JP2007322753A - Catching device and image forming apparatus having catching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide simultaneous maintenance for filters catching powder smoke of the toner generated in a plurality of places in a long maintenance period. <P>SOLUTION: The catching device 30 comprises a suction means 36, a plurality of filters 32Y, 32M, 32C, 32K which catch the powder smoke generated in each of a plurality of places, flow channels 34 which connect the suction means and the plurality of the filters, a plurality of flow rate adjusting means 40Y, 40M, 40C, 40K for adjusting the flow rate of the air flow passing each filter, a plurality of flow rate measuring means 38Y, 38M, 38C, 38K for adjusting the flow rate of the air flow passing each filter, and a control means for controlling each flow rate adjusting means based on the results of the flow rate measurement of each flow rate measuring means in such a manner the flow rate of the air flow measured by at least one flow rate measuring means does not fall below the lower limit flow at which the powder smoke is surely sucked toward the filter. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a collecting device that sucks toner dust generated at each of a plurality of locations and separately collects the toner dust smoke, and an image forming apparatus having the collecting device.

When developing the electrostatic latent image carried on the image carrier in a non-contact manner, the toner flies from the developer carrier and travels toward the image carrier. At this time, a very small amount of toner may not be carried on the image carrier and may drift as dust in the air. Toner dust (hereinafter referred to as “smoke toner”) is caused by dirt or fog inside the image forming apparatus (the toner adheres to the portion of the image carrier corresponding to the white portion of the image, and the final image) This causes a problem such as a phenomenon in which a toner color dot appears in a white portion. As an image forming apparatus that sucks the dust toner and suppresses the occurrence of a problem caused by the dust toner, there is an image forming apparatus described in, for example, Patent Document 1. In this method, the dust toner is sucked by a fan which is a suction means and collected by a filter. The dust toner collected by the filter is reused or discarded.
JP-A-7-213841

  However, collection of dust toner by the filter requires regular filter maintenance such as filter replacement or filter cleaning because the filter is clogged with dust toner. For example, when an image is formed using toners of yellow, magenta, cyan, and black, and dust toner of each color is collected separately by a filter provided for each toner of each color, maintenance of the plurality of filters is performed. Requires great effort. This is because the amount of toner used for each color is different in image formation, and therefore the timing at which dust toner cannot be reliably sucked and collected due to clogging is different for each filter, and therefore maintenance of each filter is performed separately at different timings. This is because it needs to be performed at different periods.

  As a countermeasure, it is conceivable to simultaneously maintain a plurality of filters. As a result, the simultaneous maintenance is performed at the timing when the filter that collects the largest amount of dust toner is clogged. Therefore, when the amount of dust toner of each color is extremely different, the simultaneous maintenance cycle of the filter is extremely shortened. As a result, the maintenance of the filter is frequently performed, and the labor for the maintenance of the filter is increased.

  Therefore, the present invention is a collection device in which dust toner generated at each of a plurality of locations is separately collected by a plurality of filters, and maintenance of the plurality of filters is simultaneously performed. It is an object of the present invention to provide an image forming apparatus having a collecting device and a device in which the labor for maintenance of a plurality of filters can be reduced to a small extent even if they are different from each other.

In order to achieve the above object, the collection device according to the present invention is:
A suction device that sucks dust generated at each of a plurality of places by one suction means, and collects each dust by a plurality of filters separately,
One suction means;
A plurality of filters for collecting the smoke generated in each of a plurality of places;
A flow path connecting the suction means and the plurality of filters;
A plurality of flow rate adjusting means for adjusting the flow rate of the airflow passing through each filter;
A plurality of flow rate measuring means for measuring the flow rate of the airflow passing through each filter;
Control each flow rate adjusting means based on the flow rate measurement results of each flow rate measuring means so that the flow rate of the airflow measured by at least one flow rate measuring means does not fall below the lower limit amount that reliably sucks the smoke toward the filter It has the control means to do.

An image forming apparatus according to an aspect of the present invention includes:
An image forming apparatus that sucks toner dust generated at each of a plurality of locations and collects the toner dust separately by a plurality of filters,
Toner dust is collected by the collecting device described above.

An image forming apparatus according to another aspect of the present invention includes:
An image forming apparatus that sucks toner dust generated at each of a plurality of locations and collects the toner dust separately by a plurality of filters,
A plurality of toner storage means for storing toner before being used for image formation;
A plurality of storage amount measuring means for measuring the amount of toner stored in each toner storage means;
One suction means;
A plurality of filters for collecting toner dust generated in each of a plurality of locations;
A flow path connecting the suction means and the plurality of filters;
A plurality of flow rate adjusting means for adjusting the flow rate of the airflow passing through each filter;
Based on the storage amount measurement result of each storage amount measuring means, the flow rate of the air flowing through the at least one filter does not fall below the lower limit amount for reliably sucking the toner dust to the filter. It has a control means for calculating the amount of collected dust and controlling each flow rate adjusting means based on the calculated amount of collection.

  According to the present invention, the smoke (toner dust) generated at each of a plurality of locations by one suction means is sucked toward the corresponding filter, and the flow rate of the airflow passing through at least one filter is reduced. It is adjusted by the flow rate adjusting means so that smoke does not fall below the lower limit amount for reliably sucking smoke toward the filter. For this reason, even when the amounts of powder smoke are extremely different, the maintenance cycle performed simultaneously on the plurality of filters is not extremely shortened, and a sufficiently long cycle is ensured. As a result, frequent maintenance is not performed on the plurality of filters at the same time, and the labor for maintenance of the plurality of filters is reduced.

