JP2008256921A - Waste toner collection device for full color image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste toner collection device for a full color image forming apparatus, which prepares measures to meet the blocking of waste toner at a connection part when using a screw for each photoreceptor cleaning unit and a waste toner collection pipe. <P>SOLUTION: The waste toner collection device for the full color image forming apparatus is equipped with: a photoreceptor cleaning unit 19 which removes remaining toner on each color photoreceptor; a waste toner tank 50 in which the waste toner discharged from each photoreceptor unit 19 is stored; a waste toner collection pipe 51 inside which a screw member is arranged so as to feed the waste toner to the waste toner tank 50; a screw type discharge member 58 which is connected to the waste toner collection pipe 51, and arranged in a conveying path so as to join and feed the waste toner from the discharge path of each color photoreceptor cleaning unit 19; and a fitting member 59 by which the discharge part of the photoreceptor cleaning unit 19 is fit to the waste toner collection pipe 51. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a waste toner collecting apparatus for a full color image forming apparatus that uses a screw to convey used waste toner used in an image forming system of a full color image forming apparatus such as a copying machine, a printer, and a facsimile machine. It is.

In recent years, the toner used in the electrophotographic image forming method has been changed to a polymerized toner having a smaller particle size than the pulverized toner in order to achieve higher image quality and energy saving. However, this toner has a disadvantage that it is easily hardened due to temperature and stress as compared with the conventional pulverized toner.
In particular, waste toner that is not transferred and collected by the cleaning device is easily solidified not only due to temperature (in-machine temperature) stress but also due to stress caused by rotation in the developing and collecting unit.
This characteristic is particularly problematic when the discharged waste toner may stagnate in the transport path. In such a case, when the stagnant waste toner is solidified, a waste toner lock (blocking) state may be caused.
For this reason, various techniques for preventing waste toner locking (blocking) when stagnant waste toner is solidified have been proposed (see, for example, Patent Documents 1 and 2).
Patent Document 1 discloses a technology in which a convex portion is provided on the inner surface of the waste toner conveying pipe so that the waste toner hits only this portion so that the waste toner does not receive excessive stress. Patent Document 2 discloses a technique for electrically detecting waste toner conveyance abnormality.
Japanese Patent Laid-Open No. 11-084969 JP 2000-066556 A

However, for example, when the waste toner from the photoconductor cleaning unit is transported by the waste toner discharge screw in the waste toner transport path from the photoconductor and sent to the screw in the recovery pipe, the photoconductor waste toner discharge screw and the recovery pipe There is always a gap between the screw and the screw.
The waste toner accumulated in the gap portion stagnates at the same time as the screw stops, and may solidify if temperature stress continues to be applied in this state. For this reason, at the next job, the waste toner is locked and the service man call is made, and it is not sufficient as a blocking measure for the fitting portion when a screw is used for each photoconductor cleaning unit and the waste toner collection pipe.
Accordingly, an object of the present invention is to eliminate the waste of a full-color image forming apparatus provided with a countermeasure against blocking of waste toner at a connection portion in the case where a screw is used for each photoconductor cleaning unit and waste toner collection pipe in consideration of the above situation. To provide a toner recovery device.

In order to solve the above-mentioned problems, the invention described in claim 1 is a waste toner collecting device of a full-color image forming apparatus, and a photoreceptor cleaning means for cleaning residual toner on each color photoreceptor, and each photoreceptor cleaning. A waste toner collecting container for storing waste toner discharged from the means, a waste toner collecting pipe having a screw-like member disposed therein to send the waste toner to the waste toner collecting container, and the waste toner collecting pipe. And a screw-like discharge member disposed in the discharge path for joining and sending out the waste toner from the discharge path of each color photoconductor cleaning means, a discharge portion of the photoconductor cleaning means, and the waste toner And a fitting member for fitting the recovery pipe.
The invention according to claim 2 is characterized in that the waste toner collecting device of the full-color image forming apparatus according to claim 1, wherein the fitting member has a rotation center and is rotatable.
According to a third aspect of the present invention, there is provided the waste toner recovery device for a full-color image forming apparatus according to claim 1, wherein the fitting member operates after the screw-like discharge member in the waste toner recovery pipe stops. Features.

