JPH051470B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an image forming apparatus or an image carrier;
The present invention relates to a process unit that has a process means (including part or all) that acts on the image carrier and is detachable from the apparatus main body.

Here, the image forming apparatus includes those that form information on an image carrier, such as an electronic copying machine, a facsimile machine, and a laser beam printer.

Hereinafter, an electrophotographic copying machine will be described as an example of an image forming apparatus.

Conventionally, in electrophotographic copying machines, it is necessary to periodically replace the photoreceptor as the image carrier, clean the charging wire, and replace and adjust various consumable parts.
Furthermore, these operations required skilled skills and were performed by specialized service personnel. Therefore, a service person had to come each time, which was extremely troublesome.

Therefore, recently, as shown in USP No. 3985436, a unit is constructed that integrates image forming means such as a photosensitive drum, a developer, a cleaner, and a charger, and when the photosensitive drum is replaced, each member is replaced at the same time. It is thought that this will reduce maintenance work. By configuring as above,
The user can easily replace process-related parts that require periodic maintenance, thereby reducing maintenance work by service personnel. Furthermore, by replacing the process unit with a process unit that stores toner of another color, a color image can be formed. Alternatively, by replacing the process unit with a process unit incorporating another developing means, there is an advantage that a developing means suitable for the original image can be used.

However, when a service person needs to repair a unit that was previously replaced by a user,
Replacement and positioning of photoreceptors, cleaners, developing devices, etc., have been troublesome as before.

Further, the trouble of replacing and positioning these photoreceptors, cleaners, developing devices, etc. is also inconvenient in terms of maintenance in copying machines that are not equipped with a unit.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a process unit that improves the operability of attaching and detaching an image carrier to and from a frame and the operability of attaching and detaching a developing means, and an image forming apparatus to which the process unit can be attached.

Another object of the present invention is to provide a process unit that can prevent damage to an image carrier and a developing means, and an image forming apparatus to which the process unit can be installed.

The present invention achieves the above object in a process unit that can be attached to an image forming apparatus main body, and includes an image carrier, a developing means for developing a latent image formed on the image carrier, and the image carrier. a frame body that removably supports the developing means; a closed position that is rotatably provided on the frame body and covers an upper part of the image carrier attachment position of the frame body; a first lid member that can take an open position that opens the upper part of the image carrier mounting position; and a closed position that is rotatably provided on the first lid member and covers the upper part of the developing means mounting position of the frame body. and a second lid member capable of taking an open position in which it is retracted from the closed position and opens above the developing means mounting position, and a second lid member provided on the first lid member for exposing the image carrier. an exposure aperture for guiding the exposure light of the first
A protective position provided on the lid member that covers the exposure opening, and a retracted position retracted from the protective position,
A process unit and an image forming apparatus to which the process unit can be attached are characterized in that the process unit has a cover that is movable in conjunction with attachment/detachment operations to an image forming apparatus main body.

Hereinafter, the present invention will be explained in more detail based on examples.

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

Note that the process unit here refers to a unit that houses an image carrier such as an electrophotographic photoreceptor and at least one other process means in a frame that is detachable from a predetermined position within the main body of an electrophotographic apparatus. .
The process means includes a charger that acts on an image bearing member such as a photoreceptor, a developing device for electrostatic latent images, a cleaning device that removes toner remaining on the photoreceptor, etc. to carry out the image forming process. It refers to a means for applying a predetermined action to an image carrier, and the main body of an electrophotographic apparatus includes a means for accommodating and supporting the process unit, a transfer conveyance means, and a means for fixing a toner image transferred from a photoreceptor onto a transfer paper. It has a built-in fixing means and is surrounded by an exterior plate.

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 back in the opposite direction to the arrow to scan 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. The original Y placed on the original placing table 1 is illuminated by the illumination lamp L, and the reflected light image is projected onto the electrophotographic photosensitive drum 3 by the array 2 through an opening formed in the frame of the process unit U. Slit exposure is performed through A. Note that this photosensitive drum 3 is
It rotates around the axis 3b in the direction of the arrow. A charger 4 uniformly charges the photosensitive drum 3 coated with, for example, a zinc oxide photosensitive layer, a selenium photosensitive layer, or an organic photoconductor photosensitive layer 3a. The drum 3, which is uniformly charged by the charger 4, is subjected to image exposure of the reflected light image by the element array 2, thereby forming an electrostatic latent image. This electrostatic latent image is then visualized by a developing device 5 consisting of a magnet roller 5a and a toner reservoir 5b. Note that developer can be replenished in the developing device 5 by opening the lid 5d around the shaft 5e. 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 , 10a to the transcription department. Then, the toner image on the photosensitive drum 3 is transferred by the transfer discharger 8.
The image is transferred onto the sheet P. After that, the separating means 9
(e.g. separation belt or separation corona discharger, etc.)
The sheet P separated from the drum 3 by the guide 10b is guided to the fixing device 11 and the toner image on the sheet P is fixed.
2 and is discharged onto the tray 13. (In addition, guides 10, 10a, 10b, rollers 6, 7, 12,
The transfer discharger 8, the separation means 9, and the fixing device 11 are attached to a stay or the like (not shown) fixedly supported within the main body X. In other words, the passage for the paper P is provided within the main body X at all times. After transferring the toner image, residual toner on the drum 3 is removed by a cleaner 14. This cleaner 1
4 consists of a blade 14a that is in contact with the drum 3, a waste toner reservoir 14b, and a scooping sheet 14c that receives the waste toner removed from the surface of the drum 3 by the blade 14a. The drum 3 includes an opening 15a provided in a reflective shade 15 for reflecting the lamp radiation from the lamp L onto the document Y, and a partition plate provided in the main body X of the apparatus so as to separate the upper and lower parts. The light is irradiated through an opening 16a provided in the unit U and an opening C provided in the frame of the unit U, and residual charges on the surface of the unit U are removed. (Exposure before photosensitive charging by the charger 4 is referred to as pre-exposure.)
On the other hand, before the forward movement of the document table starts and during the backward movement, the drum 3
The charge applied to the upper non-image area by the charger 4 is removed by irradiating light from the lamp Q through the aperture A (blank exposure).

