This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2018-131223 filed Jul. 11, 2018 and Japanese Patent Application No. 2018-165236 filed Sep. 4, 2018.
The present disclosure relates to particle collecting devices and image forming apparatuses.
Japanese Unexamined Patent Application Publication No. 2016-162759 (paragraphs [0002] and [0034] to [0036], FIG. 6) describes a known technology in the related art for filtering exhaust air by collecting particles therefrom using a collector, such as a filter, and then discharging the air into the atmosphere.
Japanese Unexamined Patent Application Publication No. 2016-162759 describes an electric-apparatus option device including a duct for causing exhaust air from multiple exhaust ports of an electric apparatus to merge and discharging the exhaust air into the atmosphere from a single outlet, a filter and an electric fan contained in front of the outlet of the duct, an airflow sensor that detects whether or not the exhaust air is discharged from one of the multiple exhaust ports, and a controller that controls the operation of the electric fan based on an output of the airflow sensor. In the option device, the airflow sensor is disposed in the exhaust port with the highest exhaust speed among the multiple exhaust ports.
Aspects of non-limiting embodiments of the present disclosure relate to a particle collecting device and an image forming apparatus that may collect particles while preventing the particles from leaking outside a vent pipe.
Aspects of certain non-limiting embodiments of the present disclosure address the above advantages and/or other advantages not described above. However, aspects of the non-limiting embodiments are not required to address the advantages described above, and aspects of the non-limiting embodiments of the present disclosure may not address advantages described above.
According to an aspect of the present disclosure, there is provided a particle collecting device including a vent pipe, a first air blower, a collector, and a second air blower. The vent pipe has a channel space through which air flows. The first air blower delivers air including a particle at a first end of the vent pipe into the channel space. The collector is disposed to block a channel in the channel space at an intermediate part of the vent pipe and collects the particle included in the air delivered by the first air blower. The second air blower collects the air traveling through the collector at a second end of the vent pipe and delivers the air from the channel space. The first air blower and the second air blower operate such that a first pressure in a first channel space extending from the first air blower to the collector and a second pressure in a second channel space extending from the collector to the second air blower are maintained to have a relationship in which the second pressure<the first pressure≤atmospheric pressure. The first channel space and the second channel space are included in the channel space of the vent pipe.
Exemplary embodiments of the present disclosure will be described in detail based on the following figures, wherein:
Exemplary embodiments of the present disclosure will be described below with reference to the drawings.
First Exemplary Embodiment
Reference signs X, Y, and Z in the drawings indicate the width, height, and depth directions, respectively, in a three-dimensional space assumed in the drawings. Furthermore, in
Overall Configuration of Image Forming Apparatus
The image forming apparatus 1 employs electrophotography to form an image onto a sheet 9 as an example of a recording medium. For example, the image forming apparatus 1 according to the first exemplary embodiment serves as a printer that forms an image corresponding to image information acquired from an external apparatus, such as an information terminal. The image information constitutes a text, graphic, pattern, or photographic image.
As shown in
The housing 10 is a box-shaped structural object and is constituted of various types of support members and facing materials. An operable unit 12 is disposed outside the housing 10. For example, the operable unit 12 includes a display unit that displays various types of information, as well as an input unit used for performing a selecting operation and an input operation. A controller 14 is disposed inside the housing 10. The controller 14 has a function of comprehensively controlling various types of operation in the image forming apparatus 1. The controller 14 is constituted of, for example, an arithmetic processing circuit, a storage unit, an input-output unit, and a control unit that controls these units.
The image forming device 2 employs electrophotography to form a toner image constituted of a toner as a developer. As shown in
The four image forming units 20 (Y, M, C, and K) each have a photoconductor drum 21 as an example of a photoconductor that is driven so as to rotate in the direction indicated by an arrow A. Each photoconductor drum 21 is surrounded by devices, such as a charging device 22, an exposure device 23, a developing device 24 (Y, M, C, or K), a first-transfer device 25, and a first cleaning device 26. Although the reference signs 21 to 26 are all indicated for the image forming unit 20K in
The charging device 22 electrostatically charges the outer peripheral surface serving as an image formation region of the photoconductor drum 21 to a predetermined potential. For example, the charging device 22 includes a charging member, such as a roller, that is brought into contact with the image formation region on the outer surface of the photoconductor drum 21 and that is supplied with a charging current. The exposure device 23 radiates light generated from the image information onto the electrostatically-charged outer peripheral surface of the photoconductor drum 21 so as to form an electrostatic latent image of the corresponding color component. The exposure device 23 operates by receiving an image signal obtained by an image processor (not shown) separating the image information input from the outside into color components of the four colors (Y, M, C, and K). The developing device 24 (Y, M, C, or K) develops the electrostatic latent image of the color component formed on the corresponding photoconductor drum 21 by supplying a toner of the color corresponding to that color component to the electrostatic latent image, so as to obtain a visible toner image of any one of the four colors (Y, M, C, and K).