  In order to better understand the collection device according to the present invention, first, the dust toner generated at each of a plurality of locations in the image forming apparatus is sucked, and each dust toner is collected by a filter separately. The apparatus will be described.

  As schematically shown in FIGS. 1 (a) and 1 (b), a fan (corresponding to the suction means described in the claims) and a filter for separately collecting the dust toner generated at each of a plurality of locations. There are two types of collection devices.

  First, as shown in FIG. 1 (a), there is a collection device that sucks and collects dust toner generated at each of a plurality of locations A to D by a filter and a fan provided for each dust toner. is there. In the case of this collection device, since there are a plurality of fans, the noise generated by the collection device is increased.

  The collector shown in FIG. 1B sucks and collects the dust toner generated at each of the plurality of locations A to D by a filter provided for each fan and each dust toner. . This collection device has low noise from the fan. In addition, there is a feature that the flow rate of the airflow passing through another filter changes depending on the amount of dust toner collected by one filter.

  According to the above classification, the collection device according to the present invention separately collects dust toner generated at each of a plurality of locations by one fan and a plurality of filters, as in the collection device shown in FIG. Corresponds to a collection device for suction collection. In addition, the collection device according to the present invention positively utilizes the feature that the flow rate of the airflow passing through another filter changes depending on the amount of dust toner collected by one filter.

  Based on this, the collection device according to the present invention and the image forming apparatus having the collection device will be described by taking the embodiment as an example.

(First embodiment)
FIG. 2 schematically shows the configuration of the image forming apparatus according to the first embodiment of the present invention. In the figure, an image forming apparatus denoted by reference numeral 10 forms a tandem type image forming apparatus that forms an image on a sheet-like recording material (hereinafter referred to as “recording sheet”) S using yellow, magenta, cyan, and black toners. Device.

  The image forming apparatus 10 forms an electrostatic latent image on four photosensitive members 12Y, 12M, 12C, and 12K that are image carriers, charging devices 14Y, 14M, 14C, and 14K that charge the photosensitive members. Exposure devices 16Y, 16M, 16C, and 16K, developing devices 18Y, 18M, 18C, and 18K that develop electrostatic latent images, an intermediate transfer belt 20 to which a toner image carried by each photoconductor is transferred, and each photoconductor Primary transfer rollers 22Y, 22M, 22C, and 22K for transferring the toner image from the intermediate transfer belt to the intermediate transfer belt, and a secondary transfer roller 24 for transferring the toner image carried by the intermediate transfer belt to the recording sheet S. In the figure, black dots indicate toner.

  Further, the image forming apparatus 10 includes a collecting device 30 that sucks and collects dust toner generated in the vicinity of a region where the photosensitive member and the developing device face each other (hereinafter referred to as “developing region”).

  Note that alphabets Y, M, C, and K included in the reference numerals shown in FIG. 2 indicate toner colors, yellow, magenta, cyan, and black, and are assigned to the constituent colors of the image forming apparatus 10 that are assigned reference numerals. The correspondence is shown. In the following, the components including the alphabets Y, M, C, and K have the same structure and function except for the corresponding toner colors, so the alphabet Y is included in the symbols, that is, yellow toner. Only the components involved are described.

  The photoconductor 12Y has a cylindrical shape and is configured such that a yellow toner image is formed on the outer peripheral surface thereof. The photosensitive member 12Y is rotated at a predetermined rotational speed when a rotational driving force is transmitted from a rotational driving source (not shown) such as a motor.

  The charging device 14Y is configured to face the outer peripheral surface of the photoconductor 12Y in contact or non-contact and uniformly charge the outer peripheral surface of the photoconductor 12Y that passes through the facing region.

  The exposure device 16Y is disposed at a position facing the outer peripheral surface of the photoconductor 12Y downstream of the charging device 14Y with respect to the rotation direction of the photoconductor 12Y, and exposes the charged outer peripheral surface to form an electrostatic latent image. It is configured as follows.

  The developing device 18Y has a developing roller 26Y as a developer carrying member at a position facing the outer peripheral surface of the photoconductor 12Y on the downstream side of the exposure device 16Y with respect to the rotation direction of the photoconductor 12Y, and the developing roller 26Y is used. The electrostatic latent image on the outer peripheral surface of the photoreceptor 12Y is configured to be developed with yellow toner (forms a toner image). In the development by the developing roller 26Y, a predetermined voltage is applied to each of the photosensitive member 12Y and the developing roller 26Y by a voltage applying unit (not shown), thereby generating an electric field in a developing region between the photosensitive member 12Y and the developing roller 26Y. This is achieved by the toner carried by the developing roller 26Y electrostatically moving (flying) to the photoreceptor 12Y by this electric field.

  The developing device 18Y stores therein yellow toner carried on the developing roller 26Y.

