JPH04145464A - Image forming device - Google Patents

Abstract

PURPOSE:To easily and simply clean up an electrode by providing a cleaning member cleaning an electrode and manually operating it, on a device where a process cartridge having a photosensitive body and an electrifier is made attachable. CONSTITUTION:The photosensitive belt 11, the electrifier 12, a developing unit 13, etc., are disposed to constitute the process cartridge 17, and an electrostatic latent image is formed on the belt 11. The guiding plate 171 of the cartridge 17 is fitted into the guiding groove 182 of a device main body 181, so that the cartridge 17 is attachably/detachably attached. When the cleaning member 310 is operated, a door 19 is opened, the operating part 411 of a driving member 413 operating a rack 41 is grasped by a hand to be pulled out from an initial position 411 to a terminal position 411', and then, pushed back to an original position. The cleaning member 310 reciprocatively cleans up the electrifier 12 by this operation. In other words, a pinion 42 engaging with the rack 41 is rotated and the cleaning member is moved in a direction orthogonal to the operating direction of the member 413.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus that forms images by an electrophotographic method and has an improved charging device for a photoreceptor.

[Background of the invention]

2. Description of the Related Art In image forming apparatuses such as electrophotographic copying machines and printers, charging devices that use elongated wire-like discharge wires as electrodes are used as charging means for uniformly charging a photoreceptor.

Depending on the charging conditions, a charging device may be used that has a charging control grid provided between the photoreceptor and the electrode to make corona charging by the electrode uniform and to prevent excessive charging. Due to the high voltage charge applied to the electrodes and grids of the charging device, toner powder, paper powder, solid matter such as oxide film, etc. adhere to the electrodes and grids of the charging device, and when these deposits accumulate,
The intensity distribution of the charge applied to the photoreceptor by the electrodes or grid becomes non-uniform, resulting in uneven density of the copied image.

Therefore, a cleaning member for the purpose of cleaning the electrodes and the grid is built into the charging device. It is said to be a method of cleaning by sliding it along the surface and using the rubbing action.

As a driving means for sliding the cleaning member,
There are manual methods and methods using power such as a drive motor.The manual method has a simple structure, and therefore has the advantage of fewer failures and low cost. Furthermore, when using a method using power such as a drive motor, there is no need to insert your hand into the inside of the device during cleaning, and it can be controlled so that cleaning can be done automatically at an appropriate time. It has the following advantages.

On the other hand, in an image forming apparatus, the photoreceptor on which an image is formed and the image forming means provided on the peripheral part of the photoreceptor are integrated into a process cartridge, which is removably attached to the main body of the image forming apparatus (hereinafter referred to as the apparatus main body). An image forming apparatus is also provided. The charging device is built into the process cartridge, so when cleaning the built-in charging device using the manual cleaning method, insert your hand inside the device body and manually move the cleaning member of the charging device to clean it. Alternatively, after the process cartridge is removed from the apparatus main body, the cleaning member of the charging device is manually moved and cleaned in the same manner as described above. In the case of a cleaning method using power from a drive motor, etc., the drive motor is usually installed inside the charging device, and a control device for operating the drive motor for cleaning every predetermined number of copies is also built into the main body of the device.

[The problem that the invention attempts to solve]

In the case of a manual cleaning method as described above, in order to clean the charging device by inserting your hand inside the device body and moving the cleaning member of the charging device, it is necessary to You can divide the main body into two parts and flip one side up, or pull out the unit with the built-in charging device so that there is enough room to insert your hand, or you can remove the unit with the built-in charging device from the device. One method of cleaning the charging device is to remove it from the main body so that it can be easily accessed by hand, and then move the cleaning member of the charging device by hand.

However, in any case, if you move the cleaning member by hand,
This requires manual operation in a narrow space, and is cumbersome when combined with the above-mentioned operation of a unit incorporating a charging device for inserting or reaching the first hand.

In addition, in the case of a cleaning method using power such as a drive motor, the drive motor is installed inside the charging device as described above, so the structure of the charging device is refrigerated, and the control device that operates the drive motor every specified number of copies is also a device. Since it is incorporated into the main body at the same time, the cost of the image forming apparatus increases.

The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to provide easy repair and simple structure;
The object of the present invention is to provide an image forming apparatus using a process cartridge incorporating a highly reliable and inexpensive charging device.

[Means for solving problems]

The above object is to provide an image forming apparatus in which a process cartridge having at least a photoreceptor and a charging device is removably attached to an apparatus main body, and the charging device is provided with at least an electrode and a cleaning member for cleaning the electrode. A drive means for manually operating the cleaning member is provided between the apparatus main body or the process cartridge and the charging device, and the drive member for operating the drive means is set in the cleaning operation direction of the cleaning member. This is achieved by an image forming apparatus characterized in that it is configured to operate in a direction substantially perpendicular to the image forming apparatus.

