JPH08160822A - Toner recovering device - Google Patents

Abstract

PURPOSE: To provide a toner recovering device capable of promoting the effi cient utilization of a filter bag by providing a means for detecting an optimum exchange period, judging from the life of the filter bag. CONSTITUTION: In the toner recovering device 30 scrapping and recovering toner remaining on a recording drum after passing through the transfer part of an image device by a cleaning means, the toner recovering device 30 is provided with a storage container 40 for storing the recovered toner and a detecting means detecting a life value corresponding to the quantity of the toner stored in the storage container 40, with the detection of the displacement from a fixed position of the storage container 40 is provided. Moreover, the storage container 40 is preferably composed of the filter bag and provided with a flexible part in a part of the filter bag and the flexible part is of the bellows structure of the neck part of the filter bag.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner collecting device for a printing apparatus, and more particularly to the use of the filter bag due to clogging of a filter back housed in the collecting means as the amount of accumulated toner increases. The present invention relates to a toner recovery device that is provided with a detection unit for detecting the life value of a filter bag in view of the fact that the life of the filter bag reaches its limit, so that the filter bag can be effectively used up to its service life limit.

[0002]

2. Description of the Related Art A conventional printing apparatus includes a cylindrical recording drum, and a recording head is arranged adjacent to the recording drum. At the same time as the recording drum is rotated around its rotation axis, the recording head moves along the recording drum in the direction of the rotation axis to record a latent image such as a character to be printed on the recording drum. The recording drum on which the latent image is recorded is developed by the toner stored in the developing unit in the developing unit arranged adjacent to the recording drum, and a visible image is formed on the recording drum. Next, the printing sheet is pressed against the recording drum by a transfer roller with an appropriate pressure, and the visible image on the recording drum is transferred to the printing sheet. An example of such a printing apparatus is a magnetic printing apparatus. In the magnetic printing apparatus, the latent image is recorded on the recording drum by the magnetic head and erased by the degaussing head. The latent image once recorded on the recording drum does not disappear even if the visible image is transferred to the printing paper, and therefore, when the same image is repeatedly printed, it is not necessary to form the latent image again, and the toner image is not formed. It is possible to repeat printing by simply attaching. Therefore, such a magnetic printing apparatus is suitable for printing a large amount of the same image in a short time.

The printing paper onto which the visible image has been transferred is passed through a fixing section, where the image is fixed by, for example, heat welding. Toner remains on the recording drum after the visible image is transferred to the printing paper. If the printing operation is performed a number of times with the residual toner remaining on the recording drum, the residual toner gradually accumulates on the recording drum, resulting in a finished print.
It adversely affects the latent image recording action. Therefore, removal of residual toner is necessary to improve the quality of printing.

An example of a cleaning device for removing residual toner is disclosed in Japanese Utility Model Publication No. 5582/1993. This cleaning device has a blade, and the blade is used during the printing operation. The residual toner is scraped off from the recording drum in contact with the recording drum and separated from the recording drum during the latent image recording so that the latent image recording operation is not hindered. The cleaning device further includes a toner suction device, and the toner suction device sucks the toner scraped by the blade.

An example of a toner collecting device for collecting and accumulating the sucked toner is disclosed in Japanese Utility Model Publication No. 2-19817. This toner collecting device sucks the toner on the filter. And a blower for The filter in the toner collecting device is replaceable, and the filter bag is replaced by predicting that the time when the number of printed copies reaches a certain number is the limit of the amount of toner collected in the filter bag.

As for the number of print copies that determines the replacement time, assuming that the print density in the paper is the highest density, the number of print copies that can obtain a normal print with the highest print density is specified. However, the amount of toner remaining on the recording drum varies depending on the printing density per part of paper, and in actual printing, most printing is below the maximum printing density.

[0007]

Therefore, if the replacement time of the filter bag is set as described above, the filter bag must be replaced at a time much earlier than the actual life of the filter bag. By exchanging the filter bag early, the operator's work increases and the filter bag is wasted.

The object of the present invention is to provide means for detecting the optimum replacement time from the service limit of the filter bag in order to solve the above-mentioned drawbacks, and promote efficient use of the filter bag. To provide a toner collecting device.