  The intermediate transfer belt 20 is an endless belt, and an outer peripheral surface (hereinafter referred to as an “image carrying surface”) is photosensitive belts 12Y, 12M, 12C, 12K, secondary at a predetermined speed by a belt driving roller. The transfer rollers 24 are driven so as to sequentially face the outer peripheral surfaces of the transfer rollers 24. Finally, on the image carrying surface of the intermediate transfer belt 20, the toner images of the respective colors transferred from the photoreceptors 12Y, 12M, 12C, and 12K in the opposite areas (hereinafter referred to as “primary transfer areas”). A full-color toner image that is a superposition of the toner images is formed.

  The primary transfer roller 22Y is configured to transfer the yellow toner image on the outer peripheral surface of the photoreceptor 12Y to the intermediate transfer belt 20 that passes between the photoreceptor 12Y (primary transfer region) by electrostatic force and contact pressure. Has been.

  The secondary transfer roller 24 converts the full-color toner image carried by the intermediate transfer belt 20 onto the recording sheet S conveyed between the intermediate transfer belt 20 and the electrostatic force by the sheet conveying means (not shown). Transfer is performed by contact pressure.

  From here, the collection device 30 for collecting the dust toner will be described.

  First, the dust toner will be described. The dust toner is generated in the vicinity of the developing area between the photoconductor and the developing roller, and in the case of yellow toner, for example, in the vicinity of the developing area between the photoconductor 12Y and the developing roller 26Y. This occurs when yellow toner flies from the developing roller 26Y toward the photoconductor 12Y during development, and a very small amount of toner is not carried on the photoconductor 12Y and drifts as dust in the air. This amount of dust toner is an approximately constant amount that is extremely small relative to the amount of toner used for developing the electrostatic latent image carried on the photoconductor (the amount of toner carried on the photoconductor).

  The collecting device 30 is configured to separately collect the toner particles of the respective colors generated in the vicinity of the developing region between the photosensitive member corresponding to the toner of each color and the developing roller without mixing.

  Specifically, as shown in FIG. 2, the collection device 30 includes filters 32Y, 32M, 32C, and 32K that collect the dust toner of each color, and air that moves the dust toner to the corresponding filter. , A duct (corresponding to the flow path described in the claims) 34 and the fan 36, and a flow rate sensor 38Y for measuring the flow rate of the airflow passing through each filter, 38M, 38C, 38K, flow rate adjusting valves 40Y, 40M, 40C, 40K for adjusting the flow rate of the airflow that passes through each filter, and a valve control unit that controls each flow rate adjusting valve (the control described in the claims) Corresponding to the means.) 42 (see FIG. 3). In the figure, the direction of airflow is indicated by white arrows.

  Each of the filters 32Y, 32M, 32C, and 32K is disposed at a position where dust toner generated in the vicinity of the corresponding developing area can be collected.

  Further, the filters 32Y, 32M, 32C, and 32K are incorporated in the corresponding toner collection boxes 44Y, 44M, 44C, and 44K. The toner collection boxes 44Y, 44M, 44C, and 44K are containers that store the dust toner collected by the corresponding filters 32Y, 32M, 32C, and 32K, and are configured to be detachable from the image forming apparatus 10. Yes. The filters 32Y, 32M, 32C, and 32K are replaced by replacing the toner collection boxes 44Y, 44M, 44C, and 44K.

  The duct 34 and the fan 36 generate an air flow that collects the dust toner corresponding to each of the four filters 32Y, 32M, 32C, and 32K, that is, an air current that sucks the dust toner from the vicinity of the developing area toward the filter. It is for making it happen.

  Specifically, the duct 34 branches from one fan 36 into four filters 32Y, 32M, 32C, and 32K to connect the fans and the filters. Due to the duct 34, the sum of the flow rates of the airflows passing through the four filters 32Y, 32M, 32C, and 32K matches the suction amount of the fan 32.

  The fan 36 is configured to discharge the airflow that has passed through the four filters 32Y, 32M, 32C, and 32K to the outside of the image forming apparatus 10.

  Each of the flow sensors 38Y, 38Y, 38M, 38C, and 38K measures the flow rate of the airflow that passes through the corresponding filters 32Y, 32M, 32C, and 32K. These flow rate sensors 38Y, 38M, 38C, and 38K are for confirming that the flow rate of the airflow that passes through the corresponding filters 32Y, 32M, 32C, and 32K from the development region side toward the fan 36 is equal to or more than the lower limit amount. Further, it is arranged in the duct 34 in the vicinity of the filter. This “lower limit amount” refers to the flow rate of airflow that is the minimum necessary for reliably sucking the dust toner generated in the vicinity of the developing area toward the filter.

  More specifically, the “lower limit amount” for reliably sucking the dust toner generated in the vicinity of the development area toward the filter must be an amount capable of sucking the maximum amount of the dust toner. The maximum amount of dust toner is generated in the vicinity of the development area when a solid image is formed on the photoreceptor by development. Therefore, as long as the flow rate of the airflow passing through the filter is equal to or greater than the lower limit amount, any amount of dust toner can be reliably sucked toward the filter.

  The flow sensor may be disposed at the downstream side of the filter with respect to the flow direction of the airflow as shown in the figure, but is not limited to this, and the position where the flow rate of the airflow passing through the filter can be measured (in a broad sense, the filter As long as it can measure the flow rate having a corresponding relationship with the flow rate of the airflow passing through the filter.

  Each of the flow sensors 38Y, 38Y, 38M, 38C, and 38K is configured to output a signal corresponding to the measured flow rate of the airflow to the valve controller 42 (see FIG. 3).

