JP2001228662A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the coupling of a body to be driven from being broken and a device main body from being damaged. SOLUTION: This device is equipped with the body to be driven 100 having a driven-side coupling 190 coupled with a driving-side coupling 330 provided in the device main body and constituted to be attached to/detached from the device main body, and both couplings have plural recessed parts and projecting parts extended in their axial direction and made adjacent to each other in a circumferential direction. Then, a protection cover 215a protecting the driven- side coupling is provided on the body to be driven. The edge part of the projecting part of the driven-side coupling is formed to be a pyramid or a cone. The cover 215a is a cylindrical cover provided on the outer periphery part of the driven-side coupling and its edge surface 215a1 is positioned more outward in the axial direction than the edge of the driven-side coupling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer, a facsimile, a copying machine, etc., for forming an image by using an electrophotographic technique. In particular, the present invention relates to a driven member such as an image carrier (e.g., a photoconductor) having a coupling and configured to be detachable from the apparatus main body.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus provided with a driven member having a coupling detachably mounted on an apparatus main body, an image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 9-258606 is known. As shown in FIG. 16, the image forming apparatus has a drive-side coupling 2 provided on a main body frame 1 and a driven-side coupling 3 connected to the drive-side coupling 2. And a photoreceptor 4 as a driven body which is configured to be detachable, and the couplings 2 and 3 extend in the axial direction and extend in the circumferential direction as shown in FIGS. It has a plurality of concave portions 2a (3a) and convex portions 2b (3b) adjacent to each other. As shown in FIG. 3C, the photoconductor 4 is incorporated in the apparatus main body so that the couplings 2 and 3 are engaged with each other. In the assembled state, the photoconductor 4 is driven to rotate by the driving source 5. The Rukoto. As shown in FIG. 1A, the drive-side coupling 2 is configured to be slidable in the axial direction (the left-right direction in FIG. 2A) with respect to a drive shaft 5a driven by a drive source 5. A compression spring 6 is mounted on 5a between the frame 1 and the drive-side coupling 2 as urging means. Therefore, when the photoconductor 4 is mounted, the compression spring 6 causes the coupling 2 on the driving side to couple with the coupling 3 on the driven side.
And the couplings 2 and 3 are securely engaged with each other.

[0003]

The photosensitive member 4, which is a driven member in the above-described conventional apparatus, has a coupling 3
Was exposed. For this reason, when the photoconductor 4 is attached to and detached from the apparatus main body, there is a possibility that the tip of the coupling 3 hits the apparatus main body or the like to be damaged or the tip of the coupling 3 damages the apparatus main body. There was a problem.

An object of the present invention is to provide an image forming apparatus which can solve the above-mentioned problems and can prevent damage to a coupling of a driven body and damage to an apparatus main body.

[0005]

According to another aspect of the present invention, there is provided an image forming apparatus comprising: a driving-side coupling provided in an apparatus main body; and a driven-side coupling connected to the driving-side coupling. A driven body having a ring and configured to be detachable from the apparatus main body, wherein the two couplings have a plurality of concave portions and convex portions extending in the axial direction thereof and adjacent to each other in the circumferential direction. And wherein the driven member is provided with a protective cover for protecting the driven-side coupling. An image forming apparatus according to a second aspect is characterized in that, in the image forming apparatus according to the first aspect, a tip of the convex portion of the driven-side coupling has a pyramid shape or a conical shape. In the image forming apparatus according to a third aspect, in the image forming apparatus according to the first or second aspect, the protective cover is a cylindrical cover provided on an outer peripheral portion of the driven-side coupling, and a tip end surface thereof is provided. , Characterized by being located outward in the axial direction from the tip of the driven-side coupling.

[0006]

