JP3398898B2 - Image forming unit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming unit applied to an image forming machine such as an electrostatic copying machine, a laser printer and a facsimile.

[0002]

2. Description of the Related Art An image forming unit applied to an image forming machine, such as an electrostatic copying machine, includes a photosensitive drum and a developing device. The developing device is provided with a developing housing having a front side wall and a rear side wall, and a developer applying device for applying a developer to a peripheral surface of a photosensitive drum supported between front end portions of the front side wall and the rear side wall in the developing housing. And means. One typical example of the developer applying unit is composed of a cylindrical sleeve member and a stationary permanent magnet member disposed inside the sleeve member. The developer applying means has a support shaft, and the support shaft is composed of a rotary support shaft integrated with the sleeve member and a fixed support shaft on which a stationary permanent magnet member is mounted. The rotating support shaft of the sleeve member is rotatably supported on the rear side wall via a bearing, and the fixed support shaft of the stationary permanent magnet member is supported on the front side wall via the bearing. A front side plate member is arranged on the front side wall of the developing housing, and a rear side plate member is arranged on the rear side wall. A pair of bearings, which are separate members, are attached to each of the front plate member and the rear plate member at predetermined axial center intervals. The end of the fixed support shaft of the stationary permanent magnet member is further fitted and supported by one of the bearings mounted on the front plate member, and the end of the rotary support shaft of the sleeve member is further mounted on the rear plate member. Is fitted and supported on one side. The photosensitive drum is rotatably supported by fitting both end portions of its support shaft into the other bearing mounted on each of the front plate member and the rear plate member. Each of the front plate member and the rear plate member,
The front and rear side walls of the developing housing are fastened with a plurality of screws, so that the front and rear side walls are fixed.

[0003]

In the above-mentioned conventional image forming unit, the gap between the peripheral surface of the sleeve member and the peripheral surface of the photosensitive drum in the developer applying means provides good development as desired. Is extremely important for. When assembling the photosensitive drum and the sleeve member, it is desired that the predetermined gap can be easily and surely obtained with high accuracy without causing variations and with a minimum number of assembling steps. Further, it is desired that the gap is not changed by the vibration during transportation of the image forming unit in which the photosensitive drum and the sleeve member are incorporated, or the impact such as dropping, and the gap is maintained as a predetermined value.

In the above conventional image forming unit,
As described above, the support shaft of the developer applying unit (the support shaft composed of the rotary support shaft of the sleeve member and the fixed support shaft of the stationary permanent magnet member) is attached to each of the front side plate member and the rear side plate member, Although supported by a pair of bearings, each bearing pair is composed of separate members, and the side plate members are attached to both side walls only by fastening a plurality of screws. As a result, the assembling of the photosensitive drum must be performed while adjusting the gap between the peripheral surfaces of the photosensitive drum and the sleeve member by using an assembling jig, and the assembling is complicated and difficult. Assembling man-hours increase, so the assembling performance is not good. Further, assembling variation easily occurs in the gap between the photosensitive drum and the sleeve, and it is considerably difficult, if not impossible, to obtain the gap easily and reliably with high accuracy. Furthermore, there is a high possibility that the gap will change due to vibration during transportation of the image forming unit in which the photosensitive drum and the sleeve member are incorporated, or an impact such as dropping.
May not be maintained as prescribed.

An object of the present invention is to provide a novel image which enables a predetermined gap between the peripheral surfaces of the photosensitive drum and the sleeve member to be easily and reliably obtained with high accuracy without causing assembly variations. To provide a forming unit.

Another object of the present invention is to assemble a photosensitive drum without using an assembling jig without causing a predetermined gap between the peripheral surfaces of the photosensitive drum and the sleeve member without causing assembly variations. It is to provide a novel image forming unit that can be easily and reliably obtained with high accuracy.

Still another object of the present invention is to facilitate the assembling, to reduce the number of assembling steps, to be excellent in the assembling property, and to cause the assembling variation in a predetermined gap between the peripheral surfaces of the photosensitive drum and the sleeve member. It is to provide a novel image forming unit that can be obtained with high accuracy.

Still another object of the present invention is to provide vibration during transportation,
Provided is a novel image forming unit capable of reliably preventing a predetermined gap between the peripheral surfaces of a photosensitive drum and a sleeve member from changing due to an impact such as a drop and maintaining the predetermined gap. That is.

[0009]

According to the present invention, there is provided a photosensitive drum having a supporting shaft and a developing device, the developing device having a developing housing having side walls and a supporting shaft. And an end face of both side walls of the side wall of each side wall are supported by bearings between the front ends of the side faces of both side walls of the image forming unit. Each of the side plate members is provided with a bearing body in which a pair of bearing portions are integrally formed with a predetermined axial distance, and both end portions of the support shaft of the developer applying means are further bearings. The photosensitive drum is fitted and supported by one of the bearing portions of each of the bodies, the both ends of the supporting shaft of the photosensitive drum are fitted and supported by the other of the bearing portions of each of the bearing bodies, and each of the side plate members is interposed by a positioning means. The corresponding side wall at a predetermined position In, it is fixed by fixing means,
An image forming unit is provided.

The positioning means is composed of a plurality of positioning locking pins extending from the side walls to the outside in the longitudinal direction of the developing housing, and a plurality of positioning locked holes formed in each of the side plate members. It is preferable that each positioning locked hole is fitted to a corresponding positioning locking pin of a corresponding side wall. One of the positioning locking pins on each of the side walls and one of the positioning locked holes on each of the side plate members, which corresponds to one of the positioning locking pins, is viewed in the axial direction of the developer applying means. On the straight line which is orthogonal to the straight line passing through the shaft center of the support shaft of the developer applying means and the shaft center of the photosensitive drum and passing through the shaft center of the supporting shaft of the developer applying means, or near the straight line, It is preferably arranged near the axis of the support shaft. The one of the positioning locked holes in each of the side plate members includes a plurality of small-diameter circular arc portions formed at equal angular intervals in the circumferential direction, and the peripheral edge of each of the small-diameter circular arc portions corresponds to the corresponding positioning locking. It is preferably formed to lie on a virtual circle having the same diameter as the one of the pins or a slightly smaller diameter. Other positioning locked holes in each of the side plate members,
When viewed in the axial direction of the developer applying means, a pair of parallel extending parallel to a straight line passing through the axis of the support shaft of the developer applying means and the axis of the photoconductor drum and facing each other with a space therebetween. It is preferably provided with an inner wall. One of the other positioning locking pins on each of the side walls is parallel to a straight line passing through the axis of the support shaft of the developer applying means and the axis of the photoconductor drum when viewed in the axial direction of the developer applying means. It is preferable that a slit having a pair of inner walls extending in the opposite direction and facing each other at a distance is formed in the central portion of the axial center. The fixing means is composed of a plurality of screw holes formed in each of the side walls and a plurality of screws that can be engaged with each of the screw holes, and the screw holes are respectively provided in the vicinity of each of the positioning locking pins. It is preferable that they are arranged at intervals.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an image forming unit constructed according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows the structure of the image forming unit 100. The image forming unit 100 is
The developing device 2, the photosensitive drum 4, the cleaning device 6, the charging device 8 and the like are provided and are detachably attached to an electrostatic copying machine (not shown). With the image forming unit 100 mounted on the electrostatic copying machine, the photosensitive drum 4 is rotationally driven clockwise in FIG. 1 by a driving unit (not shown), and is uniformly charged by the charger 8. An image is exposed on the peripheral surface of No. 4 by an appropriate method known per se to form an electrostatic latent image. This electrostatic latent image is developed into a toner image by the developing device 2 in the developing area. This toner image is transferred to a sheet member such as plain paper in the transfer area and then fixed by a fixing device (not shown) to obtain a copy of the image. The residual toner on the peripheral surface of the photosensitive drum 4 is scraped off by the cleaning blade 6a of the cleaning device 6 in the cleaning area, and is discharged and collected by the toner collecting spiral member 6b into a toner collecting container (not shown).