Next, the structure of one embodiment of the process unit according to the present invention will be described with reference to FIGS. 1 to 6. 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), and this frame 17.
A drum 3, a charger 4, a developer 5, which are housed inside.
It is composed of each process means of the 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 is shown in FIGS. 1 and 4.
This will be explained based on the diagram. FIG. 4 is a perspective view of the frame 17 with each process means removed. Frame 1
7 is a front side plate 17a, a rear side plate 17b, and a right stay 17c and a left stay 1 that are mutually fixed to these.
7d in a box shape, the upper left side is covered by a charger support plate 19, which will be described later, and the upper right side is covered by a developing device cover 20. Right stay 1
Guide members 17e and 17f are fixed to the outer side of 7c and the left stay 17d, respectively, and these guide members 17e and 17f can slide on positioning guide members 18a and 18b fixed inside the copying machine main body X. The process unit U is positioned and supported at a predetermined position within the main body of the copying machine, that is, at a position where the photoreceptor and other process means operate to form an image as described above. When taking out the process unit U from the copying machine main body, the front exterior plate Z' (front door) of the main body X is opened in the b direction (A, B in FIG. 2) and the The handle _17a1 can be 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. Second
Figures A and B show the process unit U being attached to and detached from the main body of the copying machine. (In order to make it easier to understand the attachment/detachment state, FIG. 2B excludes the frame 17 and shows only the drum 3, charger 4, developer 5, and cleaner 14.) Inside the main body of the unit U When the installation in the predetermined position is completed, the front door Z' is lifted in the direction opposite to arrow b and closed.

Next, a method of attaching each process means to the frame 17 of this embodiment will be explained. First, a method for attaching the charger 4 will be explained based on FIGS. 1 and 3. FIG. 3 clearly shows the mounting state of each image forming means in this process unit U, with the front side plate 17a removed. In this figure, the positioning and holding member indicated by the two-dot chain line is the front plate 1.
7a is shown. In addition,
The member indicated by the two-dot chain line is also provided at a position opposite to the front side plate of the rear side plate 17b, so that each image forming means can be positioned and held with respect to the frame body 17. Under such a configuration, the charger 4 has a plate-like member 19 that holds the charger and constitutes the upper part of the frame.
(In order to prevent external light from being exposed to the photoconductor, the leg 4a ₁ installed on the shield plate 4a slides against the guide 20 provided on the guide 20.) They are adapted to be movably fitted and positioned. Further, when the charger 4 is taken out from the unit U, the leg portion _4a1 is guided by the guide 20 and pulled out by pulling the charger 4 in the above-mentioned removal direction D (FIG. 4) of the frame 17.

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
b ₂ rotatably supports the positioning shafts 3a ₁ and 3b ₁ (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, and bearings 3a ₂ and 3b _{2 are dropped into these grooves 17a 2 and 17b 1 to be} supported. As a result, the drum 3 as a whole has a frame body 1.
7 (Figures 3 and 4). Furthermore, drum presser legs 19a and 19b are provided at positions corresponding to both ends of the drum center axis of the plate-shaped member 19, and the groove portions 17a ₂ and 17b ₁ formed of an elastic material such as rubber are provided at the tips of the legs. Bearings 3a ₂ , 3 fitted in
Drum pressing members 19a ₁ and 19b ₁ that press b ₂ are fixed. Also, the drum presser legs 19a, 19b
are provided with fixed legs 19a ₂ and 19b ₂ , and these fixed legs 19a ₂ and 19b ₂ are attached to the front and rear side plates 17a and 19b of the frame 17, respectively.
The plate-shaped member 19 as a whole constitutes the frame 17, which is fixed by fixing means 19a ₂ and 19b ₂ such as screws in the receiving parts 17a ₂ and 17b ₂ formed in the plate member 17b (Figs. 3 and 4). , Fig. 5, Fig. 6). As a result, the drum 3 is moved by the drum pressing members 19a, 19b ₁
It is reliably held by the frame body 17 which is pressed down by. A gear portion is formed on the flange 3b, and the drum 3 is rotated by connecting this gear portion to a drive source (not shown) provided on the copying machine main body X side. Further, this gear section is connected to the magnet roller 5a of the developing device 5 in the process unit U.
The driving force is transmitted to. Further, the plate member 19 is formed with fulcrum portions 19a ₄ and 19b ₄ (19b ₄ is not shown), and these fulcrum portions 19a ₄ and 19b ₄ are connected to a shaft 14d ₁ provided outside the frame 14d of the cleaner 14. ，
14d ₂ (14d ₂ is not shown). As shown in FIGS. 3 and 5, the shaft 14
d ₁ and 14d ₂ have a shape of a round shaft with a two-sided cut, and the fulcrum parts 19a ₄ and 19b ₄ have openings that are removably fitted into the two-sided cut shape,
In addition, they have a shape that allows them to rotate about the shafts 14d ₁ and 14d ₂ in the engaged state. Therefore, by removing the screws 19a ₃ and 19b ₃ , the plate member 19 can be removed from the frame 17 in the direction of arrow E when removing or replacing the cleaner or drum, and in the direction of arrow F when removing or replacing the drum. It is rotatable around the shafts 14d ₁ and 14d ₂ . Whether it is removal in the direction of arrow E or rotation in the direction of arrow F,
Since the plate member 19 is retracted from above the drum 3, the drum 3 can be taken out from the frame 17 in the direction of arrow E and replaced.