[0009]

In view of the above-mentioned object, the present invention provides a toner collecting device for scraping and collecting the residual toner of a recording drum which has passed through a transfer portion of a printing device by a cleaning means. A storage unit for storing the stored toner, and detecting means for detecting a life value corresponding to the toner storage amount of the storage container by detecting displacement of the storage container with respect to a predetermined position. A toner collecting device is provided.

[0010]

According to the above construction, when the detection means detects that the preset life value has been reached, it can be detected that the storage container has reached the use limit. It is also possible to display this result by the display means.

It is preferable that the storage container is composed of a filter bag, and a flexible portion is provided on a part of the storage bag so as to generate the above-mentioned displacement.

Further, it is preferable that the flexible portion of the filter bag is a neck portion having a bellows structure.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where the present invention is applied to a toner collecting device for residual toner of a magnetic printing device will be described below with reference to the embodiments shown in the drawings. However, the present invention
It can also be applied to a toner recovery device of an electrostatic recording device.

FIG. 1 shows the printing apparatus 10 as a whole. The printing apparatus 10 includes a cylindrical recording drum 11 and a magnetic head 12 arranged adjacent to the recording drum 11. At the same time that the recording drum 11 is rotated around its rotation axis, the magnetic head 12 is scanned and moved along the rotation drum along the recording drum 11 to record a magnetic latent image such as characters to be printed by the magnetic head 12. It is recorded on the drum 11. When the latent image is recorded on the recording drum 11, the latent image is recorded on the developing unit 1 provided adjacent to the recording drum 11.
At 3, the developing toner (magnetic toner) stored in the developing unit 13 is developed and visualized. After that, the recording drum 11 is further rotated toward a transfer portion described later.

The printing apparatus 10 comprises a cassette 15 for accommodating a printing sheet and a feed roller 14 for feeding the printing sheet. The printing sheet sent from the cassette 15 is passed between the recording drum 11 and the transfer roller 16 arranged in contact with the recording drum 11, and the transfer roller 16
Recording drum 1 while applying appropriate pressing force by
Therefore, the image formed on the recording drum 11 is transferred to the printing paper. The image transferred to the printing paper is
Appropriate pressing force is applied by passing between the pair of fixing rollers, and the image is fixed on the paper surface by, for example, heat welding. The fixed printing sheet is further conveyed along the conveying path 22 and accumulated in the receiving cassette 23.

Here, the magnetic latent image recorded on the recording drum does not disappear even during transfer. Therefore, when the same image is printed, the developing unit 13 does not record the magnetic latent image again. By repeating the passage, the development is repeated, so that the transfer can be repeated in the area of the transfer roller 16.

On the other hand, in order to print different images, it is necessary to record different magnetic latent images on the recording drum 11. At that time, first, the demagnetizing head 19 provided upstream of the magnetic head 12 records on the recording drum 11. The magnetic latent image is erased, and then the magnetic head 12 forms a magnetic latent image.

At the time of transfer, it is desirable that the toner forming a visible image can be completely transferred onto the printing paper by applying an appropriate pressing force by the transfer roller 16. However, not all toner is transferred,
A small amount of toner remains on the recording drum 11. Even if the amount of residual toner per part of the paper is very small, a large amount of printing is performed in the printing apparatus, so the residual toner is successively deposited on the recording drum. Therefore, a means for removing toner as described below is required.

A scraping blade 18 for scraping off the residual toner in order to remove the residual toner from the recording drum;
A cleaning unit having a suction member 20 for sucking the scraped toner is arranged downstream of the transfer roller 16 and adjacent to the recording drum 11. This cleaning means is connected to a toner collecting device 30 via a pipe-shaped toner collecting passage 21, and the collecting means 30 further includes a suction blower 3.
Connected to eight. The toner scraped off is collected and accumulated in the collecting means 30 by the suction force of the suction blower 38.

