JPS60156084A - Cleaning device - Google Patents

Abstract

PURPOSE:To clean a photosensitive drum well without damaging it by bringing a blade into contact with a part, where a toner does not remain, when the blade separated from the photosensitive drum at a non-use time is brought into contact with the photosensitive drum again at a use time. CONSTITUTION:A cleaning blade 22 is so provided that it can be brought into contact with and be separated from a photosensitive drum 4 which is moved relatively in both of forward and reverse directions. The blade 22 is brought into contact with the photosensitive drum 4 moving in the forward direction to clean the photosensitive drum 4. A moving means is provided which moves the photosensitive drum 4 in the forward direction furthermore by a certain extent after sweeping a toner 40 or the like off the photosensitive drum 4 by the blade 22 and moves the photosensitive drum 4 in the reverse direction by a certain extent. The blade 22 is brought into contact with the drum 4 when the drum 4 is moved in the forward direction by the certain extent by said moving means, and the blade 22 is separated from the drum 4 when the drum 4 is moved by the certain extent completely.

Description

[Detailed description of the invention] [Technical field of invention] This invention relates to a system for cleaning systems.

[Technical Background of the Invention and Problems Therewith] A blade cleaner is the cleaning mechanism most commonly used as a cleaning device for photosensitive drums in image forming apparatuses such as electronic copying machines. This brings the blade into contact with the surface of the photoreceptor drum in the direction of its movement.
In a copying machine that uses an S, e-drum, for example, as a photoreceptor drum, if the blade is kept in contact with the photoreceptor drum until it is not in use, the pressure of the blade will scrape off the residual toner. Since Se crystallizes and damages the photoreceptor drum in streaks, a mechanism is usually used to separate the blade from the photoreceptor drum when not in use.

However, in a copying machine using magnetic toner, particularly magnetic toner for pressure fixing, cleaning residue or scratches may occur on the photosensitive drum after several thousand copies have been made. Particularly by chance, this cleaning residue and drum scratches may form a linear shape.

One of the reasons for this is that when pressing the blade against the photoreceptor drum after it has been separated, for example, in the state shown in FIG. When pressing, it is possible that the toner gets trapped between the blade and the drum. When the photoreceptor drum starts rotating in this state, the blade lifts up locally, which applies an abnormal force to the trapped toner and causes it to slide into the photoreceptor drum, leading to the next cleaning. It is thought that the particles adhere to the photoreceptor drum to such an extent that they are not cleaned during the cycle.

[Object of the Invention] The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a cleaning device in a blade cleaner that can perform cleaning well without damaging a photoreceptor drum.

[Summary of the Invention 1 The present invention provides a method in which, when a blade that has been separated from a photoreceptor drum when not in use is brought into contact with the photoreceptor drum again during use, the blade is brought into contact with a portion of the surface of the photoreceptor drum to which residual toner is not attached. By bringing them into contact with each other, the above purpose is achieved.

[Embodiments of the Invention] Next, the present invention will be described in detail with reference to embodiments shown in the drawings.

FIG. 1 is a sectional view of an image forming apparatus, such as an electrophotographic copying machine, to which the present invention is applied. In the illustration, 1 is the main body;
An original is placed on the upper surface of the main body 1 and moves back and forth (arrows B and C in the figure), and an operation II (not shown) in which a copy start switch and a copy condition setting switch are attached.
etc., and a cover 3 that covers the document is provided on the document table so as to be openable and closable. Also, approximately in the center of the main body 1, a photosensitive drum 4, which is made of, for example, a drum-shaped conductive substrate on which selenium is vapor-deposited, rotates forward and backward (arrow A in the figure).
G) Possibly located. Around the one-piece photosensitive drum 4, in order from the top according to the rotation direction A, a charging device 5, a drive roller 6, a developing device 7, a transfer device 8,
A stripping device 9, a cleaning device 10, and a static elimination run and bulb 11 are arranged. Further, above the photoreceptor drum 4, there is an exposure lamp 12 which has a reflector plate 12a on the back and irradiates light onto a document placed on a document table and moves back and forth, and a charging device that directs light reflected from the document. A convergent light transmitting body 13 that projects onto the surface of the photosensitive drum 4 is arranged at a position between the beam 5 and the dry blow 56 .