With reference to FIGS. 1 to 4, the developing device 2 includes a developing housing 10. For example, the developing housing 10 which can be integrally formed from a suitable synthetic resin such as ABS has a bottom wall 12, a front side wall 14 extending upward from a front side edge in the longitudinal direction of the bottom wall 12, and a rear side in the longitudinal direction of the bottom wall 12. A rear side wall 16 extending upward from the side edge, a front end wall 17 extending upward from a width direction front end of the bottom wall 12 and connected to front ends of the front side wall 14 and the rear side wall 16, and a width direction rear end of the bottom wall 12. A rear end wall 18 extending upwardly from and connected to the rear ends of the front side wall 14 and the rear side wall 16. Front side wall 14 defines one of the side walls and rear side wall 16 defines the other side wall.
In the present specification, the longitudinal direction of the developing housing 10 refers to the front-back direction of the paper surface in FIG. 1, and the front side or front side in the longitudinal direction refers to the front-side direction of the paper surface in FIG. The rear side or rear side in the direction means the direction toward the back side or the back side of the paper surface in FIG. 1. Further, the width direction of the developing housing 10 indicates the left-right direction in FIG. 1, the front side or front side in the width direction indicates the direction toward the left side or the left side in FIG. 1, and the rear side or rear side in the width direction indicates In FIG. 1, the direction toward the right side or the right side is shown. The same applies to other figures.

The bottom wall 12 of the developing housing 6 includes the bottom wall 1
A partition wall 19 is integrally formed that extends upward from 2 and extends in the longitudinal direction at a predetermined height. Predetermined intervals are defined between the front end of the partition wall 19 in the longitudinal direction and the front side wall 14, and between the rear end of the partition wall 19 in the longitudinal direction and the rear side wall 16, respectively. Front side wall 14 and rear side wall 16 in the developing housing 10 of the developing device 2.
The front end portions 14A and 16A in the width direction are configured to extend in a direction in which they approach each other and to extend upward from the upper end surface rearward in the width direction.
The width-direction rear ends of the front end portions 14A and 16A in the width direction of the front side wall 14 and the rear side wall 16 are formed to be upright walls that are upright from the upper end surfaces of the front side wall 14 and the rear side wall 16. A developer applying unit 20 is disposed between the front end portions 14A and 16A of the front side wall 14 and the rear side wall 16 of the developing housing 10.

The developer applying means 20 is composed of a cylindrical sleeve member 22 extending substantially horizontally in the longitudinal direction and a stationary permanent magnet member 24 disposed in the sleeve member 22. The sleeve member 22 is made of a non-magnetic material such as aluminum and is rotatable, and the stationary permanent magnet member 24 is fixed at a predetermined angular position. A rotation support shaft 22a is fixed to the sleeve member 22. The rotary support shaft 22a is rotatably supported on the rear side wall 16 via a bearing 22b (see FIG. 7) which may be a radial ball bearing, and is rotationally driven counterclockwise in FIG. 1 by a driving means (not shown). One end of the rotation support shaft 22a is formed so as to extend from the rear side wall 16 to the outside in the longitudinal direction of the developing housing 10. The stationary permanent magnet member 24 is fixed to the fixed support shaft 24a, and the fixed support shaft 24a
Are supported by the front side wall 14 via bearings 24b. One end of the fixed support shaft 24a is formed so as to extend from the front side wall 14 to the outside in the longitudinal direction of the developing housing 10.
A not-shown one end wall is provided at one end in the axial direction (one end on the side of the front side wall 14) inside the sleeve member 22, and the one end of the sleeve member 22 is rotatable to the fixed support shaft 24a via the one end wall. Supported by. Another end wall (not shown) is arranged at the other end portion in the axial direction (the other end portion on the side of the rear side wall 16) in the sleeve member 22, and the other end portion of the fixed support shaft 24a rotates relative to the other end wall. It is supported freely. The rotary support shaft 22a and the fixed support shaft 24a form a support shaft of the developer applying unit 20. The front side wall 1 of the developing housing 10
4 and the front end portions 14A and 16A of the rear side wall 16 are disposed in parallel with each other in parallel to the peripheral surface of the sleeve member 22 and in parallel with each other. The ear cutting plate 26 is a sleeve member 22.
The amount of the developer held on the peripheral surface of the sheet and conveyed to the developing area is regulated.

A developer stirring / conveying mechanism is disposed behind the developer applying means 20. The developer agitating / conveying mechanism includes agitating / conveying members 30 and 32 each having a rotating shaft and a spiral blade, and an agitating / conveying member 34 including a rotating shaft and a plurality of plate blades.
It has and. The agitating / conveying members 30 and 32 are disposed on both sides in the width direction with the partition wall 19 of the developing housing 10 interposed therebetween, and extend between the front side wall 14 and the rear side wall 16 so as to extend in the longitudinal direction along the bottom wall 12, respectively. It is rotatably supported. The agitating / conveying member 30 is rotationally driven counterclockwise in FIG. 1 by a driving unit (not shown), and conveys the developer from the front side to the rear side in the longitudinal direction while stirring. The agitating / conveying member 32 is rotationally driven clockwise in FIG. 1 by a driving unit (not shown), and conveys the developer from the rear side to the front side in the longitudinal direction while stirring. Therefore, the developer is on both sides of the partition 19 and the partition 1
It is circulated and conveyed while being agitated between the developer transfer openings formed between the both longitudinal ends of 9 and the corresponding front and rear side walls 14 and 16. The toner contained in the developer is triboelectrically charged.