That is, in this embodiment, when the process unit U is pulled out from the apparatus main body X, the opening is promptly closed by a mechanism to be described later. Next, to remove the photosensitive drum 3, remove the screw _19a3 and rotate the upper plate 19 about the support shaft _14d1 in the direction of arrow F, or remove it in the direction of arrow E. Then, the drum 3 is pulled out upward (in the direction of arrow E), and the drum 3 is stored in a predetermined storage container (not shown).

Since the photosensitive drum 3 can be removed extremely easily from the unit U with the openings A, B, and C closed, the time during which the photosensitive drum 3 is exposed to external light when removed is shortened. Never deteriorates. After removing the photosensitive drum 3, remove the upper plate 19.
By returning it to its original position, you can prevent dust from entering from outside. There is an advantage that even if a general user who is not a specialized service person replaces the photosensitive drum, there will be no failure. Moreover, in this embodiment, since the charger 4 and the drum holding member 19a ₁ are integrally attached to the plate member 19, the drum 3
The positioning of the charger 4 and the charger 4 can also be performed with high precision. Furthermore, the charger 4 as a process means can be positioned around the drum shaft 3b.

In this embodiment, the fulcrum of the plate member 19 is provided in the cleaner 14. This fulcrum may be provided on the front and rear side plates 17a and 17b of the frame 17, but such a structure was used because the plate member 19
is guiding the charger 4, so this charger 4
One of the reasons for this is that it is easy to maintain the positional relationship of the cleaner 14. That is, in FIG. 1, the drum 3 is irradiated with light from the lamp L to erase the residual charge on its surface, but the irradiation width of the light is the same as the edge portion 4a ₂ of the shield plate of the charger 4.
and the interval between the blade edges 14a ₁ of the cleaner 14. When this amount of light is too large or too small, various effects appear on the drum 3, so the amount of light (irradiation width) must be set with high precision. Therefore, if the fulcrum of the plate member 19 is provided in the cleaner 14 as in this embodiment, and the charger is guided by the plate member,
The relationship (irradiation width) can be maintained at a predetermined value. Still another reason is that the purpose is to increase the degree of freedom in design. That is, due to design considerations, the fulcrum of the plate member 19 is the frame 14d of the cleaner 14 as shown in this embodiment.
That is, the front and rear side plates 17a, 1 of the frame 17
7b as well as the front and rear side plates 17a,
It may also be provided in the center between 17b. Therefore, providing the fulcrum of the plate member 19 on the cleaner 14 side rather than providing it on the frame 17 side has the advantage that it is easier to handle the design.

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, which is positioned in the frame 17, and the photoreceptor 3. Here, drum 3 is placed on the bottom surface of frame 5C.
By fitting the recess 5C ₂ provided on the side with the shaft 17a ₄ , the developing unit 5 is mounted with a clockwise rotational tendency, so that a predetermined gap is formed between the roller 5a and the photoreceptor 3. Further, the frame 5C is provided with shafts 5c ₁ and 5c ₂ . (5c ₂ is not shown, but the shaft 5c ₁
(provided at opposite positions in the direction of the center axis of the drum). On the other hand, the front side plate 17a and the rear side plate 17b have
Shafts 17a ₆ , 17b ₅ and shafts 17a ₇ , 17b ₆ are provided at opposing positions, respectively, and levers 17a 8 , _17b are rotatably attached to the shafts 17a ₆ , 17b ₅ so as to be rotatable around these axes.
17b ₇ is installed. and lever _17a8 ,
Springs 17a ₉ and 17b ₈ are applied between 17b ₇ and shafts 17a ₇ and 17b ₆ , respectively. Therefore, the tension of the springs 17a ₉ , 17b ₈ causes the levers 17a ₈ , 1
7b ₇ presses down the shafts 5c ₁ and 5c ₂ , and the developing device 5 is pressed against the frame 1.
Reliably held within 7. Further, above the developing device 5, there are supporting points 19a ₅ and 1 formed on the plate member 19.
A cover 21 is provided which is rotatable in the direction of arrow G about _9b5 . The cover 21 is the rear plate 1
One end rests on a shaft 17b ₉ provided at 7b to prevent it from falling toward the developing device 5 side. Since the developing device 5 and its surroundings are configured in this way, the cover 21 is rotated and retracted in the direction of arrow G.
By rotating and retracting the levers 17a ₈ and 17b ₇ in the direction of arrow H, the developing device 5 can be taken out from the frame 17 from the unit U in the direction of arrow I.