The first-transfer device 25 first-transfers the toner image formed on the photoconductor drum 21 in the corresponding image forming unit 20 (Y, M, C, or K) to the intermediate transfer unit 3. The first-transfer device 25 includes a first-transfer member, such as a roller, that comes into contact with the outer peripheral surface of the photoconductor drum 21 via, for example, an intermediate transfer belt 31 to be described later and that is supplied with a first-transfer current. The first-transfer device 25 constitutes a part of the intermediate transfer unit 3, which will be described later. The first cleaning device 26 cleans the outer peripheral surface of the photoconductor drum 21 by removing waste, such as toner, therefrom.
The intermediate transfer unit 3 temporarily retains and transports the toner images first-transferred from the image forming units 20 (Y, M, C, and K) in the image forming device 2, and ultimately second-transfers the toner images onto the sheet 9. As shown in
The intermediate transfer belt 31 is an annular belt capable of retaining toner images by an electrostatic effect. The intermediate transfer belt 31 is supported in a state where it receives predetermined tension from multiple support rollers 32a to 32e such that the intermediate transfer belt 31 rotates (revolves) while sequentially passing through first-transfer positions where the image forming units 20 (Y, M, C, and K) perform a first-transfer process. Furthermore, the intermediate transfer belt 31 is rotationally driven in the direction indicated by an arrow B by the support roller 32a as a drive roller. The first-transfer positions are where the intermediate transfer belt 31 and the first-transfer devices 25 face each other.
The above-described first-transfer devices 25 in the image forming units 20 (Y, M, C, and K) are disposed at the inner peripheral side of the intermediate transfer belt 31. A second-transfer device 35 and a second cleaning device 36 are disposed at the outer peripheral side of the intermediate transfer belt 31.
The second-transfer device 35 second-transfers the toner images first-transferred on the outer peripheral surface of the intermediate transfer belt 31 onto the sheet 9. The second-transfer device 35 includes, for example, a second-transfer member, such as a roller, that comes into contact with the outer peripheral surface of the intermediate transfer belt 31 supported by the support roller 32d as a second-transfer backup roller. The support roller 32d and the second-transfer member are supplied with a second-transfer current. The second cleaning device 36 cleans the outer peripheral surface of the intermediate transfer belt 31 by removing waste, such as toner, therefrom.
The sheet feeding unit 4 accommodates therein sheets 9 to be used for image formation and also feeds each sheet 9 to the second-transfer position where a second-transfer process is performed by the intermediate transfer unit 3. As shown in
For example, the sheet container 41 is attached to the housing 10 in a withdrawable manner and accommodates sheets 9 of desired sizes and types in a stacked state on a stacking plate (not shown). The feeding device 43 feeds the sheets 9 one-by-one from the sheet container 41. The sheets 9 may be of any type of media that may be transported along the transport path in the housing 10 and on which toner images may be retained and fixed. Examples of such media that may be used include plain paper, coated paper, and cardboard.
The fixing unit 5 fixes the toner images, which are unfixed images, transferred on the sheet 9 onto the sheet 9. As shown in
The thermal rotating member 52 is a structural object of a roller type, a belt type, or a belt-nip type. The thermal rotating member 52 is supported while being heated to a predetermined temperature by a heater (not shown) and rotationally driven in the direction indicated by the arrow by a driver (not shown). The pressure rotating member 53 is a structural object of a roller type, a belt type, or a belt-nip type. The pressure rotating member 53 is disposed in contact with the thermal rotating member 52 with a predetermined pressure by a pressurizing unit (not shown), and is supported so as to be slave-rotated in accordance with the rotation of the thermal rotating member 52.
In the fixing unit 5, a region where the thermal rotating member 52 and the pressure rotating member 53 are in contact with each other serves as a fixing section (fixing nip section) FN where the sheet 9 having the toner images transferred thereon travels through so as to undergo a fixing process by receiving heat and pressure.