According to a fourth aspect of the present invention, there is provided the waste toner collecting device for a full-color image forming apparatus according to the third aspect, wherein the fitting member performs a rotation operation at an arbitrary time with respect to the operation timing. And
According to a fifth aspect of the present invention, the fitting member operates when a temperature and humidity sensor is monitored after a job end and reaches a certain arbitrary temperature or more with respect to the operation timing. 3. A waste toner collecting device for a full-color image forming apparatus according to item 3.
According to a sixth aspect of the present invention, there is provided a second recovery pipe having an opening for receiving waste toner falling from the discharge path of each color photoconductor cleaning means at a lower position of the waste toner recovery pipe. Item 14. A waste toner recovery device for a full-color image forming apparatus according to Item 1.
According to a seventh aspect of the present invention, the discharge screw that can be disposed in the second waste toner recovery pipe is driven in synchronism with the operation of the discharge screw in the waste toner recovery pipe. A waste toner collecting device for the full-color image forming apparatus described above is characterized.
The invention according to claim 8 is characterized in that the waste toner collecting device of the full-color image forming apparatus according to claim 6, wherein a discharging screw installed in the second waste toner collecting pipe is driven at an arbitrary timing. To do.

  According to the present invention, by providing the rotatable fitting member, it is possible to remove the toner accumulated between the discharging screws, so that it is possible to prevent blocking of waste toner, and as a result, image formation The lifetime of the device can be extended.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing the whole of a color image forming apparatus equipped with a tandem type intermediate transfer device. In FIG. 1, the printer (image forming unit) 1 of the image forming apparatus A has an intermediate transfer unit at the center, and this intermediate transfer unit includes an intermediate transfer belt 10 which is an endless belt.
The intermediate transfer belt 10 is wound around three support rollers 14 to 16 and is driven to rotate clockwise. To the left of the second support roller 15 is an intermediate transfer member cleaning unit 17 that removes residual toner remaining on the intermediate transfer belt 10 after image transfer.
The intermediate transfer belt 10 between the first support roller 14 and the second support roller 15 has black (K), yellow (Y), magenta (M), and cyan (C) along the moving direction. There are image forming apparatuses 20 for the respective colors. The image forming apparatus 20 includes a charger unit 18, a developing unit, a photosensitive member cleaning unit (photosensitive member cleaning means) 19, a photosensitive member unit 40, and the like. The image forming apparatus 20 includes an IC tag and is detachably attached to the printer body.

Above the image forming apparatus 20, there is a writing unit 21 that irradiates each photoconductor drum of each color photoconductor unit 40 with laser light for image formation. Below the intermediate transfer belt 10 is a secondary transfer unit 22. The secondary transfer unit 22 has a configuration in which a secondary transfer belt 24, which is an endless belt, is stretched between two rollers 23, and the intermediate transfer belt 10 is pushed up and pressed against the third support roller 16. is there.
The secondary transfer belt 24 transfers the image on the intermediate transfer belt 10 onto a transfer sheet. Next to the secondary transfer device 22, there is a fixing unit 25 for fixing the transfer image on the transfer paper, and the transfer paper on which the toner image has been transferred is fed into the fixing unit 25. The fixing unit 25 is obtained by pressing a heating and pressure roller 27 against a fixing belt 26 that is an endless belt.
Below the secondary transfer unit 22 and the fixing unit 25, there is a sheet reversing unit 28 that feeds the transfer paper immediately after the image is formed on the front surface with the front and back reversed to record the image on the back surface.
When a start switch of an operation unit (not shown) is pressed, if there is a document on the document feeder 30 of the automatic document feeder (ADF) 4, it is transported onto the contact glass 32.