The stirring and conveying member 34 is rotatable between the front and rear side walls 14 and 16 so as to extend in the longitudinal direction along the bottom wall 12 between the stirring and conveying member 32 and the developer applying means 20. Supported by. In the agitating / conveying member 34, a plurality of plate blades extending outward in the radial direction at intervals in the circumferential direction are formed in a central area of the rotating shaft in the axial direction, and spiral blades are formed in both end areas of the rotating shaft. Further, one plate blade extending outward in the radial direction is formed in an intermediate region between the central region and the both end regions. The central area corresponds to the image forming area on the sleeve member 22 and the photosensitive drum 4. Agitating and transporting member 3 configured as described above
4 is rotationally driven in the counterclockwise direction in FIG. 1 by a driving means (not shown). The plurality of plate blades arranged in the central region of the stirring and conveying member 34 are
The developer existing on the downstream side in the rotation direction from the position facing the photoconductor drum 4 is conveyed to the stirring and conveying member 32 side, and the developer on the stirring and conveying member 32 side is conveyed to the sleeve member 22.
Is conveyed upstream of the position facing the bristle cutting plate 26 in the rotational direction. Further, the spiral blades arranged in both end regions of the stirring and conveying member 34 move the developer existing in both end regions of the stirring and conveying member 34 toward the inner side in the axial direction, and plate blades arranged in each of the intermediate regions. Acts so as to return the developer moved by the spiral blade to the stirring and conveying member 34.

The front end portions 14A and 16A of the front side wall 14 and the rear side wall 16 in the developing housing 10 of the developing device 2 in the width direction extend in the directions approaching each other and are upward from the upper end surface in the rear side in the width direction. Is configured to extend to. Front side wall 14 and rear side wall 16
The width-direction rear ends of the front end portions 14A and 16A in the width direction are formed so as to be upright walls upright from the upper end surfaces of the front side wall 14 and the rear side wall 16. Front wall 14
And the upper end surface of the rear side wall 16 and the front end portions 14A and 1A
At the upper end opening of the developing housing 10, which is formed by a region rearward of the upright wall formed at the rear end of 6A and the upper end surface of the rear end wall 18, the developer accommodating container 36 covers the opening. It is installed so as to cover it. The developer storage container 36 stores the start developer. The developer accommodating container 36 has a container body having a developer discharge port at the lower end, an annular flange extending outward from the peripheral edge of the discharge port, and a detachable mount on the lower surface of the container body to connect the discharge port. And a sealing film member that closes. The seal film member includes a seal portion removably attached to the lower surface from the front side to the rear side in the longitudinal direction of the container body, and an inversion superposition portion which is continuous with the seal portion and is inverted at the rear side to reach the front side. , And the peeling gripping portion formed continuously with the inverted overlapping portion. Before using the image forming machine for the first time,
When the seal portion is pulled forward with respect to the lower surface of the container body in the longitudinal direction, which is the peeling direction, the reverse polymerized portion is pulled forward relative to the seal portion, and the seal film member peels off the seal portion. Then, the discharge port is opened. The developer contained in the container body is dropped into the developing housing 10 through the discharge port and the upper end opening of the developing housing 10. In FIG. 1, all the developer in the container body of the developer storage container 36 is discharged into the developing housing 10,
The state used for development is shown.

As shown in FIG. 5, a front side plate member 40 is mounted on the front side wall 14 of the developing housing 10, and a bearing body 42 is mounted on the front side plate member 40. Further, as can be easily understood from FIGS. 7 and 8, a rear side plate member 44 is mounted on the rear side wall 16, and the bearing body 4 is attached to the rear side plate member 44.
6 is attached.

With reference to FIGS. 3, 4 and 10, the fixed support shaft 24 of the stationary permanent magnet member 24 of the developer applying means 20 is provided at the front end portion 14A of the front side wall 14 of the developing housing 10.
A notch 14a is formed into which a can be inserted from the upper end (see also FIG. 2). The lower half of the cutout portion 14a is formed to have a dominant arc-shaped inner peripheral surface, and the upper half thereof is
It is formed so as to have a pair of inner walls that extend in parallel with each other and face each other. The width of the upper half is the fixed support shaft 24
a is formed larger than the diameter of a, and the lower half has a diameter larger than the width of the upper half.
4a and the rotation support shaft 22a, and hence the support shaft of the developer applying unit 20 is defined to coincide with the center SC. In FIG. 10, the developing housing 10
The position of the axis center DC of the photosensitive drum 4 with respect to is shown relatively. A pair of screw holes 14b are formed at symmetrical positions sandwiching the lower half of the cutout 14a substantially in the width direction of the developing housing 10. The bearing 24b
Is fastened to the front side wall 14 by engaging the screw 14c with the pair of screw holes 14b (see FIG. 4).

The front side wall 14 also includes a developing housing 10.
Forming a plurality of (two in the embodiment) positioning locking pins 48 and 50 and a plurality of (two in the embodiment) screw holes 52 and 54 extending outward in the longitudinal direction.
The positioning locking pin 48 is orthogonal to the straight line L1 passing through the axial center SC of the support shaft of the developer applying means 20 and the axial center DC of the support shaft 4a of the photosensitive drum 4 when viewed in the axial direction of the developer applying means 20. And is arranged on or near the straight line L2 passing through the shaft center SC of the support shaft of the developer applying means 20 and in the vicinity of the shaft center SC (in the embodiment, it is arranged near the straight line L2. Exist). In the embodiment, the positioning locking pin 4
8 is arranged at the uppermost end portion of the front end portion 14A of the front side wall 14 (a position diagonally above and right of the axis SC in FIG. 10). The positioning locking pin 50 is provided on the front end portion 14 of the front side wall 14.
The rear end of the developing housing 10 in the width direction at the lower end of A is disposed near the straight line L1.
As shown in FIG. 15, the positioning locking pin 50 has a hollow shape, and a slit 50a having a pair of inner walls facing each other in parallel with each other in the center of the axial center thereof.
Are formed. The slit 50a is formed so as to extend to a predetermined depth in the axial direction from the distal end of the positioning locking pin 50 toward the proximal end (see FIG. 4). As shown in FIG. 10, the pair of inner walls forming the slit 50 a of the positioning locking pin 50 is formed by the developer applying means 2
Since it is positioned so as to extend parallel to the straight line L1 when viewed in the axial direction of 0, the straight line L1 is viewed when viewed in the same direction.
It is possible to elastically deform in a direction orthogonal to. The screw holes 52 are arranged in the vicinity of the positioning locking pin 48 with a gap from the positioning locking pin 48 (in the embodiment, with respect to the positioning locking pin 48, the width direction of the developing housing 10). It is arranged at a distance in the rear). Further, the screw hole 54 is provided with the positioning locking pin 50.
In the vicinity of the positioning locking pin 50 (in the embodiment, in the width direction forward of the developing housing 10 with respect to the positioning locking pin 50). . The screw holes 52 and 54
Is a screw hole for fastening the front plate member 40. The tip ends of the positioning locking pins 48 and 50 are chamfered.

