JPH02199495A - Cleaning unit - Google Patents

Abstract

PURPOSE:To surely detect that a tank is filled even when toner is ununiformly collected in a longitudinal direction by providing a side feeler which detects the swell of collected toner so that it is integrally moved together with a feeler. CONSTITUTION:When the swell of the toner in the toner collecting tank 17 is uniform, the feeler 18 and the side feeler 18d are pushed up at the same time. When the swell of the collected toner at a part corresponding to the feeler 18 is the largest, the feeler 18 is pushed up and the side feeler 18d is pushed up by the swell of the toner when the swell of the toner on the side part is larger than the part corresponding to the feeler 18. As a result, the feeler 18 is integrally fluctuated through a fluctuation shaft 18c and a photointerrupter 19 is actuated by a projecting piece 18a.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for cleaning toner remaining on a photoreceptor after transfer of an electrostatic recording device.

Conventional technology In electrostatic recording devices such as electrophotographic copying machines, electrostatic printers, and facsimile machines, a toner image formed on a photoreceptor by an electrostatic photographic process is transferred and fixed to a transfer paper to perform recording. Since some toner and paper dust remain on the photoreceptor afterward, a cleaning unit removes and collects these, and the photoreceptor is neutralized in preparation for the next image formation.

Recently, as the personal use of printers, copying machines, etc. has become widespread, there is a strong demand for users to perform their own maintenance, and it has become an essential requirement that each replaceable unit can be easily replaced by the user. In order to meet this requirement, units related to image formation such as development, photoreceptor cleaning, and charger are integrated into an image forming cartridge, and this image forming cartridge is replaced as a whole after a predetermined period of time has passed. Some have adopted .

However, since the lifespan of each unit involved in image formation varies, this cannot be said to be advantageous from an economic point of view.

Therefore, a method has also been adopted in which each unit related to image formation is set in one image forming case, the image forming case is pulled out from the machine body together with each unit, and each unit is replaced individually. FIGS. 6 and 4 are diagrams showing an example of a printer employing this method. In this printer, a charger 2 and a writing optical system 3 are provided around the photoreceptor drum 1.
The incident position of the writing light 4, the developing unit 5, the transfer and
A separate charger 6 and a cleaning unit 7 are arranged. Paper is fed from the paper feed section 8 to the transfer section between the transfer/separation charger 6 and the photoreceptor 1, and the transfer paper on which the toner image has been transferred from the photoreceptor drum 1 is conveyed to the fixing unit 10 by the conveyor belt 9. It is fixed and discharged outside the machine.

The photosensitive drum 1, the developing unit 5, and the cleaning unit 7 are mounted on an image forming case 11, as shown in FIG.
The front door of the apparatus is opened, and the support guide member 12 pulls out the photosensitive drum 1 and the toner supply tank 5a of the developing unit integrally toward the front.

The cleaning unit 7 can be taken out and replaced separately.

Meanwhile, the cleaning unit is replaced every time the amount of toner collected in the toner collection tank becomes full, so it is necessary to detect when the collected toner is full.

FIG. 1 shows the general configuration of a cleaning unit.

As shown in the figure, cleaning unit 70 casing 1
3 includes a brush roller 14 in contact with the photoreceptor drum 1.
, a cleaning blade 15 are provided, and residual toner scraped off from the photosensitive drum 1 is collected into a toner collection tank 17 within the casing 13 by a collection shaft 16 having a square cross section.

Toner collection tank 1 is used as a means for detecting fullness of collected toner.
A filler 18 is provided on the top of the tank 7, which is pushed up by the bulge of toner collected in the recovery tank, and on the top surface of the filler 18, when the filler is full, it blocks the optical path of a photo interrupter 19 fixed to the frame of the main body of the device. A protrusion 18a for actuation is provided. As a result, it is detected that the toner collection tank 17 of the cleaning unit is full of toner, and this is displayed on the display panel to serve as a guide for replacing the cleaning unit.

FIG. 5 is an exploded perspective view showing the structure of a conventional feeler 18 and its installation. It is supported so as to be swingable about a parallel shaft 18c. The holder 20 is provided with a window 20a for pushing up the filler 1W18 when the toner swells up, but in order to prevent the toner from leaking from this window 20a, the rubber sheet 21 is moved to the rubber sheet pressing member 22 by covering the window 20a. The filler 18 is mounted by a rubber sheet 21 and is pushed up by the swelling of toner.

As the sensor, in addition to a photointerrupter, a reed switch operated by a magnet can also be used. FIGS. 6(a) and 6(b) are diagrams showing an example of a full detection part in that case, and a magnet 23 is fixed to the top of a protrusion 18b provided on the upper surface of the feeler 18, and a magnet 23 is fixed to the top of a protrusion 18b provided on the upper surface of the feeler 18. An iron piece 24 is provided at a position where it is attracted by a magnet 23 when the filler is pushed up by the build-up of toner, and which operates the reed switch.