According to the first aspect of the present invention, the image forming apparatus has a drive-side coupling provided in the apparatus main body and a driven-side coupling connected to the drive-side coupling so as to be detachable from the apparatus main body. According to this image forming apparatus, the driven body includes a plurality of driven members, and the two couplings have a plurality of concave portions and convex portions extending in the axial direction and adjacent to each other in the circumferential direction. The driven body is driven in a state where the driven body is mounted on the apparatus main body such that the concave and convex portions of the two couplings are engaged with each other. According to the image forming apparatus of the first aspect, since the driven body is provided with the protective cover for protecting the driven-side coupling, when the driven body is attached to and detached from the apparatus main body. This prevents the tip of the coupling from being damaged by hitting the device body or the like, or the device body from being damaged by the tip of the coupling. According to the image forming apparatus of the second aspect, the first aspect is provided.
In the image forming apparatus described above, since the tip of the convex portion of the driven-side coupling has a pyramid shape or a conical shape, the following operation and effect can be further obtained. That is, in the above-described conventional structure (FIG. 16), the tips 2b1 and 3b1 of the protrusions 2b and 3b of the couplings 2 and 3 are provided.
Has a linear shape located on a plane orthogonal to the axis of the coupling (that is, a linear shape parallel to a plane orthogonal to the axis), so that the couplings 2 and 3 are attached when the photoconductor 4 is mounted.
When the two mesh with each other, the projections 2 of the two couplings 2 and 3
b, 3b, linear tips 2b1, 3 parallel to each other
It is easy for b1 to come into contact with a so-called straight line. For this reason, there is a problem that it is not always easy to engage the couplings smoothly, and it is not always easy to mount the photoconductor 4. On the other hand, according to the image forming apparatus of the present invention, since the tip of the convex portion of the driven-side coupling has a pyramid shape or a conical shape, the sharpest end (apex) has a small area. It becomes a point state. Therefore, when the couplings are engaged with each other at the time of mounting the driven body, it is extremely unlikely that the distal ends of the convex portions of both the couplings come into contact with each other. Therefore, the couplings smoothly mesh with each other, and as a result, the driven body can be easily mounted. By the way, in the case where the tip of the convex portion in the driven-side coupling has a pyramid shape or a conical shape, if no measures are taken, when attaching and detaching the driven body to and from the apparatus main body, Therefore, there is a high possibility that the leading end of the driven-side coupling hits the device main body or the like to be damaged, or the tip of the driven-side coupling damages the device main body. On the other hand, according to the image forming apparatus of the second aspect, since the driven body is provided with the protective cover for protecting the driven-side coupling, the driven body is attached to and detached from the apparatus main body. In this case, it is possible to prevent the tip of the coupling from being damaged by hitting the device main body or the like, or the device main body from being damaged by the tip of the coupling. That is, according to the image forming apparatus of the second aspect, the driven body having the coupling can be easily mounted, and at the same time, when the driven body is attached to and detached from the apparatus main body, The effect of preventing the distal end of the coupling from being damaged by hitting the apparatus main body or the like, or preventing the distal end of the coupling from damaging the apparatus main body can be obtained. In other words, the configuration according to claim 1 is particularly effective when the tip of the protrusion in the driven-side coupling has a pyramid shape or a conical shape. According to the image forming apparatus of the third aspect, in the image forming apparatus of the first or second aspect, the protective cover is a cylindrical cover provided on an outer peripheral portion of the driven-side coupling. Face
Since the driven coupling is located outward in the axial direction from the distal end of the driven coupling, when the driven body is attached to and detached from the apparatus main body, the distal end of the coupling is connected to the apparatus main body or the like. And damage to the main body of the apparatus at the tip of the coupling can be more reliably prevented. Moreover, the protection cover is a cylindrical cover provided on the outer peripheral portion of the driven coupling, and the distal end surface thereof is located outward in the axial direction from the distal end of the driven coupling. As a result, when the driven body is mounted on the apparatus main body, the meshing portion between the driven side coupling and the driving side coupling is covered with the protective cover over the entire outer peripheral portion thereof. Become. Therefore, dust (including the toner when the image forming apparatus is an apparatus using a toner) does not easily enter into the meshing portion between the driven-side coupling and the driving-side coupling, and deterioration in drive transmission accuracy is reduced. The effect that hardly occurs is obtained.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 is a schematic front view showing a first embodiment of an image forming apparatus according to the present invention. This image forming apparatus can form a full-color image on both sides of the recording material S using a developing device using four color toners of yellow (Y), cyan (C), magenta (M), and black (K). Device.

Reference numeral 100 denotes an image carrier cartridge as an example of a driven member. In this embodiment, the image carrier cartridge is constituted as a photosensitive member cartridge, and the photosensitive member 140 is rotationally driven in a direction indicated by an arrow in FIG. You. Around the photoreceptor 140, a charging roller 160 as a charging unit, a developing device 10 (Y, C, M, K) as a developing unit, an intermediate transfer device 30, and a cleaning unit 170 are arranged along the rotation direction. Are located. Charging roller 1
60 contacts the outer peripheral surface of the photoconductor 140 and uniformly charges the outer peripheral surface. On the outer peripheral surface of the uniformly charged photoconductor 140, a selective exposure L1 according to desired image information is performed by the exposure unit 40, and an electrostatic latent image is formed on the photoconductor 140 by the exposure L1. . This electrostatic latent image is
The toner is applied and developed by the developing device 10. As a developing device, a developing device 10Y for yellow and a developing device 1 for cyan
0C, a magenta developing device 10M, and a black developing device 10K are provided. These developing units 10Y,
Each of 10C, 10M, and 10K is configured to be swingable, so that only the developing roller 11 of one developing unit can selectively contact the photoconductor 140. Therefore, these developing units 10 apply any one of yellow, cyan, magenta, and black toners to the photoconductor 14.
0 to develop the electrostatic latent image on the photoconductor 140. The developed toner image is transferred onto the intermediate transfer belt 36 of the intermediate transfer device 30. Cleaning means 170
Is a cleaning blade 17 for scraping off the toner remaining on and adhering to the outer peripheral surface of the photoconductor 140 after the transfer.
1 (see FIG. 10) and the cleaning blade 171
And a receiving portion 172 for receiving the toner scraped off.

The intermediate transfer device 30 includes a driving roller 31 and
Four driven rollers 32, 33, 34, 35 and an endless intermediate transfer belt 36 stretched around these rollers.
And The drive roller 31 is substantially the same as the photoconductor 140 because a gear (not shown) fixed to an end of the drive roller 31 meshes with a gear 192 coaxial with a coupling 190 (see FIG. 2) of the photoconductor 140. The intermediate transfer belt 36 is driven to rotate at a peripheral speed, and is thus driven to circulate in the direction indicated by the arrow in FIG. The driven roller 35 includes the driving roller 31.
The intermediate transfer belt 36 is disposed at a position where the intermediate transfer belt 36 is pressed against the photosensitive member 140 by its own tension, and a primary transfer portion T1 is formed at a pressure contact portion between the photosensitive member 140 and the intermediate transfer belt 36. . The drive roller 31 is provided with an electrode roller (not shown) via an intermediate transfer belt 36, and a primary transfer voltage is applied to the conductive layer of the intermediate transfer belt 36 via the electrode roller. The driven roller 32 is a tension roller, and urges the intermediate transfer belt 36 in the tension direction by an urging means (not shown). The driven roller 33 is a backup roller that forms the secondary transfer portion T2. A secondary transfer roller 38 is opposed to the backup roller 33 via an intermediate transfer belt 36. The secondary transfer roller 38 can be moved toward and away from the intermediate transfer belt 36 by a contact / separation mechanism (not shown). A secondary transfer voltage is applied to the secondary transfer roller 38. The driven roller 34 is a backup roller for the belt cleaner 39.