Referring to FIGS. 5 and 11, the front side plate member 40, which can be formed of an appropriate steel plate, has a fixed support shaft 24a for the stationary permanent magnet member 24 of the developer applying means 20.
Has a predetermined gap and a circular hole 58 into which the support shaft 4a (see FIG. 1) of the photosensitive drum 4 can be inserted with a sufficient gap. Has been formed. The axis of the long hole 56 is formed to coincide with the axis SC of the support shaft of the developer applying means 20, and the axis of the circular hole 58 is formed to coincide with the axis DC of the support shaft 4a of the photosensitive drum 4. ing. The longitudinal direction of the long hole 56 is arranged so as to match the direction of the straight line L1 passing through the axis SC and the axis DC. In FIG. 11, screw holes 57 and 59 are formed at positions below the long hole 56 and at positions to the right of the circular hole 58, respectively. Screw hole 5
Reference numerals 7 and 59 are screw holes for mounting the bearing body 42.

The front plate member 40 is also formed with a plurality of (two in the embodiment) positioning locked holes 60 and 62. As shown by reference numeral 16, the positioning locked holes 60 include a plurality of (three in the embodiment) small-diameter circular arc portions 60a formed at equal angular intervals in the circumferential direction.
And a large-diameter circular arc portion 60b formed between each of the small-diameter circular arc portions 60a. The peripheral edge of each of the small-diameter circular arc portions 60a is formed so as to exist on one virtual circle 60c, and the circumferential lengths thereof are formed to be substantially the same. The diameter of the virtual circle 60c is the same as the diameter of the positioning locking pin 48 or slightly smaller than the positioning locking pin 48. Further, each peripheral edge of the large-diameter circular arc portion 60b is formed so as to exist on one piece (not shown), and each circumferential length thereof is substantially the same. Each of the small diameter circular arc portions 60a and each of the large diameter circular arc portions 60b are connected by a step portion extending in the radial direction. Since the positioning locked holes 60 have the peripheral edges of the plurality of small-diameter circular arc portions 60a fitted to the positioning locking pins 48, the front side plate member 40 can be positioned with respect to the front side wall 14 of the developing housing 10 without play. Therefore, it can be performed accurately with high accuracy. Also, the fitting operation becomes easy. The positioning locked hole 60 is a straight line L1 passing through the axis SC of the support shaft of the developer applying means 20 and the axis DC of the photosensitive drum 4 when viewed in the axial direction of the developer applying means 20.
Is disposed on or near a straight line L2 that passes through the axis SC of the support shaft of the developer applying unit 20 and is in the vicinity of the axis SC (in the embodiment, is disposed on the substantially straight line L2). Has been). In the embodiment, the positioning locked hole 60 is arranged at the upper right position of the shaft center SC in FIG. 11. The positioning locked hole 62 is a straight line L passing through the axis SC of the support shaft of the developer applying means 20 and the axis DC of the photosensitive drum 4 when viewed in the axial direction of the developer applying means 20.
1 is formed by a slotted hole having a pair of inner walls extending parallel to each other and facing each other in parallel with each other. The width of the positioning locked hole 62 is specified to be the same as or slightly smaller than the diameter of the positioning locking pin 50. The positioning locked hole 62 is located at a position obliquely downward to the right with respect to the elongated hole 56 in FIG. 1, and is arranged in the vicinity (lower side) of the straight line L1.

The front plate member 40 is also formed with a plurality of (two in the embodiment) mounting holes 64 and 66.
The mounting hole 64 is arranged in the vicinity of the positioning locked hole 60 at a distance from the positioning locked hole 60 (in the embodiment, with respect to the positioning locked hole 60, as shown in FIG.
1 is spaced to the right). Further, the mounting hole 66 is arranged near the positioning locked hole 62 with a space from the positioning locked hole 62 (in the embodiment, with respect to the positioning locked hole 62,
(In FIG. 11, it is arranged at an interval on the left side).
The mounting holes 64 and 66 are mounting holes for screwing the front plate member 40 to the front side wall 14. The positioning locked holes 60 and 62 are substantially aligned with the positioning locking pins 48 and 50 of the front side wall 14, and the mounting hole 64 is provided.
And 66 are arranged to substantially align with the threaded holes 52 and 54 in the front side wall 14.

Referring to FIG. 5, the bearing body 42, which can be integrally molded from an appropriate synthetic resin such as ABS, is used.
Includes a plate-shaped main body 42a, and a pair of bearings 42b and 42c are integrally formed on the main body 42a with a predetermined axial distance. The shaft center of the bearing portion 42b is formed to coincide with the shaft center SC of the support shaft of the developer applying means 20, and the shaft center of the bearing portion 42c is formed to coincide with the shaft center DC of the support shaft 4a of the photosensitive drum 4. There is. The bearing portions 42b and 42c include cylindrical portions extending from both surfaces of the main body portion 42a. The bearing portion 42b is a bearing portion for supporting the tip portion of the fixed support shaft 24a of the stationary permanent magnet member 24, and the bearing portion 42c rotatably supports one end portion of the support shaft 4a of the photosensitive drum 4. For bearings. A cylindrical bearing member made of an appropriate synthetic resin is press-fitted into the bearing portion 42c for supporting the support shaft 4a. Mounting holes 42d and 42e are formed in the body portion 42a. The mounting holes 42d and 42e are mounting holes for screwing the bearing body 42 to the front plate member 40, and are arranged so as to be aligned with the screw holes 57 and 59 of the front plate member 40. The bearing body 42 configured as described above has the mounting hole 4
2d and 42e are screw holes 57 and 59 of the front plate member 40.
Screws 68 and 69 in a state of being aligned with the screw hole 57.
By engaging with 59, the front plate member 40 is fastened (see FIG. 6).

2 and 13, the rotary support shaft 22a of the sleeve 22 of the developer applying means 20 can be inserted into the front end portion 16A of the rear side wall 16 of the developing housing 10 with a sufficient gap. A hole 16a is formed (Fig. 3
See also). The hole 16a has a diameter larger than that of the rotation support shaft 22a. A boss 16c having a circular inner peripheral surface 16b outside the hole 16a in the longitudinal direction of the developing housing 10.
Are formed. Inner peripheral surface 1 of hole 16a and boss 16c
The shaft center of 6b has a rotary support shaft 22a and a fixed support shaft 24a.
It is specified that it coincides with the axis center of, and therefore the axis center SC of the support shaft of the developer applying means 20. Note that, in FIG. 13, the position of the shaft center DC of the photosensitive drum 4 with respect to the developing housing 10 is shown relatively. Boss 16
A bearing 22b (see FIG. 7), which may be a radial ball bearing, is press-fitted into the inner peripheral surface 16b of c, the rotation support shaft 22a of the sleeve 22 is fitted into the bearing 22b, and is rotatably attached to the front end portion 16A of the rear side wall 16. Supported.

