JP2518583B2 - Image forming device - 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 apparatus such as an electrophotographic apparatus, a printer or a micro device which uses a process unit.

An electrophotographic apparatus using an electrophotographic process unit will be described below as an example.

Here, the electrophotographic process unit is
The electrophotographic photosensitive member and at least one other process means are housed in a frame that can be attached to and detached from a predetermined position in the main body of the electrophotographic apparatus. The process means is a means for applying a predetermined action to the photoconductor in order to execute the image forming process, such as a charger for the photoconductor, a developing device for the electrostatic latent image, a cleaning device for removing the toner remaining on the photoconductor, and the like. Say that. Further, the electrophotographic apparatus main body means means for accommodating and supporting the above process unit, transfer paper conveying means,
It is a unit that includes a fixing unit that fixes the toner image transferred from the photoconductor onto the transfer paper, and is surrounded by an exterior plate.

[0004]

2. Description of the Related Art In an electrophotographic apparatus, replenishment of a photosensitive member as an image bearing member with developer, disposal of waste toner cleaned from the photosensitive member after transfer, cleaning of charging lines, and various consumable parts. It is necessary to replace or adjust the items as necessary.

Most of the above-mentioned operations are concentrated around the photoconductor, which has been time-consuming in the past, but in recent years, the photoconductor and the process means around the photoconductor such as a developing device, a cleaner, and a charger have been used. The electrophotographic apparatus is configured to be housed in one frame and can be pulled out and held from a predetermined position of the apparatus main body, or the unit for each frame can be detached from the apparatus main body to facilitate the above-mentioned respective operations. Proposed. In this way, the workability is improved, the work time can be shortened, the running cost can be reduced, and the work can be performed by the user himself instead of the service person. Further, since the developing device can be easily replaced with that of another color, an image of a desired color can be easily formed.

Further, a photoconductor, a developing device, a cleaner,
It has been considered to reduce the maintenance work by forming a process unit in which an image forming means such as a charger is integrally incorporated in a frame, and replacing the entire unit when replacing the photoconductor. With such a configuration, the user can easily replace each process-related unit that requires regular maintenance, and the maintenance work by the service person can be eliminated or reduced, so that the work efficiency is improved. Greatly improved. Further, an image of a desired color can be formed by replacing the toner of another color with a process unit storing the toner. Alternatively, there is an advantage that the developing unit corresponding to the original image can be used by replacing the developing unit with another developing unit.

[0007]

[0008]

If the process unit is mounted on the main body of the apparatus while the photosensitive member and the process means are not properly mounted on the frame, the photosensitive member is responsive to the mounting operation of the process unit on the main body of the apparatus. It seeks to be able to position the body or process means in the correct position.

[0009]

SUMMARY OF THE INVENTION The main invention for solving the above-mentioned problems is to provide an image forming apparatus in which a process unit is detachable, a frame body, and a photoconductor detachable in the frame body.
A mounting unit for removably mounting a process unit having the process unit acting on the photoconductor, and the photoconductor of the process unit is positioned at a predetermined mounting position according to the mounting operation of the process unit. And a means for positioning the electrophotographic photosensitive member at a predetermined mounting position when the electrophotographic photosensitive member is not mounted.

Still another main aspect of the present invention is, in an image forming apparatus in which a process unit is attachable / detachable, a frame body, a photoconductor, and process means which is detachably provided on the frame body and acts on the photoconductor. A mounting unit for removably mounting the process unit having, and the process unit having the process unit is not positioned at a predetermined position with respect to the photoconductor according to the mounting operation of the process unit, An image forming apparatus comprising: a means for positioning the process means at a predetermined position.

[0011]

[0012]

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

First, an electrophotographic copying machine using an embodiment of the process unit according to the present invention will be described.

