JP2017072707A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can suppress a reduction in toner separation efficiency by properly determining a replacement time of a cyclone part and a filter.SOLUTION: An image forming apparatus 1A comprises a cyclone part 41 that centrifugally separates a toner from a toner-containing air; a recovery part 42 that recovers the toner separated by the cyclone part 41; a filter part 43 including filters 43ato 43athat passes the air from which the toner is separated by the cyclone part 41 therethrough to collect a residual toner; and a toner collection part 4 provided with an air blowing part 44 that sucks the air. The image forming apparatus determines the replacement time of the filters 43ato 43aon the basis of information on the volume of the air after the passage through the filters 43ato 43aand determines the replacement time of the cyclone part 41 on the basis of air volume information after the replacement of the filters.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus that forms an image by transferring and fixing a toner image onto a sheet.

  Conventionally, an image forming apparatus that forms an image on a sheet using toner is known. In such an image forming apparatus, an electrostatic latent image is formed on the photoreceptor in accordance with the image, and in a process called development, toner is attached to the electrostatic latent image on the photoreceptor by the developing apparatus, and the electrostatic latent image is formed. Is visualized to form a toner image.

  The toner image formed on the photosensitive member is primarily transferred to the intermediate transfer member and secondarily transferred from the intermediate transfer member to the sheet. The sheet on which the toner image is transferred is conveyed to a fixing device, and the toner image is fixed on the sheet by heating and pressing.

  By the way, in each process such as the development described above, toner scattering occurs in the image forming apparatus. Therefore, an image forming apparatus including a toner collecting unit that collects scattered toner has been proposed (see, for example, Patent Document 1).

  The toner collecting unit passes a cyclone unit that centrifuges the toner from the toner-containing air, a collection unit that collects the toner separated by the cyclone unit, and the air from which the toner is separated by the cyclone unit. The image forming apparatus includes a filter that collects toner, and the cyclone unit and the filter are integrally replaced with the image forming apparatus.

JP 2013-160843 A

  In the toner collecting unit in which the cyclone unit and the filter are replaced integrally, workability is improved because only one part needs to be replaced. On the other hand, under conditions where the image printing rate is high for a color image using four colors of toner, the amount of toner scattering increases and the frequency of replacing the cyclone unit and the filter increases, leading to an increase in the cost of operation of the apparatus. .

  Therefore, a technique has been proposed in which the cyclone part and the filter part are separated so that only the filter can be replaced. However, all the toner cannot be separated from the toner-containing air in the cyclone portion, and the toner adheres to the air path in the cyclone portion as the number of prints accompanying the image forming operation increases.

  When the toner adheres to the cyclone portion, the image forming operation is performed with the separation efficiency lowered. When the image forming operation is performed in a state where the toner separation efficiency in the cyclone portion is lowered, the filter is soiled and the frequency of replacement of the filter is increased.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of appropriately determining the replacement timing of a cyclone unit and a filter and suppressing a decrease in toner separation efficiency. The purpose is to do.

  In order to solve the above-described problem, the invention according to claim 1 is an image forming unit that forms an image by transferring toner to a sheet, and a fixing unit that fixes the image on the sheet on which the image is formed by the image forming unit A toner collecting means for sucking the toner-containing air in the apparatus and collecting the toner, and the toner collecting means includes a cyclone section for centrifuging the toner from the toner-containing air, and a toner separated by the cyclone section A filter unit having a recovery unit that collects the toner separated by the cyclone unit, and a filter unit having a filter that collects residual toner in the air; and a blower unit that sucks air, and after passing through the filter The filter replacement time is determined based on the air volume information of the air, and the cyclone replacement time is determined based on the status information of the toner collecting means after the filter replacement. An image forming apparatus including a control unit that.

  The invention according to claim 2 is the image forming apparatus according to claim 1, wherein the control unit acquires the air volume information of the air after passing through the filter by the air volume detecting unit provided in the filter unit.

  The invention according to claim 3 is the image forming apparatus according to claim 1, wherein the control means acquires the air volume information of the air after passing through the filter from the number of rotations of the fan of the blower.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the control unit acquires the state information of the toner collecting unit after the filter replacement by the air volume detecting unit provided in the filter unit. is there.

  The invention according to claim 5 is the image forming apparatus according to claim 2 or 3, wherein the control means acquires the status information of the toner collecting means after filter replacement from the filter replacement cycle.

  According to the present invention, it is possible to appropriately determine the replacement timing of the cyclone unit and the filter, and it is possible to suppress the use in a state where the toner separation efficiency is lowered.