〔Example〕

An embodiment of the image forming apparatus of the present invention is shown in FIGS. 1 to 5.

FIG. 1 shows a main cross section of an image forming apparatus to which the present invention is applied.

The photoreceptor belt 11 includes a driving roller 15 and a driven roller 16.
A charging device 112, a developing device 13, a cleaning plate 14, etc. are arranged as shown in the figure to constitute a process cartridge 17, and an electrostatic image is formed on the photoreceptor belt by a known method. and process cartridge 17
A guide plate 171 of the process cartridge 17 is fitted into a guide groove 182 of an apparatus main body 181 of the image forming apparatus 18 and is detachably mounted.

This figure also shows a cleaning member 31 for cleaning electrodes, etc. in an initial position (described later), and a Hasuba rack (hereinafter referred to as a rack) 41 and a Hasuba pinion (hereinafter referred to as a pinion) 42 meshing together. The relative positions are also shown.

In this state, the rack 41 is pushed into the left cup, that is, to the deepest position, and the drive member 4 that operates the rack 41
The position of the operation part 411 of No. 13 is such that it does not prevent the drive door 19 of the exterior casing from closing.

Image formation is possible in the state shown in this figure in which the drive door 19 is closed.

FIG. 2 shows a state in which the charging device 12 is being cleaned by operating the rack 41 and operating the cleaning member 310.

The detailed operating situation will be explained later in a separate figure, or the general operating situation is as follows.

That is, when operating the rack 41 to operate the cleaning member 310, open the drive 119 as shown in the figure and open the rack 41.
1, and hold the operation part 411 of the drive member 413 that operates the cleaning member 310 with your hand, and move the rack 4 indicated by the solid line, which is the initial position of the cleaning member 310, to the rack 4.
1. Drive member 413, operation section 411, cleaning member 31
The rack 41', the drive member 413', and the operation part 411' shown by the two-dot chain line are pulled out to the end position of 0, and then pushed back to the original position shown by the solid line. Through this operation, the cleaning member 310 cleans the charging device 12 back and forth.

Also, when removing the process cartridge 17 from the apparatus main body 181, open the drive shaft 19 as shown in the figure and move the process cartridge 17 to the right through the guide groove 182 of the apparatus main body 181.
Then, the process cartridge 17 is pulled out until the guide plate 171 of the process cartridge 17 comes off.

In addition, the rack 41 and pinion 42 are not "right next to each other"
"Hasuba" is used when the removed process cartridge 17 is inserted into the main body 181 of the apparatus, and when the rack 41
This is to allow the pinion 42 to mesh smoothly.

3 and 4 are perspective views showing the charging device 12 installed in the process cartridge 17 and its surroundings in an image forming apparatus to which the present invention is applied.

FIG. 3 shows a state in which the cleaning member incorporated in the slider 31 is cleaning the corona wire 26 and the screen grid 25, which are electrodes.

The charging devices 12 are arranged symmetrically with a certain interval apart.
L-shaped back plate a2 that is a shielding member for the electrode
1. A box-shaped end plate a231 and a box-shaped end plate b24 having insulating properties are sandwiched by the back plate b22 at both ends in the longitudinal direction. The slider 31 or cleaning member is slidably guided in regularly spaced grooves in the two back plates 21,22. Then, from above, it is covered with a screen grid 25 having a U-shaped lid having a surface processed into a shape that acts as a grid on the upper surface.

The corona wire 26, which is an electrode, is attached to both the back plates 21, 22, . It is stretched between box-shaped end plates 23 and 24 at both ends in a rectangular tube surrounded by a screen grid 25.

The slider 31 has an axis a 311. A shaft b312 is provided, and a felt stand a 313. A felt stand b 314 is pivotally supported. Felt stand a 313 has felt a 3
15 is pasted at a position suitable for rubbing and cleaning the corona wire 26, and a felt b
316 is attached at a symmetrical position to felt a 315. Then, sandwich both felts 315 and 316 or corona wire 26, and make it possible to rub and clean both felt stands 3.
Both shafts 311 of the slider 31 supporting the shafts 13 and 314
．． Both presser springs 318 are inserted into 312 .

On the other hand, the grid blade (indicated by a two-dot chain line) is made of a relatively thin flexible plate material such as urethane rubber.