  Each of the flow rate adjusting valves 40Y, 40M, 40C, and 40K has a flow path through which the air flow passes, and adjusts the flow rate of the air flow by changing the cross-sectional area of the flow path. That is, each of the flow rate adjusting valves 40Y, 40M, 40C, and 40K functions as a flow resistance (flow resistance having a variable resistance value) that acts on the airflow that passes through the corresponding filters 32Y, 32M, 32C, and 32K.

  Each of the flow rate adjusting valves 40Y, 40M, 40C, and 40K is disposed on the downstream side of the corresponding filter with respect to the airflow direction in order to adjust the flow rate of the airflow that passes through the corresponding filter 32Y, 32M, 32C, and 32K. (When the flow sensor is arranged on the downstream side of the filter, it is arranged on the downstream side of the flow sensor.)

  Further, the flow rate adjusting valves 40Y, 40M, 40C, and 40K are arranged in parallel to the fan 36. Therefore, when the flow rate of the airflow passing through the corresponding filter is adjusted by any of the flow rate adjusting valves 40Y, 40M, 40C, and 40K, the flow rate of the airflow passing through the remaining filters changes. For example, when the flow rate adjustment is performed so that the flow rate passing through the corresponding filters 32Y, 32M, and 32C is reduced by the three flow rate adjustment valves 40Y, 40M, and 40C (the flow resistance values of the flow rate adjustment valves 40Y, 40M, and 40C are increased). The flow rate of the airflow passing through the filter 32K increases.

  The flow rate adjustment by the flow rate adjustment valves 40Y, 40M, 40C, and 40K (that is, the change of the flow resistance value of each flow rate adjustment valve) is performed by the valve control unit 42 controlling each flow rate adjustment valve.

  As shown in FIG. 3, the valve control unit 42 determines that the flow rate of the airflow measured by at least one flow rate sensor is below the lower limit based on the output signals from the flow rate sensors 38Y, 38Y, 38M, 38C, 38K. It is configured to control the flow rate adjusting valve 40Y, 40M, 40C, 40K so as not to become.

  Specifically, the valve control unit 42 monitors the output signals from the flow sensors 38Y, 38M, 38C, and 38K, and the flow rates of the airflows that pass through the filters 32Y, 32M, 32C, and 32K are substantially the same. Change the flow resistance values of the flow control valves 40Y, 40M, 40C, and 40K so that the flow rate is as high as possible (so that each flow sensor is approximately the same and outputs a signal indicating the maximum flow rate possible). To do.

  The flow rate of the corresponding flow rate adjusting valves 40Y, 40M, 40C, and 40K is eventually set to the maximum possible flow rate through the filters 32Y, 32M, 32C, and 32K. The sum of the flow resistance values of the filters 32Y, 32M, 32C, and 32K corresponding to the values is substantially the same and is set to the smallest possible value.

  When the dust toner is collected, the filter functions as a flow resistance having a resistance value proportional to the collected amount.

  The sum of the flow resistance value of the filter and the flow resistance value of the flow rate regulating valve affects the flow rate of the airflow passing through the filter. That is, the flow rate of the airflow passing through the filter increases as the sum of the flow resistance value of the filter and the flow resistance value of the flow rate adjustment valve decreases, and conversely decreases as the sum increases.

  For example, when the amount of toner collected by the filter 32K is a relatively large amount compared to the amount of toner collected by the other filters 32Y, 32M, and 32C, the valve control unit 42 results in relative to the filter 32K. Therefore, the flow resistance value of the valve 40K is set to a relatively small value so that a large amount of airflow passes. In addition, as a result, the flow resistance values of the valves 40Y, 40M, and 40C are set to relatively large values so that a relatively small amount of airflow passes through the filters 32Y, 32M, and 32C. .

Further, the valve control unit 42 adjusts the flow rate passing through the filters 32Y, 32M, 32C, and 32K through the flow rate adjustment valves 40Y, 40M, 40C, and 40K to approximately the same and the maximum possible flow rate, at least. When the flow rate of the airflow passing through one filter is smaller than the lower limit amount, the user of the image forming apparatus 10 is requested to perform filter maintenance (replacement of the collection box in the present embodiment).

  More specifically, the valve control unit 42 makes the flow rate of the airflow passing through the filters 32Y, 32M, 32C, and 32K through the flow rate adjustment valves 40Y, 40M, 40C, and 40K substantially the same and the maximum possible flow rate. Of course, the adjusted flow rate becomes smaller as the number of times of image formation increases. This is because the amount of toner collected by each of the filters 32Y, 32M, 32C, and 32K increases as the number of times of image formation increases, and the flow resistance value of each filter increases accordingly. Therefore, in any case, the flow rate of the airflow passing through at least one of the filters 32Y, 32M, 32C, and 32K becomes smaller than the lower limit amount, and the filter needs to be maintained.

  As shown in FIG. 3, the valve control unit 42 outputs a signal 46 requesting filter maintenance to the control unit of the image forming apparatus 10 as shown in FIG. This is done by displaying a comment requesting filter maintenance on a display (not shown) that displays information relating to image formation. The control unit of the image forming apparatus 10 corresponds to the filter maintenance request unit described in the claims.