1 is a configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. FIG. 3 is a configuration diagram illustrating an example of a toner collecting unit according to an exemplary embodiment. 3 is a functional block diagram illustrating an example of a control function of the image forming apparatus according to the present exemplary embodiment. FIG. 6 is a graph showing the relationship between a plurality of filters and the amount of collected toner. 4 is a flowchart illustrating an example of an operation of the image forming apparatus according to the present exemplary embodiment. It is a graph which shows the change of the dirt and air volume of a cyclone part and a filter. 10 is a flowchart illustrating another example of the operation of the image forming apparatus according to the present exemplary embodiment. It is a graph which shows the dirt of a cyclone part and a filter, and the change of fan rotation speed. 10 is a flowchart illustrating another example of the operation of the image forming apparatus according to the present exemplary embodiment.

  Hereinafter, an embodiment of an image forming apparatus of the present invention will be described with reference to the drawings.

<Example of Configuration of Image Forming Apparatus of Embodiment>
FIG. 1 is a configuration diagram illustrating an example of an image forming apparatus according to the present embodiment, and FIG. 2 is a configuration diagram illustrating an example of a toner collecting unit according to the present embodiment. The image forming apparatus 1A is an electrophotographic image forming apparatus such as a copying machine. In this example, a plurality of photoconductors face a single intermediate transfer belt and are arranged in a vertical direction to form a full color image. This is a so-called tandem color image forming apparatus.

  The image forming apparatus 1 </ b> A includes a document reading unit 10, an image forming unit 11, a paper transport unit 2, a fixing unit 3, and a toner collecting unit 4.

  The document reading unit 10 scans and exposes an image of a document with the optical system of the scanning exposure apparatus, reads the reflected light with a line image sensor, and obtains an image signal. Note that the image forming apparatus 1A may have a configuration in which an automatic document feeder (not shown) that feeds a document is provided at the top.

  The image forming unit 11 is an example of an image forming unit, and forms an image forming unit 11Y that forms a yellow (Y) image, an image forming unit 11M that forms a magenta (M) image, and a cyan (C) image. And an image forming unit 11BK that forms a black (BK) image.

  The image forming unit 11Y includes a photosensitive drum Y and a developing device 12Y, a charging unit, an optical writing unit, a drum cleaner, and the like (not shown). Similarly, the image forming units 11M, 11C, and 11BK include photosensitive drums M, C, and BK and developing devices 12M, 12C, and 12BK, a charging unit, an optical writing unit, a drum cleaner, and the like (not shown).

  A latent image is formed on the photosensitive drum Y by scanning exposure. The developing device 12Y develops the latent image on the photosensitive drum Y by developing with toner. As a result, an image (toner image) of a predetermined color corresponding to yellow is formed on the photosensitive drum Y.

  Similarly, a latent image is formed on the photosensitive drum M by scanning exposure. The developing device 12M develops the latent image on the photosensitive drum M by developing with toner. As a result, a toner image of a predetermined color corresponding to magenta is formed on the photosensitive drum M.

  A latent image is formed on the photosensitive drum C by scanning exposure. The developing device 12C develops the latent image on the photosensitive drum C by developing with toner. As a result, a toner image of a predetermined color corresponding to cyan is formed on the photosensitive drum C.

  A latent image is formed on the photosensitive drum BK by scanning exposure. The developing device 14BK develops the latent image on the photosensitive drum BK by developing with toner. As a result, a toner image of a predetermined color corresponding to black is formed on the photosensitive drum BK.

  The images formed on the photosensitive drums Y, M, C, and BK are sequentially moved to predetermined positions on the intermediate transfer belt 16 that is a belt-like intermediate transfer member by the primary transfer rollers 17Y, 17M, 17C, and 17BK. Transcribed.

  The image composed of each color transferred onto the intermediate transfer belt 16 is transferred by the secondary transfer unit 18 to the paper P conveyed at a predetermined timing by the paper conveyance unit 2. The secondary transfer unit 18 forms a transfer nip 19 by the secondary transfer roller 18a being disposed in pressure contact with the intermediate transfer belt 16, and transfers the image onto the paper P while conveying the paper P.

  In the secondary transfer unit 18, a positive voltage is applied from the back side of the paper P by the secondary transfer roller 18 a in order to transfer the toner image onto the paper P. As a result, the sheet P that has passed through the secondary transfer portion 18 is charged with the negative electrode on the image forming surface side to which the toner is transferred and with the positive electrode on the back surface.

  In this example, the paper transport unit 2 includes a plurality of paper feed trays 21 and a paper feed unit 21 a that feeds the paper P stored in the paper feed tray 21. The paper transport unit 2 also includes a main transport path 23 through which the paper P fed from the paper feed tray 21 is transported, and a reverse transport path 24 that reverses the front and back of the paper P.