In the process of circulating the intermediate transfer belt 36, the toner image on the photosensitive member 140 is transferred onto the intermediate transfer belt 36 in the primary transfer portion T1, and the toner image transferred onto the intermediate transfer belt 36 is Is transferred to a sheet (recording material) S, such as a sheet, supplied between the secondary transfer roller 38 and the secondary transfer unit T2. The sheet S is fed from the sheet feeding device 50, and is supplied to the secondary transfer portion T2 at a predetermined timing by the gate roller pair G. Secondary transfer unit T
The sheet S to which the toner image has been transferred in Step 2 passes through the fixing device 60, where the toner image is fixed.
0 and is discharged onto a sheet receiving portion 81 formed on a case of the apparatus main body 80. The paper discharge path 70 forms a switchback path for a return path 71 for returning the sheet S on which an image is formed on one side to the secondary transfer unit T2 again.

FIG. 2 shows the image carrier cartridge 100.
9 is a partially cut-away plan view showing a state where is mounted on a frame 82 of the image forming apparatus main body. As shown in this figure, the image forming apparatus includes a driving coupling 330 provided in the apparatus main body and a driving coupling 33.
And an image carrier cartridge 100 as a driven body having a driven coupling 190 connected to the main body 0 and detachably mounted on the apparatus main body. The image carrier cartridge 100 includes an image carrier unit 101 having a photoconductor 140 as a unit, and a cartridge case 200 for holding the image carrier unit 101 and the like. The two couplings 330, 190 are shown in FIG.
As shown in (a) and (b), a plurality of concave portions 330a extending in the axial direction and adjacent to each other in the circumferential direction.
190a and convex portions 330b and 190b.

Since the basic configuration of the two couplings 330 and 190 is the same, the following description will be made in detail by taking the driven coupling 190 as an example. 4A and 4B are views showing the coupling 190, wherein FIG. 4A is a perspective view and FIG. 4B is a partially enlarged view thereof. FIG.
(A) is a plan view, (b) is a front view, (c)
FIG. 4 is an explanatory diagram of a tooth shape (shape of a convex portion). As shown in these figures, the tip 190b1 of the projection 190b of the coupling 190 has a pyramid shape. Further, the tip 190b11 of the tip 190b1 is located on the outer peripheral side of the coupling 190. That is, the foremost end 190b11 on the outer peripheral side of the tip 190b1.
Is formed so as to be higher than the tip 190b12 on the inner peripheral side, whereby the tip 190 of the projection 190b is formed.
b1 has a pyramid shape. Further, as shown in the conceptual diagram of FIG.
1, the angle θ4 is equal to the base 190b1 of the projection 190b1.
3 is larger than the angle θ3. That is,
Tip portion 190b of convex portion 190b in this embodiment
1 is formed with a so-called two-step angle change. Although the contour 190c of the projection 190b is straight in this embodiment, it may be a curve slightly bulging outward. Such a coupling 1
Numeral 90 is separate from the photosensitive member 140, which is a driven member, and is made of metal.

The image carrier unit 101 and the cartridge case 200 constituting the image carrier cartridge 100 will be described in detail below. FIG. 6 shows the image carrier unit 10
FIG. This image carrier unit 101
Is a shaft 110 that does not rotate by itself,
Of a pair of disk-shaped members 1 rotatably attached to
20, 130, and a pair of these disc-shaped members 120, 13
0 both ends are supported and fixed by the disc-shaped members 120, 1
A flexible thin cylindrical image carrier (photoreceptor) 140 that rotates together with the image carrier 30, which is attached to the shaft 110 inside the image carrier 140, and contacts the image carrier 140 from outside. A cleaning blade 171 (see FIG. 10) as a contact member, and a backup drum 150 as a backup member that supports the image carrier 140 from the inside at the contact position where the charging roller 160 contacts.
And

Each of the pair of disk-shaped members 120 and 130 is rotatably provided on the shaft 110 via a bearing 114, and the outer peripheral surfaces 121 and 131 of the disk-shaped members 120 and 130 are used to support the image carrier. 140 at both ends 14
1 is supported and fixed. Disc-shaped members 120, 13
FIG. 7 shows a fixing structure of the image bearing member 140 and both ends 141 of the image carrier 140.
Shown in FIG. 7 shows the fixing structure of the end 141 of the image carrier 140 to one disk-shaped member 120, but the end 1 of the image carrier 140 to the other disk-shaped member 130.
The same applies to the fixing structure 41.

The outer diameter D of the outer peripheral surface 121 of the disc-shaped member 120
Numeral 3 is formed to be slightly larger than the inner diameter D2 of the image carrier 140, and the disc-shaped member 120 is press-fitted into an end 141 of the image carrier 140. In order to facilitate the press-fitting, a tapered surface 121a is formed inside the disc-shaped member 120 so as to be continuous with the outer peripheral surface 121 and has a diameter D4 at an inner end portion smaller than an inner diameter D2 of the image carrier 140. Is formed. By this press-fitting, the image carrier 140 and the disc-shaped member 1
20 is connected to the disk-shaped member 120 to form an adhesive receiving groove 122. The adhesive receiving groove 122 is formed on the outer peripheral surface 121 of the disk-shaped member 120 in order to further secure the connection therebetween. The image carrier 140 is filled with the adhesive 123 injected into the image carrier 140.
And the disc-shaped member 120 are adhered.