  The valve control unit 42 adjusts the flow rate of the airflow passing through the filters 32Y, 32M, 32C, and 32K through the flow rate adjustment valves 40Y, 40M, 40C, and 40K to approximately the same and the maximum possible flow rate. For example, it is executed at regular intervals. Alternatively or in addition, it may be executed based on the signal 48 output from the control unit of the image forming apparatus 10 immediately after the image formation is executed or immediately before the image formation is executed.

  As described above, based on the output signals from the flow sensors 38Y, 38Y, 38M, 38C, and 38K, the valve control unit 42 prevents the airflow measured by the at least one flow sensor from falling below the lower limit amount. The effect of controlling the flow rate adjusting valves 40Y, 40M, 40C, and 40K will be described.

4A and 4B show the relationship between the flow rates Q _Y , Q _M , Q _C and Q _{K of} the airflow passing through the filters 32Y, 32M, 32C and 32K, respectively, and the cumulative image formation time t. FIG.

In the figure, Q ₀ is the flow rate of the airflow when the filters 32Y, 32M, 32C, and 32K are not collecting the corresponding dust toner (so-called new state). Q _L is the above lower limit amount.

FIG. 4A shows the flow rate Q _Y , Q of the airflow passing through the filters 32Y, 32M, 32C, 32K in the collection device 30 when there is no valve control unit 42 or flow rate adjustment valves 40Y, 40M, 40C, 40K. _M, is a diagram showing a _Q C, _{Q K,} the relationship between the image formation time t cumulative.

As shown in FIG. 4 (a), when there is no valve control unit 42 or flow rate adjustment valves 40Y, 40M, 40C, 40K, the flow rates Q _Y , Q _M , of the airflow passing through the filters 32Y, 32M, 32C, 32K, respectively. Q _C, the timing at _{which Q K} is less than or equal to the lower amount _{Q L} are different. This is because the amount of each dust toner generated during development is different, and the rate of increase in the amount of collected toner (so-called clogging progress rate) of each of the filters 32Y, 32M, 32C, 32K is different. When the filters 32Y, 32M, 32C, and 32K are simultaneously maintained (replaced), the simultaneous maintenance is performed at the timing t when the flow rates Q _Y , Q _M , Q _C , and Q _{K of} the airflow passing through the filters reach the lower limit amount Q _{L. Y, t} M, _t C, is performed in earliest timing _{t K} at _{t K.}

On the other hand, FIG. 4B shows the flow rate Q of the airflow passing through the filters 32Y, 32M, 32C, and 32K in the collection device 30 when the valve control unit 42 and the flow rate adjusting valves 40Y, 40M, 40C, and 40K are provided. _Y, and _{Q M, Q C, Q K} , is a diagram showing the relationship between the image formation time t cumulative.

As shown in FIG. 4 (b), the valve control unit 42 has substantially the same flow rate that passes through the filters 32Y, 32M, 32C, and 32K through the flow rate adjustment valves 40Y, 40M, 40C, and 40K. to adjust the flow rate, the flow rate _{Q Y, Q M, Q C} , Q K lower limit amount _{Q L} timings made below substantially at the same timing _{t i.} When the filters 32Y, 32M, 32C, and 32K are simultaneously maintained (replaced), the simultaneous maintenance is executed at the timing ti.

Further, the timing t _i will timing after the earliest timing t _K shown in Figure 4 (a). This is because the valve control unit 42 adjusts the flow rate passing through the filters 32Y, 32M, 32C, and 32K through the flow rate adjustment valves 40Y, 40M, 40C, and 40K to substantially the same maximum flow rate. the rate of decrease in the flow rate Q _K of air flow through the filter and 32K, is to be smaller than when there is no valve control unit and a plurality of flow rate adjusting valve. Accordingly, when the valve control unit 42 and the flow rate adjusting valves 40Y, 40M, 40C, and 40K are provided, the period of simultaneous maintenance of the plurality of filters becomes longer compared to the case where these are not provided. As a result, the maintenance of the filter is not frequently performed, and the labor for maintenance of the plurality of filters is reduced.

  Next, the flow of processing for confirming the necessity of filter maintenance will be described with reference to the flow shown in FIG.

  The flow shown in FIG. 5 shows an example of a flow of processing that is periodically executed or performed immediately before or after image formation.

  When processing for confirming the necessity of filter maintenance is started, first, in step 100, the flow rate of the airflow passing through the corresponding filters 32Y, 32M, 32C, and 32K is measured by the flow rate sensors 38Y, 38M, 38C, and 38K. Is done.

  Next, in step 110, the valve controller 42 determines at least the flow rate of the airflow passing through each of the filters 32Y, 32M, 32C, 32K based on the measurement results of the flow sensors 38Y, 38M, 38C, 38K in step 100. Check if one is below the lower limit. If at least one flow rate is less than or equal to the lower limit amount, proceed to step 120. Otherwise, the process for confirming the necessity of filter maintenance ends.

  In step 120, the valve control unit 42 adjusts the flow rate of the airflow that passes through the filters 32Y, 32M, 32C, and 32K through the flow rate adjustment valves 40Y, 40M, 40C, and 40K to the maximum possible flow rate that is substantially the same. To do.

  Subsequently, in step 130, the flow rate of the airflow passing through the corresponding filters 32Y, 32M, 32C, 32K is measured by the flow rate sensors 38Y, 38M, 38C, 38K.