The rear side wall 16 also includes the developing housing 10.
(Three in the embodiment) locating locking pins 70, 72 and 74 extending outward in the longitudinal direction and a plurality of (three in the embodiment) screw holes 76, 78 and 79 are formed. . The positioning locking pin 70 is orthogonal to the straight line L1 passing through the axis SC of the support shaft of the developer applying means 20 and the axis DC of the photosensitive drum 4 as viewed in the axial direction of the developer applying means 20, and the developer. It is arranged on or near a straight line L2 passing through the axis SC of the support shaft of the applying means 20 and in the vicinity of the axis SC (in the embodiment, it is arranged substantially on the straight line L2). In the embodiment, the positioning locking pin 70 includes the uppermost end portion of the front end portion 16A of the rear side wall 16 (see FIG. 13).
In, at a position diagonally above and to the left of the axis SC). The positioning locking pin 72 is used for the front end portion 16 of the rear side wall 16.
At the lower end of A, the front end in the width direction of the developing housing 10 is arranged at a position below the positioning locking pin 70 with a space. The positioning locking pin 72 is
Since the positioning locking pin 50 (see FIG. 15) described above has substantially the same configuration, the description thereof will be omitted. As shown in FIG. 13, the pair of inner walls forming the slit 72a (corresponding to the slit 50a) of the positioning locking pin 72 are aligned with the straight line L1 when viewed in the axial direction of the developer applying unit 20. Positioned to extend in parallel. The positioning locking pin 74 is the lower end portion of the rear side wall 16,
The developing housing 10 is arranged at a position closer to the rear end portion in the width direction. The screw hole 76 is arranged in the vicinity of the positioning locking pin 70 at a distance from the positioning locking pin 70 (in the embodiment, the positioning locking pin 7).
It is arranged at a distance in the rear of the developing housing 10 in the width direction with respect to 0). The screw hole 78 is arranged in the vicinity of the positioning locking pin 72 at a distance from the positioning locking pin 72 (in the embodiment, with respect to the positioning locking pin 72, the width direction of the developing housing 10). It is arranged at a distance in front. In addition, the screw hole 7
9 is arranged in the vicinity of the positioning locking pin 74 at a distance from the positioning locking pin 74 (in the embodiment, at a distance above the positioning locking pin 74). Exist). The screw holes 76, 78 and 79 are screw holes for fastening the rear plate member 44. The tip ends of the positioning locking pins 70, 72 and 74 are chamfered.

Referring to FIGS. 7 and 14, the rotation support shaft 22a of the sleeve 22 of the developer applying means 20 is inserted into the rear plate member 44, which can be formed of an appropriate steel plate, with a sufficient gap. Long hole 80 that can be formed and the photosensitive drum 4
The support shaft 4a (see FIG. 1) is formed at a predetermined interval with a circular hole 82 into which the support shaft 4a can be inserted with a sufficient gap. The axis of the long hole 80 is formed to coincide with the axis SC of the support shaft of the developer applying means 20, and the axis of the circular hole 82 is formed to coincide with the axis DC of the support shaft 4a of the photosensitive drum 4. ing. In FIG. 14, screw holes 81 and 83 are formed at a position spaced to the left of the elongated hole 80 and a position spaced diagonally to the upper right of the circular hole 82, respectively. The screw holes 81 and 83 are screw holes for mounting the bearing body 46.

The rear side plate member 44 is also formed with a plurality of (three in the embodiment) positioning locked holes 84, 85 and 86. The positioning locked hole 84 has substantially the same configuration as the positioning locked hole 60 (see FIG. 16) described above, and thus description thereof will be omitted. Positioning locked hole 8
4 small-diameter circular arc portion 84a (small-diameter circular arc portion 60a in FIG. 16)
(equivalent to a) is formed so as to exist on one virtual circle, but the diameter of the virtual circle is the same as the diameter of the positioning locking pin 70 or more than that of the positioning locking pin 70. It has a slightly smaller diameter. In the positioning locked hole 84, since the peripheral edges of the plurality of small-diameter circular arc portions 84a are fitted to the positioning locking pin 70, the rear side plate member 44.
The positioning of the developing housing 10 with respect to the rear side wall 16 of the developing housing 10 can be performed accurately without any play. Also, the fitting operation becomes easy. The positioning locked hole 84 is a straight line L1 passing through the axis SC of the support shaft of the developer applying means 20 and the axis DC of the support shaft 4a of the photosensitive drum 4 when viewed in the axial direction of the developer applying means 20.
Is disposed on or near a straight line L2 that passes through the axis SC of the support shaft of the developer applying unit 20 and is in the vicinity of the axis SC (in the embodiment, is disposed on the substantially straight line L2). Has been). In the embodiment, the positioning locked hole 84 is arranged diagonally above and to the left of the axis SC in FIG.

The positioning locked hole 85 has a length provided with a pair of inner walls extending in parallel to the straight line L1 and facing each other in parallel with each other when viewed in the axial direction of the developer applying means 20. It is formed from holes. In the embodiment, since the lower end of the long hole is opened to the lower end of the rear plate member 44, it may be a slit, but in the present invention, its function is substantially the same as that of the long hole. The slit is also referred to as a long hole as included in the category of the long hole. The width of the positioning locked hole 85 is defined to be the same as or slightly smaller than the diameter of the positioning locking pin 72. The positioning locked hole 85 is the long hole 8 in FIG.
At a position that is slightly diagonally left and downward with respect to 0,
It is arranged at a position slightly spaced to the right of the straight line L1. The positioning locked hole 86 forms a straight line L1 passing through the axis SC of the support shaft of the developer applying means 20 and the axis DC of the support shaft 4a of the photosensitive drum 4 when viewed in the axial direction of the developer applying means 20. It is formed of a slot provided with a pair of inner walls extending in parallel and facing each other in parallel with each other. The width of the positioning locked hole 86 is defined to be the same as or slightly smaller than the diameter of the positioning locking pin 74. The positioning locked hole 86 is the long hole 8 in FIG.
It is arranged at a position diagonally downward to the left with respect to 0 and at a position left to the left with respect to the straight line L1.

The rear plate member 44 also has a plurality of (three in the embodiment) mounting holes 87, 88 and 89 formed therein. The mounting hole 87 is provided near the positioning locked hole 84,
The positioning locked holes 84 are spaced apart (in the embodiment, the positioning locked holes 84 are spaced leftward in FIG. 14). The mounting hole 88 is provided near the positioning locked hole 85,
The positioning locked hole 85 is spaced apart (in the embodiment, the positioning locked hole 85 is spaced rightward in FIG. 14). The mounting hole 89 is provided near the positioning locked hole 86,
The positioning locked hole 86 is spaced apart (in the embodiment, the positioning locked hole 86 is spaced above in FIG. 14). The mounting holes 87, 88 and 89 are mounting holes for screwing the rear side plate member 44 to the rear side wall 16. The positioning locked holes 84, 85 and 86 are substantially aligned with the positioning locking pins 70, 72 and 74 of the rear side wall 16, and the mounting holes 87, 88 and 89 are the rear side wall 1.
6 are arranged to substantially align with the screw holes 76, 78 and 79.