As shown in FIGS. 6 and 8, the coupling 190 described above is fixed to the outside of the other disc-shaped member 130. The coupling 190 is formed separately from the disc-shaped member 130, and is formed by a plurality of (for example, three (only one is shown)) screws 194.
30. The disk-shaped member 130 is integrally formed with a cylindrical portion 132 as a mounting portion extending outward from a receiving portion of the bearing 114, and a coupling 190 is fixed to a distal end portion thereof. That is, the driven-side coupling 190 is provided so as not to slide with respect to the cylindrical portion 132 as an attachment portion thereof. The coupling 190 is provided with a slide bearing 191 at the inner center thereof, and the coupling 190 is rotatably supported by the one end 111 of the shaft 110 by the slide bearing 191. That is, the coupling 19
0 and the disc-shaped member 130 are combined with each other on the shaft 110 by the sliding bearing 191 and the bearing 114.
The structure is supported by points.

Further, between the supporting portions supported at the above-mentioned two points, it is fixed to the coupling 190 and rotates together with the coupling 190, and is a rotating member other than the image carrier. A drive gear 192 for driving the transport screw 173 (see FIG. 9), and a combined body A of the coupling 190 and the disc-shaped member 130 are rotatably supported with respect to the cartridge case 200 (see FIG. 9). A bearing 193 as a bearing member is provided.

As shown in FIG. 6, the backup drum 1
50 includes a pair of disk-shaped side plates 151 and 151 and a cylindrical member 152 having both ends fixed by the outer peripheral surfaces of these side plates 151 and 151. The outer diameter of the cylindrical member 152 is formed slightly smaller than the inner diameter of the image carrier 140. A boss 155 is provided on the side plate 151, and a slide bearing 156 is mounted on the boss 155. The slide bearing 156 is made of an oil-impregnated metal (for example, a Cu-based oil-impregnated metal). The shaft 110 has support portions 115 formed on both ends of the disc-shaped members 120 and 130.
An eccentric portion (eccentric shaft portion) 1 formed at the center and eccentric to the support portion 115 as shown in FIG.
The backup drum 150 is rotatably supported by the eccentric portion 116. The eccentric part 116
The cleaner blade 171 as a contact member (see FIG. 10) and the contact position side (the right side in FIG. 10) where the charging roller 160 comes into contact are eccentric, whereby the outer peripheral surface of the backup drum 150 ( A part of the outer peripheral surface of the cylindrical member 152 supports the image carrier 140 from the inside over a relatively wide range at the contact position. The backup drum 150 is mounted on the shaft 11
As shown in FIG. 2, when the image carrier cartridge 100 is incorporated in the apparatus main body and the image carrier 140 is driven to rotate as shown in FIG. At an abutting position of the cleaning blade 171 or the like, the outer peripheral surface 152 a of the cylindrical member 152 abuts on the inner peripheral surface 140 a of the image carrier 140 so as to rotate following the image carrier 140. Eccentric part 11 of shaft 110
Retaining rings 117 and 118 are attached to both end portions of 6, and the movement of the backup drum 150 in the axial direction is restricted by the retaining rings 117 and 118. A compression coil spring 102 for preventing backlash is provided between one of the retaining rings 117 and the bearing 114.

The image carrier unit 101 as described above is
Specifically, for example, it is assembled as follows. A side plate 151 which should constitute the backup drum 150;
Each of the slide bearings 156 is press-fitted into the corresponding 151. The side plates 151 and 151 obtained as described above are pressed into both ends of the cylindrical member 152 constituting the backup drum 150. Thus, the backup drum 150 is configured. The shaft 11 is attached to the backup drum 150 obtained above.
0, and the retaining rings 117 and 118 are attached to fix the movement of the backup drum 150 in the axial direction. On the other hand, the slide bearing 191 and the drive gear 192 are set on the coupling 190. The bearings 114 and 193 are mounted on the disk-shaped member 130, and the coupling 190 with the sliding bearing 191 and the driving gear 192 obtained above is connected to the disk-shaped member 130.
And fixed with screws 194. The one end 111 of the shaft 110 with the backup drum 150 obtained above is inserted into the disk-shaped member 130 obtained above. The image carrier 140 is mounted from the other end (112) of the shaft 110 (temporarily press-fits the disc-shaped member 130 into one end of the image carrier 140). The spring 102 is mounted from the other end (112) side of the shaft 110, and the disk-shaped member 120 to which the bearing 114 is mounted in advance is mounted (the disk-shaped member 120 is mounted on the image carrier 140).
Tentatively press-fit the other end). Disc-shaped members 120 and 130 are provided at both ends of the image carrier 140.
Is completely press-fitted, and the adhesive 123 is injected into the adhesive receiving grooves 122 formed on the outer peripheral surface thereof, so that the image carrier 140 and the disk-shaped member 120 are securely bonded and fixed. By the way, for example, as described above, the image carrier unit 10
When the disk-shaped member 1 is assembled, when the disk-shaped member 130 is temporarily pressed into one end of the image carrier 140 in the above-described process, the disk-shaped member 1
30 may be press-fitted in a slightly inclined state with respect to the image carrier 140 (therefore, the coupling 190 is also inclined). In such a case, if one of the disc-shaped members 130 is The combination with 190 is
If the bearing 10 is supported by the bearing 114 at one point, the inclined state cannot be corrected. In this embodiment, however, the coupling between the coupling 190 and the disc-shaped member 130 is not performed. Since the body A is supported at two points on the shaft 110 by the slide bearing 191 and the bearing 114, the other disc-shaped member 120 is attached to the other end of the image carrier 140 in the above process. When the disc-shaped members 120 and 130 are completely press-fitted into both ends of the image carrier 140 in the above-described process,
The inclined state of the combined body A is corrected.

The image carrier unit 101 as described above is
The cartridge is assembled into the cartridge case 200 in a state as shown in FIGS. FIG. 9 shows the image carrier unit 101.
FIG. 1 is a partially cut-away plan view showing a cartridge case 200 in which a side cover described later is omitted.
0 is a right side sectional view (a sectional view as viewed from the front side of the image forming apparatus in which the cartridge case 200 is incorporated), and FIG. 11 is a left side view. As shown in these figures, the cartridge case 200 includes a pair of side parts 210 and 220, a main connecting part 230 connecting one side of these side parts 210 and 220, and a side part 210 and 220. And a sub-connecting portion 240 connecting the lower side of the other side. The cleaning means 170 (see FIG. 10) is first incorporated into the case 200, then the charging roller 160 is incorporated, and then the image carrier unit 101 is incorporated.

