JPH0475507B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a unit comprising an image carrier and a process means acting on the image carrier, and one of the image carrier and/or the process means is removable. The present invention relates to a wearable image forming apparatus. Here, the image forming apparatus includes an electrophotographic apparatus, a printer, a micro device, and the like.

Hereinafter, an electrophotographic apparatus including an electrophotographic process unit will be described as an example.

Here, the electrophotographic process unit refers to a unit in which an electrophotographic photoreceptor and at least one other process means are accommodated in a frame that is detachable from a predetermined position within the main body of an electrophotographic apparatus. The process means means a means for performing a predetermined action on the photoreceptor in order to carry out the image forming process, such as a charger for the photoreceptor, a developer for electrostatic latent images, and a cleaning device for removing toner remaining on the photoreceptor. say something about
Furthermore, the electrophotographic apparatus main body includes means for accommodating and supporting the process unit, a transfer paper transport means, a fixing means for fixing the toner image transferred from the photoreceptor onto the transfer paper, and is surrounded by an exterior plate. say something.

Now, in an electrophotographic apparatus, in addition to replacing the photoreceptor as an image carrier, replenishing developer, disposing of waste toner that has been cleaned and removed from the photoreceptor after transfer, and cleaning the charging wire, various consumable parts are replaced and adjusted. etc., as necessary.

Many of the above-mentioned operations are concentrated around the photoreceptor, which traditionally took time and effort, but in recent years, the photoreceptor, developing device, cleaner, charger, and other process means around the photoreceptor have been integrated into one framework. An electrophotographic device has been proposed which is housed in the body and configured so that the unit can be pulled out and held from a predetermined position in the device body, or in which each frame unit is configured to be removable from the device body, thereby making it easier to perform each of the above operations. ing. In this way, work efficiency can be improved, work time can be shortened, running costs can be reduced, and the work can be done by the user himself rather than by a service person. Furthermore, since the developing device can be easily replaced with one for another color, it becomes possible to easily form an image in a desired color.

Furthermore, a process unit is constructed in which image forming means such as a photoreceptor, developer, cleaner, and charger are integrated into a frame, and when the photoreceptor is replaced, the entire unit can be replaced, making maintenance easier. The idea is to reduce the workload. With this configuration, the user can easily replace each process-related unit that requires periodic maintenance, and the maintenance work by service personnel can be eliminated or reduced, improving work efficiency. Significantly improved. Furthermore, by replacing the process unit with a process unit that stores toner of another color, it is also possible to form an image of a desired color. Alternatively, by replacing the process unit with a process unit incorporating another developing means, there is an advantage that the developing means can be used in accordance with the original image.

On the other hand, in order to make it replaceable as mentioned above, the photoreceptor,
Since the developing device and the like are configured to be removable from the process unit frame, it is possible for the process unit to be attached to the mounting main body while the photoreceptor, developing device, and other process unit means are not fully attached to the process unit frame. The photoreceptor, process means,
Inconveniences have arisen in which the processing unit or mounting body may be damaged or an incomplete image may be produced.

In contrast, a patent application has proposed a means for bringing the process means into contact with and separating from the photoreceptor in the process unit in conjunction with the attachment and detachment of the process unit to the main body of the apparatus.
It is disclosed in Publication No. 56-155952.

However, according to the technology disclosed above, (1) While the process unit is attached to the device body, the process unit always receives a reaction force from the device body to the acting force for attaching the process means. Therefore, for example, the frictional resistance increases in the positioning member of the process unit, etc.
The force required to attach the process unit increases.

(2) When the process unit is removed from the apparatus main body, the process means is separated, and therefore, when the process means is operated, the position of the process means itself is unstable, making it difficult to operate. Furthermore, when the process unit is moved or transported by itself, the process means is likely to move and cause a failure.

(3) The process unit, etc. must be strong enough to receive constant pressure, which increases the size and weight of the process unit.

It is conceivable that problems such as the following may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to check the attachment operation of the image carrier to the process unit when the process unit is attached to the main body of the apparatus, and to check whether the image carrier is It is an object of the present invention to provide an image forming apparatus having means that does not change the body or the mounting relationship of process means such as a developing device.

The present invention that achieves the above object includes an image carrier and a process means that acts on the image carrier,
In an image forming apparatus in which one of the image carrier and/or the process means can be attached to a removable unit, an actuating force is applied to the unit in the process of attaching the unit to the apparatus body, and the unit is attached to the apparatus body. The image carrier has a pressing means that does not apply an actuation force to the unit when it is mounted at a predetermined position of the unit, and the image carrier and/or the process means are positioned at a predetermined position of the unit by the actuation force. DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 explained.