Therefore, as the photoreceptor drum 4 rotates, it is first uniformly charged by the charging device 5, and then the convergent light transmitter 13 is charged uniformly by the charging device 5.
An image of the original is formed through the lens. Here, an electrostatic latent image is formed on the surface of the photoreceptor drum 4, and this electrostatic latent image is transferred to the developing device @7.
toner is attached and developed. The developing device 7 is
It is equipped with a density measuring device 7a that measures the density of the developer consisting of toner and carrier accumulated and conveyed therein, and a toner hopper 7b that replenishes toner according to the measurement results, and the above-mentioned static electricity is always maintained at a constant rate. Cap the latent image. The toner image formed on the photoreceptor drum 4 by the developing device 7 is transferred onto copy paper by a transfer device W18 at a transfer position between the photoreceptor drum 4 and the transfer device 8. The copy papers are stored in a stacked state in a cassette 14 detachably attached to the lower right side of the main body 1 in the figure.

Copy paper is fed out one sheet from the cassette 14 each time a paper feed roller 14b rotatably provided above the cassette mounting portion 14a of the main body 1 rotates once, and is provided midway in the feeding direction. By the rotation of the registration roller 15,
The photoreceptor drum 4 is fed into the transfer position in synchronization with the rotation of the photoreceptor drum 4. Further, the copy paper on which the toner image has been transferred is peeled off from the photosensitive drum 4 by a peeling device 9, and is conveyed to the fixing device 16 via a conveyance guide 17 which is numbered along its extension direction. The fixing device @16 includes a pair of heat rollers and is provided on the left side of the main body 1 in the figure.
By holding and conveying the above 1-layer paper with heat rollers,
Heat fixes the toner image onto copy paper. After fixing, copy paper is
Heat Roller Conveyance 7 The sheet is ejected to the outside of the main body 1 by a pair of ejection rollers provided at the front in the feeding direction. On the other hand, on the photosensitive drum 4 from which the copy paper has been peeled off, the toner remaining without being transferred is removed by the cleaning device 10, and the static elimination lamp 1
1, the static electricity is removed and returned to the initial state. In addition, 1 in the illustration
8 is a main motor that drives each part of the main body, and 19 is a cooling fan for suppressing a temperature rise inside the main body 1.

The above is an outline of, for example, an electronic copying machine to which the present invention is applied. Next, a cleaning device 10 according to the present invention will be explained with reference to FIG. 2.

FIG. 2 is a sectional view of the cleaning device 10. The cleaning device 10, together with the photosensitive drum 4, constitutes one unit 20, and this unit 20 is detachably installed in the main body 1 of the electronic copying machine. . That is, the cleaning device 10 includes a pair of side frames 10a and 10b.
and a cleaning section X21 whose periphery is protected by a casing 10C supported between both frames, and a drive roller supported on a rotating shaft rotatably supported by the pair of side frames 10a and 10b for forward and reverse rotation. Consists of 6. Further, the rotating shaft 4a of the photosensitive drum 4 is supported by the pair of side frames 10a and 10b. The photoreceptor drum 4 and the drive roller 6 are brought into contact with each other so as to be able to follow each other, and the photoreceptor drum 4 and the cleaning section 2
1 are opposed to each other through the front side opening of the casing 10c. The cleaning section 21 includes a removal blade 22,
Collection blade 23. and a collection auger 24. The removal blade 22 is supported at its other end by a support mechanism 25 so that the etching on one end thereof can come into contact with and separate from the surface of the photoreceptor drum 4 in the rotational direction of the photoreceptor drum 4 . The support mechanism 25 has a lever 27, and a holder 26 that holds the other end of the blade 22 on the lever 27 is attached to a fixing member 27.
It is supported through b. The lever 27 is supported by the pair of side frames 10a and 10b, and
One end of the rotary shaft 27a is attached to a rotating shaft 27a, which can be rotated in the direction of the arrow shown when a solenoid (not shown) is turned off, and rotated in the direction of the arrow E shown when the solenoid is turned on. A weight 28 is attached and is biased in the direction of arrow E. Further, the collection blade 23 has one end fixed to the cleaning 100 at the bottom of the cleaning section 21 and the other end fixed to the photoreceptor drum 4 in the rotational direction of the photoreceptor drum 4.
Surface is in contact with the surface. The collection A-gager 24 is rotatably disposed at the bottom of the cleaning section 21 along the rotation direction 4f of the photoreceptor drum 4. Further, a mold plane 29 is attached to the wall surface of the pair of side frames 10a and 10b located inside the cleaning section 21.