As shown in FIG. 10, the cleaning means 170 includes a cleaning blade 171 for scraping off the toner remaining on and adhering to the outer peripheral surface of the photoconductor 140, and temporarily removing the toner scraped off by the cleaning blade 171. A receiving portion 172 for receiving the toner overflowing from the storing portion 1721, and a toner conveying screw 173 disposed at the bottom of the receiving portion 172 as a conveying means for conveying the toner. .

The upper portion of the cleaning blade 171 is fixed to a blade holder 174. The blade holder 174 is made of sheet metal, and arms 174a, 174a (only one is shown) provided at both ends thereof
11 (only one is shown), it is swingably attached to the side parts 210 and 220. A blade urging spring (compression coil spring) 175 is provided between the main connecting portion 230 and the blade holder 174. When the image carrier unit 101 is incorporated into the cartridge case 200 as shown in FIG. The tip (edge) 1 of the cleaning blade 171 is formed by the urging force of the urging spring 175 and the elasticity of the cleaning blade 171 itself.
71 a comes into contact with the surface of the photoconductor 140. According to such a structure, the blade 171 can be pressed against the photoconductor 140 at a constant pressure regardless of the shape accuracy and the rubber hardness of the blade 171. Further, filming of the photoconductor 140 can be prevented by reducing pressure fluctuation.

The receiving portion 172 is formed integrally with the main connecting portion 230 by a lower portion of the main connecting portion 230. A sealing member 176 made of a foam material is provided between the upper surface of the blade holder 174 and the groove 231 formed on the inner surface of the main connecting portion 230. A rake sheet 177 is provided below the tip of the cleaning blade 171. The base of the rake sheet 177 is fixed to the main connecting portion 230, and the leading edge of the rake sheet 177 is
The sliding contact with the surface of No. 0 prevents toner leakage.

As shown in FIG. 9, the toner conveying screw 173 has one end 173a1 of a screw shaft 173a.
Are rotatably supported by the side wall 172a of the receiving portion 172. The other end 173a2 of the shaft 173a is
Is in a free state (unsupported state) near the end of the cylindrical member 178 for toner conveyance connected to the cylindrical member 178. Axis 17
A gear 173b is fixed to one end of the gear 3a, and this gear 173b is connected to a reduction gear 173c as shown in FIG.
Through the gear 19 of the image carrier unit 101 described above.
2 is engaged. Therefore, the image carrier unit 1
01 is rotated, the toner conveying screw 173 is rotated.
Is also driven to rotate, and the toner in the receiving portion 172 is conveyed rightward (in the direction of the arrow X1) in FIG. The transported toner falls from an opening (toner outlet) 178a formed near the end of the toner transporting cylindrical member 178, and is collected in a waste toner bottle (not shown).

The cylindrical member 178 is provided with a shutter 172c slidable in the axial direction. When the exterior cover (not shown) of the image forming apparatus is closed, the shutter 172c slides to the left to open the toner outlet 178a as shown by a virtual line in FIG. 9, and is shown by a solid line in FIG. 9 when the exterior cover is opened. As described above, the toner outlet 178a is closed by sliding to the right.

The charging roller 160 is rotatably mounted to the case 200 after the cleaning means 170 is mounted. In the mounted state, the charging roller 160 is urged by a biasing means (spring) 161 to attach the photosensitive member 140 ( FIG.
0). Therefore,
As shown in FIG. 10, when the image carrier unit 101 is incorporated in the cartridge case 200, the charging roller 16
A value of 0 indicates that the photosensitive member 140 rotates following the surface of the photosensitive member 140.

As shown in FIG. 6, the image carrier unit 10
At one end of the fixed shaft 110, a pin 113 is provided on a protruding portion 112 protruding outward from the disc-shaped member 120, and a side portion 2 of the cartridge case 200 is provided.
20 is provided with a pin receiving portion (not shown) for receiving the pin 113, and the pin 113 and the pin receiving portion constitute a positioning means for determining a position around the fixed shaft 110 (see FIG. 2). .

One side 210 of the cartridge case 200
Is formed with a slit 214 (see FIGS. 9 and 11) for guiding the bearing 193 when the image carrier unit 101 is incorporated. The other side 220 has the shaft 11
A slit 224 (see FIG. 9) for guiding the zero is formed, and the above-mentioned pin receiving portion (not shown) is formed at the end of the slit 224. Therefore, the image carrier unit 101 can be mounted on the case 200 by inserting the bearing 193 and the shaft 110 in alignment with the slits 214 and 224.
13, and as shown in FIG.
5 (see FIG. 2) is fixed to the case 200 by attaching it to the case 200.

When the image carrier unit 101 is assembled in the case 200 in this manner, the coupling 190 and the disc-shaped member 13 in the image carrier unit 101 are provided.
0 through the bearing 193 to the case 2
00 is supported rotatably.

FIG. 12 is a partially cut plan view of the image carrier cartridge 100, and FIG. 13 is a left side view (view from the back side of the image forming apparatus in which the image carrier cartridge 100 is incorporated). As shown in these figures, the side cover 2
15 is provided with a protective cover 215 a for protecting the driven-side coupling 190. This protective cover 215
Reference symbol a denotes a cylindrical cover provided on the outer peripheral portion of the driven coupling 190, and the distal end surface 215a1 is located outside the distal end 190b11 of the driven coupling 190 in the axial direction. The side cover 215 is fixed to the one side portion 210 with a plurality of screws 216, and the side cover 225 is fixed to the plurality of screws 227.
At the other side 220.