When there is no document on the ADF 4, the scanner of the image reading unit 3 is driven and the first carriage 33 and the second carriage 34 are driven to scan to read a manually placed document on the contact glass 32.
Then, light is emitted from the light source on the first carriage 33 to the contact glass 32, and reflected light from the document surface is reflected by the first mirror on the first carriage 33 toward the second carriage 34, and the second carriage 34. The image is reflected by the upper mirror and imaged on the CCD 36 as a reading sensor through the imaging lens 35. Based on the image signal obtained by the reading sensor 36, each color recording data of K, Y, M, and C is generated.
Further, when the start switch is pressed, the rotational driving of the intermediate transfer belt 10 is started, the image forming preparation of each unit of the image forming apparatus 20 is started, and the image forming sequence of each color image is started. Then, an exposure laser modulated based on each color recording data is projected onto the photosensitive drum for each color, and each color toner image is transferred onto the intermediate transfer belt 10 as a single image by each color image forming process. .
When the leading edge of the toner image enters the secondary transfer unit 22, the transfer paper is fed to the secondary transfer unit 22 at a timing so that the leading edge enters the secondary transfer unit 22 at the same time. The upper toner image is transferred onto the transfer paper on the secondary transfer belt 24.
The transfer paper on which the toner image has been transferred is sent to the fixing unit 25 where the toner image is fixed on the transfer paper. Here, a mechanism having two transfer belts, the intermediate transfer belt 10 and the secondary transfer belt 24, has been described. However, there is also a transfer mechanism that can be performed by one belt.
Note that the transfer paper described above is obtained by selectively rotating and driving one of the paper feed rollers 42 of the paper feed unit (paper feed table) 2 to transfer the transfer paper from one of the paper feed trays 44 provided in the paper feed unit 43 in multiple stages. The sheet is unwound and separated by the separation roller 45 to be put into the transport roller unit 46.

Next, the transfer paper is transported by the transport roller 47 and guided to the transport roller unit 48 in the printer 1, abutted against the registration roller 49 of the transport roller unit 48 and stopped, and then transferred to the secondary transfer unit 22 at the timing described above. It is designed to send out.
The transfer paper discharged after receiving the fixing process by the fixing unit 25 is guided to the discharge roller 56 by the switching claw 55 and stacked on the paper discharge tray 57. Alternatively, the sheet is guided to the sheet reversing unit 28 by the switching claw 55, reversed there and led again to the transfer position, and the image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the residual toner remaining on the intermediate transfer belt 10 after the image transfer is removed by an intermediate transfer body cleaning unit 17 provided below the intermediate transfer belt 10 to prepare for another image formation.
The portion related to the present invention relates to a portion where waste toner discharged from the photoconductor cleaning unit 19 joins the recovery pipe. In the tandem type full-color copying machine (full-color image forming apparatus) A, waste toner is discharged from the photoreceptor cleaning unit 19 for each color.

FIG. 2 is a schematic perspective view illustrating a waste toner conveyance path from the process cartridge unit to the waste toner collection container. A tandem type full-color copying machine is usually provided with a waste toner collecting container (waste toner tank) 50 as shown in FIG.
Waste toner is generated by a photoreceptor cleaning unit included in a process cartridge unit (PCU) 52. The waste toner is sent from the photosensitive member cleaning unit to the waste toner collection container 50 through a waste toner collection pipe 51 containing a discharge screw (not shown).