FIG. 2 shows a toner collecting device 30 according to the present invention.
In more detail. The toner collecting device 30 is
The housing 39 has a substantially rectangular parallelepiped shape, and the housing 39
The upper wall has an opening. A filter box 40 having a predetermined box shape is housed inside the side wall of the housing 39, and a rigid support plate 33 for supporting the filter bag 40 is provided at the bottom. Filter bag 40
The distance between the upper wall of the housing 39 to which the filter is attached and the support plate 33 is such that the bellows structure portion of the neck portion 42 of the filter bag 40 can be accommodated so as to be folded, and the main body of the filter bag 40. The entire surface of the portion 41 is formed so as to have an internal volume that can be stored away from the housing 39. One end of the support plate 33 is pivotally attached to the side wall via a horizontal pivot shaft 34, and the other end is supported from below by a compression spring 35 arranged at the bottom of the housing 39. Therefore, the support plate 33 has a structure capable of pivoting downward around the pivot axis when a downward pressure exceeding the biasing force of the compression spring 35 is applied to the other end. The support plate 33 is preferably plate-shaped, but if the filter back 40 can be supported, a plurality of rods may form a support plane. In addition, the compression spring 35
Such a supporting member may be any member that supports or holds the supporting plate 33 so that it can be displaced when pressure is applied to the supporting plate 33. Further, in this embodiment, the rigid support plate 33 and the compression spring 35 are combined to be displaceable, but the support plate 33 itself may be formed of a flexible member or an elastic member.

Further, for example, a well-known limit switch is provided in the housing 39, and the support plate 33 compresses the compression spring 35 to detect that a predetermined displacement state is reached. That is, the amount of the residual toner collected in the filter bag 40 is gradually increased as described later, so that the support plate 3 supporting the filter bag 40.
When 3 is displaced, the limit switch 37 is actuated by the displacement of the support plate 33.

Also, the limit switch is preferably
Although it is arranged near the compression spring 35 having a large displacement amount, it may be arranged near the pivot shaft 34 as long as it can be operated by displacement. Further, the displacement of the support plate 33 may be detected through the detection of the rotation amount of the pivot shaft, or the support plate 33 may be detected.
The amount of displacement at the end of may be detected using an optical sensor provided on the lower portion of the side wall of the housing 39.

FIG. 3 is a partial sectional view of the filter bag 40, and FIG. 4 is a perspective view of the filter bag 40. The filter back 40 includes a substantially rectangular parallelepiped main body portion 41 having a substantially square opening portion 44, and a neck portion 42 having an opening portion 45 having substantially the same size as the opening portion 44. A plate 43 having a substantially circular opening 46 is attached to the upper end of the neck portion 42. The neck portion 42 is the body portion 4
Although it is provided at the corner of the upper wall of the No. 1, it may be provided at the center in some cases.

The body portion 41, as can be seen in FIG.
Each of them is composed of an outer layer 46 and an inner layer 47 which are gas permeable, and separates the toner from the mixture of the toner and the air flowing into the filter back 40. The outer layer 46 is the filter back 40.
In order to enhance the filtering function of the main body 41, the outer wall of the main body portion 41 has a three-layer structure. The wall of the neck portion 42 is
It has a one-layer structure using the same material as the outermost layer of the filter bag 40, and is formed into a bellows structure so as to have flexibility. Of course, the wall of the neck portion 42 may be made of an elastic material, such as a rubber material, to make it flexible.

The opening 46 of the plate 43 of the filter bag 40, the opening of the housing 39 of the toner collecting device 30, and the end of the toner collecting passage 21 are hermetically connected. Further, the suction blower 38 is hermetically connected to the side wall of the housing 39.

At the same time when the printing operation starts, the suction blower 3
8 is also activated, and the suction force of the suction blower 38 passes through the toner collecting device 30 and the toner collecting passage 21 and the suction member 20.
Up to. The residual toner scraped off the recording drum 11 by the scraping blade 18 passes through the toner collecting passage 21 by the suction action of the suction blower 38 and is passed through the filter bag 4
It flows into 0.

In the initial state, that is, when toner is not present in the filter back 40, the detection plate 33 is in a substantially horizontal state shown by the solid line in FIG. The residual toner is collected from the suction member 20, and the toner is deposited on the filter back 40, and the weight of the entire filter back 40 increases. Therefore, the filter bag 40 and the support plate 33 are supported by the pivotable support plate 33 and have a flexible bellows-shaped neck portion 42.
Is a filter back 40, as indicated by the dashed line in FIG.
Pivot downwards about its pivot axis with increasing weight. When the support plate 33 further pivots downward and reaches a predetermined displacement amount, the limit switch 37 is actuated. As will be described in detail below, this predetermined displacement amount corresponds to a life value at which the filtering function of the filter bag 40 does not work sufficiently.