  The main transport path 23 constitutes a transport path from the paper feed tray 21 to the paper discharge tray 25. When the external paper feed tray 22, which is called a manual feed tray, is opened and used, the transport path from the external paper feed tray 22 joins the main transport path 23 upstream from the junction of the main transport path 23 and the reverse transport path 24. To do.

  The sheet conveyance unit 2 corrects the inclination of the sheet P called skew and the deviation of the position in the width direction of the sheet P perpendicular to the conveyance direction with respect to the sheet P conveyed on the main conveyance path 23. Is provided. The paper transport unit 2 also includes a loop roller 27 that abuts the paper against the registration roller 26.

  The registration roller 26 is composed of a pair of rollers facing each other with the paper P conveyed through the main conveyance path 23, and includes a shaft orthogonal to the conveyance direction of the paper P and rotates along the conveyance direction of the paper P To do.

  The loop roller 27 is composed of a pair of rollers facing each other with the paper P conveyed through the main conveyance path 23 interposed therebetween, and is provided on the upstream side of the registration roller 26 with respect to the conveyance direction of the paper P. The loop roller 27 includes an axis orthogonal to the conveyance direction of the paper P, and conveys the paper P by rotating along the conveyance direction of the paper P.

  In a state where the registration roller 26 is stopped, the paper P is conveyed by the loop roller 27, the leading end of the paper P is abutted against the nip portion 26a formed by the contact portion of the pair of rollers, and is curved called a loop. By conveying the paper P until it reaches the state, the inclination in the direction along the surface of the paper P is corrected.

  After the inclination of the paper P is corrected, the registration roller 26 is rotationally driven along the transport direction of the paper P, whereby the paper P is nipped and transported. Further, the position of the sheet P in the width direction is corrected by moving the registration roller 26 in the width direction of the sheet P perpendicular to the conveyance direction of the sheet P. As described above, a series of sheet position correction operations for correcting the deviation of the position in the width direction while transporting the sheet P is referred to as registration swing.

  The reverse conveyance path 24 branches from the main conveyance path 23 on the downstream side of the fixing unit 3, and includes a switching gate 23 a at a branch point between the main conveyance path 23 and the reverse conveyance path 24. The reverse conveyance path 24 includes a first reverse conveyance path 24 a that branches from the main conveyance path 23 and extends in a substantially horizontal direction below the main conveyance path 23. In the first reverse conveyance path 24a, the conveyance direction of the paper P is reversed from the arrow D1 direction to the arrow D2 direction.

  The reverse conveyance path 24 is branched upward from the first reverse conveyance path 24a with respect to the conveyance direction indicated by the arrow D2, and from the second reverse conveyance path 24b and the second reverse conveyance path 24b that bend in a substantially U shape. And a third reverse conveyance path 24c extending along the first reverse conveyance path 24a. Further, the reverse conveyance path 24 includes a fourth reverse conveyance path 24 d that bends in a substantially U shape from the third reverse conveyance path 24 c and joins the main conveyance path 23.

  In the image forming apparatus 1A, an image is formed on the surface of the paper P that has been transported through the main transport path 23 and has passed through the transfer nip portion 19 and the fixing portion 3 and directed upward. When images are formed on both sides of the sheet P, the sheet P on which an image is formed on one side facing upward is conveyed from the main conveyance path 23 to the first reverse conveyance path 24 a of the reverse conveyance path 24. The image forming surface faces downward.

  The sheet P transported to the first reverse transport path 24a is transported from the second reverse transport path 24b to the third reverse transport path 24c, so that the image forming surface faces upward. Then, the sheet P transported to the third reverse transport path 24c is transported from the fourth reverse transport path 24d to the main transport path 23, so that the image forming surface faces downward. As a result, the paper P is turned upside down, and an image can be formed on the other side facing upward.

  The fixing unit 3 is an example of a fixing unit, and performs a fixing process for fixing an image on the paper P onto which the image has been transferred. The fixing unit 3 includes a fixing roller 31 and a fixing roller 32 as a pair of fixing members arranged in pressure contact with each other, and a fixing nip portion 33 is formed by the fixing roller 31 and the fixing roller 32 being pressed against each other.

  The fixing unit 3 includes a fixing heater 34 that heats the fixing roller 31 as a heating unit that heats the fixing member. The fixing heater 34 is turned on by energization, and for example, a halogen lamp can be used. The fixing unit 3 conveys the paper P and fixes the image on the paper P by performing pressure fixing with the pair of fixing rollers 31 and 32 and heat fixing with the fixing heater 34.

  The toner collecting unit 4 is connected to a duct 40 attached to the image forming apparatus 1A. The duct 40 includes a first duct 40a provided corresponding to each of the image forming units 11Y, 11M, 11C, and 11BK, and a second duct 40b that collects the first ducts 40a into one air path. Each first duct 40a is provided at a position where toner scattered by the image forming units 11Y, 11M, 11C, and 11BK can be sucked.