FIG. 1 shows a sectional view of a copying machine main body X surrounded by an exterior plate Z. As shown in FIG. In the figure, 1 is a document mounting table made of a transparent member such as glass, and the main body
It moves forward in the direction of arrow a to scan the original, and moves backward in the opposite direction of the arrow when scanning the original. Reference numeral 2 denotes an imaging optical system in which a large number of short-focus, small-diameter imaging elements such as SELFOC (trade name) and bar lenses are arranged in an array, and is fixed to a plate 16 fixed within the main body X. Original Y placed on original table 1
is irradiated by an illumination lamp L, and the reflected light image is slit-exposed onto the electrophotographic photosensitive drum 3 by the array 2 through an opening A formed in the frame of the process unit 17. Note that this photosensitive drum 3 rotates in the direction of the arrow around the shaft 3b.
A charger 4 uniformly charges the photosensitive drum 3 coated with, for example, a zinc oxide photosensitive layer or an organic photoconductor photosensitive layer 3a. This charger 4
Image exposure of the reflected light image is performed on the drum 3 uniformly charged by the element array 2,
An electrostatic latent image is formed. This electrostatic latent image is then visualized by a developing device 5 consisting of a magnetic roller 5a and a toner reservoir 5b. On the other hand, the sheet P on the transfer paper storage box S (removable from the main body X) is
The paper is sent to the transfer station under the guidance of guides 10 and 10' by a feeding roller 6 and a registration roller 7 that rotates in synchronization with the image on the photosensitive drum 3. Then, the toner image on the photosensitive drum 3 is transferred onto the sheet P by the transfer discharger 8. Thereafter, 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 a fixing device 11 by a guide 10'', where the toner image on the sheet P is fixed. After that, it is discharged onto the tray 13 by the discharge roller 12. (Note that the guides 10, 1
0', 10'', rollers 6, 7, 12, transfer discharger 8, separation means 9, and fixing device 11 are attached to a stay or the like (not shown) fixedly supported within the main body X. In other words, the path for the paper P is always provided in the main body X.) After transferring the toner image, the remaining toner on the drum 3 is removed by the cleaner 14.
removed by This cleaner 14 includes a blade 14a in contact with the drum 3 and a waste toner reservoir 1.
4b, and a scooping sheet 14c that receives the waste toner removed from the surface of the drum 3 by the blade 14a. After this, drum 3 will be connected to lamp L.
In the apparatus body
The light is irradiated through an opening 16' provided in the partition plate 16, which is provided so as to separate the upper and lower parts, and an opening c provided in the frame of the unit U, and residual charges on the surface thereof are removed. (Exposure before photosensitive charging by the charger 4 is referred to as pre-exposure.) On the other hand, before the document table starts moving forward and during the backward movement, the light applied by the charger 4 to the non-image area on the drum 3 is The charge is the lamp Q
It is irradiated with light through the aperture A (Brang exposure) and removed.

Next, the configuration of one embodiment of the process unit according to the present invention is shown in FIGS. 1, 2, 3, and 4.
This will be explained with reference to FIGS. This process unit U mainly includes a frame 17 (made of opaque synthetic resin, metal, etc. to prevent exposure of external light to the photoreceptor), a drum 3 housed in the frame 17, and a charger. 4, a developing device 5, and a cleaner 14. In addition, if necessary, the unit U may include other process means, such as a static elimination corona discharger placed between the separate corona discharger 9 and the cleaner 14, or may include a drum and other process means. It may also include at least one process means. First, the structure of the frame 17 will be explained based on FIGS. 1 and 4.
Figure 4 shows frame 1 with each process means removed.
7 is a perspective view of FIG. The frame 17 has a box-like structure including a front side plate 17a, a rear side plate 17b, and a right stay 17c and a left stay 17d mutually fixed to these. It is configured to cover the upper right side. Outside of right stay c, left stay 17
Guide members 17e and 17f are fixed on the outside of d, respectively, and these guide members 17e and 17f
is slidably placed on positioning guide members 18a and 18b fixed in the copying machine main body Means is operatively positioned and supported for image formation as described above. When taking out the process unit U from the copying machine main body X, open the front exterior plate Z' (front door) of the main body in direction b (Fig. 2).
The handle _17a1 provided on the front side plate 17a is grasped, guided in the direction of arrow D, and pulled out under the guidance of the members 18a and 18b. When installing the unit U at a predetermined position within the main body, the above operation is reversed. FIG. 2 shows the state in which the process unit is attached to and detached from the copying machine main body X. (In this figure, the frame 17 is excluded and only the drum 3, charger 4, developer 5, and cleaner 14 are shown to make it easier to understand the attachment/detachment state.) When the installation is completed, the front door Z' is lifted in the direction opposite to arrow b and closed.