As shown in
For example, a sheet-feed transport path Rt1 along which the sheet 9 fed from the sheet feeding unit 4 is transported to the second-transfer position is provided between the sheet feeding unit 4 and the second-transfer position of the intermediate transfer unit 3. The sheet-feed transport path Rt1 includes, for example, multiple transport rollers 45a to 45d and multiple transport guide members (not shown).
Furthermore, a relay transport path Rt2 along which the sheet 9 having undergone the second-transfer process is transported to the fixing unit 5 is provided between the fixing unit 5 and the second-transfer position of the intermediate transfer unit 3. The relay transport path Rt2 includes, for example, sheet transport devices 46a and 46b of belt transport types.
Moreover, an output transport path Rt3 along which the sheet 9 having undergone the fixing process is transported to a sheet outlet 11 in the housing 10 is provided between the fixing unit 5 and the sheet outlet 11. The output transport path Rt3 includes, for example, transport rollers 47a and 47b and a transport guide member (not shown).
According to the image forming apparatus 1 having the above-described configuration, various types of images to be described below may be formed (printed) by selectively actuating the four image forming units 20 (Y, M, C, and K) in the image forming device 2.
For example, by actuating all of the image forming units 20 (Y, M, C, and K), a multicolor image, that is, a so-called full-color image, constituted of a combination of toners of four colors (Y, M, C, and K) may be formed on the sheet 9 via the intermediate transfer unit 3 and the fixing unit 5. Furthermore, by actuating any one of the image forming units 20 (Y, M, C, and K), a monochromatic image constituted of a toner of a single color may be formed on the sheet 9 via the intermediate transfer unit 3 and the fixing unit 5. Moreover, by actuating two or three of the image forming units 20 (Y, M, C, and K), a multicolor image constituted of toners of multiple colors, other than a full-color image, may be similarly formed.
Configuration Related to Particle Collector
The particle collecting device 6 described above collects particles generated from the fixing unit 5 and the vicinity thereof in the image forming apparatus 1.
For example, the particles to be collected by the particle collecting device 6 are generated when a component, such as wax, contained in toner vaporizes by being heated during the fixing process and is subsequently cooled, and each have a particle diameter of 1 μm. The particles desirably include so-called ultra fine particles (UFP) with a particle diameter of 0.1 μm or smaller or smaller than 0.1 μm.
As shown in
The vent pipe 61 is a structural object having a channel space 60 that allows air to flow therethrough.
As shown in
The vent pipe 61 extends upward from a rear end of the housing 51 in the fixing unit 5 along a rear inner wall of the housing 10 in the image forming apparatus 1 and extends to a position in front of an exhaust port 13 (
More specifically, as shown in
As shown in
Furthermore, as shown in
Furthermore, as shown in
The first air blower 62 blows air including particles at the first end of the vent pipe 61 into the channel space 60.
It is desirable that the first air blower 62 have performance for efficiently collecting particles generated in the fixing unit 5 and the vicinity thereof together with air and for blowing the air and the particles into the channel space 60 of the vent pipe 61.
In the first exemplary embodiment, the first air blower 62 used is an axial fan. Furthermore, in the first exemplary embodiment, the first air blower 62 is disposed in the widest part of the channel space 60 in the expanded lower-end section 61A of the vent pipe 61.
For example, as shown in
The collector 63 is disposed to block the channel in the channel space 60 at an intermediate part of the vent pipe 61, and collects particles included in air blown in by the first air blower 62.
In the first exemplary embodiment, the collector 63 is disposed so as to extend crosswise across the channel space 60 at a substantially intermediate position thereof in the expanded upper-end section 61B of the vent pipe 61. The collector 63 has a relatively long shape in one of the crosswise directions. This crosswise direction of the collector 63 is a longitudinal direction C of the collector 63.
In the first embodiment, the collector 63 used has performance for collecting particles included in air, particularly, ultra fine particles. In detail, the collector 63 used is a filter having a relatively high initial pressure loss (e.g., 50 Pa or higher when the flow rate is 1 m/s) and having a particle collection efficiency of 95% or higher.
Furthermore, as shown in
The second air blower 64 collects air traveling through the collector 63 at the second end of the vent pipe 61 and blows out the air from the channel space 60.