  The toner collecting unit 4 includes a cyclone unit 41, a recovery unit 42, a filter unit 43, a blower unit 44, and a wind speed sensor 45. The cyclone unit 41 is an example of a centrifugal separator, and includes a separation unit 41a that generates an air flow for separating the toner from the toner-containing air, a toner collection path 41b that connects the separation unit 41a and the collection unit 42, and a separation unit 41a. And a cyclone section discharge air passage 41c that communicates with the filter section 43.

  The separation unit 41a communicates with the second duct 40b, and centrifuges the toner from the toner-containing air sucked from the image forming units 11Y, 11M, 11C, and 11BK through the duct 40. The separation unit 41a includes a wind path forming member that generates a rotating air flow and also has a cylindrical axial direction along the vertical direction in order to drop the centrifuged toner in the direction of gravity.

  The cyclone unit 41 generates a flow of air swirling by suction by the blower unit 44 at the separation unit 41a. Since the toner in the swirling toner-containing air moves radially outward by centrifugal force, most of the toner is centrifuged from the air. The separated toner falls downward due to its own weight, passes through the toner collection path 41b, and is stored in the collection unit 42.

  The cyclone discharge air passage 41 c includes a reversing unit that vertically reverses the flow direction of the air from which the toner has been separated, and introduces the air from which the toner has been separated into the filter unit 43.

The filter unit 43 is configured such that a plurality of filters, in this example, five filters 43a _{1 to} 43a ₅ can be attached to and detached from the exhaust air passage 43b communicating with the cyclone unit exhaust air passage 41c. The filter unit 43 collects the toner remaining in the air from which the toner has been centrifuged by the filters 43a ₁ to 43a ₅ and transmits the air.

Blowing section 44 is one example of the blowing means, to the flow of air through the exhaust air passage 43b, is provided in the discharge air passage 43b on the downstream side of the filter _43a 1 _{~43a 5.} Blower unit 44, a fan 44a, a motor for driving the fan 44a, which both generates a flow of air swirling in the separation portion 41a of the cyclone unit 41, the air passing through the filter _43a 1 _{~43a 5} outside of the apparatus to Discharge.

The wind speed sensor 45 is an example of the air volume detection means, and is provided in the exhaust air passage 43b between the filters 43a _{1 to} 43a ₅ and the blower 44, and the wind speed for calculating the air volume of the air that has passed through the filters 43a _{1 to} 43a _5. Is detected.

  The toner collecting unit 4 is configured to be detachable from the image forming apparatus 1A. As shown in FIG. 2, the cyclone unit 41 includes a separation unit 41 a, a toner collection path 41 b, and a cyclone unit discharge air path 41 c as one unit, and the cyclone installation unit 41 d of the toner collection unit 4 It is configured to be detachable.

  When the toner collecting unit 4 is attached to the image forming apparatus 1A and the cyclone unit 41 is attached to the toner collecting unit 4, the suction port 41e of the separation unit 41a of the cyclone unit 41 is connected to the second duct 40b of the duct 40. Communicate. Further, the cyclone exhaust air passage 41 c of the cyclone unit 41 communicates with the filter unit 43.

Furthermore, the filter unit 43, a plurality of the filters _43a 1 _{~43a 5} as one filter unit 43c, may be detachable to the filter mounting portion 43d of the filter unit 43. The filter unit 43 may be configured such that the plurality of filters 43a _{1 to} 43a ₅ can be attached to and detached from the toner collecting unit 4 independently.

<Example of Control Function of Image Forming Apparatus of Present Embodiment>
FIG. 3 is a functional block diagram illustrating an example of a control function of the image forming apparatus according to the present embodiment. In FIG. 3, on the basis of such a volume of the air passing through the filter _43a 1 _{~43a 5,} the replacement timing and control functions related to the operation of determining the replacement time of the cyclone part 41 of the filter _43a 1 _{~43a 5} Description To do.

  The image forming apparatus 1A includes a control unit 100 that performs a series of controls for feeding paper P, forming an image, and discharging the paper. The control unit 100 is an example of control means, and includes a microprocessor called CPU and MPU, and memory such as RAM and ROM as storage means.

  In addition, the image forming apparatus 1A includes an operation unit 101a as an operation unit that performs various operations and selection of the basis weight, size, paper type, and the like of the paper P.