As shown in the figure, a circular hole is provided approximately in the center to avoid the corona wire 26, and the grid blade above this hole is divided into left and right sides. Felt stand a
Pin a319 of 313 is inserted into the hole of grid blade a321 on the right side of the grid blade, and similarly the bottle b320 of felt stand b 314 is inserted into the hole of grid blade b322 on the left side of the grid blade. . When the felts 315 and 316 are holding the corona wire 26, the upper end surfaces of the grid blades 321 and 322 are linear and come into contact with the inner surface of the upper surface of the screen grid 25, which is rubbed and cleaned. It seems possible.

The charging device 12 is removably attached to the process cartridge 17 with a screw (not shown).

- The rack 41 is assembled to the blade device main body 181 as follows.

That is, the rack 41 has a long groove 412 that guides the rack 41.
An L-shaped support plate 183 is attached to the apparatus main body 181 to support the rack 41 in parallel to the large arrow, which is the direction in which the process cartridge 17 is attached and removed. The guide pin 184 that guides the rack 4I is connected to the L-shaped support plate 18.
3, and the long groove 412, ie, the rack 41, is slidably guided in a direction substantially perpendicular to the cleaning operation direction of the slider 31, which is a mounting base for the cleaning member. Rack 41
The drive member 4 has its tip or operating portion 411.
13 are connected. The rack 41 is engaged with a pinion 42 coaxial with a drive pulley 45. A drive wire 47 is stretched between the drive pulley 45 and the driven pulley 46, with both ends thereof fixed to the slider 31.

When the operating portion 411 of the drive member 413 is grasped and pulled out toward the lower left, the drive pulley 45 coaxial with the pinion 42 that engages with the rack 41 rotates in the direction of the arrow. As mentioned above,
A drive wire 4 is connected between the drive pulley 45 and the driven pulley 46.
7 and both ends thereof are fixed to the slider 31 and stretched, so the slider 31, that is, the cleaning member moves in the lower right direction. And both felts 315 and 316 are
As described above, since the corona wire 26 is held between the two presser springs 318 by the spring force, the corona wire 26 is moved while being rubbed and cleaned. Further, the upper end surfaces of both grid blades 321 and 322 are also moved while cleaning the inner surface of the screen grid 25 as described above. Then, when the slider 31, that is, the cleaning member moves to the terminal position at the lower right end of the drawing (hereinafter referred to as the second
(See also the figure) The relative position of the rack 41 and the pinion 42 at that time is the relationship between the rack 41' and the pinion 42 as indicated by the two-dot chain line.

Next, when the operating portion 411 is grasped and pushed toward the upper right, the pinion 42 rotates in the opposite direction, and the slider 411, that is, the cleaning member moves toward the upper left. In this way, the inner surfaces of the corona wire 26 and the screen grid 25 are cleaned back and forth.

FIG. 4 shows the state in which the slider 31 has returned to the upper left end, that is, the state in which the cleaning member is in its initial position.

In this figure, since the slider 31, that is, the cleaning member is located at the upper left end as described above, both felt tables 313 and 314
is in a state where the upper side is opened by a cam 231.

Therefore, there is a gap between both felts 315 and 316,
The corona wire 26 and both felts 315 and 316 are in a non-contact state. Image formation will be performed in this state.

Like felt, grid braid a 321. The grid blade b322 is also separated and placed in an open state. Corona wire 2 made the grid blade into this shape.
This is to make it easier to stretch the frame 6 during assembly.

Also, a brake spring 185 attached to the device main body 181
The rack 41 is lightly pressed from above by its spring force, and the right angle bent protrusion at the tip of the braking spring 185 presses the rack 41 in the upper right direction until it stops. As shown in the figure, it falls exactly into the stepped part of the connecting part. That is, the position of the rack 41 at this time is the initial position of the slider 31, that is, the cleaning member. Therefore, when trying to operate the rack 41, the operating section 41
1 and pull it out in the lower left direction, the rack 41 will not be able to operate unless the drive member 413 and the stepped portion of the rack 41 push up the right angle bent protrusion at the tip of the brake spring 185.

The reason for providing such a brake spring 185 is that the slider 31
That is, the cleaning member should not be easily moved from its initial position, and the process cartridge 17 should not be moved easily from its initial position.
This is to prevent the rack 41 from being pulled out together with the engaged pinion 42 when the rack 41 is removed from the rack 1. However, even if the rack 41 is pulled out together, the sliding direction of the rack 41 and the process cartridge 17
Since the attachment/detachment directions are parallel as described above, the rack 41 and pinion 42 will not become disengaged from each other.

Also, when removing the process cartridge 17 from the apparatus main body 181, do you need to open the drive door and pull out the process cartridge 17 in the direction of the large arrow as described above?
The rack 41 and pinion 42 are engaged, and the rack 4
1 is stopped by the brake spring 185 as described above, the pinion 42 attempts to rotate in a direction that pulls the slider 31, that is, the cleaning member further upward and to the left from the initial position.