The second air blower 64 desirably has performance for setting the channel space 60 of the vent pipe 61 to negative pressure. The second air blower 64 desirably includes a housing having an inner wall surface to which particles not collected by the collector 63 may adhere, and is desirably of a type that generates a flow of air that strikes against the inner wall surface of the housing. An example of such a second air blower 64 used includes a multi-blade centrifugal fan.
In the first exemplary embodiment, a sirocco fan, which is one example of a multi-blade centrifugal fan, is used as the second air blower 64.
Furthermore, in the first exemplary embodiment, the second air blower 64 is disposed facing the outlet 67 provided in an upper surface 61Ba of the expanded upper-end section 61B of the vent pipe 61.
Moreover, as shown in
For example, as shown in
The sirocco fan is disposed such that the intake hole 641a of the housing 641 faces the outlet 67 in the vent pipe 61. Although the exhaust passage 641b of the housing 641 in the sirocco fan is configured to discharge air along the upper surface 61Ba of the expanded upper-end section 61B of the vent pipe 61, as shown in
As shown in
Strictly speaking, the atmospheric pressure is the pressure outside the vent pipe 61 when the particle collecting device 6 is operating and is substantially equal to the atmospheric pressure outside the housing 10 of the image forming apparatus 1. The first pressure (P1) is desirably a lower pressure (negative pressure) than the atmospheric pressure or may be equal to the atmospheric pressure. The second pressure (P2) may be lower than the first pressure (P1).
The first pressure (P1) is measured by a first pressure measuring unit 71 disposed within the first channel space 60A. The second pressure (P2) is measured by a second pressure measuring unit 72 disposed within the second channel space 60B. For example, internal pressure gauges capable of measuring negative pressure are used as the first pressure measuring unit 71 and the second pressure measuring unit 72.
Furthermore, the first air blower 62 and the second air blower 64 in the particle collecting device 6 operate such that a first air quantity (Q1) of the first air blower 62 and a second air quantity (Q2) of the second air blower 64 are maintained to have the relationship “Q1<Q2”.
The first air quantity (Q1) is obtained in accordance with the rotation speed of the first air blower 62. The second air quantity (Q2) is obtained in accordance with the rotation speed of the second air blower 64. Therefore, the first air quantity (Q1) and the second air quantity (Q2) are adjustable by changing the rotation speed of the first air blower 62 and the rotation speed of the second air blower 64.
Each of the first air quantity (Q1) and the second air quantity (Q2) is normally a quantity of air moved per unit time and is a numerical value (m3/h) obtained as a multiplier of a passing wind speed (m/s) and a passing area (m2). The first air quantity (Q1) and the second air quantity (Q2) in the particle collecting device 6 are measured by using, for example, measuring units, such as anemometers.
As shown in
The controller 70 has a configuration identical to that of the controller 14 in the image forming apparatus 1 and is configured as a control system independent of the controller 14 or operates as a part of the controller 14. In a case where the controller 70 is a control system independent of the controller 14, the initiation and termination of the operation of the controller 70 are controlled by the controller 14.
As shown in
The first pressure measuring unit 71 and the second pressure measuring unit 72 are constituted of the aforementioned internal pressure gauges disposed within the first channel space 60A and the second channel space 60B, respectively. The PV-information acquiring unit 15 receives PV information counted by the controller 14 of the image forming apparatus 1 and stored in the storage unit.
As shown in
During air blowing operation, the air-blower drive controller 75 controls the operation of a drive motor 625 that drives the first air blower 62 and the operation of a drive motor 645 that drives the second air blower 64, and is also capable of specifically controlling the rotation speeds of the drive motors 625 and 645.
As shown in
Examples of the information processing function include a calculator 76 that calculates a pressure difference ΔP between the first pressure (P1) and the second pressure (P2), an adjuster 77 that adjusts the rotation speeds of the first air blower 62 and the second air blower 64 during the air blowing operation, and a lifespan detector 78 that detects whether the filter serving as the collector 63 has reached its pre-lifespan and provisional lifespan.
The calculator 76 for the pressure difference ΔP calculates the pressure difference ΔP (=P1−P2) from the first pressure (P1) obtained from the first pressure measuring unit 71 and the second pressure (P2) obtained from the second pressure measuring unit 72.
The rotation-speed adjuster 77 functions to adjust the rotation speeds of the drive motors 625 and 645 during the air blowing operation so that the pressure difference ΔP obtained by the calculator 76 is maintained within a fixed range set in advance. Although the adjuster 77 desirably adjusts the rotation speeds of both the drive motors 625 and 645 of the first air blower 62 and the second air blower 64, the adjuster 77 may adjust only the rotation speed of the drive motor 645 of the second air blower 64, as described below, so long as the pressure difference ΔP may be maintained within the fixed range.