Next, a method for attaching the cleaner 14 to the unit U will be explained based on FIGS. 3 and 4. On both sides of the cleaner frame 14d in the direction of the drum center axis, there are shafts 14d ₃ , 14d ₄ and a shaft 14 at opposing positions, respectively.
d ₅ , 14d ₆ are formed (axes 14d ₄ , 14d ₆
(not shown). These shafts are connected to grooves 17a ₁₀ provided in the front side plate 17a and rear side plate 17b of the frame 17,
By being removably placed on the drum 17b ₁₀ , the blade 14a is positioned so as to come into contact with the drum 3. Further, shafts 1 are provided on both sides of the cleaner frame 14d.
4d ₇ and 14d ₈ (14d ₈ is not shown) are formed at opposing positions. The side plates 17a and 17b are provided with shafts 17a ₁₁ and 17b ₁₁ (17b ₁₁ is not shown), and levers 17a ₁₂ and 17b ₁₂ that are rotatable around these shafts 17a ₁₁ and 17b ₁₁ are installed. Also, levers 17a ₁₂ , 17b ₁₂ and grooves 17a ₁₀ , 17
Spring 17a ₁₃ and 17b ₁₃ (17b ₁₃ is not shown) are applied between b _{10 and b 10} . This spring 17a ₁₃ ,1
The levers 17a _{12 and} 17b ₁₂ press down on the cleaner shafts 14d ₇ and 14d ₈ due to the tension of the cleaner 14.
is securely held in the frame 17. Also cleaner 1
4 is a lever 17 as in the case of the developing device 5 described above.
By rotating and retracting a ₁₂ and 17b ₁₂ in the direction of arrow J, they can be taken out from the frame 17 in the direction of arrow K.

The frame structure of the process unit U and the mounting state of each process means have been explained above.
A transfer opening B is formed in the transfer station where the transfer discharger 8 faces the drum. When the process unit is taken out from the main body of the copying machine, external light enters into the unit U through these openings and has an adverse effect on the photoreceptor. Therefore, it is necessary for the process unit to take steps to close these openings, but the following requirements are required for the configuration for performing this step. First, the opening is closed when the process unit is taken out from the copying machine main body.
It must be done as soon as possible. this is,
This is because the influence of external light on the photoreceptor increases as the time the photoreceptor is exposed to external light increases. Next, the treatment must be carried out reliably. This is because if the person handling the process unit is expected to open and close the opening, he or she may forget to do so. To this end, it is necessary to configure the system so that the treatment is performed as automatically as possible. The present invention has been made in consideration of the above matters. Before explaining the light shielding mechanism that closes the exposure aperture, let us first explain the light shielding mechanism that closes the transfer aperture B in Fig. 3.
This will be explained based on FIGS. 4 and 9. In FIG. 3, the state where the light shielding mechanism for blocking the transfer opening B closes the opening B and the positioning members 18a and 18b provided on the main body of the copying machine are also shown by two-dot chain lines. FIG. 9 shows the light shielding mechanism of the transfer aperture B by the frame 17.
FIG. 2 is a perspective view from the inside, with the cleaner 14 excluded. The state shown in FIG. 9 shows the position of the light shielding mechanism when the opening B is open, and the front plate 17a side of the frame 17 is indicated by a two-dot chain line.
On the other hand, the state of the light shielding mechanism shown in FIG.
It shows the state where it is blocked. Front plate 1 of frame body 17
Shafts 17a 14 , 17b ₁₄ and 17a ₁₅ , 1 are provided on the outer surfaces of the rear plate 17a and the rear plate _17b , respectively, at opposing positions.
7b ₁₅ is formed, and levers 22 and 23 are rotatably attached to the shafts 17a ₁₄ and 17b ₁₄ . Further, shafts 22 ₁ , 23 ₁ are fixed to the lever 22 and lever 23, and these shafts 22 ₁ ,
A spring 2 is installed between 23 ₁ and the aforementioned shafts 17a ₁₅ and 17b ₁₅ .
It is multiplied by 4,25. In addition, holes 22 ₂ and 23 2 provided in the levers 22 and ₂₃ are provided with pins 26 1 and ₂ made of opaque synthetic resin, metal, etc., which protrude from a cover 26 that can shield the photoreceptor from external light.
6 ₂ are loosely fitted together.

