 2c by installing a motor 29 in each of the plurality of installation portions 28a, 28b, and 28c. Therefore, the printer 1 can cope with both a single motor system and a plurality of motor systems only by changing the installation part where the motor is installed, and the effort to develop the drive mechanism individually according to the number of motors equipped. It can be made unnecessary.
Accordingly, there is provided an image forming apparatus having a photosensitive drum driving mechanism capable of supporting a plurality of models equipped with different numbers of motors.

In addition, the printer 1 of the present embodiment includes one or more motors 29 installed in one or more installation units 28a, 28b, 28c among the plurality of installation units 28a, 28b, 28c.
Therefore, for example, by setting two or more installation parts for installing the motors 29, it is possible to reduce the load acting on each motor 29 and improve the rotation accuracy of each photosensitive drum.

In addition, in the printer 1 of the present embodiment, the plurality of installation units 28a, 28b, and 28c have an existing installation unit in which the motor 29 is installed and an uninstalled unit in which the motor 29 is not installed.
Therefore, the user (manufacturer) can further improve the rotational operation performance by additionally installing the motor 29 in the non-installed part.

Further, in the printer 1 of the present embodiment, when the motor 29 is installed in any one of the plurality of installation units 28a, 28b, 28c, all of the plurality of drive gears 26a, 26b, 26c are included. The drive gears 26a, 26b, and 26c are driven to rotate (in the same rotation direction).
Therefore, for example, even if only one motor 29 can be incorporated in the photosensitive drum drive mechanism 21 due to limitations on manufacturing costs, the position where the motor 29 is incorporated is not limited, and the user (manufacturer) can select the photosensitive drum drive mechanism. The arrangement of the motor 29 can be adjusted flexibly in consideration of the empty space around the area 21, and the arrangement design of the motor 29 can be facilitated.

The printer 1 of the present embodiment is a case member 41 that houses a plurality of drive gears 26a, 26b, and 26c and one or a plurality of idle gears 27a and 27b, and includes a plurality of drive gears 26a, 26b, and 26c. And a case member 41 having a plate member 44 that is disposed outside the first rotation shafts 23a, 23b, and 23c in the plurality of idle gears 27a and 27b and supports each of the plurality of first shaft members 25a, 25b, and 25c. And comprising. The installation portions 28a, 28b, and 28c include openings 47a, 47a, and 47a formed in the plate member 44, and a plurality of drive gears 26a, 26b, and 26c and a plurality of idle gears 27a and 27b in the plate member 44. And the surrounding area 48 of the openings 47a, 47a, 47a on the opposite surface.
Therefore, in the printer 1, the space where the drive gears 26a, 26b, 26c and the idle gears 27a, 27b are arranged and the space where the motor 29 is arranged are partitioned by the plate member 44, and the oils and fats applied to the gears It is possible to prevent wear powder or the like generated by friction between the gears from adhering to the control board attached to the motor 29.

  Further, in the printer 1 of the present embodiment, a plurality of photosensitive drums 2a, 2b, and 2c that are rotationally driven by one photosensitive drum driving mechanism 21 are a yellow photosensitive drum 2a on which toner development of yellow toner is formed. The cyan photosensitive drum 2b on which cyan toner development is formed and the magenta photosensitive drum 2c on which magenta toner development is formed. The motor 29 is installed in the installation unit 28b or the installation unit 28c corresponding to the cyan photosensitive drum 2b or the magenta photosensitive drum 2c.

In general, the drive gears 26a, 26b, and 26c that are rotationally driven from the motor 29 via other gears are more likely to be displaced due to rotational errors as they are separated from the motor 29, which may cause image displacement. On the other hand, image shift may be noticeable or not noticeable depending on the color. The colors that are not easily noticeable are yellow, cyan, and magenta in order, and the photosensitive drums that are easily noticeable are required to have higher rotation accuracy.
In the case of the present embodiment, the motor 29 is installed in the installation unit 28c or the installation unit 28b corresponding to the magenta photosensitive drum 2c or cyan photosensitive drum 2b, where the deviation is easily noticeable. Since the arrangement is close to that of the motor 29, the printer 1 can suppress a decrease in image quality due to deviation even in the case of a single motor system in which a plurality of photosensitive drums are rotationally driven by a single motor.