Moreover, the lifespan detector 78 for the pre-lifespan and the provisional lifespan of the filter detects a time point at which the rotation speeds obtained from the adjuster 77 reach predetermined rotation speeds corresponding to a preset pre-lifespan and a preset provisional lifespan. The pre-lifespan is set to, for example, a time point at which the collection efficiency of the filter decreases by a predetermined rate from an initial value. The provisional lifespan is set to, for example, a time point at which the collection efficiency of the filter further decreases by a predetermined rate from the pre-lifespan value. Data D1 of the predetermined rotation speeds for the pre-lifespan and the provisional lifespan used in the lifespan detector 78 are stored in the storage unit 73.
Furthermore, as shown in
The front channel-space section 60C is partially provided with the aforementioned inlet 66 that allows air in the first channel space 60A to actually flow into the front channel-space section 60C. Moreover, the front channel-space section 60C is capable of causing air to uniformly come into contact with the entire filter serving as the collector 63 in the longitudinal direction C thereof, and tentatively increases the thickness of the filter.
As shown in
In the first exemplary embodiment, a rectangular opening is provided as the inlet 66, and the inlet 66 extends from one end of the front channel-space section 60C in the expanded upper-end section 61B of the vent pipe 61 in the longitudinal direction C of the collector 63 to a substantially middle position in the longitudinal direction C. Furthermore, in the first exemplary embodiment, a circular opening is provided as the outlet 67, and the outlet 67 is provided in an offset fashion near the other end of the expanded upper-end section 61B of the vent pipe 61 in the longitudinal direction C of the collector 63.
As shown in
Moreover, the front channel-space section 60C is configured such that a distance H2 between the collector 63 and an inner wall surface 68a of the second space section 60Cb that faces the collector 63 is smaller than a distance H1 between the collector 63 and an inner wall surface 61Bc of the first space section 60Ca that faces the collector 63 (H2<H1).
The distance H2 in the second space section 60Cb is set to a value of, for example, 2 cm or smaller.
As shown in
The raised section 68 has a slope 68b that is located at an end serving as a boundary with the first space section 60Ca and that is inclined so as to continuously rise toward the inner wall surface 68a of the raised section 68 from the inner wall surface 61Bc of the first space section 60Ca.
Operation of Particle Collecting Device
For example, the particle collecting device 6 having the above-described configuration operates as follows.
The particle collecting device 6 operates in conjunction with the operation of the image forming apparatus 1 at least during a period in which the image forming apparatus 1 is operating.
In detail, the particle collecting device 6 operates by causing the controller 70 to drive the drive motor 625 for the first air blower (axial fan) 62 and the drive motor 645 for the second air blower (sirocco fan) 64.
In the particle collecting device 6, the rotation speeds of the first air blower 62 and the second air blower 64 are controlled by the controller 70 so that the first pressure P1 in the first channel space 60A of the vent pipe 61 and the second pressure P2 in the second channel space 60B of the vent pipe 61 are maintained to have the aforementioned specific relationship (P2<P1≤atmospheric pressure).
Furthermore, in the particle collecting device 6, the controller 70 controls the rotation speeds of the first air blower 62 and the second air blower 64 so that the air quantity Q1 of the first air blower 62 and the air quantity Q2 of the second air blower 64 are maintained to have the aforementioned specific relationship (Q1<Q2). In particular, the first air blower 62 and the second air blower 64 operate such that the relationship Q1<Q2 is maintained, whereby the aforementioned relationship “P2<P1≤atmospheric pressure” may be achieved relatively easily, as compared with a case where the air blowers do not operate in accordance with that relationship. As shown in
As shown in
In this case, because the first air blower 62 is an axial fan, the air including the particles is efficiently collected and is delivered to the first channel space 60A, as compared with a case where the first air blower 62 is not an axial fan.
Subsequently, as shown in
In this case, the particles included in the air are collected by the collector 63 as the air passes through the collector 63. Consequently, the air delivered from the second air blower 64 becomes filtered air with no particles.