FIG. 3 is a schematic perspective view showing a drive mechanism for driving the photosensitive drum 4 and the drive roller 6. FIG. The drive roller 6 has its rotating shaft 6a directly connected to the sub motor 30. A drive gear 31 is attached to the rotation axis pa of the photosensitive drum 4, and the drive gear 31 is driven to rotate the photosensitive drum 4.

The drive gear 31 has a first driven gear 32 meshed therewith.
and a second driven gear 3 meshed with the first driven gear 32
3. This second driven gear 330 is driven by the main motor 34 via a drive pulley 35 attached to the drive shaft of the main motor 34, and a belt 37 passed around these pulleys 33, 35, and 36. be done.

FIG. 4 is a partially enlarged sectional view showing the contact and separation relationship between the blade 22 and the photosensitive drum 4, and with reference to this figure and FIG. explain. First, copy switch (not shown)
When turned on, a solenoid (not shown) is operated in the cleaning device 10, and the lever 27 becomes rotatable in the direction of the arrow E, and is rotated in the direction of the arrow E by the biasing force of the weight 28. Therefore, the blade 2 is supported by the lever 27 via the holder 26 and the fixing member 27b.
2 on the surface of the photoreceptor drum 4 (Fig. 4(a)
)). This contact position IQ is a position apart from a position P where residual toner 40 from the cleaning process in the previous copying process remains, for reasons to be described later. Photoreceptor me/mu 4y-Residual I atrophy
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When the blade 22 is brought into contact with the surface of the photoreceptor drum 4 in this manner, the main motor 34 in the copying machine is operated to rotate the photoreceptor drum 4, and each device is operated to achieve a predetermined result. The copying process progresses to form a copy image on the copy paper. When the photoreceptor drum 4 is rotated (in the six directions of arrows in the figure), the blade 22 scrapes off the toner remaining after cleaning and the toner 40 remaining on the photoreceptor drum 4 during the current copying process. (See Figure 4(b)).

At this time, since the sub-motor 30 is not operated, the drive reeler 6 is rotated according to the rotation of the photosensitive drum 4 (arrow i!> in FIG. 2).

- When the photosensitive drum 4 finishes forming the copy image on the copy paper, the main motor 34 is turned off and its rotation is stopped (see FIG. 4(C)). At this time, the blade 22 is in contact with the IR at the surface of the photoreceptor drum. Thereafter, the sub motor 30 is operated for a predetermined period of time, and the drive roller 6 is rotated in the direction of arrow F. Therefore, the photosensitive drum 4 is rotated again in the six directions of the arrows according to the rotation of the drive roller 6 (see FIG. 4(d)), and is moved ahead of the normal meshing position between the drive gear 31 and the first driven gear 32. In other words, it is rotated by the backlash of the gear and then stopped (see FIG. 4(e)). In the drive roller 6, even after the photoreceptor drum 6 is rotated by the amount of backlash and stopped, the energized state of the sub motor 30 is maintained until the predetermined time elapses.
If the output of 0 is large, slip rotation is performed. Also,
When the output of the sub motor 30 is small, it is stopped at the same time as the photosensitive drum 4 is stopped. In addition, the above figure 4 (C)
In this state, the photosensitive drum 4 may already rotate by one gear backlash due to its inertial force and then stop. In this case, this is sufficient time for the drive roller 6 to rotate the photosensitive drum 4 by the amount of backlash, assuming that it does not rotate by the amount of dog lash. Furthermore, while the photosensitive drum 4 rotates by the amount of backlash and stops, the contact position of the blade 22 on the surface of the photosensitive drum 4 moves from R to S, and the remaining toner 40 is removed by the amount of the movement. will be scraped off again. Then, the photosensitive drum 4 is stopped in this way (FIG. 4(e)), and the drive roller 6 is stopped.
When the lever 2 is stopped, the solenoid is turned off and lever 2 is turned off.
7 is rotated in the direction of the arrow. Therefore, the blade 22 is separated from the photoreceptor drum 4 (see Fig. 4(')).
f)). When the separation of the blade 22 from the photosensitive drum 4 is completed, the sub motor 30 is then energized again to rotate the drive roller 6 in the opposite direction for the predetermined period of time.