FIG. 6 shows a state in which a motor 29 as a rotational drive unit is disposed in each of a plurality of installation portions 28a, 28b, 28c on the plate member 44 in the photosensitive drum drive mechanism 21 as a second embodiment of the present invention. It is the perspective view seen from the opposite side to a photoconductive drum.
As described above, when the motors 29 are provided in all of the plurality of installation portions 28a, 28b, and 28c set on the plate member 44, the torque transmitted to each of the photosensitive drums 2a, 2b, and 2c increases, and the photosensitive member Even when the body drums 2a, 2b, and 2c are heavy, it is possible to rotate all the photosensitive drums 2a, 2b, and 2c with good responsiveness.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various forms can be adopted.
The type of the image forming apparatus of the present invention is not particularly limited, and may be a copier, a printer, a facsimile, or a complex machine thereof.
The sheet-shaped transfer material is not limited to paper, and may be a film sheet, for example.

  DESCRIPTION OF SYMBOLS 1 ... Printer (image forming apparatus), 2a ... Photosensitive drum for yellow (photosensitive drum), 2b ... Photosensitive drum for cyan (photosensitive drum), 2c ... Photosensitive drum for magenta (photosensitive drum) ), 21... Photoconductor drum drive mechanism, 23a, 23b, 23c... First rotation shaft, 25a, 25b, 25c... First shaft member, 26a, 26b, 26c. Idle gear, 28a, 28b, 28c ... installation part, 29 ... motor (rotary drive part), 29a ... output part, 41 ... case member, 43 ... case body, 44 ... plate member, 47a ... Opening 48, surrounding area, 100a, 100b, 100c, second shaft member, 110, output shaft (output unit), 112, output gear (output unit)

Claims (6)

A plurality of photosensitive drums rotatable around a first rotation axis;
A plurality of first shaft members disposed on one end side of each of the plurality of photosensitive drums and a plurality of second shaft members disposed on the other end side;
A plurality of drive gears coupled to each of the plurality of first shaft members and arranged rotatably about the first rotation shaft;
One or a plurality of idle gears that are arranged to mesh with both of the drive gears adjacent to each other among the plurality of drive gears and transmit the rotational drive force from one drive gear to the other drive gear;
A rotary drive unit formed corresponding to each of the plurality of drive gears and having an output unit for outputting a rotary drive force can be installed so that the output unit is in contact with and arranged to transmit the rotary drive force to the drive gear. A plurality of installation units. The image forming apparatus according to claim 1, further comprising: one or a plurality of rotation driving units installed in one or a plurality of installation units among the plurality of installation units. The image forming apparatus according to claim 2, wherein the plurality of installation units include an existing installation unit in which the rotation driving unit is installed and an uninstalled unit in which the rotation driving unit is not installed. When the rotation drive unit is installed in any one of the plurality of installation units,
The image forming apparatus according to claim 2, wherein all of the plurality of drive gears are rotationally driven in the same rotational direction. A case member that accommodates the plurality of drive gears and the one or more idle gears, and is disposed on the outer side in the first rotation axis direction of the plurality of drive gears and the one or more idle gears. A case member having a main body and a plate member attached to the case main body and pivotally supporting each of the plurality of first shaft members;
The installation part is
An opening formed in the plate member;
The image according to any one of claims 1 to 4, comprising the plurality of drive gears in the plate member and a peripheral region of the opening on a surface opposite to the one or the plurality of idle gears. Forming equipment. The plurality of photosensitive drums are:
A yellow photosensitive drum on which toner development of yellow toner is formed;
A cyan photosensitive drum on which toner development of cyan toner is formed;
A magenta photosensitive drum on which toner development of magenta toner is formed,
The image forming apparatus according to claim 2, wherein the rotation driving unit is installed in an installation unit corresponding to the cyan photosensitive drum or the magenta photosensitive drum.

Images