Further, pins 26 ₃ and 26 ₄ are fixed to the cover 26, and arcuate grooves 17a ₁₆ and 17b ₁₆ that slidably guide these pins 26 ₃ and 26 ₄ are formed on the front side plate 17a and the rear side plate of the frame 17, respectively. 17b. On the other hand, a guide groove 17d ₁ is formed in the left stay 17d of the frame 17, and a slidable slide member 27 is installed in this groove 17d ₁ . Further, shafts 17d ₂ , 17d ₃ , and 17d ₄ are fixed to the left stay 17d, and pulleys 28 and 2 are rotatable around these shafts.
9,30 are installed. One end of a wire 31 is fixed to one end of the cover 26, and the other end of the wire 31 is fixed to the slide member 27 via a pulley 30. Further, one end of a wire 32 is fixed to the other end of the cover 26, and this wire 32
The other end is fixed to the slide member 27 via pulleys 28 and 29. In addition, the left stay 1 in Figure 9
The member shown by the two-dot chain line behind 7d is the locking member 33 fixed to the positioning member 18b in FIG. 3. The light shielding mechanism for closing the transfer opening B configured as described above operates as follows. First, Figure 3,
Process unit U as shown in FIG.
When the cover 26 is positioned at a predetermined position inside the copying machine body, the cover 26 is subjected to a force to move in the direction of the arrow N by the springs 24 and 25 via the levers 22 and 23, but the slide member 27 is The groove 17 is in contact with the locking member 33.
Since the cover 26 is prevented from moving during _d1 , the cover 26 is in a position retracted from the transfer section opening B, and the opening B is open. And process unit U is the fourth
As the slide member 27 is pulled out in the direction D shown in the figure, the tension force of the springs 24 and 25 causes the slide member 27 to
moves relatively in the direction of arrow M in the guide groove _17d1 while in contact with the locking member 33 (FIG. 9).
As the slide member 27 moves, the cover 26 is pulled by the springs 24, 25 and moves in the direction of the arrow N (Fig. 3), and when the slide member 27 reaches the end _17d5 of the guide groove _17d1 , The position shown by the two-dot chain line 26 in FIG. 3 is reached, that is, the position where the opening B is completely closed and external light is prevented from being exposed to the photoreceptor. Thereafter, the process unit U is further pulled out in the direction of arrow D and taken out from the main body of the copying apparatus. Cover 26 also prevents damage to the photoreceptor through opening B. When the unit U is inserted into the main body of the copying machine and set in a predetermined position, the cover 26 is moved by the member 27 coming into contact with the member 33 and moving in the direction opposite to the M in the groove _17d1 , contrary to the above. When the unit moves in the direction opposite to N and is set in a predetermined position within the main body, the opening B is open.

Next, the exposure openings A and B provided in the plate member 19 are
The light blocking mechanism will be explained below. First, the light shielding mechanism in the aperture A will be explained using FIGS. 3, 5, 6, and 7. As is clear from the explanation of the image forming process of the copying machine main body at the beginning and FIG. 1, and as shown in FIGS. An opening A is made for this purpose. Further, the plate member 19 is formed with fulcrum portions 19a ₆ and 19b ₆ , and shafts 19a ₇ and 19b ₇ are fixed to these fulcrum portions. The axes 19a ₇ and 19b ₇ are used to open and close the opening A around these axes.
A rotatably mounted cover 34 (made of opaque synthetic resin, metal, etc.) is installed.
Here, the state shown in FIGS. 3 and 5 is a state in which the cover 34 is in contact with the upper surface of the plate member 19 to close the opening A and prevent the photoreceptor from being exposed to external light. . Now, the process unit U is undergoing work such as replacing the developing device 5 and replacing the drum 3.
When the cover 34 is inserted in the direction D' opposite to the arrow D (FIG. 4), that is, into the copying machine main body (FIG. 6), the inclined portion ₃₄₁ formed at the end of the cover 34 moves toward the copying machine main body. It rides on the slope of the fixed guide member 35. When the process unit U is further inserted, the inclined portion ₃₄₁ is guided by the guide member 35, the cover 34 as a whole begins to rotate about the shafts _19a7 , _19b7 , and the process unit is moved to a predetermined position within the main body of the copying machine. When finally installed in the position, as shown in FIG. 7, it rests on the guide member 35 with the opening A completely opened. In this state, image exposure using the optical system 2 and plunging exposure using the lamp Q become possible. When the process unit U is taken out from the copying machine main body X, the operation of the cover ₃₄ is the reverse of the above operation.
The cover 34 rotates in the S direction due to gravity and
Returning to the state shown in FIG. 5, the opening A is completely closed before the unit U is removed from the main body. Therefore, there is no risk of the drum 3 being exposed to external light, and damage to the drum through the opening A is also prevented. Note that the cover 34 may be biased to rotate in the S direction by a spring.

Next, Fig. 1 shows the light shielding mechanism in the aperture C.
The explanation will be given based on FIGS. 3, 5, and 8. A cover 36 (made of opaque synthetic resin, metal, etc.) is slidably placed on the plate member 19, and the plate member 1 is inserted into the elongated holes 36 ₁ and 36 ₂ of the cover 36.
Guide pins 19a ₈ and 19b ₈ provided at 9 are loosely fitted. Therefore, the cover 36 has an opening C.
It can be slid in the direction of arrow O in FIG. 8 to open and close it. Further, springs 37 and 38 are stretched between the cover 36 and spring hooks 19a ₉ and 19b ₉ provided on the plate member 19.
is biased in the direction of closing the opening C. Under such a configuration, the cover 36 is in the state shown by the two-dot chain line 36 in FIGS. 3, 5, and 8.
In this state, the opening C made in the photoreceptor is closed to prevent external light from being exposed to the photoreceptor. As in the case of opening B, the process unit U replaces the developing device 5,
When the drum 3 is replaced and inserted into the copying machine main body (moved in the D′ direction), the inclined portion 36 ₃ formed at the end of the cover 36 is fixed to the copying machine main body. guide members 39, 40 (Fig. 1,
(Fig. 8), as shown in Fig. 8.
Move from the previous position where opening C was blocked (double-dashed line) to the position where opening C is opened, and when the process unit is installed in the specified position inside the copying machine body, opening C will be completely opened. Stand still (solid line).
In this state, the photoreceptor can be pre-exposed. Note that FIG. 1 shows a state in which the opening C is opened. When _the process unit U is taken out from the copying machine main body Figure 3, Figure 5
The opening C is completely closed before the unit U is removed from the main body. Therefore, there is no risk of the drum 3 being exposed to external light, and damage to the drum through the opening C is also prevented.