FIG. 1 shows a cross-sectional view of a copying machine main body X surrounded by an exterior plate Z. In the figure, reference numeral 1 denotes a document placing table made of a transparent member such as glass, which is provided on the upper part of the main body X, and moves forward in the direction of arrow a for scanning the document, and when the scanning of the document is completed, it moves backward in the direction opposite to the arrow. . Reference numeral 2 denotes an image-forming optical system in which a large number of short-focus small-diameter image-forming elements such as SELFOC (trade name) and a bar lens are assembled in an array, and is fixed to a plate 16 fixed inside the main body X. A document Y placed on the document table 1 is illuminated by an illumination lamp L, and a reflected light image thereof is passed through an opening A formed in a frame body of a process unit 17 on the electrophotographic photosensitive drum 3 by the array 2. Slit exposure is performed. The photosensitive drum 3 rotates about the shaft 3b in the arrow direction. Reference numeral 4 is a charger, which uniformly charges the photosensitive drum 3 covered with, for example, a zinc oxide photosensitive layer or an organic photoconductor photosensitive layer 3a. Image exposure of the reflected light image is performed by the element array 2 on the drum 3 that is uniformly charged by the charger 4, and an electrostatic latent image is formed. The electrostatic latent image is then visualized by the developing device 5 including the magnet roller 5a and the toner reservoir 5b. On the other hand, the sheet P on the transfer paper storage box S (which can be attached to and detached from the main body X) is guided by a feeding roller 6 and a registration roller 7 which rotates at a timing so as to synchronize with an image on the photosensitive drum 3. , 10 'is sent to the transcription department. Then, the transfer discharger 8 transfers the toner image on the photosensitive drum 3 onto the sheet P. After that, the sheet P separated from the drum 3 by the separating means 9 (for example, a separating belt or a separating corona discharger) is guided to the fixing device 11 by the guide 10 ″ to fix the toner image on the sheet P, and Discharge roller 1
The sheet is discharged onto the tray 13 by 2. (Note that Guide 1
0, 10a, 10b, rollers 6, 7, 12, transfer discharger 8, separating means 9, and fixing device 11 are attached to a stay (not shown) fixedly supported in the main body X. That is, the passage for the paper P is provided so as to be always inside the main body X. After the toner image is transferred, the residual toner on the drum 3 is removed by the cleaner 14. The cleaner 14 includes a blade 14 a that contacts the drum 3, a waste toner reservoir 14 b, and a rake sheet 14 that receives the waste toner removed from the surface of the drum 3 by the blade 14 a.
It consists of c and. After that, the drum 3 is provided so that the upper part and the lower part are pressure-divided into the opening 15 'of the apparatus main body X provided in the reflection shade 15 for reflecting the light emitted from the lamp L onto the original Y. Irradiation is performed through the opening 16 'provided in the partition plate 16 and the opening C provided in the frame of the unit U, and residual charges on the surface thereof are removed. Exposure is called pre-exposure). On the other hand, the electric charges applied by the charger 4 to the non-image portion on the drum 3 before starting the forward movement of the platen and during the backward movement are removed by being irradiated with light (Plung exposure) from the lamp Q through the opening A. It