  The normal operation of forming an image on the paper P by the image forming apparatus 1A will be described. The control unit 100 controls the paper transport unit 2 to transport the paper P. The control unit 100 controls the image forming unit 11 based on the image data acquired from the document by the document reading unit 10 or the image data acquired from the outside, and adjusts the image to the photosensitive drums Y, M, C, and BK. Then, an electrostatic latent image is formed, and the toner images are attached to the electrostatic latent images on the photosensitive drums Y, M, C, and BK by the developing devices 12Y, 12M, 12C, and 12BK, thereby forming toner images. The toner images formed on the photosensitive drums Y, M, C, and BK are primarily transferred to the intermediate transfer belt 16 and secondarily transferred from the intermediate transfer belt 16 to the paper P to form an image on the paper P. Then, the control unit 100 controls the fixing unit 3 to fix the image on the paper P, and discharges the paper P on which the image is formed.

Control unit 100 obtains the air volume information at the discharge air path 43b through which air having passed through the respective filters _43a 1 _{~43a 5,} it is determined whether or not it is necessary to exchange the filter _43a 1 _{~43a 5.} Furthermore, the control unit 100, after the operation replacing the filters _43a 1 _{~43a 5,} obtains the air volume information at the discharge air path 43 b, it is determined whether or not the interchangeable cyclone unit 41 is required.

In the toner collecting unit 4, all the toner cannot be separated from the toner-containing air in the cyclone unit 41, and a part of the toner is sucked into the cyclone unit discharge air passage 41 c and is adsorbed by the filters 43 a _{1 to} 43 a _5. The

The separation efficiency of the cyclone unit 41 is expressed by the following equation (1).
Separable toner amount / Aspirated toner amount (1)

The cyclone unit 41, to separate the toner from the toner containing air by centrifugal force, reduces the the separation efficiency centrifugal force decreases, the amount of toner is attracted to the filter 43a ₁ ~43a ₅ increases.

The centrifugal force acting on the toner in the cyclone unit 41 is expressed by the following equation (2).
Centrifugal force = particle (toner) weight × particle (toner) velocity squared / radius (2)

As described above, the toner that cannot be separated from the toner-containing air in the cyclone unit 41 is adsorbed by the filters 43a _{1 to} 43a ₅ . As the amount of toner adsorbed by the filters 43a _{1 to} 43a ₅ increases, the pressure loss in the discharge air passage 43b increases, and the air speed in the toner collecting portion 4 decreases.

  Here, since the speed of the particles can be regarded as the wind speed, it can be seen from the formula (2) that when the wind speed decreases, the centrifugal force decreases and the separation efficiency in the cyclone portion 41 decreases.

When the separation efficiency in the cyclone unit 41 decreases, the amount of toner that cannot be separated by the cyclone unit 41 and is sucked into the cyclone unit exhaust air passage 41c increases, and the amount of toner adsorbed by the filters 43a _{1 to} 43a ₅ increases. Further increase. Further, the amount of toner adhering to the wall surface in the cyclone discharge air passage 41c increases, the pressure loss in the cyclone discharge air passage 41c increases, and the wind speed in the toner collecting portion 4 decreases. Thereby, the separation efficiency in the cyclone part 41 further falls.

FIG. 4 is a graph showing the relationship between a plurality of filters and the amount of collected toner. The toner can not be separated from the toner-laden air in the cyclone unit 41, it is collected by suction on the first sheet of filter 43a _1, toner that has passed unable recovered in the first sheet of filter 43a ₁ is, the second sheet go adsorbed on the filter 43a _2. Thus, since the toner that cannot be separated from the toner-containing air adheres from the upstream filter, the amount of toner that cannot be separated by the cyclone portion 41 and is sucked into the cyclone discharge air passage 41c increases. As shown in FIG. 4, the toner adhesion amount increases from the upstream filter.

In the configuration of the filter unit 43 of this example, the separation efficiency in the cyclone unit 41 decreases, the amount of toner adsorbed by the filters 43a _{1 to} 43a ₅ increases, and the toner adhering to the _fifth filter 43a ₅ increases. When the amount exceeds the recovery allowable amount, the wind speed further decreases and the toner is discharged from the toner collecting unit 4 to the outside of the apparatus.

Even if the filters 43a _{1 to} 43a ₅ are replaced, the wind speed in the toner collecting unit 4 increases as the amount of toner adhering in the air path of the cyclone unit 41 such as the wall surface in the cyclone unit exhaust air channel 41c increases. It does not recover to the expected value, and the separation efficiency in the cyclone section 41 is not sufficiently improved.

Therefore, in the air volume information acquired in the exhaust air passage 43b through which the air after passing through the filters 43a _{1 to} 43a ₅ passes, whether or not the filter is replaced is increased as the amount of toner adhering to the filters 43a _{1 to} 43a ₅ increases. A filter replacement threshold Th ₁ to be determined is set. Further, as the amount of toner adhering to the air path of the cyclone unit 41 increases, a cyclone replacement threshold Th ₂ for determining whether or not the cyclone unit 41 is replaced is set.