In the above embodiments, the light shielding mechanism is first provided to the plate member that holds the charger, so this member has the function of holding the charger and fixing the drum as well as the light shielding function of the opening. By combining these features, multi-functionality is achieved, which is highly effective in reducing the size of the process unit itself. In addition, since the light shielding mechanism is simple, there is no risk of malfunction, and at the same time, it is inexpensive and can function reliably, and it can be configured to be small and lightweight.
The handling of the unit is also easier.

Now, as mentioned at the beginning, in addition to the type shown in this embodiment, there is a type of process unit that can be pulled out from a predetermined position within the copying machine main body and held outside the copying machine main body. These are the guide members 17e and 17f on the process unit side and the positioning member 1 on the copying machine main body side explained in this embodiment.
8a and 18b are engaged with each other by drawing out the unit of members 18a and 18b and providing a stopper at the side end thereof, so that the process unit cannot be removed from the main body of the copying machine. Therefore, there is essentially no difference between such a process unit and the process unit shown in the above embodiment in which the unit can be removed from the main body, and the light shielding mechanism described above can be easily applied.

FIG. 10 is another embodiment of the present invention,
In the embodiment described above, the photoreceptor and processing means are detachably attached to the unit, whereas the photoreceptor and each processing means are integrally constructed in a cartridge type process unit. Such a unit is replaced as a whole and installed in the main body of the copying machine when the photoreceptor is replaced or when a unit containing a different color developer is used. This process unit includes a drum 3 whose surface is coated with a photoreceptor, a charger 4, a developer 5, and a cleaner 14, which are integrated into a mold frame 17a. Even in such a cartridge type unit, the exposure openings A and C and the transfer opening B are opened, so that when the unit is removed from the copying machine main body or before it is installed in the main body,
Again, the same measures as in the previous embodiment are required. The light shielding mechanism for closing the transfer opening B of this embodiment is the same as that of the previous embodiment. On the other hand, the light shielding mechanism for closing the image exposure apertures A and C is also the same mechanism as in the previous embodiment, but in this embodiment it is installed in a frame 17' formed integrally with a mold.
Since the light shielding effect of this embodiment is the same as that of the previous embodiment, a description of the operation and effect will be omitted.

In addition, in the embodiment, both a slide type cover and a rotation type cover were shown and explained in order to close the exposure opening, but it is possible to use either type as needed. Of course. The material of the cover is an elastic body such as metal, resin, or rubber, but it goes without saying that it may be made of any non-transparent material. Furthermore, it goes without saying that it may be a filter material that blocks light of a wavelength that adversely affects the photoreceptor, or a member that attenuates external light to the extent that it does not adversely affect the photoreceptor.

In this specification, such a filter material light attenuation member will also be referred to as a light shielding member for convenience.

Further, the present invention can be applied not only to ordinary copying machines but also to electrophotographic apparatuses in which an electrophotographic photoreceptor is exposed to light using a laser beam or a light emitting diode array in response to electrical signals. In addition to the process unit shown in this embodiment, there is one shown in FIG. 11. In either case, the opening is closed using a mechanism similar to that of the previous embodiment when the unit is taken out from a predetermined position within the main body of the copying machine. FIG. 11A shows the embodiment shown in FIG. 10 with an imaging lens 2 added.
B is the one with the lens 2 and separation means (separation belt) 46 added, C is the one without the charger cleaner,
D is the product excluding the charger and developer, E is the product excluding the cleaner, and F is the product excluding the developer.
In addition to these, it is conceivable to install a corona discharger for static elimination under the cleaner, but in any case, it is sufficient as a unit as long as it includes a photosensitive drum and at least one other process means. The type shown in Figure 11 may be used as a cartridge type.

As described above, the opening and closing operations of the light shielding member to prevent external light from being exposed to the photoconductor, damage to the photoconductor, and prevention of external dust from entering the unit are performed by attaching and detaching the process unit to a predetermined position within the electrophotographic apparatus body. Since it is linked to the operation, the light is automatically blocked, and it is possible to prevent forgetting to do the task when manually blocking the light. and,
Since light shielding is completed when the process unit comes out of the main body, the time that the photoreceptor (drum) is exposed to external light is zero or very short, completely preventing the influence of external light on the photoreceptor. can.

Still other examples will be shown.

In this embodiment, the drum 3 cannot be removed from the unit V until after the developing device 5 has been removed from the unit V. As a result, in this embodiment, before the developing device 5 is removed from the unit V, the drum 3 is inadvertently removed from the unit V.
This can prevent damage to the drum 3 that may occur when attempting to remove it from the drum.