Next, the structure of an embodiment of the process unit according to the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5 and 6. The process unit U mainly includes a frame 17 (which is an opaque synthetic resin, metal, or the like to prevent external light exposure to the photoconductor), the drum 3 housed in the frame 17, and a charger. 4, a developing device 5, and a cleaner 14. In addition to this, if necessary, the unit U may include other process means, for example, a charge-eliminating corona discharger placed between the separation corona discharger 9 and the cleaner 14, or a drum and another unit. It may include at least one process means. First, the configuration of the frame 17 will be described with reference to FIGS. 1 and 4. FIG. 4 shows the frame 1 with each process means removed.
FIG. 7 is a perspective view of FIG. The frame 17 includes a front side plate 17a and a rear side plate 1.
7b, and a right stay 17c fixed to each other,
The left stay 17d is formed into a box shape, and the left upper part is covered by a charger support plate 19 described later, and the right upper part is covered by a developing device cover 21. A guide member 17 is provided outside the right stay 17c and outside the left stay 17d, respectively.
e, 17f are fixed, and these guide members 17e,
17f is slidably mounted on the positioning guide members 18a and 18b fixed in the main body X of the copying machine.
The process unit U is positioned and supported at a predetermined position in the main body of the copying machine, that is, a position where the photosensitive member and other process means are operated to form an image as described above. And
When the process unit U is taken out from the copying machine main body X, the front exterior plate Z ′ (front door) of the main body is opened in the b direction (FIG. 2), and the handle 17a ₁ provided on the front side plate 17a is opened. It can be grasped, guided in the direction of arrow D, and pulled out under the guidance of the members 18a and 18b. When mounting the unit U at a predetermined position in the main body, the operation reverse to the above is performed. Figure 2
Shows a state in which the present process unit is attached to and detached from the main body X of the copying machine (in this figure, the frame 17 is omitted and the drum 3, Only the charging device 4, the developing device 5, and the cleaner 14 are shown). When the mounting of the unit U at a predetermined position in the main body is completed, the front door Z ′ is lifted in the direction opposite to the arrow b and closed.

FIG. 3 shows the front side plate 1 in this process unit.
7a is excluded and the mounting state of each image forming unit is shown in an easy-to-understand manner. In the figure, the positioning and holding member shown by the two-dot chain line is the member installed on the front side plate 17a. The member shown by the chain double-dashed line is also provided at a position facing the front side plate of the rear side plate 17b, and each image forming means can be positioned and held with respect to the frame 17. With such a configuration, the charger support plate 19
Is a plate-like member 19 which holds the charger 4 and constitutes the upper part of the frame body.
The leg portion 4a ₁ installed on the shield plate 4a is slidable with respect to the guide 20 provided on the photosensitive member (for preventing the external light from being exposed to the photoconductor, metal, opaque synthetic resin, or the like). It is fitted and positioned.

Next, a method of attaching the drum 3 to the unit U will be described with reference to FIGS. 3, 4, 5, and 6.
Here, FIG. 5 is a perspective view for explaining a state in which the blocking light means closes the exposure openings A and C, including the drum 3, and FIG. 6 closes the image exposure and blank exposure openings A. 3 is a view for explaining the means as viewed from the cross section of the central axis of the drum 3. FIG. Flanges 3a and 3b are press-fitted and fixed to both end surfaces of the drum 3 in the central axis direction. Also, the flange 3a,
The drum positioning shafts 3a ₁ and 3b ₁ are fixed to 3b,
Bearings 3a ₂ , are provided on the outer circumferences of the positioning shafts 3a ₁ , 3b ₁ .
3b ₂ is fitted therein, and the positioning shafts 3a ₁ and 3b ₁ are rotatably supported by the bearings 3a ₂ and 3b ₂ (FIGS. 5 and 6). On the other hand, the front side body 17a and the rear side plate 17b of the frame body 17 have U-shaped groove portions 17a ₂ and 17b, respectively.
₁ is formed.

Inside the groove portions 17a ₂ and 17b ₁ , that is, in FIG.
, The curved portion C indicated by the hatching H is the bearing 3a.
_The spring member 1 has the same diameter as the outer circumference of ₂ , 3b _2.
When the bearings 3a ₂ and 3b ₂ are pressed against the corresponding portions (hatched portions H) by 9a ₁ and 19b ₁ , the drum 3 is positioned at a predetermined position in the process unit U. Here, the outer diameters of the bearings 3a ₂ and 3b ₂ are different from each other, and the bearings 3a ₂ and 3b ₂ are larger than the outer diameter of 3a _{2.
No. 2} cannot fit into the groove 17b ₁ and is set so as not to be set by mistake. The spring members 19a ₁ , 1
9b ₁ is fixed to the charger support plate 19. Further, the charger support plate 19 includes a charger support plate lock member 19a,
19b is rotatably held around the shafts 19a ₂ and 19b ₂ . The lock members 19a and 19b are the frame side plates 1
7a, 17b corresponding to portions 17a _3, 17b ₂ are engageable disposed of, toward the inside of the apparatus by conventional compression spring 19c, are then (in the direction of the photosensitive drum 3) with the tip bias . Also, the lock members 19a, 19b
The abutting portion is provided on the charging device holding plate 19
However, when the rib unit tips 19a 'and 19b' partially abut against the charger holding plate 19, the lock members 19a and 1b are not set at the predetermined positions of the process unit U.
The tip of 9b is configured so as not to enter the inside of the engaging portions 17a ₃ and 17b _{2 of the} frame side plate.