The image carrier cartridge 100 assembled as described above is removably mounted on the frame 82 of the image forming apparatus as shown in FIG. The frame 82 includes a pair of plate-like frames 82 provided in parallel with each other.
a and 82b. The drive unit 300 is provided on one plate-shaped frame 82a, and the other plate-shaped frame 82b is used for inserting and removing (inserting and removing) the image carrier cartridge 100 in the directions of arrows X1 and X2 in FIG. A hole 83 is provided.

The drive unit 300 has a motor 310 as a drive source, a transmission case 320 in which a gear transmission mechanism is housed, and the drive-side coupling 330 fixed to an output shaft 321. Coupling 33
Numeral 0 is provided so as not to slide with respect to the output shaft 321 which is the mounting portion. The drive unit 300 is attached to the plate-shaped frame 82a by attaching the flange portion 322 of the transmission case 320 to the plate-shaped frame 82a via a compression spring 323 as an urging means. A pin 324 is provided on the flange portion 322. The pin 324 is slidably attached to the plate-shaped frame 82 a in the directions of the arrows X <b> 1 and X <b> 2, and the compression spring 323 is provided around the pin 324. Therefore, the drive unit 300 includes the compression spring 323
However, when the image carrier cartridge 100 is mounted as shown in the drawing, the image carrier cartridge 100 is moved in the direction of arrow X2 and is driven by the biasing force of the compression spring 323 and the driven coupling 330 and the driven side. Coupling 1
90 is securely connected. That is, the compression spring 323 biases the entire drive unit 300 to bias the drive-side coupling 330 toward the driven-side coupling 190 via the output shaft 321 as an attachment portion thereof. ing.

The other plate-shaped frame 82b is provided with a positioning hole 84 into which a positioning pin 226 provided in the image carrier cartridge 100 is inserted.
Lever 85 for attaching / detaching image carrier cartridge 100
Is provided. As shown in FIG. 14, the lever 85 is pivoted by a shaft 86 provided on the frame 82b.
b so as to be rotatable with respect to
a and pressing portions 85b, 85b integral therewith. The plate-like frame 82b has a flange 87
a, and the lever 85 has an engaging portion 8 which can be disengaged from the engaging portion 87 of the frame between the pressing portions 85b, 85b.
5c is formed. Therefore, when the image carrier cartridge 100 is inserted as shown in FIG. 2 and the lever 85 is rotated to the position shown by the solid line in FIGS. 2 and 14, the engaging portion 85c of the lever 85 is engaged with the engaging portion 87 of the frame. (The flange portion 87a) and the pressing portions 85b, 85b press the front surface 100a of the image carrier cartridge 100,
The image carrier cartridge 100 is fixed, and the driving-side coupling 330 and the driven-side coupling 190 are reliably engaged by the urging force of the compression spring 323, as described above. Further, the lever 85 is rotated from the above state as shown by a virtual line in FIG.
By releasing the engagement between the engaging portion 87 and the engaging portion 87 (the flange portion 87a) of the frame and releasing the pressing portion 85b against the front surface 100a of the image carrier cartridge 100, the image carrier cartridge 100 is moved in the direction of the arrow. It becomes possible to extract in the X1 direction.

When the image carrier cartridge 100 is incorporated in the image forming apparatus as shown in FIG. 2, the coupling 190 is connected to the drive side coupling 33 of the drive unit 300.
When the 0 is engaged, the image carrier 140 is rotationally driven.

According to the above-described image forming apparatus, the following functions and effects can be obtained. (A) Drive-side coupling 330 provided in the apparatus main body
And the driven body 100 having the driven-side coupling 190 connected to the driving-side coupling 330 and configured to be detachable from the apparatus main body. The image carrier 140 of the driven body 100 is driven in a state where the driven body 100 is mounted on the apparatus main body so as to engage with each other. According to this image forming apparatus, the driven body 10
0 is provided with a protective cover 215a for protecting the driven side coupling 190, so that when the driven body 100 is attached to and detached from the apparatus main body, the coupling 19
0 of the coupling 190 may damage the tip 190b11 of the coupling 190, or the tip 190b1 of the coupling 190 may be damaged.
1 does not damage the apparatus body. (B) Protrusion 190b in driven-side coupling 190
Is formed in a pyramid shape, the point 190b11 of the tip is a point having a small area. Therefore, when the couplings are engaged with each other when the driven body 100 is mounted, it is extremely unlikely that the tips of the protrusions of both couplings will come into contact with each other. Therefore, the couplings smoothly mesh with each other, and as a result, the driven body 100 can be easily mounted. Incidentally, the distal end portion 190b of the convex portion 190b in the driven-side coupling 190.
In the case where the driven body 100 has a pyramid shape, if no measures are taken, when the driven body 100 is attached to and detached from the apparatus main body, the driven side coupling 190
Of the driven side coupling 190 may be damaged by hitting the tip 190b1 of the
The risk of damaging the apparatus body in b1 increases.
On the other hand, according to the image forming apparatus of this embodiment,
Since the driven body 100 is provided with the protective cover 215a for protecting the driven-side coupling 190, when the driven body 100 is attached to and detached from the apparatus main body, the distal end of the coupling 190 is attached to the apparatus main body. This prevents damage to the apparatus main body due to damage to the apparatus body or damage to the apparatus main body at the tip end of the coupling 190. That is, according to this image forming apparatus, the driven body 100 having the coupling 190 can be easily mounted, and at the same time, when the driven body 100 is attached to and detached from the apparatus main body, the coupling is performed. The operation and effect of preventing the tip of the coupling 190 from being damaged by hitting the apparatus main body or the like, or preventing the distal end of the coupling 190 from damaging the apparatus main body can be obtained. In other words, the driven body 1
00, the protection cover 215a for protecting the driven coupling 190 is provided when the tip 190b1 of the convex portion of the driven coupling 190 has a pyramid shape or a conical shape as described later. Especially effective. (C) The protection cover 215a is
0 is a cylindrical cover provided on the outer peripheral portion of the driven coupling 190.
Since the driven member 100 is attached to and detached from the apparatus main body, the distal end portion 190b1 of the coupling 190 hits the apparatus main body or the like when the driven body 100 is attached to or detached from the apparatus main body. Or damage to the apparatus main body by the distal end of the coupling 190 is more reliably prevented. Moreover, the protective cover 215a is a cylindrical cover provided on the outer peripheral portion of the driven-side coupling 190,
As shown in FIG. 2, the driven body 100 is attached to the main body of the apparatus as a result of the configuration in which the distal end surface 215a1 is located more outward in the axial direction than the distal end 190b11 of the driven-side coupling 190. In this case, the meshing portion between the driven-side coupling 190 and the driving-side coupling 330 extends over the entire outer peripheral portion thereof.
15a. Therefore, dust (including toner) does not easily enter into the meshing portion between the driven-side coupling 190 and the driving-side coupling 330, and the effect that the drive transmission accuracy is hardly deteriorated is obtained.