  In step 140, the valve control unit 42 determines that the flow rates of the airflows passing through the filters 32Y, 32M, 32C, and 32K are substantially the same based on the measurement results of the flow sensors 38Y, 38M, 38C, and 38K in step 130. It is confirmed whether or not. When the flow rate of each airflow is substantially the same, the process proceeds to step 150. Otherwise, return to step 120.

  In step 150, the valve control unit 42 determines that at least one of the flow rates of the airflow passing through the filters 32Y, 32M, 32C, and 32K is the lower limit amount based on the measurement results of the flow sensors 38Y, 38M, 38C, and 38K in step 130. Check whether it is the following. If at least one flow rate is less than or equal to the lower limit amount, proceed to step 160. Otherwise, the process for confirming the necessity of filter maintenance ends.

  In step 160, the valve control unit 42 outputs a signal 46 for requesting filter maintenance to the control unit of the image forming apparatus 10. And the process for confirming the necessity of filter maintenance is complete | finished.

  According to this embodiment, the dust toner generated at each of the plurality of locations by one fan is sucked toward the corresponding filter, and the flow rate of the airflow passing through at least one filter ensures the dust toner. It is adjusted by the flow rate adjustment valve so as not to be less than the lower limit amount sucked toward the filter. Therefore, even when the amount of each dust toner is extremely different, the period of maintenance performed simultaneously on a plurality of filters is not extremely shortened, and a sufficiently long period is ensured. As a result, frequent maintenance is not performed on the plurality of filters at the same time, and the labor for maintenance of the plurality of filters is reduced.

(Second Embodiment)
In the first embodiment, based on the flow measurement results of a plurality of flow sensors, the flow rate of the airflow that passes through each of the plurality of filters is adjusted to be the same as the maximum possible flow rate. The embodiment is executed without using a flow sensor.

  In this embodiment, a toner storage amount sensor is used in place of the flow rate sensor, and the flow rate of the airflow passing through each of the plurality of filters is adjusted to the maximum possible flow rate that is substantially the same.

  FIG. 6 schematically shows the configuration of the image forming apparatus according to the second embodiment. The image forming apparatus denoted by reference numeral 110 in the figure has the same components as those in the first embodiment, except that the flow sensor of the image forming apparatus in the first embodiment is not provided. Constituent elements that are the same as those in the first embodiment are given numerical symbols obtained by adding 100 to the numerical symbols assigned to the constituent elements in the first embodiment. Hereinafter, differences from the image forming apparatus according to the first embodiment will be mainly described.

  As shown in FIG. 6, each of the toner storage amount sensors 150Y, 150M, 150C, and 150K is provided in each of the corresponding developing devices 118Y, 118M, 118C, and 118K, and the storage amount of the toner stored in the inside thereof. And a signal indicating the toner storage amount is output to the control unit of the image forming apparatus 110. Based on the output signals from the toner storage amount sensors 150Y, 150M, 150C, and 150K, the control unit of the image forming apparatus 110, for example, notifies the user of the remaining amount of each toner via an output unit (not shown) such as a display. A new developing device that indicates the amount or requests that a developing device having a toner storage amount of substantially zero be replenished (if the developing device is replaceable and also a container for distributing toner) Request an exchange to.)

  The toner storage amount sensor is also provided in the image forming apparatus according to the first embodiment.

  A method for adjusting the flow rate of the airflow passing through each of the plurality of filters 132Y, 132M, 132C, and 132K through the toner storage amount sensors 150Y, 150M, 150C, and 150K to approximately the same and the maximum possible flow rate will be described.

  First, as a premise, as a matter of course, the toner storage amount in the developing devices 118Y, 118M, 118C, and 118K decreases each time image formation is performed. The reduced toner is the toner used to develop the electrostatic latent image. In addition, as described above, the amount of dust toner corresponds to the amount of toner used for development (development amount). Therefore, the amount of dust toner, that is, the amount of toner collected by the filter can be known from the toner storage amount. For example, when the amount of toner dust is approximately 0.5% of the development amount, the dust toner collected in the filter while the toner storage amount is reduced to 50% of the maximum toner storage amount The amount of toner (the amount of toner collected) is approximately 0.25% of the maximum toner storage amount. The ratio of the amount of toner smoke to the amount of development needs to be checked in advance.

  Strictly speaking, the amount of toner collected by the filter at a certain point in time is an amount related to the number of times the toner has been replenished (the number of times the developing device has been replaced). This is because toner replenishment (or replacement of the developing device) is performed a plurality of times between the maintenance of the filter and the next maintenance. Therefore, the amount of toner collected by the filter at a certain point in time is determined by the amount of toner used in the developing device at a certain point in time (or the amount of decrease in toner) and the number of toner replenishments performed until a certain point in time (or It can be obtained from the sum of the product of the number of times of replacement) and the maximum toner storage amount of the developing device (that is, the cumulative development amount from the time when the filter maintenance is performed until a certain time). In this case, counting means (not shown) for counting the number of toner replenishments (or the number of times of developing device replacement) after the filter is maintained is required.

  If the respective toner collection amounts of the filters 132Y, 132M, 132C, and 132K are obtained, the flow resistance value of each filter can be calculated. However, it is necessary to investigate the relationship between the amount of collected toner and the flow resistance value of the filter in advance.