Therefore, the groove portions 17a ₂ and 17b _{1 of the} frame body 17 are
The bearings 3a ₂ and 3b ₂ of the photosensitive drum 3 are dropped into the upper surface of the photosensitive drum 3, and then the charger holding plate 19 is attached to the fulcrums 19a ₄ and 19b ₄
When it is rotated around the center and closed, the spring members 19a ₁ , 19a
b ₁ presses the bearings 3 a _2, 3 b ₂ to position the photosensitive drum 3 at a predetermined position, and at the same time, the lock members 19 a, 1
9b engages with the engaging portions 17a ₃ and 17b ₂ of the frame side plate and is set to a predetermined position by the reaction force of the spring members 19a ₁ and 19b ₁ . Further, when the charger holding plate 19 is pressed by a force greater than the reaction force of the spring members 19a ₁ and 19b ₁ , the side surfaces 19 of the rib portions of the lock members 19a and 19b are
a ″ and 19b ″ are engaging portions 17a ₃ and 17 of the frame side plate.
It is configured to hit the upper surface of b ₂ . Therefore, even if excessive pressure is applied, the charging device holding plate 19 and the members such as the charging device 4 mounted on it do not damage the photosensitive drum 3. Further, the releasing of the charger holding plate 19 is performed by operating the operating surfaces 19a ″ ″, 19b of the lock members 19a, 19b.
By pushing b ″ ″ inward against the compression spring 19c, the lock members 19a and 19b are disengaged,
It is performed by popping up by the reaction force of the spring members 19a ₁ and 19b ₁ .

A gear portion is formed on the flange 3b of the photosensitive drum 3, and this drum portion is connected to a drive source (not shown) provided on the main body of the copying machine.
Is rotated. Further, the gear portion transmits the driving force to the magnet roller 5a of the developing device 5 in the process unit.

Next, a method of attaching the developing device 5 to the unit U will be described with reference to FIGS. 3, 4 and 5.

The developing device 5 has a frame 5c constituting the frame 1
7, the rollers 5a positioned in the frame 17 by being detachably mounted on the shafts 17a ₄ , 17b ₃ and 17a ₅ , 17b ₄ provided at positions facing the front side plate 17a and the rear side plate 17b. A predetermined gap is formed between the photoconductors 3. Further, the frame 5c are axial 5c _1, 5c ₂ is provided (It should be noted, 5c ₂ is although not shown, is provided in a position facing the drum axial direction axis 5c _1). On the other hand, the front side plate 17a, the rear side plate 17b, the shaft 17a at a position opposing each, 17b and the shaft 17a _7, 17b are provided, the shaft 17a, rotatably lever 17a is around these axes 17b, 17b ₇ is installed. The lever 17a, 17b ₇ and the shaft 17a _7, each of the 17b between the spring 17a, 17b is applied. Therefore, the tension of the springs 17a, 17b causes the levers 17a, 17b to
b ₇ presses the shafts 5c ₁ and 5c ₂ , and the developing device 5 holds the frame 17
Securely retained inside. Further, above the developing device 5, a cover 21 is provided which is rotatable in the direction of arrow G around the fulcrums 19a and 19b formed on the plate-shaped member 19. The cover 21 is a shaft 17b provided on the rear side plate 17b.
One end is placed on the top so that it does not fall to the developing device 5 side. Since the developing device 5 and its peripheral members are configured in this manner, the developing device 5 is moved by rotating the cover 21 in the direction of arrow G and retracting the levers 17a and 17b in the direction of arrow H. It can be taken out from the frame 17 in the direction of the arrow I from the unit U.