Note that the configuration newly added in this embodiment is shown by the two-dot chain line in FIGS. 3 and 5, and the other configurations are the same as in the previous embodiment.

In this embodiment, a developing device 5 is provided on the bottom surface of the plate member 19.
A substantially "S"-shaped downward protruding member _19a10 is provided toward the bottom. Further, a member 19a is placed on the pestle 5c of the developing device 5 at a position above the tip of the member 19a ₁₀ and not in contact with the lid 5d when the lid 5d of the developing device 5 is opened around the shaft 5e. A fixed abutment member 5f is provided. Therefore, even if an attempt is made to rotate or remove the plate member 19 upward in order to take out the drum 3 from the unit V with the developing unit 5 still attached, the projecting member 19a ₁₀ and the abutting member 5f will When engaged, the plate member 19 cannot be retracted from above the drum 3. Therefore, the drum 3 cannot be removed from the unit V.

Therefore, in this embodiment, the drum 3 is connected to the unit V.
When taking out the developing device 5 from the unit V, first
the abutting member 5f from the protruding member 1.
9a and ₁₀ .
Drum 3 cannot be taken out.

Still another embodiment is shown in FIG.

In this embodiment, the drum 3 is operated while the process means provided in contact with or close to the peripheral surface of the drum 3, such as the developing unit 5 and the cleaner 14, are attached.
The drum 3 can be taken out from the unit V without damaging it.

In this embodiment, the developing area of the magnet roller 5a and the cleaner area of the blade 14a are provided below the center of the drum shaft 3b (below the straight line 1 passing through the center of the drum shaft 3b). Therefore, the magnet roller 5a and the blade 14a
Even if the rollers 5a and blades 14a are in contact with or close to the circumferential surface of the drum 3, the rollers 5a and blades 14a will strongly rub against the circumferential surface of the drum 3 and damage the circumferential surface of the drum 3 when the drum 3 is taken out from the unit V. It can be prevented.

Although the present embodiment has been described for the purpose of blocking light, the present invention is not limited to this, and can of course be applied to dealing with damage or dirt.

Still other examples will be shown.

This embodiment shows another embodiment for loading the unit into the main body of a copying machine.

FIG. 13 is a sectional view of a copying machine to which this embodiment is applied.

In the figure, 53 is a photosensitive drum that rotates in the direction of the arrow around a shaft 53a. 52 is a short focus lens array, 54 is a primary charger, 55 is a developer, 5
8 is a transfer charger, 59 is a separation charger, 57 is a fixing device, and 64 is a cleaner. Each of these devices is for forming a copy image of the original O on the transfer material P sent from the transfer material storage box S.

Among these process devices, the photosensitive drum 53, charger 54, developer 56, and cleaner 64 are housed in the process unit 67 as described above.

In the state shown in the figure, the unit 67 is connected to the main body of the device
It is directly supported by the holding frame 68, and is not engaged with the holding frame 68, leaving a gap.

As shown in FIG. 14, when the unit 67 is in a fixed position within the apparatus main body X, it is separated from the holding frame 68 and is directly positioned on the chassis of the apparatus main body X. A taper pin 84 attached to the front side of the unit 67 fits into a positioning hole 85 provided in the front plate 74 of the main body chassis. A taper pin 86 attached to the chassis front plate 74 fits into a positioning hole 87 provided on the front side of the unit. Similarly, on the rear side, the pin 88 on the rear side of the cartridge fits into the hole 77 provided in the rear chassis plate 75 of the main body, and the pin 76 provided on the rear chassis plate 75 fits into the hole 39 on the rear side of the unit. The unit 67 is thus positioned in the body by these pins and holes.

Handle 80 attached to the front of the unit 67
When the unit 67 is pulled in the direction of arrow Y, the unit 67 is released from being held in position with the chassis of the main body of the apparatus, is held by the holding frame 68, and is pulled out from the main body of the apparatus.

FIG. 16 shows details of this engagement relationship.
In the figure, the solid line indicates that the unit 67 has been pushed in and the pin 88 is just before engaging the hole 77, but the holding frame 6 is still
8, and the chain line shows the state when they are engaged and held in the main body of the device. Therefore, in the state shown by the chain line, the process equipment outside the unit and the unit are in the correct positional relationship. Assuming that when the pin 88 is held in the holding frame 68 and held in the device body X, it is lifted by a amount a as shown in the figure, the thickness b of the tapered portion of the pin 88 should be made slightly larger than a. This ensures that the pin 88 will enter the hole 77 when the unit 67 is pushed in. The left and right positional relationships also have similar dimensional relationships.

FIG. 15 is a perspective view of the unit 67 pulled out. The engagement between the device main body X and the holding frame 68 is as follows.
A hollow movable rail 82 is loosely fitted into a rail guide frame 81 attached to the main body X, and a holding frame 6 is fitted in the hollow part.
A fixed rail 83 attached to the holding frame 68 is loosely fitted, and each rail slides when the holding frame 68 is pushed or pulled. An elongated hole 82a drilled in the center of the rail 82 engages with a pin 83a attached to the rail 83 and a pin (not shown) attached to the guide frame 81, and when pulled out to the position shown in the figure. It becomes a stop.