Referring to FIG. 8, the bearing body 4 can be integrally molded from a suitable synthetic resin such as ABS.
6 includes a plate-shaped main body 46a, and the main body 46a
A pair of bearings 46b and 46c are integrally formed at a predetermined axial center distance. The shaft center of the bearing portion 46b is formed to coincide with the shaft center SC of the support shaft of the developer applying means 20, and the shaft center of the bearing portion 46c is formed to coincide with the shaft center DC of the support shaft 4a of the photosensitive drum 4. There is. The bearing portions 46b and 46c include a cylindrical portion that extends from one surface of the main body portion 46a (the one surface on the back surface side in FIG. 8). Bearing part 46
Reference numeral b denotes a bearing portion for rotatably supporting the tip end portion of the rotary support shaft 22a of the sleeve 22, and the bearing portion 46.
Reference numeral c is a bearing portion for rotatably supporting the other end of the support shaft 4a of the photosensitive drum 4. Bearing portions 46b and 46
A cylindrical bearing member made of an appropriate synthetic resin is press-fitted into c. The mounting holes 46d and 46 are provided in the main body 46a.
e is formed. The mounting holes 46d and 46e are mounting holes for screwing the bearing body 46 to the rear side plate member 44, and are arranged so as to be aligned with the screw holes 81 and 83 of the rear side plate member 44. In the bearing body 46 configured as described above, the screws 90 and 91 are engaged with the screw holes 81 and 83 with the mounting holes 46d and 46e aligned with the screw holes 81 and 83 of the rear plate member 44. Thus, the rear plate member 44 is fastened.

Referring to FIGS. 6 and 9 to 11, in the front side plate member 40 to which the bearing body 42 is attached as described above, the bearing portion 42b is the fixed support shaft 24a of the developer applying means 20. And the positioning locked hole 60 is fitted to the positioning locking pin 48, and the positioning locked hole 62 is fitted to the positioning locking pin 50. The side wall 14 is automatically positioned at a predetermined position and temporarily mounted. Positioning and temporary mounting of the front side plate member 40 with respect to the front side wall 14 of the developing housing 10 are performed by a substantially one-touch and extremely easy operation. Also, the number of assembling steps is small and the assembling property is excellent. The mounting holes 64 and 66 are the screw holes 52 of the front side wall 14.
And 54 are substantially aligned with each other, so that by engaging the screws 92 and 93 with the screw holes 52 and 54, the front plate member 40 is moved to the front side wall 14 of the developing housing 10.
It is fastened (fixed) to the specified position. Positioning locking pins 48 and 50, positioning locked holes 60 and 62
Is the front side wall 1 of the developing housing 10 of the front side plate member 40.
4, which constitutes a positioning means. Also, the screw hole 52
And 54, screws 92 and 93, and the like constitute a fixing means for fixing the front side plate member 40 to the front side wall 14.

Referring to FIGS. 8 and 12 to 14, in the rear side plate member 44 to which the bearing body 46 is attached as described above, the bearing portion 46b is the rotary support shaft 22a of the developer applying means 20. The positioning locked hole 84 is fitted to the positioning locking pin 70, the positioning locked hole 85 is fitted to the positioning locking pin 72, and the positioning locked hole 86 is positioned. By being fitted to the locking pin 74, the developing housing 10 is automatically positioned at a predetermined position on the rear side wall 16 and temporarily mounted. Positioning and temporary mounting of the rear side plate member 44 with respect to the rear side wall 16 of the developing housing 10 are performed by a substantially one-touch and extremely easy operation. Also, the number of assembling steps is small and the assembling property is excellent. The mounting holes 87, 88 and 89 are formed on the rear side wall 16.
Of the screws 94, 9 in the screw holes 76, 78 and 79, respectively.
By engaging 5 and 96, the rear side plate member 44 is fastened (fully mounted) to a predetermined position on the rear side wall 16 of the developing housing 10. The positioning locking pins 70, 72 and 74 and the positioning locked holes 84, 85 and 86 constitute a positioning means of the rear plate member 44 with respect to the rear side wall 16 of the developing housing 10. Further, the screw holes 76, 78 and 79, the screws 94, 95 and 96, etc. form a fixing means for fixing the rear plate member 44 to the rear side wall 16.

As described above, the front side plate member 40 is mounted at a predetermined position on the front side wall 14 of the developing housing 10, and the rear side plate member 44 is attached to the rear side wall 16 of the developing housing 10.
After mounting the photoconductor drum 4 on the front side wall 1
4 and the rear side wall 16 are rotatably supported via the bearing portion 42c of the bearing body 42 and the bearing portion 46c of the bearing body 46. The photoconductor drum 4 is mounted as follows. That is, the bearing portion 42 c of the bearing body 42 between the front plate member 40 and the rear plate member 44 is the photosensitive drum 4.
And the bearing portion 46c of the bearing body 46 are positioned substantially coaxially therewith. Next, the bearing portion 46c, the photosensitive drum 4, and the bearing portion 42c are fitted in this order to the support shaft 4a which is a drive shaft. End walls are provided at both ends of the photosensitive drum 4, and a through hole is formed at each axial center of the end walls. One end of the support shaft 4a is fitted into one through hole of the end wall so as to be rotatable relative to it, while the other end of the support shaft 4a is fitted into the other through hole of the end wall so as not to be able to rotate relative to each other. Drive coupled. Needless to say, the axial positioning and the relative movement of the support shaft 4a with respect to the photosensitive drum 4, the front plate member 40, and the rear plate member 44 are appropriately controlled by known means. As described above, the support shaft 4a of the photosensitive drum 4 is simply fitted and supported by the bearing portions 42c and 46c, and the shaft center of the support shaft 4a of the photosensitive drum 4 and the support shaft (22a) of the developer applying unit 20 are provided. , 24a) is set to a predetermined value, so that the peripheral surface of the photosensitive drum 4 and the sleeve member 2 of the developer applying means 20 are set.
It is possible to easily and surely obtain a predetermined gap between the peripheral surface of the first and second peripheral surfaces with high accuracy without causing assembly variations. Further, in assembling the photosensitive drum 4, it is not necessary to adjust the gap between the peripheral surfaces of the photosensitive drum 4 and the sleeve member 22 by using an assembling jig as in the conventional case. Since the assembling becomes simple and the number of assembling steps is reduced, the assembling property is improved. The cleaning device 6 and the charger 8 are arranged between the front plate member 40 and the rear plate member 44 (the charger 8 is not shown in FIG. 6).

As described above with reference to FIGS. 9 to 14, the positioning locked holes 60 and 62 of the front plate member 40 are provided.
Is simply fitted to the positioning locking pins 48 and 50 of the front side wall 14, the positioning and temporary mounting of the developing housing 10 to the front side wall 14 are automatically performed. Similarly,
Positioning locked holes 84, 85 and 86 of the rear plate member 44
The positioning locking pins 70, 72 and 74 of the rear side wall 16.
The rear side wall 16 of the developing housing 10
Positioning and temporary mounting for the are automatically performed. As a result, the developing housing 10 of the front plate member 40 and the rear plate member 44 is assembled by using an assembly jig as in the conventional case.
Since it is not necessary to position the front plate member 40 and the rear plate member 44 with respect to the developing housing 10, the number of assembling steps is reduced and the assemblability is improved. Further, since the front side plate member 40 and the rear side plate member 44 are easily and reliably positioned with respect to the developing housing 10, the assembly is easy, the number of assembling steps is small, and the assembling property is excellent. The predetermined gap between the peripheral surfaces of the member 22 can be obtained with high accuracy without causing assembly variations. Furthermore, it is possible to reliably prevent a change in a predetermined gap between the peripheral surfaces of the photosensitive drum 4 and the sleeve member 22 due to a vibration during transportation of the image forming unit 100, or an impact such as a drop, and to perform a predetermined operation. Can be maintained.