Further, a pressing roller 41 is arranged above the process unit U insertion opening of the apparatus main body X while being biased by a spring 42. FIG. 7 shows a cross-sectional view from the K direction in FIG. 1 (the upper right portion of FIG. 1 is not a cross-sectional view of the apparatus main body X but a front view).

FIG. 7 shows a state in which the process unit is being inserted. The pressing roller 41 has a shaft 44a provided on an arm 44 which is rotatable around a shaft 43a of a substrate 43 fixed to the side plate of the apparatus main body X. It is possible to fit and rotate. The pressing roller 41 is urged by a pressing spring 42 via an arm 44, and the developing device cover 21 of the process unit U.
Is set to a position where the upper surface of the can be pressed. Further, a part of the arm 44 is engaged with the hole of the substrate 43 so that the pressing roller 41 does not go down below a predetermined position when the process unit U is not mounted.

When the process unit U is to be inserted into the main body X of the apparatus along the guide members 18a and 18b of the main body, first, the developing device cover 21 and the pressing roller 41 come into contact with each other,
Therefore, the charging device holding plate 19 receives a downward force via the developing device cover 21 and the shafts 19a ₅ and 19b ₅ . As a result, if the above-mentioned lock members 19a and 19b are not engaged, they are newly engaged, and the photosensitive drum 3 is held at the regular position. The pressing spring 42 is selected so as to apply a force larger than the pressure applied by the spring members 19a ₁ and 19b ₁ . Furthermore, the charging device 4 includes a holding plate 1.
3 is urged downwards in FIG. 3 by a spring disposed between the springs 9 and 9, and the positioning of the charger 4 with respect to the photosensitive drum 3 is ensured by the spring urging force on the end faces of the frame side plates 17a and 17b. In other words, the operating force of the pressing spring 42 is selected to be equal to or more than the sum of the reaction force of the spring members 19a ₁ and 19b ₁ and the reaction force of the spring that biases the charger 4. When the process unit U is completely inserted into the apparatus main body X, the pressing roller 41 is arranged so as to be located between the charger holding plate 19 and the part 17a ₁ of the frame front side plate 17a, and in this state. As a result, the arm 44 is positioned by engaging with the hole 43b of the substrate 43 and does not contact the developing device cover 21 or the frame front side plate 17a.

Therefore, the process unit U is the main body X of the apparatus.
Since the actuation force for setting the photosensitive drum 3 to the regular position is not working at the time of being mounted and positioned in, the frictional resistance force at the positioning and fitting portions of the process unit U is minimized, The operability of the process unit U is improved. Therefore, it is possible to reduce the occurrence of an abnormal image due to imperfect insertion of the process unit U, a paper jam, or the like. Further, according to this method, it is sufficient that the operating force has a sufficient force to lock one lock member of the charger holding plate, and this can be used sequentially as the process unit is inserted. Therefore, the photosensitive drum 3 can be set to the regular position with a comparatively light force. Also,
The structure of the process unit and the structure of the guide rail portion of the apparatus body can be reduced in weight. Further, even when the process unit is pulled out for the replacement of the developing device or the replenishment of the toner, the photosensitive drum 3 which is once locked and set at the regular position is provided with the operation portion 19 of the lock members 19a and 19b.
It is not released unless it is touched with a ″ ″, 19b ″ ″. Therefore, since the positional relationship between the photosensitive drum 3 and the cleaner portion does not change when the process unit is pulled out, the cleaning blade 14a and the scooping sheet 14 are not changed.
Since the residual toner does not drop from the vicinity of b, the contamination of the device can be reduced. Further, the positioning of the photosensitive drum 3 is not released even after the process unit is pulled out to replace the developing unit, and the developing unit cover 21 is opened to pull out the developing unit. Does not damage the photosensitive drum 3. Furthermore, when replacing the entire process unit, or the process unit U
Even when the inside of the main body of the apparatus is removed by maintenance, the positional relationship between the photosensitive drum 3 and each process means is not maintained. Therefore, the photosensitive drum and each process means may dance and be damaged by vibrations such as movement and transportation of the process unit. Or
Also, the toner is not scattered.