Figure 3 shows the front plate 1 in this process unit.
7a is excluded, and the mounting state of each image forming means is clearly shown. In this figure, the positioning and holding member indicated by the two-dot chain line is the front plate 17a.
It shows the parts installed in. Note that the members indicated by the two-dot chain lines are also provided at positions of the rear side plate 17b facing the front side plate, so that each image forming means can be positioned and held with respect to the frame 17. Under such a configuration, the charger and the holding plate 19
is a guide 20 provided on a plate member 19 (made of metal, opaque synthetic resin, etc. to prevent external light from being exposed to the photoreceptor) that holds the charger 4 and constitutes the upper part of the frame. , the leg portion 4a ₁ installed on the shield plate 4a is slidably fitted and positioned.

Next, a method for attaching the drum 3 to the unit U will be explained with reference to FIGS. 3, 4, 5, and 6. Here, FIG. 5 is a perspective view illustrating a state in which the exposure openings A and C are closed by the respective shielding means, including the drum 3, and FIG. 6 is a perspective view of the opening A for image exposure and blank exposure. 3 is a diagram illustrating a means for closing the drum 3 when viewed from a central axis cross section of the drum 3. drum 3
flanges 3a, respectively on both end faces in the central axis direction.
3b is press-fitted and fixed. Also, the flange 3a,
Drum positioning shafts 3a ₁ and 3b ₁ are fixed to 3b, and bearings 3 are mounted on the outer peripheries of these positioning shafts 3a ₁ and 3b ₁ .
a ₂ , 3b ₂ are fitted, and this bearing 3a ₂ , 3
The positioning shafts 3a ₁ and 3b ₁ are rotatably supported by b ₂ (FIGS. 5 and 6). On the other hand, U-shaped grooves 17a ₂ and 17b ₁ are formed in the front side plate 17a and rear side plate 17b of the frame body 17, respectively.

The inside of these grooves 17a ₂ and 17b _1, that is, the curved portion C shown by hatching H in _FIG .
It is configured to have the same diameter as the outer circumference of b ₂ , and the spring member 19
When the bearings 3a ₂ and 3b ₂ are pressed against the corresponding portions (portions indicated by hatching H) by a 1 and 19b ₁ , the drum 3 is positioned at _a predetermined position within the process unit U. Here, the outer diameters of the bearings 3a ₂ and 3b ₂ are different, and the outer diameter of the bearing 3a ₂ is configured to be larger than the outer diameter of the bearing 3b ₂ , so that in the unlikely event that the photosensitive drum 3 is mounted in the reverse direction, Also, the bearing 3a ₂ has a groove 17b ₁
It is designed so that it cannot be mated and set by mistake. Note that these spring members 19a ₁ , 19b ₁
is fixed to the charger support plate 19. The charger support plate 19 also includes a charger support plate lock member 1.
9a and 19b are rotatably held around shafts 19a ₁ and 19b ₂ . This locking member 19a, 1
9b is the corresponding portion 17 of the frame side plates 17a, 17b.
a ₃ and 17b ₂ so as to be able to engage with each other, and the tip thereof is normally biased toward the inside of the apparatus (in the direction of the photosensitive drum 3) by a compression spring 19c. Further, the locking members 19a and 19b are provided with abutting portions, and when the charger holding plate 19 is not set at a predetermined position of the process unit U, the ends of the rib portions 19a' and 19b' are charged. The locking member 19 hits a part of the container holding plate 19
The tips of a and 19b are the engaging portions 17a ₃ and 1 of the frame side plate.
It is configured so that it does not go inside than 7b ₂ .