  The acquisition of the air volume information in the discharge air path 43b is calculated from the wind speed information detected by the wind speed sensor 45, for example. A value obtained by multiplying the wind speed detected by the wind speed sensor 45 by the cross-sectional area of the exhaust air passage 43b is the air volume. In addition, when the arrangement location of the wind speed sensor 45 is determined, the wind speed itself detected by the wind speed sensor 45 may be used for determination.

Further, the acquisition of the air volume information in the exhaust air passage 43b can also be detected by the rotation speed of the fan 44a by the blower unit 44. In other words, contamination due to adhesion of the toner to the air passage of the cyclone unit 41, the pressure loss by contamination due to adhesion of the toner to the filter 43a ₁ ~43a ₅ is increased, air volume is reduced by the wind speed decreases as described above .

When the air volume decreases, the load applied to the blades of the fan 44a decreases, and the rotational speed of the fan 44a increases even if the motor 44b is controlled with a constant voltage or a constant current. Therefore, by detecting the rotational speed of the fan 44a in an example of a rotational speed detecting means rotation speed sensor 44c, airflow information changes in air volume due to the increase of the pressure loss in the filter 43a ₁ ~43a ₅ and the air path Can be obtained as

Therefore, the filter replacement threshold Th ₁ and the cyclone replacement threshold Th ₂ are set as values of air volume or wind speed. Alternatively, filter replacement threshold Th ₁ and the cyclone exchanger threshold Th ₂ is set at a rotation speed value of the fan 44a.

<Example of Control Function of Image Forming Apparatus of Present Embodiment>
FIG. 5 is a flowchart showing an example of the operation of the image forming apparatus according to the present embodiment, and FIG. 6 is a graph showing changes in the dirt and air volume of the cyclone unit and the filter. An operation example of the image forming apparatus 1A according to the present embodiment will be described.

Control unit 100, at step SA1 in FIG. 5, the air volume calculated from the wind speed detected by the wind velocity sensor 45, determines whether below the filter replacement threshold Th _1. Air volume to obtain the discharge air passage 43b of the air after passing through the filters _43a 1 _{~43a 5} passes is, it is determined to be below the filter replacement threshold Th _1, the control unit 100, in step SA2 of Fig. 5, the operation portion A filter replacement instruction for prompting replacement of the filter is output by display output at 101a, output by sound, or the like.

In step SA3 in FIG. 5, the control unit 100 performs the replacement operation of the filters 43a _{1 to} 43a ₅ by detecting filter replacement by a sensor (not shown) or inputting information on completion of filter replacement by the operation unit 101a. Judge that

When determining that the replacement operation of the filters 43a _{1 to} 43a ₅ has been performed, the control unit 100 determines whether the air volume calculated from the wind speed detected by the wind speed sensor 45 is below the cyclone replacement threshold Th ₂ in step SA4 of FIG. To do.

As shown in FIG. 6, an increase in the number of prints accompanying an image forming operation in the image forming apparatus ₁ </ b> A causes an increase in toner adhering to the filters 43 a _{1 to} 43 a ₅ and an increase in toner adhering to each air path of the cyclone unit 41. Accordingly, the air volume in the exhaust air passage 43b decreases. When the air volume acquired in the exhaust air path 43b falls below the filter replacement threshold Th ₁ and the filters 43a _{1 to} 43a ₅ are replaced, the air volume in the exhaust air path 43b increases.

However, pressure loss due to the toner adhering to each air passage of the cyclone portion 41 occurs, so that after the replacement of the filters 43a _{1 to} 43a ₅ according to the increase of the toner adhering to each air passage of the cyclone portion 41 as the number of prints increases. The air volume gradually decreases.

If the air volume does not recover even after the filters 43a _{1 to} 43a ₅ have been replaced, it is determined that the toner has adhered to each air path of the cyclone unit 41 and the life of the cyclone unit 41 has been reached.

Therefore, it is determined whether or not it is time to replace the cyclone unit 41 by obtaining the air volume after the replacement of the filters 43a _{1 to} 43a ₅ .

Control unit 100, the air volume to get the discharge air passage 43b after replacement of the filter _43a 1 _{~43a 5} is, when it is determined to be below the cyclone exchanger threshold Th _2, in step SA5 in FIG. 5, the display output of the operation unit 101a Then, a cyclone unit replacement instruction for prompting replacement of the cyclone unit 41 is output by voice output or the like.

  In step SA6 of FIG. 5, the control unit 100 performs the replacement operation of the cyclone unit 41 by detecting the replacement of the cyclone unit 41 by a sensor (not shown) or inputting information on the completion of the replacement of the cyclone unit by the operation unit 101a. Judge that it was broken.