Therefore, the photosensitive drum 4 is rotated in the opposite direction G according to the rotation of the drive roller 6, and is returned to its original position by the amount of backlash (see FIG. 4 (0)), and the cleaning action by the cleaning 81110 is completed. be done.

Therefore, when the copy start switch is turned on again and the next copying process is started, the blade 22 is positioned at the surface of the photoreceptor drum 4ff1R as shown in FIG. 4(h).
In other words, the amount of toner remaining after cleaning from the cleaning process in the previous copying process remains.
It is contacted at a position farther away than S. In addition, Fig. 4(b)
In the state of (d>), the I/toner scraped from the photosensitive drum 4 by the blade 22 scatters and falls due to its own weight, and the collection blade 23 prevents the toner from scattering outside the cleaning section 21 by the cleaning 9. Further, the toner collected in the cleaning section 21 is conveyed by the auger 24 into the illustrated collection container and collected.

As explained above, in this embodiment, after the normal cleaning shown in FIG.
2, the remaining toner is scraped off from the photoreceptor drum 4, the blade 22 is then separated from the photoreceptor drum 4, and then the photoreceptor drum 4 is returned to its original position by the amount of backlash. Therefore, the blade 22
When the blade 22 is brought into contact with the surface of the photoreceptor drum 4, the remaining toner from the cleaning process in the previous copying process is not attached to the contact position, that is, the blade 22 is brought into contact with the remaining toner on the surface of the photoreceptor drum 4. It is possible to reliably contact the non-adhered portion. Therefore, the surface of the photosensitive drum 4 can be cleaned well without causing the above-mentioned conventional problems.

Note that the present invention is not limited to this embodiment, and various modifications can be made without changing the gist thereof. for example,
From the state shown in FIG. 4(C), the photoreceptor drum 4 is directly rotated by a predetermined amount by the motor for driving the photoreceptor drum 4, regardless of the amount of backlash, and then reversely rotated by the predetermined amount in FIG. 4(9). It's okay. However, it goes without saying that in order to minimize the above-mentioned predetermined amount, it is desirable to configure as in this embodiment.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a cleaning device in a blade cleaner that can perform good cleaning without damaging the photoreceptor drum.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an electronic copying machine to which the present invention is applied, and FIG. 2 is a sectional view showing an embodiment of the present invention. 4... Photosensitive drum, 6... Drive roller, 10
. . . Cleaning device, 22 . . . Removal blade. Agent Patent attorney Kensuke Norichika (and 1 other person) Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] Cleaning includes a cleaning blade that is movable toward and away from an image carrier that moves relatively in both forward and reverse directions, and that cleans the image carrier by bringing the cleaning blade into contact with the image carrier that moves in the forward direction. In the apparatus, a moving means for roughly moving the image carrier by a predetermined amount in the forward direction after cleaning the image carrier by the cleaning blade, and then moving the image carrier by the predetermined amount in a direction opposite to the forward direction; , the cleaning blade is brought into contact with the image carrier which is being moved in the forward direction by the predetermined amount by the moving means, and after the image carrier has been moved in the forward direction by the predetermined amount, the cleaning blade is moved against the image carrier. Cleaning lul! characterized by comprising a contact/separation means for separating the lul! .