(D) Both couplings 330 and 190 are
Each of the mounting portions 321 and 132 is provided so as not to slide, and the urging means 323 is
This biases the coupling 330 to its mounting portion 3
Since it is configured to be urged through the coupling 21, no backlash occurs between the coupling 330 and the mounting portion 321 thereof, and as a result, the driven body 140 can be driven with high accuracy. . (E) The biasing means 323 biases the entire drive unit 300 having the drive source 310 toward the driven-side coupling 190, so that a stable biasing action is obtained, and as a result, The driving body 140 can be driven with higher accuracy. (F) Convex part 33 in both couplings 330 and 190
Since the tip portions 330b1 and 190b1 of 0b and 190b have a pyramid shape, their extreme ends (apex) 330b
11, 190b11 is a point state having a small area. Therefore, when the couplings are engaged with each other at the time of mounting the driven body, it is extremely unlikely that the sharpest ends (apex) 330b11, 190b11 of the convex portions of both couplings 330, 190 will come into contact with each other. Therefore, the couplings smoothly mesh with each other, and as a result, the driven body 100 can be easily mounted. (G) Tip 330b of coupling 330, 190
The sharpest end 330b11, 190 at 1,190b1
Since b11 is located on the outer peripheral side of the coupling, the probabilities that the sharpest ends (apex) 330b11 and 190b11 of the convex portions of both couplings come into contact with each other when the driven body is mounted are further reduced. Therefore, the couplings can be more smoothly engaged with each other, and as a result, the driven body can be more easily mounted. (H) Protrusion 330 in couplings 330 and 190
Since the angle θ4 forming the tip portions 330b1 and 190b1 of b and 190b is larger than the angle θ3 forming the base portions 330b13 and 190b13 of the convex portions, the following operation and effect can be obtained. That is, the tip portion 330b of the convex portion
The angle θ4 forming 1,190b1 is the base 330b of the projection.
13, 190b13, the power is transmitted by the engagement of the couplings by the abutment of the bases 330b13, 190b13 (see FIG. 3). Therefore, at the time of power transmission, no force acts on the tips 330b1 and 190b1 of the convex portions (see FIG. 3), and therefore, the tips 330b1 and 190b1 are not damaged by the power transmission. Further, even when the tip portions 330b1 and 190b1 of the protrusions of the coupling come into contact with each other at the time of mounting the driven body, the angle θ4 of the tip portions 330b1 and 190b1 does not matter.
Is relatively large, so damage is unlikely to occur. On the other hand, the bases 330b13, 1
Since the angle θ3 forming 90b13 is relatively small, the force acting in the direction of disengagement is small. Therefore, the urging force of the urging means 323 for urging the coupling can be small, and as a result, the force required for mounting the driven body can be small. That is, according to this image forming apparatus, the coupling protrusions 330b, 190
b is less likely to be damaged, and the driven body can be easily mounted. Moreover, the angle θ4 forming the tips 330b1 and 190b1 of the projections is
Angle θ3 forming bases 330b13 and 190b13 of the protrusions
As a result, the length L of the protrusions 330b and 190b in the axial direction of the coupling (FIG. 5)
(C)), it is possible to obtain an effect that the sliding stroke in the axial direction when the coupling is engaged is also short. (I) Since the couplings 330 and 190 are metal couplings formed separately from the driven body,
Compared to a case made of synthetic resin, the foremost portion 33 of the convex portion
0b1 and 190b1 can be formed sharply. Therefore, the driven body can be more easily mounted. Further, since the rigidity and accuracy of the coupling can be improved, high-precision drive transmission is possible.

(J) According to the image carrier unit 101 of this embodiment, the combined body of the coupling 190 and the disc-shaped member 130 is supported on the shaft 110 at two points. Therefore, the following operation and effect can be obtained. That is, the disk-shaped member 130 and the coupling 1
Even if the combined body of the coupling 190 and the disc-shaped member 130 is pressed into the image carrier 140 while being slightly inclined with respect to the image carrier 140,
Since the structure is supported at the points, the inclined state of the combined body with respect to the image carrier 140 is corrected. Therefore, the coaxiality of the image carrier 140 with the disc-shaped member 130 and the coupling 190 is improved, and the engagement accuracy between the coupling 190 and the coupling 330 for driving the same is improved. Is less likely to occur, and at the same time, the distortion of the flexible thin cylindrical image carrier 140 is reduced, the deflection of the image carrier 140 is reduced, and the cleaning blade 171 and the developing roller ( The contact state of the contact member such as the reference numeral 11 in FIG. 1) is stabilized, and as a result, the image quality is improved. (K) for driving a rotating member (toner conveying screw 173 in this embodiment) other than the image carrier 140 by rotating together with the coupling 190 between the supporting portions supported at the two points. Since the drive gear 192 is provided, the distance between the two points (the bearing 114 and the sliding bearing 1)
At the same time, the space between them can be effectively used. (L) The image carrier unit 101 is a unit attached to the case 200, and a bearing for rotatably supporting the combined body with respect to the case 200 between the support portions supported at the two points. Since the member 193 is provided, the distance between the two points can be increased, and at the same time, the space between them can be effectively used.
Moreover, since the combined body is supported by the case 200 with the bearing member 193, the rotational state of the combined body and the image carrier 140 is further stabilized, and as a result, the image quality is further improved.