  FIG. 7 is a flowchart showing another example of the operation of the image forming apparatus according to the present embodiment, and FIG. 8 is a graph showing changes in the cyclone section and filter contamination and fan rotation speed. With reference to the drawings, another operation example of the image forming apparatus 1A according to the present embodiment will be described.

Control unit 100, in step SB1 in FIG. 7, the rotation speed of the fan 44a of the blower unit 44 determines whether above a filter change threshold Th _1. Filter the rotational speed of the fan 44a is determined to exceed the filter replacement threshold Th _1, the control unit 100, at step SB2 in FIG. 7, prompting display output of the operation unit 101a, the output or the like by voice, the replacement of the filter Output replacement instructions.

In step SB3 of FIG. 7, the control unit 100 performs the replacement operation of the filters 43a _{1 to} 43a ₅ by detecting filter replacement by a sensor (not shown) or inputting information on completion of filter replacement by the operation unit 101a. Judge that

When determining that the replacement operation of the filters 43a _{1 to} 43a ₅ has been performed, the control unit 100 determines whether the rotational speed of the fan 44a exceeds the cyclone replacement threshold Th ₂ in step SB4 of FIG.

As shown in FIG. 8, the increase in the number of prints accompanying the image forming operation in the image forming apparatus ₁ </ b> A increases the toner adhering to the filters 43 a _{1 to} 43 a ₅ and increases the toner adhering to each air path of the cyclone unit 41. Accordingly, the rotational speed of the fan 44a increases. Rotational speed of the fan 44a exceeds the filter replacement threshold Th _1, when replacing the filter _43a 1 _{~43a 5,} the rotational speed of the fan 44a is reduced.

  However, pressure loss due to the toner adhering to each air passage of the cyclone portion 41 occurs, so that the rotation speed of the fan 44a gradually increases as the amount of toner adhering to each air passage of the cyclone portion 41 increases as the number of prints increases. To go.

Then, even after replacement of the filter 43a ₁ ~43a _5, when the rotational speed of the fan 44a is not restored, a state in which the toner adheres to the air path of the cyclone unit 41, if it is the life of the cyclone part 41 to decide.

Therefore, by obtaining the rotational speed of the fan 44a after replacement of the filter _43a 1 _{~43a 5,} it is determined whether it is time to replace the cyclone unit 41.

Control unit 100, the rotation speed of the fan 44a after replacement of the filter _43a 1 _{~43a 5} is, when it is determined to exceed the cyclone exchanger threshold Th _2, in step SB5 in FIG. 7, the display output of the operation unit 101a, the voice Or the like, a cyclone part replacement instruction for prompting replacement of the cyclone part 41 is output.

  In step SB6 of FIG. 7, the control unit 100 performs the replacement operation of the cyclone unit 41 by detecting the replacement of the cyclone unit 41 by a sensor (not shown) or inputting information on the completion of the replacement of the cyclone unit by the operation unit 101a. Judge that it was broken.

  FIG. 9 is a flowchart showing another example of the operation of the image forming apparatus according to the present embodiment. Hereinafter, another example of the operation of the image forming apparatus 1A according to the present embodiment will be described with reference to each drawing. explain.

Control unit 100, at step SC1 in FIG. 9, the air volume calculated from the wind speed detected by the wind velocity sensor 45, determines whether below the filter replacement threshold Th _1. Air volume to obtain the discharge air passage 43b of the air after passing through the filters _43a 1 _{~43a 5} passes is, it is determined to be below the filter replacement threshold Th _1, the control unit 100, at step SC2 of FIG. 9, the operation unit A filter replacement instruction for prompting replacement of the filter is output by display output at 101a, output by sound, or the like.

In the case of determining the replacement timing of the filter from the rotational speed of the fan 44a, when the rotational speed of the fan 44a is determined to exceed the filter replacement threshold Th _1, and outputs the filter replacement instructions to prompt the user to exchange the filter.

In step SC3 of FIG. 9, the control unit 100 performs the replacement operation of the filters 43a _{1 to} 43a ₅ by detecting filter replacement with a sensor (not shown) or inputting information on completion of filter replacement at the operation unit 101a. Judge that

Control unit 100, at step SC4 in FIG. 9, the count value of the period from the replacement of the previous filter _43a 1 _{~43a 5} to replace the current filter _43a 1 _{~43a 5,} a predetermined section, such as per a paper The filter replacement cycle T is calculated by dividing by the average printing rate.

When determining that the replacement operation of the filters 43a _{1 to} 43a ₅ has been performed, the control unit 100 sets the number of prints per print rate as the cyclone replacement threshold Th ₂ in step SC5 of FIG. It is judged whether the number of prints per unit is lower.