Now, in the fullness detection means having the above configuration, the casing of the cleaning unit, the cleaning blade, etc. are provided over the entire length of the photoreceptor drum, and the cleaning is performed by the image density distribution in the longitudinal direction of the image formed on the photoreceptor. The amount of toner collected in the toner collection tank of the unit varies in the longitudinal direction. However, since the filler for detecting fullness mentioned above is only installed in one place in the toner recovery tank, there will be no problem if it is installed in the part where the collected toner swells up the most, but if the filler is always installed The maximum amount of toner does not always reach the area where the filler is installed, and if the maximum amount of toner reaches the area other than the filler installation area, the toner may overflow before the sensor detects that it is full, or the collection shaft may This may cause the unit to lock, resulting in damage to the unit or the machine itself.

Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned problems of the fullness detection means of the conventional cleaning unit having the above-mentioned structure, and is capable of reliably filling the toner collection tank even when toner is collected non-uniformly in the longitudinal direction. To provide a cleaning unit that can detect fullness, change the cleaning unit at an appropriate time, and prevent damage to the unit and machine body due to toner overflow, locking of a collection shaft, etc. That is the issue. .

In order to solve the above-mentioned problem, the present invention is characterized in that side fillers are provided on both sides of the toner recovery tank of the filler in the width direction (longitudinal direction) to sense the swell of collected toner so as to move integrally with the filler. shall be.

With the above configuration, even if the toner buildup in the toner collection tank is uneven in the longitudinal direction, the filler or side filler is pushed up by the highest portion and the sensor is activated.

Embodiments Below, embodiments of the present invention will be described in detail based on the drawings.

In this embodiment, the swing shaft of the filler of the cleaning unit previously described with reference to FIG. 1 is extended to both sides, and a side filler is provided at that portion to be pushed up by the swelling of toner. FIG. 2 is an exploded perspective view showing the structure of the feeler and its vicinity in this embodiment.

Therefore, the cross-sectional view of the cleaning unit is the same as in FIG. However, since the swing shaft of the feeler 18 extends on both sides, grooves 20b are provided on both sides of the holder 20, through which the swing shaft 18c of the feeler 18 can pass, as shown in FIG.

This cleaning unit is similar to the conventional cleaning unit in that the rubber sheet 21 covering the opening 20a of the holder 20 is attached to the holder 20 while being pressed by a pressing member 22. A side feeler 18d is fixed to an extension of the swing shaft 18c of the feeler 18 to both sides. The side filler 18d is pushed up when the height of the recovered toner in that area reaches a height comparable to that of a full tank.

Therefore, if the toner in the toner recovery tank 17 is uniform, the filler 18 and the side filler 1
8d are pushed up at the same time, but if the bulge of collected toner in the part corresponding to the filler 18 is the largest, the filler 18 is pushed up, and if the bulge of toner on that side is larger than the part of the filler 18, the side filler 18 is pushed up. 18d is pushed up by the swell of toner, the feeler 18 swings integrally via the swing shaft 18c, and the protruding piece 1
8a activates the photointerrupter 19. If the sensor is a reed switch operated by a magnet,
It goes without saying that the actuating portion of the filler may be configured as shown in FIG.

Effects As described above, according to the present invention, even when toner is collected unevenly in the longitudinal direction in the toner collection tank, the full state is reliably detected, and the necessity of replacing the cleaning unit can be detected at an appropriate time. This can prevent toner spills from the cleaning unit, locking of the shaft, and damage to the machine body.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a cleaning unit according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the filler for detecting fullness and components in its vicinity, and FIG. 3 is an example of a printer to which the present invention is applied. 4 is an explanatory diagram showing a state in which the imaging case is pulled out and replacement parts are taken out; FIG. 5 is an exploded perspective view of a conventional full detection feeler and its surrounding components. 6(a) is a sectional view of another conventional fullness detection means, and FIG. 6(b) is a perspective view of another example of the filler for fullness detection. 1...Photoconductor 7...Cleaning unit 17...Toner recovery tank 18...Feeler 18a...Sensor operating section 18c...Feeler swing axis d...Side filler

Claims (1)

[Claims] After the toner image formed on the photoreceptor is transferred to transfer paper by the electrostatic photographic process, it is installed downstream of the transfer position to collect the toner remaining on the photoreceptor, and is provided over the entire width of the photoreceptor. In a cleaning unit for an electrostatic recording device, the cleaning unit for an electrostatic recording device includes a toner collection tank, a filler that is displaced by the swell of toner collected in the collection tank, and an operating part that is displaced together with the filler and operates a full detection sensor. A cleaning device characterized in that side fillers are provided on both sides of the toner recovery tank in the longitudinal direction to sense the build-up of recovered toner so as to move integrally with the filler.