FIG. 5 shows the relationship between the suction air volume of the blower 38 and the filter back weight. In FIG. 5, the vertical axis represents the amount of suction air (mm / s) by the blower 38 in the opening 46 of the filter back 40, and the horizontal axis represents the weight of the filter back 40 containing toner. In the case shown in FIG. 5, the weight of the filter bag 40 is 300 when the filter bag 40 does not contain toner.
g, and the suction air volume at that time is 1.2 mm / s. When the toner is gradually accumulated on the filter bag 40 and the weight of the filter bag 40 reaches about 800 g, the conventional replacement time display, that is, the replacement time of the filter back with a predetermined number of copies is reached. When the weight of the filter bag 40 further increases to reach about 1500 g, the suction air volume actually begins to decrease at this point. That is, the filter bag 40 has become clogged and has reached the limit region of the service life. What should be noted here is that the amount of toner actually accumulated reaches about twice as much as the conventional amount,
It can be seen that if the filter bag 40 is used up to this point, the useful life of the filter bag 40 can be significantly increased, and the filter bag can be effectively used.

That is, when the filter bag 40 used in the experiment of FIG. 5 is used, the weight of the filter bag is about 15
The life value should be set to correspond to 00 g or air volume of 1.2 mm.

When a limit switch is used as the detecting means, the compression spring 35 that starts the limit switch 37 when the filter back weight reaches about 1500 g may be selected in advance. When using an optical detection means, the displacement amount of the support plate 33 at about 1500 g is measured in advance, and the replacement time display signal is output based on the displacement amount. It is also possible to use an appropriate air volume measuring means as the detecting means, and the air volume is 1.
It may be set to display the replacement time when it is reduced to 2 mm / s or less. That is, the life value corresponding to the toner accumulation amount of the filter back 40 is detected through the displacement of the filter back 40 with respect to the predetermined position, and the operator of the printing apparatus confirms that the toner accumulation amount exceeds the predetermined amount. In addition, for example, an alarm lamp, a display, a buzzer sound or the like is displayed to allow the operator to know the proper replacement time of the filter bag 40.

[0031]

As is apparent from the above description, according to the present invention, the residual toner on the recording drum which has passed through the transfer portion of the printing apparatus is scraped by the cleaning means and collected. A storage unit for storing the stored toner, and detecting means for detecting a life value corresponding to the toner storage amount of the storage container by detecting displacement of the storage container with respect to a predetermined position. Since the toner collecting device is characterized by being provided, it becomes possible to more accurately detect the service life value corresponding to the increase in the toner storage amount of the storage container, typically the filter bag.

Since the service life value can be accurately detected, the filter bag can be used for a longer period of time.

Further, since the filter bag can be used for a longer period of time, the number of maintenance, that is, the number of times of replacement of the filter bag is reduced, which leads to a reduction in the work of the operator.

Furthermore, since it is possible to reduce the number of times of replacement of the filter bag, the number of filter bags to be used can be reduced and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing components of a printing apparatus as a whole.

FIG. 2 is a side view of the toner collecting device according to the present invention.

FIG. 3 is a partial cross-sectional view of a filter bag according to the present invention.

FIG. 4 is a perspective view showing a filter bag.

FIG. 5 is a diagram showing a relationship between a suctioned air volume and a filter back weight.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Printing device 11 ... Recording drum 12 ... Magnetic head 13 ... Development part 14 ... Feed roller 15 ... Cassette 16 ... Transfer roller 17 ... Fixing roller 18 ... Scraping blade 19 ... Degaussing head 20 ... Suction member 21 ... Toner recovery path 22 ... Conveyance path 23 ... Receiving cassette 24 ... Auxiliary fixing roller 30 ... Toner collecting device 33 ... Support plate 34 ... Pivot shaft 35 ... Compression spring 37 ... Limit switch 38 ... Suction blower 39 ... Housing 40 ... Filter back 41 ... Main body part 42 ... Neck part 44, 45, 46 ... Opening part 47 ... Outer layer 48 ... Inner layer

Claims (2)

[Claims] 1. A toner collecting device for scraping and collecting residual toner on a recording drum, which has passed through a transfer section of a printing device, by a cleaning means, comprising a storage container for storing the collected toner. In other words, the toner collecting device is provided with a detecting unit that detects a life value corresponding to the toner storage amount of the storage container through the displacement detection of the storage container with respect to a predetermined position. 2. The toner collecting apparatus according to claim 1, wherein the storage container is a filter bag, and a flexible portion is provided in a part of the filter bag.