As shown in FIG. 6, an increase in the number of prints accompanying an image forming operation in the image forming apparatus ₁ </ b> A causes an increase in toner adhering to the filters 43 a _{1 to} 43 a ₅ and an increase in toner adhering to each air path of the cyclone unit 41. Accordingly, the air volume in the exhaust air passage 43b decreases. When the air volume acquired in the exhaust air path 43b falls below the filter replacement threshold Th ₁ and the filters 43a _{1 to} 43a ₅ are replaced, the air volume in the exhaust air path 43b increases.

Further, as shown in FIG. 8, the increase in the number of prints accompanying the image forming operation in the image forming apparatus ₁ </ b> A causes an increase in toner adhering to the filters 43 a _{1 to} 43 a ₅ and a toner adhering to each air path of the cyclone unit 41. As the speed increases, the rotational speed of the fan 44a increases. Rotational speed of the fan 44a exceeds the filter replacement threshold Th _1, when replacing the filter _43a 1 _{~43a 5,} the rotational speed of the fan 44a is reduced.

  However, pressure loss due to the toner adhering to each air passage of the cyclone portion 41 occurs, so that the filter replacement cycle T becomes shorter as the toner adhering to each air passage of the cyclone portion 41 with the increase in the number of prints. Therefore, by acquiring the filter replacement cycle T, it is determined whether or not it is time to replace the cyclone unit 41.

Control unit 100, the replacement cycle T of the filter is determined to be below the cyclone exchanger threshold Th _2, in step SC5 of FIG. 9, the display output of the operation unit 101a, the output or the like by voice, the replacement of the cyclone part 41 Outputs prompt cyclone replacement instructions.

  In step SC6 of FIG. 9, the control unit 100 performs the replacement operation of the cyclone unit 41 by detecting the replacement of the cyclone unit 41 by a sensor (not shown) or inputting the information on the completion of the replacement of the cyclone unit by the operation unit 101a. Judge that it was broken.

As described in the operation example described above, by exchanging operation of the filter _43a 1 _{~43a 5} based on filter replacement threshold Th ₁ is done, the filter 43a at an appropriate timing in accordance with dirt filter _43a 1 _{~43a 5 1 to} 43a ₅ are exchanged. Further, since the exchanging operation of the cyclone unit 41 on the basis of the cyclone exchanger threshold Th ₂ is performed, a cyclone 41 is replaced at a proper timing in accordance with the dirt of the cyclone unit 41. Then, when both filters _43a 1 _{~43a 5} a cyclone unit 41 is replaced, the air volume to obtain the discharge air passage 43b is restored to the desired value.

  Thereby, it is possible to suppress the use in a state where the toner separation efficiency is lowered. Further, when only the filter needs to be replaced, it is possible to appropriately determine when the cyclone unit and the filter need to be replaced, thereby reducing the operation cost. Furthermore, it is possible to suppress an increase in filter replacement frequency due to a decrease in toner separation efficiency, to reduce the filter replacement frequency, and to reduce the operation cost.

  The present invention is applied to an image forming apparatus that charges a sheet and transfers a toner image.

  DESCRIPTION OF SYMBOLS 1A ... Image forming apparatus, 2 ... Paper conveyance part, 3 ... Transfer part, 4 ... Toner collection part, 100 ... Control part

Claims (5)

Image forming means for transferring toner to paper to form an image;
Fixing means for fixing an image on a sheet on which an image is formed by the image forming means;
A toner collecting means for sucking the toner-containing air in the apparatus and collecting the toner;
The toner collecting means includes
A cyclone unit for centrifuging the toner from the toner-containing air, a recovery unit for collecting the toner separated by the cyclone unit, and a filter for passing the air separated by the cyclone unit and collecting residual toner A filter unit having a blower unit for sucking air;
Based on the air volume information of the air after passing through the filter, determining the replacement time of the filter,
An image forming apparatus comprising: a control unit that determines a replacement timing of the cyclone unit based on state information of the toner collecting unit after the filter replacement. The image forming apparatus according to claim 1, wherein the control unit obtains air volume information of air after passing through the filter by an air volume detection unit provided in the filter unit. The image forming apparatus according to claim 1, wherein the control unit obtains air volume information of air after passing through the filter from a rotation speed of a fan of the air blowing unit. 4. The image forming apparatus according to claim 2, wherein the control unit acquires state information of the toner collecting unit after filter replacement by an air volume detection unit provided in the filter unit. 5. The image forming apparatus according to claim 2, wherein the control unit acquires status information of the toner collecting unit after filter replacement from a filter replacement cycle.

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