As described above, according to this embodiment, the mounting and positioning of, for example, the photosensitive drum 3 and the charger rail 4a, which are relatively infrequently operated, are linked with the insertion of the process unit. It is possible to configure a fool-proof mechanism that does not cause inconvenience to relatively frequently-operated operations such as developer replenishment and developing device replacement while preventing errors and errors due to insufficient positioning.

In a device in which the cleaner can be replaced, for example, in a device in which waste toner is stored in the cleaner container and replaced with the cleaner, the above lockfool proof mechanism is used for positioning the cleaner. Is also effective. Further, in the present embodiment, the image bearing member has been described by taking the photosensitive member as an example, but the image bearing member is not limited to this, and it is needless to say that a recording drum, a magnetic drum, an endless belt, or the like is used. .

As described in detail above, the present invention provides an image forming apparatus capable of positioning the image carrier according to the mounting operation of the process unit to the apparatus main body.

[0031]

[0032]

As described above in detail, according to the present invention, there is provided an image forming apparatus capable of positioning the photoconductor / process means at a predetermined mounting position according to the mounting operation of the process unit to the apparatus main body. can do.

[Brief description of drawings]

FIG. 1 is a side sectional view of an electrophotographic apparatus to which an embodiment of the present invention is applied.

FIG. 2 is a perspective view of the electrophotographic apparatus shown in FIG.

FIG. 3 is a side view of a process unit.

FIG. 4 is a perspective view of a frame body of a process unit.

FIG. 5 is a perspective view of an upper portion of the process unit.

FIG. 6 is a side view showing a loaded state of the process unit.

FIG. 7 is a side view showing a loaded state of the process unit.

[Explanation of symbols]

3 Photosensitive drums 3a ₂ , 3b ₂ Bearings 17a ₂ , 17b ₁ Grooves 19a ₁ , 19b ₁ Spring members 19a, 19b Lock member 19e Compression spring 41 Pressing roller 44 Arm U Process unit

Claims (6)

(57) [Claims] 1. An image forming apparatus in which a process unit is attachable / detachable, wherein a process unit having a frame body, a photoconductor removable from the frame body, and process means acting on the photoconductor is removably mounted. Mounting means for doing, according to the mounting operation of the process unit, means for positioning the photoconductor at a predetermined mounting position when the photoconductor of the process unit is not positioned at a predetermined mounting position, An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein the processing unit is a cleaning unit that removes toner remaining on the photoconductor. 3. The charging device according to claim 1, wherein the process means is a charging means for charging the photoconductor.
The image forming apparatus according to item 1. 4. The image forming apparatus according to claim 1, wherein the processing means is a developing means for developing the latent image formed on the photoconductor. 5. The image forming apparatus according to claim 1, wherein the process means is also attachable to and detachable from the frame body. 6. An image forming apparatus in which a process unit is attachable / detachable, wherein a process unit having a frame body, a photoconductor, and process means detachably mounted on the frame body and acting on the photoconductor is detached. A mounting means for mounting the processing unit in a predetermined position, and a mounting means for mounting the processing unit according to a mounting operation of the process unit, when the processing means included in the process unit is not positioned at a predetermined position with respect to the photoconductor, An image forming apparatus comprising: