JPH04134372A - Image forming device - Google Patents

Abstract

PURPOSE:To use a process cartridge incorporating an electrifier reduced in cost by providing a cleaning member cleaning an electrode on the electrifier and a driving means driving the cleaning member between a device main body and the electrifier. CONSTITUTION:When the process cartridge 17 is operated in the direction of the large arrow, a driving pulley 45 on the same shaft as a pinion 42 engaged with a rack 41, is rotated in the direction of the arrow. At this time, both ends of a driving wire 47 are fixed/strechted on a slider 31, between the driving pulley 45 and a follower pulley 46, so that the slider 31, that is, the cleaning member can be moved clockwise. Then, since both felts 315 and 316 sandwich a corona wire 26 by the spring force of both pressing spring 318, the felts 314 and 316 are moved while rubbing and cleaning the corona wire 26. Thus, the process cartridge incorporating the electrifier reduced in the cost is used.

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, or solid matter such as oxide film adheres to the electrodes and grids of the charging device. As a result, the intensity distribution of the applied charge on the photoreceptor becomes non-uniform, resulting in uneven density of the copied image.

Therefore, the charging device has a built-in cleaning member for cleaning the electrodes and grids. For example, a cleaning member supported by a back plate, which is a shielding member for the electrodes, is periodically slid along the electrodes and grids. ,
It is said to be a method of cleaning by the rubbing action.

As a driving means for sliding the cleaning member,
There are manual methods and methods using power from a drive motor, etc. The manual method has the advantage of having a simple structure, fewer breakdowns, and lower cost.

On the other hand, in an image forming apparatus, a photoreceptor on which an image is formed is held in place, and an image forming means provided on the periphery of the photoreceptor is 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 above process cartridge has a built-in charging device, so when cleaning the built-in charging device, either insert your hand inside the device body and manually move the cleaning member of the charging device to clean it, or remove the process cartridge from the device. After the charging device is removed from the main body, the cleaning member of the charging device is manually moved and cleaned in the same manner as described above.

[Problem to be solved by the invention] As mentioned 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, for example, a known clam shell method is used. You can do this by splitting the main body into two and flipping one side up, or by pulling out the unit that incorporates the charging device.
Cleaning the charging device by making room for your hand to be inserted, or by removing the unit in which the charging device is installed from the main body of the device so that you can easily reach the cleaning member with your hand. There is a method of cleaning by moving it 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 for a unit that incorporates a charging device for first inserting or reaching the hand.

On the other hand, if a jam occurs around a unit that incorporates a charging device, in order to remove the jammed paper, you can divide the main body into two parts and flip up one side of the main body in exactly the same way as above. A method is adopted in which a unit in which the charging device is incorporated is pulled out, or the unit is removed from the main body of the device.

In other words, the same method is used when cleaning the charging device and when dealing with jams.

The inventor of the present invention has focused on this point and has made improvements, and the purpose of the present invention is to provide a process cartridge incorporating a charging device that is easy to repair, has a simple structure, is highly reliable, and is low in cost. An object of the present invention is to provide an image forming apparatus using the method.

[Means to solve the problem]

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 the main body of the apparatus, and the charging device is provided with at least an electrode and a cleaning member for cleaning the electrode. A driving means for driving the cleaning member is provided between the apparatus main body and the charging device, and the driving means is driven by an operating force when attaching and detaching the process cartridge. This is achieved by an image forming apparatus having the following characteristics.

〔Example〕

An embodiment of the image forming apparatus of the present invention is shown in FIGS. 1 to 4.

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 12, a developing device 13, a cleaning blade 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. The process cartridge 17 is removably attached to the apparatus main body 181.

This figure further shows the meshing of a helical rack (hereinafter referred to as a rack) 41 and a helical pinion (hereinafter referred to as a pinion) 42 with a cleaning member 310 for cleaning electrodes etc. in an initial position which will be explained later. The relative positions are also shown.

FIG. 2 shows the process cartridge 17 being pulled out by opening the cartridge drawer lid 19, and with the cleaning member 310 at the cleaning end position to be described later, the rack 41 and pinion 42 are disengaged from each other, or are at the starting relationship position. It shows the state at a certain time.

The reason why ``hasuba'' is used instead of ``sukuba'' (rack 41 and pinion 42) is to ensure that the rack and pinion mesh smoothly when the removed process cartridge is inserted into the main body of the apparatus.

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
A box-shaped end plate a233 and a box-shaped end plate b24 having insulating properties are sandwiched by a 1° 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, a screen grid 25 of a U-shaped lid having a surface processed into a shape that acts as a grid is placed on the upper surface.

The corona wire 26, which is an electrode, is attached to both the hack 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 b 312 is provided, and a felt stand a 313. A felt stand b 314 is pivotally supported. felt a31 on felt stand a313
5 is attached to a suitable position for rubbing and cleaning the corona wire 26, and the felt base b 314
316 or felt a is pasted in a symmetrical position with 315. Then, sandwich both felts 315 and 316 or corona wire 26, and make it possible to rub and clean both felt stands 3.
13.Both shafts 311 of the slider 31 that pivotally support 314
, 312 have both presser springs 318 inserted therein.

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
The pin a319 of 313 is inserted into the hole of the grid blade a321 on the right side of the grid blade, and similarly the pin b320 of felt base b314 is inserted into the hole of the left side of the grid blade on the left side of the grid blade b322. ing. When both felts 315 and 316 are sandwiching the corona wire 26, the upper end surfaces of both grid and throat blades 321 and 322 form a straight line and come into contact with the inner surface of the upper surface of the screen grid, 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).

On the other hand, a rack 41 is attached to the device main body 181, and the rack 41 meshes 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 process cartridge 17 is operated in the direction of the large arrow (as shown in FIG. 2, the cartridge drawer lid 19 is opened and the process cartridge 17 is pulled out to the right).
The drive pulley 45 coaxial with the pinion 42 meshing with the rack 41 is rotated in the direction of the arrow. As mentioned above, since the drive wire 47 or both ends thereof are fixed to the slider 31 and stretched between the drive pulley 45 and the driven pulley 46, the slider 31, that is, the cleaning member moves to the right. . Then, both felts 315 and 316 are pressed against the corona wire 2 by the spring force of both presser springs 318 as described above.
6 is in between, so move it while scrubbing and cleaning it. 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. When the slider 31, that is, the cleaning member, moves to the right end position (see also FIG. 2 below), the relative position of the rack 41 and pinion 42 at that time becomes a state in which they are disengaged, and when the process cartridge 17 is further pulled out, the slider 31, that is, the cleaning member is pulled out together with the process cartridge chef while remaining in the final position, and is finally removed from the guide plate 17 of the process cartridge 17.
1 or the process cartridge 17 comes off from the guide groove 182.
will come off from the device main body 181.

Next, when the guide plate 171 of the process cartridge 17 is inserted into the guide groove 182 and the process cartridge 17 is pushed in, the pinion 42 eventually engages with the rack 41 and rotates in the opposite direction from when it is pulled out, and the slider 31, that is, the cleaning member will move towards the left. In this way, the inner surfaces of the corona wire 26 and the screw slit 25 are cleaned back and forth.

FIG. 4 shows a state in which the slider 31 has returned to the left end, that is, a state in which the cleaning member is in its initial position. In this figure,
Since the slider 31, that is, the cleaning member is at the left end position as described above, the upper side of both felt stands 313 and 314 is connected to the cam 23.
1, it is in an open state. Therefore, there is a gap or empty space between the two felts 315 and 316, and the corona wire 26
Both felts 315 and 316 are in a non-contact state.

Similar to the felt, the grid blade a321 and the grid blade b322 are also separated and placed in an open state. Corona wire 26 made the grid blade into this shape.
This is to make it easier to stretch during assembly.

By the way, if the pinion rotates for some reason while the process cartridge is removed from the apparatus main body, the slider, that is, the cleaning member will move from the end position. For this purpose, for example, it is conceivable to provide a friction clutch with appropriate frictional resistance between the pinion and the drive pulley. If such a friction clutch is installed, no matter where the slider or cleaning member is located, when the process cartridge is inserted into the main body of the apparatus and pushed in, the slider, i.e., the cleaning member, will always be moved before the process cartridge is pushed in to the deepest position.
That is, the cleaning member goes to the initial position and stops, and then the friction clutch slips and the process cartridge goes to the innermost position and stops.

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

In the image forming apparatus of this embodiment, a rack and pinion are used to convert the linear motion of the process cartridge into rotational motion of the drive pulley, but the present invention is not limited thereto. For example, the same objective 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 of the charging device is automatically performed at the same time as jam removal, and even when cleaning is required, it can be easily and easily performed, so that high-quality images can always be obtained, and it is also simple. An image forming apparatus using a process cartridge incorporating a highly reliable and low-cost charging device has been provided.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relative positions of a rack and a pinion in a state where the main body of an image forming apparatus to which the present invention is applied has been completely set in the apparatus main body. FIG. 2 is a diagram showing the state when the process cartridge is pulled out and the rack and pinion are in a relative position where they disengage or begin to engage. Figures 3 and 4
The figure shows a charging device used in the image forming apparatus of the present invention,
FIG. 3 is a perspective view showing the surrounding situation, and FIG. 3 shows the situation during cleaning by the cleaning member, and FIG. 4 shows the situation where the cleaning member is in the initial position. 11... Photosensitive belt belt 12... Charging device 17...
Process cartridge 18...Image forming apparatus 181...Image forming apparatus main body 25...Screen grid 26...Corona wire 31...Slider 310
... Cleaning member 41 ... Hasuba rack 42 ...
・Hasuba pinion

Claims (1)

[Scope of Claims] An image forming apparatus in which a process cartridge having at least a photoconductor and a charging device is removably attached to an image forming apparatus main body, the charging device having at least an electrode and a device for cleaning the electrode. A cleaning member is provided, and a driving means for driving the cleaning member is provided between the image forming apparatus main body and the charging device, and the driving means receives an operating force when attaching and detaching the process cartridge. An image forming apparatus characterized in that it is driven by.