FIG. 3 is a schematic plan view partially showing the waste toner collecting pipe and the photosensitive member cleaning unit in order to explain the joining point of the waste toner. In the plan view of FIG. 3, for example, reference numerals 52a and 52b of the process cartridge 52 of FIG.
As shown in FIG. 3, waste toner of each color is sent to the waste toner collecting pipe 51 including the discharge screw 53 from the discharge path 54 of each color photoconductor cleaning unit while being merged.
Since the discharge screw 53 in the waste toner collecting pipe 51 described above stops at the job end (end of image forming operation), a portion where the toner is accumulated is generated in a part of the waste toner conveyance path. This portion is a gap between the discharge screw 53 of the waste toner collecting pipe 51 and the discharge screw 58 in the discharge path 54 of the photosensitive member cleaning unit arranged at right angles as shown in FIG.
Although this joining portion is set to be as narrow as possible, a gap of about 2 to 5 mm is generated in consideration of component variations and the like. Since there is no screw for transporting the waste toner in the gap portion, the waste toner obtains a force to advance by being pushed by the waste toner sent later.
However, when the job is finished and the rotation of the discharge screw 53 is stopped, the waste toner always remains in the gap of the joining portion. If the waste toner is solidified due to an increase in the temperature in the image forming apparatus (inside the apparatus), blocking occurs in the next job. As a result, a service man call may occur.

FIG. 4 is a schematic view showing a fitting member provided in a gap portion generated in the waste toner joining portion. In FIG. 4, a fitting member 59 is provided on the discharge path 54 side of the photosensitive member cleaning unit in a gap portion generated at the junction. Actually, the fitting member 59 is disposed on the peripheral portion of the waste toner collecting pipe 51 so as to open and close the discharge path 54 of the photosensitive member cleaning unit in which the discharge screw 58 is disposed.
The fitting member 59 is rotated after the discharge screw 53 is stopped, so that the toner accumulated in this portion is eliminated. The fitting member 59 has, for example, a rotation center on the peripheral portion of the waste toner collecting pipe 51 and can be rotated around this.
Specifically, the waste toner in the fitting portion is to be dropped down by moving (opening) the portion that becomes the bottom cover of the discharge path 54 of the photosensitive member cleaning unit downward in the drawing. The fitting member 59 serving as the bottom lid functions by moving after the discharging screw (not shown) of the waste toner collecting pipe 51 stops.
However, the timing at which the fitting member 59 starts moving may be immediately after the discharging screw is stopped. Further, this rotation operation is effective even after an arbitrary time has elapsed after the end of the job.
Further, after this arbitrary time, a temperature / humidity sensor (not shown) provided in the image forming apparatus is usually monitored and operated when the temperature rises to an arbitrary temperature after the job is completed. Can be effectively implemented.
In general, the threshold temperature is determined by the characteristics of the toner. In addition, the internal temperature of the image forming apparatus is often higher than during a job when the residual heat during fixing circulates in the image forming apparatus.
This phenomenon occurs because the cooling fan stops with the end of the job. However, the temperature can be kept below a certain level during a job because the cooling fan in the image forming apparatus is driven.

FIG. 5 is a schematic view showing a second waste toner recovery pipe provided below the waste toner recovery pipe. As described above, when the fitting member 59 (FIG. 4) is operated, the waste toner falls to the lower side thereof.
For this purpose, for example, at a position where the waste toner falling by the rotation of the fitting member 59 can be collected immediately below the waste toner collecting pipe 51, for example, the waste in which the fitting member 59 is opened and dropped in FIG. A second waste toner recovery pipe 60 is installed at a position where the toner can be received (a position below the discharge path 54 of the photosensitive member cleaning unit in FIG. 4).
On the upper surface of the second waste toner collecting pipe 60, there is an opening 60a for receiving the falling waste toner. Although not shown, it is also possible to configure the second recovery pipe 60 so that a discharging screw is arranged.
With respect to driving of the discharging screw disposed in the second recovery pipe 60, two control methods are possible. In the first control method, when the discharge screw 53 (FIG. 2) of the waste toner recovery pipe 51 is rotating, the screw in the second waste toner recovery pipe 60 is also rotated simultaneously.
In the second control method, the screw in the second waste toner collection pipe 60 is rotated independently of the discharge screw 53 of the waste toner collection pipe 51. For example, even after the discharging screw 53 in the waste toner collecting pipe 51 is stopped, it is rotated for an arbitrary time. Thereby, after catching the dropped waste toner, the waste toner can be prevented from becoming a lump.
In this way, by providing the second waste toner collection pipe 60, the waste toner collection device can receive the toner falling from the waste toner delivery section, and therefore, scattering of the toner into the image forming apparatus is prevented. And contamination of the transfer paper can be prevented.