In addition, in the operating state of the copying machine (FIG. 13), in the unit 67, the optical path from the lens 52 and the light source Q is at the opening A, the charger 58, 59 charging area is at the opening B, and the optical path from the light source L is at the opening A. The position where this occurs is the opening C. The opening A is covered by a rotating lid 69 that rotates clockwise in conjunction with the operation of pulling out the unit 67, and the opening C is covered by the upper lid 72.
The opening B is covered by a movable lid 71 that moves upward and to the right as the opening B is closed by the cover 70.

Unit 67 with the electronic copying machine configured as above.
When pulled, the tapered pins and holes of the device body chassis and the unit 67 slide, and the unit 67 gradually lowers and is released from its positioning hold. At this time, the unit 67 is held silently by the holding frame 68 without impacting and is pulled out safely and reliably from the main body of the apparatus. To store the unit 67 in the main body
Since the dimensions are as shown in the figure, it will fit and be stored in the correct position with high accuracy. Since it is automatically performed in conjunction with a series of these operations, there is an advantage that even if a general user who is not a professional service person replaces the process unit, there will be no failure.

As described above, the present invention has a compact structure, makes it possible to attach and detach the image carrier and the developing means to the frame, and improves the operability of attaching and detaching the two. The developing means can be attached and detached without exposing it to light.
After the above-mentioned both have been attached to the frame, even if the process unit is removed from the apparatus main body, the above-mentioned both can be completely protected from light, external force, dust, etc., and so on. The present invention provides an image forming apparatus to which a unit and the process unit can be attached.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a copying machine using an embodiment of the process unit according to the present invention, FIGS. 2A and B are diagrams illustrating how the process unit is pulled out from the copying machine body, and FIG. 4 is a diagram illustrating the mounting state of each image forming means in the unit, FIG. 4 is a diagram illustrating the frame structure of the process unit, FIG.
6, 7, and 8 are diagrams for explaining the light shielding mechanism of the exposure aperture, FIG. 9 is a diagram for explaining the light shielding mechanism of the transfer aperture, and FIG. 10 is a diagram of the cartridge type according to the present invention. Figures 11A to 11F are diagrams illustrating one embodiment of a process unit, and Figures 12A to 12F are diagrams illustrating other configuration examples of a process unit to which the present invention can be applied.
Figure 13 is a diagram of another embodiment of the process unit.
The figure is a sectional view of an electronic copying machine to which another embodiment is applied.
Fig. 14 is a diagram showing the engaged state of the process unit and the main body of the apparatus, Fig. 15 is a perspective view of the same as above with the process unit pulled out, and Fig. 16 is a diagram illustrating the engagement relationship between the taper pin and the hole. . In the figure, 3...photosensitive drum, 14...cleaner, 17...frame, 19...plate member, 19a ₁
...Drum holding member, 26...Cover, V...Process unit.

Claims (1)

[Scope of Claims] 1. A process unit that can be attached to an image forming apparatus main body, comprising: an image carrier, a developing means for developing a latent image formed on the image carrier, the image carrier and the developer. a frame body that removably supports the means; a closed position rotatably provided on the frame body and covering an upper part of the image carrier mounting position of the frame body; and a frame body that is retracted from the closed position and that supports the image carrier a first lid member that can take an open position that opens the upper part of the body mounting position; a closed position that is rotatably provided on the first lid member and covers the upper part of the developing means mounting position of the frame body;
a second lid member that can take an open position in which it is retracted from the closed position and opens above the developing means mounting position; and an exposure light provided on the first lid member for exposing the image carrier. An exposure aperture for guiding light, a protective position provided in the first lid member that covers the exposure aperture, and a retracted position retracted from the protective position in conjunction with the attachment/detachment operation to the image forming apparatus main body. A process unit comprising: a movable cover; 2. When the process unit is attached to the image forming apparatus main body, the cover is retracted from the closed position to the open position by engaging with an engaging member provided in the apparatus main body, and the process unit is mounted on the image forming apparatus main body. Claim 1: When removed from the image forming apparatus main body, the image forming apparatus moves from the open position to the closed position by being disengaged from the engaging member.
The process unit described in section. 3. The process unit according to claim 1, wherein the exposure aperture is an aperture through which exposure light for forming a latent image on the image carrier passes. 4. The process unit according to claim 1, wherein the exposure aperture is an aperture through which exposure light is passed to remove residual charges on the image carrier prior to image formation. 5. In an image forming apparatus in which a process unit can be attached to the apparatus main body, an image carrier, a developing means for developing a latent image formed on the image carrier, and the image carrier and the developing means are attachable and detachable. a closed position in which the frame body covers an area above the image carrier mounting position, and an open position in which the frame body is evacuated from the closed position and opens above the image carrier mounting position. a first lid member; a closed position rotatably provided on the first lid member and covering an upper part of the developing means mounting position of the frame;
a second lid member that can take an open position in which it is retracted from the closed position and opens above the developing means mounting position; and an exposure light provided on the first lid member for exposing the image carrier. An exposure aperture for guiding light, a protective position provided in the first lid member that covers the exposure aperture, and a retracted position retracted from the protective position in conjunction with the attachment/detachment operation to the image forming apparatus main body. a movable cover; a mounting means capable of mounting a process unit; an optical means for irradiating the image carrier with exposure light through the exposure opening of the mounted process unit; and mounting of the process unit. An image forming apparatus comprising: means for opening a cover of the process unit in conjunction with the operation.