FIG. 7 shows that the sum of the flow resistance values of the filters 132Y, 132M, 132C, and 132K and the flow resistance values of the flow rate adjusting valves 140Y, 140M, 140C, and 140K is substantially the same and is as small as possible. The valve control unit 142 shown controls each flow rate adjustment valve (changes the flow resistance value of each flow rate adjustment valve). As a result, the flow rate of the airflow passing through each filter is substantially the same and the maximum possible flow rate. Adjusted to

  When the sum of the flow resistance values of the filters 132Y, 132M, 132C, and 132K and the flow resistance values of the flow rate adjusting valves 140Y, 140M, 140C, and 140K is set to the smallest possible value, The flow rate is almost the same and the maximum possible flow rate, but the specific flow rate value is unknown. A specific value of the flow rate can be obtained from the suction amount of the fan 136. Since the sum of the flow rates of the airflows passing through the four filters 132Y, 132M, 132C, and 132K substantially matches the suction amount of the fan 136, the suction amount of the fan, the flow resistance value of each filter, and the flow rate adjusting valves 140Y, 140M , 140C, and 140K, the flow rate of the airflow passing through each filter can be calculated. The suction amount of the fan 136 can be calculated from a current value input to a motor (not shown) that rotates the fan. For example, when the sum of the flow resistance values of the flow control valve valves 140Y, 140M, 140C, and 140K corresponding to the flow resistance values of the four filters 132Y, 132M, 132C, and 132K is the same, the airflow that passes through each filter The flow rate is a quarter of the suction amount of the fan 136.

  In order to adjust the flow rate of the airflow passing through each of the plurality of filters 132Y, 132M, 132C, and 132K via the toner storage amount sensors 150Y, 150M, 150C, and 150K to be approximately the same and the maximum possible flow rate, The valve control unit 142 is configured as follows.

  As illustrated in FIG. 7, the valve control unit 142 receives a signal 148 indicating the toner storage amount from the toner storage amount sensors 150Y, 150M, 150C, and 150K via the control unit of the image forming apparatus 110, and based on the signal 148. The toner collection amounts of the filters 132Y, 132M, 132C, and 132K are calculated, the flow resistance value of each filter is calculated from the calculated collection amount, and the flow rate adjustment valve 140Y corresponding to the calculated flow resistance value of each filter is calculated. Each flow valve is controlled so that the sum of the flow resistance values of 140M, 140C, and 140K is substantially the same and becomes the smallest possible value.

  In addition, the valve control unit 142 is configured as follows in order to output a signal 146 requesting filter maintenance to the control unit of the image forming apparatus 110.

  The valve control unit 142 receives the signal 152 indicating the suction amount of the fan 136 from the control unit of the image forming apparatus 110 that controls the rotation of the fan 136, and the signal 152 and the flow resistance values of the filters 132Y, 132M, 132C, and 132K. When the flow rate of substantially the same airflow that passes through each filter is calculated based on the flow resistance value of each of the flow rate adjustment valves 140Y, 140M, 140C, and 140K, and at least one calculated flow rate of the airflow is equal to or less than the lower limit amount, A signal 146 for requesting maintenance is output to the control unit of the image forming apparatus 110.

  Next, the flow of processing for confirming the necessity of filter maintenance using the toner storage amount sensors 150Y, 150M, 150C, and 150K will be described with reference to the flow shown in FIG.

  The flow shown in FIG. 8 shows an example of a flow of processing that is periodically executed or performed immediately before or after image formation.

  First, in step 200, the valve control unit 142 confirms the number of toner replenishment times for each color toner from a counting means (not shown).

  Next, in step 210, the toner storage amounts in the corresponding developing devices 118Y, 118M, 118C, and 118K are measured by the toner storage amount sensors 150Y, 150M, 150C, and 150K.

  In step 220, the valve control unit 142 calculates a cumulative development amount for each color toner based on the number of toner replenishments confirmed in step 200 and the toner storage amount measured in step 210.

  In step 230, the valve control unit 142 calculates the toner collection amounts of the filters 132Y, 132M, 132C, and 132K from the cumulative development amount calculated in step 220.

  In step 240, the valve control unit 142 calculates the flow resistance values of the filters 132Y, 132M, 132C, and 132K from the cumulative development amount calculated in step 230.

  In step 250, the valve control unit 142 substantially omits the sum of the flow resistance values of the filters 132Y, 132M, 132C, and 132K calculated in step 240 and the flow resistance values of the flow rate adjusting valves 140Y, 140M, 140C, and 140K. Each flow control valve is controlled to be the same and the smallest possible value (the flow resistance value of each flow control valve is changed).

  In step 260, the valve control unit 142 outputs the signal 152 indicating the suction amount of the fan 136 output from the control unit of the image forming apparatus 110 and the flow resistance values of the filters 132Y, 132M, 132C, and 132K calculated in step 240. Then, based on the flow resistance values of the flow rate adjusting valves 140Y, 140M, 140C, and 140K changed in step 250, the flow rate of the airflow that passes through each filter is calculated.

  In step 270, the valve control unit 142 confirms whether at least one of the airflow rates passing through the filters 132Y, 132M, 132C, and 132K calculated in step 260 is equal to or less than the lower limit amount. If at least one calculated flow rate is less than or equal to the lower limit amount, proceed to step 280. Otherwise, the process for confirming the necessity of filter maintenance ends.