1 is a schematic view showing an entire color image forming apparatus equipped with a tandem type intermediate transfer device. FIG. 6 is a schematic perspective view illustrating a waste toner conveyance path from a process cartridge unit to a waste toner collection container. FIG. 4 is a schematic plan view partially showing a waste toner recovery pipe and a photosensitive member cleaning unit in order to explain a joining point of waste toner. FIG. 6 is a schematic diagram illustrating a fitting member provided in a gap portion generated in a waste toner joining portion. FIG. 6 is a schematic diagram illustrating a second waste toner recovery pipe provided below the waste toner recovery pipe.

Explanation of symbols

A Full-color image forming apparatus (full-color copying machine), 1 printer (image forming unit), 2 paper feeding device, 10 intermediate image carrier (intermediate transfer belt), 19 photoconductor cleaning device (photoconductor cleaning unit), 20 image forming Equipment (development unit), 22 secondary transfer unit, 24 secondary transfer belt, 25 fixing device, 40 photoconductor unit (photoconductor), 50 waste toner collection container (waste toner tank), 51 waste toner collection pipe, 52 process Cartridge unit (PCU), 53 screw-shaped member (discharge screw), 54 discharge path of photoconductor cleaning unit, 58 screw-shaped discharge member (screw of discharge path 54), 59 fitting member, 60 second waste toner recovery Pipe, 60a opening

Claims (8)

  In a waste toner collecting apparatus of a full-color image forming apparatus, a photosensitive member cleaning unit for cleaning residual toner on each color photosensitive member, a waste toner collecting container for storing waste toner discharged from each photosensitive member cleaning unit, and the waste toner collecting unit A waste toner collecting pipe having a screw-like member disposed inside to send waste toner to the toner collecting container, and connected to the waste toner collecting pipe, and the waste toner is joined from the discharge path of each color photoconductor cleaning means. And a screw-like discharge member disposed in the discharge path, and a fitting member that fits the discharge portion of the photoconductor cleaning means and the waste toner collecting pipe. A waste toner collecting device for a full color image forming apparatus.   2. The waste toner collecting apparatus of a full color image forming apparatus according to claim 1, wherein the fitting member has a rotation center and is rotatable.   2. The waste toner collecting apparatus of a full color image forming apparatus according to claim 1, wherein the fitting member operates after the screw-like discharge member in the waste toner collecting pipe stops.   4. The waste toner collecting apparatus of a full-color image forming apparatus according to claim 3, wherein the fitting member performs a rotation operation at an arbitrary time with respect to the operation timing.   4. The full-color image formation according to claim 3, wherein the fitting member is operated when a temperature and humidity sensor is monitored after the end of the job with respect to the operation timing, and the temperature becomes higher than a certain arbitrary temperature. Waste toner recovery device for the device.   2. The full-color image according to claim 1, wherein a second collection pipe having an opening for receiving waste toner falling from the discharge path of each color photoconductor cleaning means is disposed at a lower position of the waste toner collection pipe. Waste toner collecting device for forming apparatus.   The full-color image forming apparatus according to claim 6, wherein the discharge screw that can be disposed in the second waste toner recovery pipe is driven in synchronization with the operation of the discharge screw in the waste toner recovery pipe. Waste toner recovery device.   7. The waste toner collecting apparatus of a full color image forming apparatus according to claim 6, wherein the discharging screw installed in the second waste toner collecting pipe is driven at an arbitrary timing.

Images