<Second Embodiment> FIGS. 15A and 15B show a projection of a coupling in an image forming apparatus according to a second embodiment of the present invention. FIG. 15A is a partial plan view, and FIG. () Is a partial front view, and (c) is a partial perspective view. This embodiment differs from the first embodiment in the shape of the projection of the coupling, and there is no other difference. The coupling 190 (330) in this embodiment is
The tip 190b1 (3) of the projection 190b (330b)
A surface 190b14 (330b14) is added to 30b1), and the shape of the tip 190b1 (330b1) is a pentagonal pyramid. Such a number of corners can be further added, and thus, ultimately, the tip 190b1
It is also possible to make the shape of (330b1) conical. According to such an embodiment, the same operation and effect as those of the above-described first embodiment can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be appropriately modified within the scope of the present invention. For example, in the above-described embodiment, the photoreceptor is described as an example of the driven body. However, the driven body is not limited to this. For example, an intermediate transfer body that is another example of the image carrier is used. It doesn't matter.

[0040]

In any of the image forming apparatuses according to the first to third aspects, when the driven body is attached to or detached from the apparatus main body, the distal end of the coupling hits the apparatus main body or the like, and is damaged. The end of the coupling will not damage the device body. Further, according to the image forming apparatus of the second aspect, the driven body having the coupling can be easily mounted, and at the same time, when the driven body is attached to and detached from the apparatus main body, the cup is removed. It is possible to prevent the distal end of the ring from being damaged by hitting the device main body or the like, or the device main body from being damaged by the distal end of the coupling. According to the image forming apparatus of the third aspect, it is difficult for dust to enter the meshing portion between the driven-side coupling and the drive-side coupling, and the drive transmission accuracy is unlikely to be deteriorated.

[0041]

[Brief description of the drawings]

FIG. 1 is a schematic front view showing a first embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a partially cutaway plan view showing a state in which the image carrier cartridge 100 is mounted on a frame 82 of the image forming apparatus.

3A is a side view showing a state where both couplings 330 and 190 are engaged with each other, and FIG. 3B is a partially enlarged view of FIG.

FIG. 4 is a view showing a coupling, (a) is a perspective view,
(B) is a partially enlarged view thereof.

5 (a) is a plan view, FIG. 5 (b) is a front view, and FIG. 5 (c) is an explanatory view of a tooth profile.

FIG. 6 is a longitudinal sectional view showing an image carrier unit.

FIG. 7 is a partially enlarged view of FIG. 6;

FIG. 8 is a partially enlarged view of FIG. 6;

FIG. 9 is a partially cutaway plan view showing a part of the cartridge case 200 in which the image carrier unit 101 is incorporated.

FIG. 10 is a right sectional view of the same (cartridge case 20).
0 is a cross-sectional view as viewed from the front side of the image forming apparatus into which the image forming apparatus is incorporated.

FIG. 11 is a left side view of the same (cartridge case 200).
FIG. 2 is a view as viewed from the rear side of the image forming apparatus in which the image is incorporated.

FIG. 12 is a partially cut plan view of the image carrier cartridge 100.

FIG. 13 is a left side view of the same (image carrier cartridge 100).
FIG. 2 is a view as viewed from the rear side of the image forming apparatus in which the image is incorporated.

FIG. 14 is a diagram of the image carrier cartridge 100 and a lever 85 for attachment / detachment viewed from the front side of the image forming apparatus.

FIGS. 15A and 15B are diagrams showing convex portions of the coupling in the image forming apparatus according to the second embodiment of the present invention, wherein FIG. 15A is a partial plan view, FIG. 15B is a partial front view, and FIG. It is a perspective view.

FIGS. 16 (a), (b) and (c) are explanatory views of a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Image carrier cartridge (driven body) 190 Driven side coupling 190b Convex portion 190b1 Tip portion 215a Protective cover 215a1 Tip surface 310 Motor (drive source) 330 Drive side coupling

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Makoto Sato 3-3-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation F-term (reference) 2H035 CA07 CB01 CD05 CD07 CG03 2H071 BA03 BA13 BA16 CA02 CA05 DA15

Claims (3)

[Claims] An apparatus includes: a drive-side coupling provided in an apparatus main body; and a driven body having a driven-side coupling coupled to the drive-side coupling and configured to be detachable from the apparatus main body. An image forming apparatus in which both the couplings have a plurality of concave portions and convex portions extending in the axial direction and adjacent to each other in the circumferential direction, wherein the driven body has a driven side cup. An image forming apparatus provided with a protective cover for protecting a ring. 2. The image forming apparatus according to claim 1, wherein a tip portion of the convex portion in the driven-side coupling has a pyramid shape or a conical shape. 3. The protection cover is a cylindrical cover provided on an outer peripheral portion of the driven-side coupling, and a distal end surface thereof is located outward in the axial direction from a distal end of the driven-side coupling. 2. The method according to claim 1, wherein
Or the image forming apparatus according to 2.