  In step 280, the valve control unit 142 outputs a signal 146 for requesting the filter maintenance to the control unit of the image forming apparatus 110. And the process for confirming the necessity of filter maintenance is complete | finished.

  According to this embodiment, since the toner storage amount sensor executes what the flow sensor of the first embodiment has executed, the flow sensor is omitted.

  Although the present invention has been described with reference to two embodiments, the present invention is not limited to these two embodiments.

  For example, in the above-described embodiment, a plurality of filters are maintained at the same time, and each filter is incorporated in a corresponding toner collection box. Accordingly, when the filter is maintained outside the image forming apparatus (when the toner collection box is replaced), it is necessary to individually remove a plurality of toner collection boxes from the image forming apparatus. As a countermeasure, a plurality of collection boxes may be integrated. By integrating, a plurality of filters are taken out of the image forming apparatus at a time.

  Moreover, although the above-mentioned embodiment attracts | sucks and separately collects the dust toner which generate | occur | produces in the vicinity of a development area, ie, generate | occur | produces at the time of image development, it is not limited to this. For example, dust toner generated when the toner remaining without being transferred to the recording sheet remaining on the intermediate transfer belt is scraped with a cleaning blade may be collected by suction.

  Further, in the above-described embodiment, the dust toner generated at four places is sucked by one suction means (fan). Of course, the number of places where the dust toner sucked to one suction means is generated. It is not limited. Further, when it is not necessary to consider the noise caused by the fans, for example, the dust toner generated at four locations may be sucked by two fans, that is, each fan sucks the dust toner generated at two locations. In a broad sense, the present invention does not limit the number of fans and the number of places where dust toner is generated in the image forming apparatus as long as one fan sucks the dust toner generated at at least two places.

  Furthermore, the above-described embodiment requires the maintenance of the filter at a timing at which the dust toner cannot be reliably sucked. For example, in order to provide the user with a period for preparing a new toner collection box, the dust toner is added. Preparation for filter maintenance may be proposed to the user before the timing at which suction cannot be performed reliably.

  In this case, when at least one of the flow rates of the airflows passing through each of the plurality of filters becomes slightly larger than the lower limit amount, image formation is proposed to the user via the output unit such as a display to prepare for filter maintenance. What is necessary is just to comprise an apparatus.

It is a figure for demonstrating the classification | category of a collection apparatus. 1 is a diagram schematically showing a configuration of an image forming apparatus according to a first embodiment of the present invention. It is a figure which shows the structure of the control system of the collection apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the effect of this invention. It is a flowchart of the process which confirms the necessity for the filter maintenance of 1st Embodiment. It is a figure which shows schematically the structure of the image forming apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the control system of the collection apparatus which concerns on 2nd Embodiment. It is a flowchart of the process which confirms the necessity for the filter maintenance of 2nd Embodiment.

Explanation of symbols

30: Collection device 32Y, 32M, 32C, 32K: Filter 34: Channel (duct)
36: Suction means (fan)
38Y, 38M, 38C, 38K: Flow rate measuring means (flow rate sensor)
40Y, 40M, 40C, 40K: Flow rate adjusting means (flow rate adjusting valve)

Claims (5)

A suction device that sucks dust generated at each of a plurality of places by one suction means, and collects each dust by a plurality of filters separately,
One suction means;
A plurality of filters for collecting the smoke generated in each of a plurality of places;
A flow path connecting the suction means and the plurality of filters;
A plurality of flow rate adjusting means for adjusting the flow rate of the airflow passing through each filter;
A plurality of flow rate measuring means for measuring the flow rate of the airflow passing through each filter;
Control each flow rate adjusting means based on the flow rate measurement results of each flow rate measuring means so that the flow rate of the airflow measured by at least one flow rate measuring means does not fall below the lower limit amount that reliably sucks the smoke toward the filter A collection device comprising control means for performing   The collection device according to claim 1, wherein a plurality of filters are integrated. An image forming apparatus that sucks toner dust generated at each of a plurality of locations and collects the toner dust separately by a plurality of filters,
An image forming apparatus that collects toner dust by the collecting device according to claim 1. An image forming apparatus that sucks toner dust generated at each of a plurality of locations and collects the toner dust separately by a plurality of filters,
A plurality of toner storage means for storing toner before being used for image formation;
A plurality of storage amount measuring means for measuring the amount of toner stored in each toner storage means;
One suction means;
A plurality of filters for collecting toner dust generated in each of a plurality of locations;
A flow path connecting the suction means and the plurality of filters;
A plurality of flow rate adjusting means for adjusting the flow rate of the airflow passing through each filter;
Based on the storage amount measurement result of each storage amount measuring means, the flow rate of the air flowing through the at least one filter does not fall below the lower limit amount for reliably sucking the toner dust to the filter. An image forming apparatus comprising: a control unit that calculates a collected amount of dust and controls each flow rate adjusting unit based on the calculated collected amount. A filter maintenance request that requires the user to maintain the filter when the flow rate of the airflow passing through each filter does not exceed the lower limit amount even if the flow rate of the airflow passing through each filter is adjusted via each flow rate adjusting means. 5. The image forming apparatus according to claim 3, further comprising a unit.

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