Therefore, the bearings 3a ₂ and 3b ₂ of the photosensitive drum 3 are dropped into the grooves 17a ₂ and 17b ₁ of the frame 17, and then the charger holding plate 19 is rotated around its fulcrums 19a ₄ and 19b ₄ to close it. , spring members 19a ₁ , 19b ₁
presses the bearings 3a ₂ and 3b ₂ to position the photosensitive drum 3 at a predetermined position, and at the same time, the locking member 19
a and 19b engage with the engaging portions 17a ₃ and 17b ₂ of the frame side plates, and are set at predetermined positions by the reaction forces of the spring members 19a ₁ and 19b ₁ . In addition, charger holding plate 1
9 is pressed by a force greater than the reaction force of the spring members 19a ₁ and 19b ₁ , the lock members 19a and 19b
The side surfaces 19a'' and 19b'' of the rib portions are configured to abut against the upper surfaces of the engaging portions 17a ₃ and 17b ₂ of the frame side plates. Therefore, even if excessive pressure is applied, the charger holding plate 19 and members such as the charger 4 attached thereto will not damage the photosensitive drum 3. Further, the charger holding plate 19 can be released by locking members 19a,
The operation surfaces 19a and 19b of 19b are compressed by the compression spring 1.
9c, the locking members 19a and 19b are disengaged and the spring member 19 is released.
This is done by popping up due to the reaction forces of a ₁ and 19b ₁ .

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

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

The developing device 5 is removably mounted on 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 of the frame 17, with a frame _5c constituting the developing device 5. As a result, a predetermined gap is formed between the roller 5a and the photoreceptor 3, which are positioned in the frame 17. Further, the frame 5c is provided with shafts 5c ₁ and 5c ₂ (although 5c 2 is not shown, the shaft 5c ₂ is not shown).
c ₁ ) are located at opposite positions in the direction of the drum center axis. On the other hand, the front side plate 17a and the rear side plate 17b have
Shafts 17a and 17b and shafts 17a ₇ and 17b are provided at opposing positions, respectively, and shafts 17a and 17b are provided.
The lever 17 is rotatable around these axes.
a, 17b ₇ are installed. and lever 17
Spring 17a, 17b is applied between a, 17b ₇ and shafts 17a ₇ , 17b, respectively. Therefore, the tension of the springs 17a and 17b causes the lever 17 to
a, 17b ₇ press down the shafts 5c ₁ , 5c ₂ , and the developing device 5
is securely held in the frame 17. Further, above the developing device 5, a fulcrum portion 19 formed on the plate-like member 19 is provided.
A cover 21 is provided which is rotatable in the direction of arrow G about a and 19b. One end of the cover 21 rests on a shaft 17b provided on the rear side plate 17b, so that the cover 21 does not fall toward the developing device 5 side. Since the developing device 5 and its peripheral members are configured in this manner, the developing device 5 can be opened by rotating the cover 21 in the direction of the arrow G and retracting the levers 17a and 17b in the direction of the arrow H. The unit U can be taken out of the frame 17 in the direction of arrow I.

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

FIG. 7 shows a state in which the process unit is being inserted, and the pressing roller 41 is fitted onto a shaft 44a provided on an arm 44 that is rotatable around a shaft 43a of a base plate 43 fixed to the side plate of the main body X of the apparatus. can be rotated together. This pressing roller 41 is biased by a pressing spring 42 via an arm 44, and is set at a position where it can press the upper surface of the developing device cover 21 of the process unit U. Further, a part of the arm 44 is engaged with a hole in the substrate 43, so that the pressing roller 41 does not fall below a predetermined position when the process unit U is not installed.

Now, when trying to insert the process unit U into the apparatus main body X along the guide members 18a and 18b of the main body, the developing device cover 21 and the pressing roller 41 first come into contact, and therefore the developing device cover 21 and the shaft 19
The charger holding plate 19 receives a downward force via a ₅ and 19b ₅ . As a result, the aforementioned locking member 1
If 9a and 19b have not been engaged, they are newly engaged, and the photosensitive drum 3 is held at the normal position. Note that the pressing spring 42 is the spring member 1
9a ₁ and 19b 1 are selected so as to provide a force greater than the pressure caused by 19b ₁ . Furthermore, the charger 4 is biased downward in FIG. 3 by a spring disposed between the charger 4 and the holding plate 19, and
In the type in which the positioning against the frame side plates 17a, 17b is secured by the spring urging force on the end faces of the frame side plates 17a, 17b, the operating force of the pressing spring 42 is applied to the spring member 19.
It is selected so that it is greater than the sum of the reaction force caused by a 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 U, the pressing roller 41 is positioned between the charger holding plate 19 and the part _17a1 of the frame front side plate 17a, and in this state, In this case, the arm 44 is attached to the board 4.
It is positioned by engaging with the hole 43b of No. 3, and does not come into contact with either the developing device cover 21 or the frame front side plate 17a.