The positioning locking pin 48 of the front side wall 14 and the corresponding positioning locked hole 60 of the front side plate member 40.
And the positioning locking pin 70 of the rear side wall 16 and the corresponding positioning locked hole 84 of the rear side plate member 44 when viewed in the axial direction of the developer applying means 20.
Axis S of the support shafts (22a, 24a) of the developer applying means 20 and the axis S of the support shafts (22a, 24a) of the photosensitive drum 4 and the shaft center DC of the support shaft 4a of the photosensitive drum 4.
On the straight line L2 passing through C or in the vicinity thereof, and the axis SC
It is located near. Generally, when the front side plate member 40 and the rear side plate member 44 are mounted on the developing housing 10, there is a tendency that relative rotation occurs between the front side plate member 40 and the rear side plate member 44 and the developing housing 10.
However, in the present invention, since it is configured as described above, the support shaft (22a, 22a,
24a) tangential direction of the peripheral surface of the photosensitive drum 4 and the sleeve member 22 of the axis SC (extending direction of the straight line L2)
Relative displacement (relative displacement due to backlash of the bearing 22b, the bearing 24b, etc.) can be sufficiently reliably and effectively prevented. Even if the relative displacement of the axial center SC in the tangential direction is slight, the change in the gap between the peripheral surfaces of the photoconductor drum 4 and the sleeve member 22 becomes large, so the relative movement in the tangential direction is strictly regulated. It can be said that this is effective in preventing the fluctuation of the gap. As a result, it is possible to easily and reliably obtain a predetermined gap between the peripheral surfaces of the photosensitive drum 4 and the sleeve member 22 with high accuracy without causing assembly variations. The relative displacement in the direction in which the axis DC of the support shaft 4a of the photosensitive drum 4 and the axis SC of the support shaft of the developer applying unit 20 approach or separate from each other (relative displacement in the direction of the straight line L1) is , Bearing body 42
And 46 prevent it reliably and effectively.

Positioning locked hole 60 of the front side plate member 40
Includes a plurality of small-diameter circular arc portions 60a formed at equal angular intervals in the circumferential direction, and the peripheral edge of each of the small-diameter circular arc portions 60a has the same diameter as the corresponding positioning locking pin 48 or a slightly smaller diameter. It is formed so as to exist on one virtual circle, and the positioning locked hole 8 of the rear side plate member 44 is formed.
4 includes a plurality of small-diameter circular arc portions 84a formed at equal angular intervals in the circumferential direction, and the peripheral edge of each of the small-diameter circular arc portions 84a has the same diameter as the corresponding positioning locking pin 70 or a slightly smaller diameter. It is formed so as to exist on one virtual circle that it has. In the positioning locked hole 60, since the peripheral edges of the plurality of small-diameter circular arc portions 60a are fitted to the positioning locking pins 48, the front side plate member 40 is positioned with respect to the front side wall 14 without rattling, and thus with high accuracy. It allows it to be carried out accurately. Further, the fitting operation of the positioning locked hole 60 to the positioning locking pin 48 becomes easy. Similarly, the positioning locked hole 84 is
Since the peripheral edges of the plurality of small-diameter circular arc portions 84a are fitted to the positioning locking pin 70, the rear side plate member 44 can be accurately positioned with respect to the rear side wall 16 without rattling. It is something to do. Also, the fitting operation of the positioning locked hole 84 to the positioning locking pin 70 becomes easy.

Positioning locked hole 62 of the front plate member 40,
The positioning locked holes 85 and 86 of the rear side plate member 44 are viewed from the developer applying means 20 in the axial direction.
Is provided with a pair of inner walls extending parallel to a straight line L1 passing through the axis SC of the support shaft of the support shaft and the axis DC of the support shaft 4a of the photosensitive drum 4 and facing each other with a space therebetween. There is. Therefore, the positioning locked hole 6 of the front side plate member 40
2 is fitted to the positioning locking pin 50 of the front side wall 14, and the positioning locked holes 85 and 86 of the rear plate member 44 are fitted to the positioning locking pins 72 and 74 of the rear side wall 16, respectively. The member 40 and the rear plate member 44 are attached to the developing housing 10 by a support shaft (22) of the developer applying means 20.
It is possible to sufficiently and effectively prevent the relative rotation in which the shaft center SC of a, 24a) is relatively displaced in the tangential direction. As a result, it is possible to easily and surely obtain a predetermined gap between the photosensitive drum 4 and the peripheral surface of the sleeve member with high accuracy without causing assembly variations.

Positioning locking pin 50 of the front plate member 40,
The positioning locking pin 72 of the rear side plate member 44, when viewed in the axial direction of the developer applying unit 20, supports the shaft center SC of the support shafts (22a, 24a) of the developer applying unit 20 and the support shaft 4a of the photosensitive drum 4. Slits 50a and 72a that extend in parallel to the straight line L1 passing through the axis DC of and have a pair of inner walls facing each other with a space therebetween are formed in the center of the axis.
With this configuration, an assembly error when the front side plate member 40 and the rear side plate member 44 are positioned at a predetermined position of the developing housing 10 is changed by the gap between the peripheral surfaces of the photosensitive drum 4 and the sleeve member 22. It is possible to absorb without.

Front side wall 1 for fastening the front side plate member 40
The screw holes 52 and 54 of No. 4 are arranged at intervals in the vicinity of the positioning locking pins 48 and 50, and the screw holes 76, 78 and 79 of the rear side wall 16 for fastening the rear side plate member 44 are The positioning locking pins 70, 72, and 74 are arranged at intervals in the vicinity thereof. As a result, the front side plate member 40 positioned at a predetermined position with respect to the front side wall 14 of the developing housing 10 and the rear side plate member 44 positioned at a predetermined position with respect to the rear side wall 16 are firmly fastened / fixed to that position. can do. With this configuration, it is possible to reliably prevent the front plate member 40 and the rear plate member 44 from being displaced with respect to the developing housing 10 due to vibrations during transportation of the image forming unit 100, or shocks such as dropping. Also, it is possible to reliably prevent a change in a predetermined gap between the peripheral surfaces of the sleeve member 22 and maintain the predetermined gap.

The image forming unit 100 is detachably attached to a copying machine (not shown) for use. It should be noted that the copying operation itself by the copying machine, including the developing operation by the developing device 2, may utilize well-known operations, and the description is omitted because it does not itself form the feature of the present invention. In the illustrated embodiment, the developer including the magnetic carrier and the toner is used, but another embodiment in which the developer including only the magnetic toner is used is also established.

[0043]

According to the image forming unit of the present invention, it is possible to easily and surely obtain a predetermined gap between the peripheral surfaces of the photosensitive drum and the sleeve member with high accuracy without causing assembly variations. To Moreover, even if the photoconductor drum is assembled without using an assembly jig,
A predetermined gap between the peripheral surfaces of the photosensitive drum and the sleeve member can be easily and reliably obtained with high accuracy without causing assembly variations. Furthermore, it is easy to assemble, the number of assembling steps is small, the assembling property is excellent, and a predetermined gap between the peripheral surfaces of the photosensitive drum and the sleeve member can be obtained with high accuracy without causing assembly variation. to enable. Furthermore, it is possible to reliably prevent a change in a predetermined gap between the peripheral surfaces of the photosensitive drum and the sleeve member due to vibration during transportation or impact such as dropping.
Allows to be maintained as prescribed.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of an image forming unit configured according to the present invention.

FIG. 2 is a perspective view of a developing housing of a developing device included in the image forming unit shown in FIG. 1, viewed from a certain angle.

FIG. 3 is a perspective view of the developing housing shown in FIG. 2 viewed from another angle.

FIG. 4 is a perspective view partially showing a part of both ends in the width direction of the developing device included in the image forming unit shown in FIG. 1 in the width direction.

5 is a partial perspective view showing a part of the image forming unit shown in FIG. 1 in an exploded manner.

FIG. 6 shows a part of the image forming unit shown in FIG.
The partial perspective view which shows the state which mounted the bearing body on the front side plate member.

FIG. 7 is a partial perspective view showing another part of the image forming unit shown in FIG. 1 in an exploded manner.

8 is a partial perspective view showing an exploded state of another part of the image forming unit shown in FIG. 7, to which another member is added.

9 is a configuration diagram schematically showing a main part of the image forming unit shown in FIG. 1 in a state where a front side plate member is attached to a developing housing, the diagram being viewed from a front side wall side of the developing housing.

10 is a configuration diagram of the developing housing shown in FIG.

11 is a configuration diagram of a front plate member shown in FIG.

FIG. 12 is a configuration diagram schematically showing a main part of the image forming unit shown in FIG. 1 in a state where a rear plate member is attached to a developing housing, the diagram being viewed from a rear side wall side of the developing housing.

13 is a configuration diagram of the developing housing shown in FIG.

14 is a configuration diagram of a rear plate member shown in FIG.

FIG. 15 is an enlarged view showing one of positioning lock pins provided in the developing housing shown in FIG.

16 is an enlarged view showing one of the positioning locked holes provided in the front plate member shown in FIG.

[Explanation of symbols]

2 Development device 4 photoconductor drum 4a Support shaft 10 Development housing 14 Front wall 16 Rear wall 20 Developer Application Means 22 Cylindrical sleeve member 22a Rotating support shaft 24 Static permanent magnet member 24a Fixed support shaft 40 Front plate member 42 Bearing body 44 Rear plate member 46 Bearing body 48, 50, 70, 72, 74 Positioning locking pin 60, 62, 84, 85, 86 Positioning locked hole 100 image forming unit SC Center of support shaft of developer applying means DC photo conductor drum support shaft axis

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kenichi Tanabe 1-2-2 Tamatsukuri, Chuo-ku, Osaka City Kyocera Mita Co., Ltd. (72) Hirotaka Kawakita 1-2-2 Tamatsukuri, Chuo-ku, Osaka No. Kyocera Mita Co., Ltd. (72) Inventor Hiroshi Kinoshita 1-22, Tamazukuri, Chuo-ku, Osaka Kyocera Mita Co., Ltd. (56) Reference JP 10-133541 (JP, A) JP JP 9-152826 (JP, A) JP 62-17761 (JP, A) JP 6-130799 (JP, A) JP 61-153670 (JP, A) Actual development 63-109949 (JP, U) Actual development Sho 62-16956 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/00 550 G03G 21/16-21/18 G03G 15/08-15/08 507 G03G 21/00 350-352

Claims (7)

(57) [Claims] 1. A photosensitive drum having a supporting shaft and a developing device, the developing device comprising a developing housing having both side walls, and a supporting shaft, both ends of which are supported by bearings on both side walls. An image forming unit that is supported between the front end portions of the photosensitive drums and has a developer applying unit for applying a developer to the peripheral surface of the photosensitive drum. Has
A bearing body is integrally mounted with a pair of bearing portions with a predetermined axial distance, and both ends of the support shaft of the developer applying means are further fitted and supported by one of the bearing portions of each bearing body. , The both ends of the support shaft of the photosensitive drum are fitted and supported by the other of the bearing portions of each of the bearing bodies, and each of the side plate members is positioned at a predetermined position of the corresponding side wall via the positioning means. An image forming unit, wherein the image forming unit is fixed by a fixing unit. 2. The positioning means comprises a plurality of positioning locking pins extending from the side walls to the outside in the longitudinal direction of the developing housing, and a plurality of positioning locked holes formed in each of the side plate members. The image forming unit according to claim 1, wherein the positioning locked hole of each of the members is fitted to a corresponding positioning locking pin of a corresponding side wall. 3. One of the positioning locking pins on each of the side walls and one of the positioning locked holes in each of the side plate members corresponding to one of the positioning locking pins is a shaft of the developer applying means. In a direction orthogonal to a straight line passing through the shaft center of the support shaft of the developer applying unit and the shaft center of the photosensitive drum, and on or near the straight line passing through the shaft center of the supporting shaft of the developer applying unit, The image forming unit according to claim 2, wherein the image forming unit is arranged near an axis of a support shaft of the developer applying unit. 4. The positioning locked hole in each of the side plate members comprises a plurality of small-diameter circular arc portions formed at equal angular intervals in the circumferential direction, and the peripheral edge of each of the small-diameter circular arc portions is
The image forming unit according to claim 3, wherein the image forming unit is formed so as to exist on an imaginary circle having the same diameter as the one of the corresponding positioning locking pins or a diameter slightly smaller than that of the corresponding one of the positioning locking pins. 5. The other positioning locked hole in each of the side plate members is a straight line passing through the axis of the support shaft of the developer applying means and the axis of the photoconductor drum when viewed in the axial direction of the developer applying means. The image forming unit according to claim 3 or 4, further comprising a pair of inner walls extending in parallel with each other and facing each other in parallel with each other with a space therebetween. 6. One of the other positioning locking pins on each of the side walls has an axial center of a support shaft of the developer applying means and an axial center of the photoconductor drum when viewed in the axial direction of the developer applying means. The image forming unit according to claim 3 or 4, wherein a slit having a pair of inner walls extending parallel to a straight line passing through and facing each other with a space therebetween is formed in a central portion of the axial center. 7. The fixing means is composed of a plurality of screw holes formed in each of the side walls and a plurality of screws that can engage with each of the screw holes, and the screw holes are respectively provided with the positioning locking pin. The device according to claim 2, wherein each of them is arranged at a distance from each other.
The image forming unit according to claim 6.