Supposing that there is a particle not collected by the collector 63, since the second air blower 64 is a sirocco fan, the particle is carried to the inner wall surface of the housing 641 by striking against the inner wall surface or coming into contact with the inner wall surface together with the air due to a centrifugal force produced by the rotation of the multi-blade rotating section 643 of the sirocco fan, as compared with a case where the second air blower 64 is not a sirocco fan. As a result, the particle is captured by adhering to the inner wall surface of the accommodation space in the housing 641 or the inner wall surface of the exhaust passage 641b.
Accordingly, the particle collecting device 6 operates such that the first pressure P1 in the first channel space 60A and the second pressure P2 in the second channel space 60B in the vent pipe 61 are maintained to have the relationship “P2<P1≤atmospheric pressure”, so that the air including the particles generated in the fixing unit 5 passes through the collector 63 without leaking from the vent pipe 61, whereby the particles included in the air are collected by the collector 63.
As shown in
In this case, the air (E2) flowing into the front channel-space section 60C is dispersed within the front channel-space section 60C, which is wider than the inlet 66, before reaching the collector 63, as indicated by arrows E3a, E3b, and E3c in
Accordingly, in the particle collecting device 6, the entire collector 63 is effectively utilized in the longitudinal direction C thereof, whereby the particles may be efficiently collected.
The air (E2) flowing into the front channel-space section 60C receives the air blowing (suction) effect of the second air blower 64 through the outlet 67 disposed in an offset fashion near the end different from the inlet 66 in the longitudinal direction C of the collector 63.
Accordingly, in the particle collecting device 6, the air passing through the collector 63 moves diagonally through the collector 63 relative to the longitudinal direction C, as indicated by an arrow E6 in
Furthermore, the raised section 68 is provided in the second space section 60Cb where the inlet 66 does not exist such that the space between the raised section 68 and the collector 63 is smaller than the first space section 60Ca where the inlet 66 exists. Thus, the air (E2) flowing into the front channel-space section 60C is less likely to flow into the second space section 60Cb, as compared with the first space section 60Ca.
Accordingly, in the particle collecting device 6, the air passing through the collector 63 is more likely to move diagonally through the collector 63, as indicated by the arrow E6 in
Furthermore, in this particle collecting device 6, the second space section 60Cb is provided with the raised section 68, so that the collector 63 may be prevented from being locally clogged with particles, as will be described below.
Specifically, supposing that the second space section 60Cb is not provided with the raised section 68, the air blowing (suction) effect of the second air blower 64 acts relatively strong on an area of the collector 63 that faces the outlet 67 via the outlet 67 located in an offset fashion at one end in the longitudinal direction C of the collector 63. Therefore, a large quantity of air passes through this area of the collector 63 that faces the outlet 67, thus causing this area to collect particles in a concentrated manner so as to be locally clogged with particles.
In contrast, in this particle collecting device 6, the air flowing into the front channel-space section 60C is relatively less likely to flow toward the second space section 60Cb provided with the raised section 68, as compared with the first space section 60Ca. As a result, the percentage of air passing through the area of the collector 63 that faces the outlet 67 decreases, so that a state where this area is locally clogged with particles due to collecting particles in a concentrated manner is less likely to occur.
In addition, in this particle collecting device 6, the channel length of the first channel space 60A in the vent pipe 61 is larger than the channel length of the second channel space 60B.
Accordingly, the air including the particles delivered into the first channel space 60A of the vent pipe 61 in accordance with the air blowing effect of the first air blower 62 is retained for a relatively longer period of time in the first channel space 60A than in the second channel space 60B. Therefore, in the particle collecting device 6, the particles included in the air come into contact with the inner wall surface of the first channel space 60A at an increased percentage before passing through the collector 63, as compared with a case where the channel length of the first channel space 60A is smaller than the channel length of the second channel space 60B, whereby the particles are more likely to be captured by adhering to the inner wall surface.
Then, in the particle collecting device 6, the rotation speeds of the first air blower 62 and the second air blower 64 are controlled by the controller 70 in the following manner.
Specifically, in the particle collecting device 6, the pressure difference ΔP calculator 76 in the controller 70 calculates a pressure difference ΔP (=P1−P2) by using measurement information about the first pressure P1 and the second pressure P2 respectively measured by the first pressure measuring unit (measuring unit) 71 and the second pressure measuring unit (measuring unit) 72, and the rotation-speed adjuster 77 in the controller 70 adjusts the rotation speed of the first air blower 62 and the rotation speed of the second air blower 64 by appropriate amounts so that the calculated pressure difference ΔP is set within a predetermined fixed numerical range.