Therefore, the process unit U is the equipment body X.
When the photosensitive drum 3 is installed and positioned, no actuation force is applied to set the photosensitive drum 3 in the correct position, so the frictional resistance at the positioning and fitting parts of the process unit U is minimized. The operability of the process unit U is improved. Therefore, the occurrence of abnormal images or paper jams caused by incomplete insertion of the process unit U can be reduced. Further, according to this system, the operating force only needs to be sufficient to lock one locking member of the charger holding plate, and this can be used sequentially as the process units are inserted. Therefore, the photosensitive drum 3 can be set at the normal position with a relatively light force. Furthermore, the structure of the process unit and the structure of the guide rail portion of the apparatus body can be reduced in weight. Furthermore, when the process unit is taken out for replacing the developing device or replenishing toner, the photosensitive drum 3, once locked and set at the normal position, is touched by the operating parts 19a'', 19b'' of the locking members 19a, 19b. It will not be canceled unless it is. Therefore, when the process unit is taken out, the positional relationship between the photosensitive drum 3 and the cleaner section does not change, so that the cleaning blade 14a section and the scooping sheet 14 do not change.
There is no residual toner falling from the vicinity of b, and it is possible to reduce the amount of dirt on the device. In addition, even after the process unit is removed to replace the developer, the developer cover 21 is opened, and the developer is removed.
Since the positioning of the photosensitive drum 3 is not released, the photosensitive drum 3 will not be damaged even when the developing device is installed next time. Furthermore, when replacing the entire process unit, or when removing the process unit U for maintenance inside the main body of the apparatus, the positional relationship of the photosensitive drum 3 and each process means is not maintained, so it is difficult to move or transport the process unit. The photosensitive drum and various process means will not be damaged by dancing due to vibrations, and toner will not be scattered.

As described above, according to the present embodiment, by linking the adhesion and positioning of parts that are relatively infrequently operated, such as the photosensitive drum 3 and the charger rail 4a, with the insertion of the process unit, it is possible to prevent malfunctions and malfunctions. It is possible to construct a foolproof mechanism that does not cause any inconvenience to relatively frequent operations such as developer replenishment and developer replacement while preventing errors due to insufficient positioning.

Note that in devices where the cleaner is replaceable, for example, in devices where waste toner is accumulated in a cleaner container and the entire cleaner is replaced, it is effective to use the above locking fluid roof mechanism for positioning the cleaner. be. Further, in this embodiment, a photoreceptor is used as an example of the image carrier, but the image carrier is not limited to this, and it goes without saying that a recording drum, a magnetic drum, an endless belt, etc. can be used as the image carrier.

As detailed above, according to the present invention, an operating force is applied to the unit during the process of attaching the unit to the apparatus main body, and no operating force is applied to the unit when the unit is attached to a predetermined position on the apparatus main body. The present invention provides an image forming apparatus having a pressing means and capable of positioning the image carrier and/or the processing means at a predetermined position in the unit by the actuating force.

[Brief explanation of the drawing]

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 thereof, FIG. 3 is a side view of a process unit, and FIG. 4 is a perspective view of its frame. Figure 5 is a perspective view of the upper part of the unit;
Figure 7 is a side view showing the loaded state of the unit.
It is. In the figure, 3... photosensitive drum, 3a ₂ , 3b ₂ ...
... Bearing, 17a ₂ , 17b ₁ ... Groove, 19a ₁ , 19
b ₁ ... Spring member, 19a, 19b... Lock member, 19e... Compression spring, 41... Pressing roller, 4
4...Arm, U...Process unit.

Claims (1)

[Scope of Claims] 1. An image having an image bearing member and a processing means acting on the image bearing member, to which a unit to which one of the image bearing member and/or the processing means is removable can be attached. The forming apparatus includes a pressing means that applies an operating force to the unit during the process of attaching the unit to the apparatus main body, and does not apply an operating force to the unit when the unit is attached to a predetermined position of the apparatus main body, An image forming apparatus characterized in that the image carrier and/or the process means are positioned at a predetermined position in the unit by actuation force. 2. The image forming apparatus according to claim 1, wherein the image carrier is an electrophotographic photoreceptor. 3. The image forming apparatus according to claim 1, wherein the pressing means includes a spring and a roller pressed by the spring.