For this purpose, for example, it is conceivable to provide a friction clutch (not shown) having an appropriate frictional resistance between the pinion 42 and the drive pulley 45.

If such a friction clutch is provided, the drive pulley 45
While stopped, only the pinion 42 rotates slightly and immediately engages or disengages from the rack 41. If the process cartridge 17 is further pulled out, the process cartridge 17 can be removed from the apparatus main body 181. Also, if such a friction clutch is provided, even if the slider 31°, that is, the cleaning member is located somewhere, or the rack 41 is pulled out to any position,
After the process cartridge 17 has been installed in the apparatus main body 181, if you pull out the rack 41 all the way and push it in once, the friction clutch will slip during that process, and the slider 31, that is, the cleaning member, will always return to its initial position. Will go and stop.

In this state, the image forming apparatus becomes ready for use, and the corona wire 26 of the charging device 12 and the screen grid 2
By applying a high voltage charge to the photoreceptor belt 5, the photoreceptor belt is uniformly charged.

FIG. 5 shows a situation in which the drive door 19 cannot be closed if the rack 41 is not pushed to its deepest position and the operating portion 411 of the drive member 413 is slightly protruding from the exterior casing. . If an interlock switch (not shown) is provided which is activated by the drive door 19 when the drive door 19 is completely closed, no image will be formed in the case shown in this figure.

Therefore, push the rack 41 completely to the innermost position and drive the drive member 4.
When the operation unit 411 of No. 13 is prevented from coming out from the exterior housing and the drive door is completely closed, the interlock switch is activated and image formation becomes possible.

FIG. 6 is a diagram of another embodiment. In this embodiment, the rack 41 (driving member 413, operating section 411) is incorporated into the process cartridge 17 in the same way as the rank in the previous embodiment is incorporated into the main body of the apparatus. Therefore, in this case, the sliding direction of the rank 41 and the attachment/detachment direction of the process cartridge 17 do not have to be parallel (also, since the rack 41 and pinion 42 are always engaged and cannot be separated, the rack 41 and pinion 42 cannot be processed There is an advantage that a friction clutch is not required.However, there is also a disadvantage that a rack and its sliding mechanism must be installed for each set of process cartridges.

In the image forming apparatuses of these embodiments, a rank and pinion are used to convert the linear motion of the drive member into rotational motion of the drive pulley, but the present invention is not limited thereto. For example, the same purpose can be achieved by replacing the rack and pinion gear system with a similar friction wheel system, and the friction clutch between the pinion and drive pulley described above becomes unnecessary.

〔Effect of the invention〕

According to the present invention, cleaning can be carried out easily and easily whenever necessary, so high-quality images can always be obtained, and the charging device has a simple structure, high reliability, and low cost. An image forming apparatus using a built-in process cartridge is now available.

[Brief explanation of drawings]

FIG. 1 is a main cross-sectional configuration diagram of an image forming apparatus to which the present invention is applied, and is a state in which the rank is pushed into the apparatus body to the deepest position and image formation is possible. This figure also shows the relative position of the rack and pinion. FIG. 2 shows the charging device being cleaned, with the rack pushed in to its deepest position and pulled out to the -fragrance stone position. The relative position of the rack and pinion at that time is also shown. 3 and 4 are perspective views showing the charging device used in the image forming apparatus of the present invention and the surrounding situation thereof. FIG. 3 shows the situation during cleaning by the cleaning member, and FIG. The figure shows the situation with the cleaning member in its initial position. FIG. 5 is a diagram showing a state in which the drive door cannot be closed because the rack has not been pushed to its deepest position. FIG. 6 is a diagram showing another embodiment in which the rack or process cartridge is incorporated. 11... Photosensitive belt 12... Charging device 17.
...Process cartridge 18...Image forming apparatus 181...Image forming apparatus main body 19...Drive door 25...Screen grid

Claims (2)

[Claims] (1) In an image forming apparatus in which a process cartridge having at least a photoreceptor and a charging device is removably attached to the main body of the image forming apparatus, the charging device includes at least an electrode and a cleaning member for cleaning the electrode. A drive means for manually operating the cleaning member is provided between the image forming apparatus main body or the process cartridge and the charging device, and a drive member for operating the drive means is provided between the cleaning member and the charging device. An image forming apparatus characterized in that it is configured to operate in a direction substantially perpendicular to the direction of cleaning operation. (2) The exterior casing of the image forming apparatus is provided with a drive door for operating the drive member, and the drive door opens only when the drive member is at a predetermined position. 2. The image forming apparatus according to claim 1, wherein the drive door can be closed, and image formation is enabled by closing the drive door.