As shown in
The fixed numerical range for the pressure difference Δ is demanded for maintaining a difference value in the relationship “P2<P1” set in advance based on the relationship “P2<P1≤atmospheric pressure”. In this case, although the rotation speeds of both the first air blower 62 and the second air blower 64 are adjusted, the air quantity Q1 of the first air blower 62 and the air quantity Q2 of the second air blower 64 are adjusted so that the aforementioned relationship “Q1<Q2” is maintained in either adjustment stage.
Furthermore, because particles tend to be generated in the fixing unit 5 the most when the fixing unit 5 is new, the particle collecting device 6 executes an “initial collection mode” of controlling both the first air blower 62 and the second air blower 64 in accordance with that timing such that the rotation speeds thereof are maintained in a relatively high range, as shown in
This initial collection mode ends when, for example, the print volume (PV) of printed sheets reaches a predetermined sheet value from the start point of use of the new fixing unit 5. This end timing is determined by the controller 70 acquiring and detecting information about the print volume from the PV-information acquiring unit 15. The predetermined sheet value is set to, for example, 2,800 sheets.
In the particle collecting device 6, control is performed based on this initial collection mode so that a large number of particles generated when the fixing unit 5 is new are properly collected.
After the control period of the initial collection mode, the number of particles generated in the fixing unit 5 tends to start decreasing in the particle collecting device 6. Therefore, the particle collecting device 6 executes a “collection reduction mode” of controlling both the first air blower 62 and the second air blower 64 in accordance with that timing such that the rotation speeds thereof change in the decreasing direction, as shown in
In this collection reduction mode, the rotation speeds of both the first air blower 62 and the second air blower 64 are continuously decreased at a fixed rate at a predetermined timing or are decreased in a stepwise fashion in accordance with the PV information. The collection reduction mode ends when, for example, the information about the print volume reaches a predetermined sheet value different from the predetermined sheet value for the initial collection mode.
In the particle collecting device 6, control is performed based on this collection reduction mode so that particles are appropriately collected in correspondence with the generation status of particles.
Alternatively, this collection reduction mode may be omitted. In this case, a transition is immediately made to a low-noise low-power collection mode upon completion of the initial collection mode.
After the control period of the collection reduction mode (or the initial collection mode), the number of particles generated in the fixing unit 5 decreases in the particle collecting device 6. Therefore, the particle collecting device 6 executes a “low-noise low-power collection mode” of controlling both the first air blower 62 and the second air blower 64 in accordance with that timing such that the rotation speeds thereof are maintained at relatively-low minimal values selected from the standpoint of prioritizing low noise and low power consumption, as shown in
In the low-noise low-power collection mode, the first air blower 62 and the second air blower 64 are similarly controlled for adjusting the rotation speeds thereof such that the pressure difference ΔP is maintained within a fixed range. This point is similar to the case of the above-described collection reduction mode and other collection modes to be described later.
Furthermore, as shown in
In the particle collecting device 6, control is performed based on this low-noise low-power collection mode so that particles are appropriately collected while low noise and low power consumption are achieved.
The lifespan detector 78 provided in the controller 70 for detecting whether the filter has reached its pre-lifespan and provisional lifespan detects that the filter has reached its pre-lifespan. In this case, as shown in the upper part of
The predetermined rotation speed for the pre-lifespan in this case is set as a rotation speed corresponding to a timing at which the collection efficiency of the filter is predicted to decrease by about 10% from the initial value with reference to actual measurement results obtained from tests.
Furthermore, it is determined that the filter has reached its pre-lifespan by detecting that the rotation speed of the second air blower 64 has reached the predetermined rotation speed. Alternatively, it may be determined that the filter has reached its pre-lifespan by detecting that the rotation speed of the first air blower 62 and the rotation speed of the second air blower 64 have individually reached predetermined separately-set rotation speeds.
After the control period of the low-noise low-power collection mode, the collection efficiency of the filter serving as the collector 63 starts decreasing. Therefore, the particle collecting device 6 executes a “pre-lifespan collection mode” of controlling both the first air blower 62 and the second air blower 64 in accordance with that timing such that the rotation speeds thereof are increased to compensate for the decrease in the collection efficiency of the filter, as shown in
Furthermore, as shown in
In the particle collecting device 6, control is performed based on this pre-lifespan collection mode so that particles are appropriately collected while the decrease in the collection efficiency of the filter serving as the collector 63 is compensated for.
The lifespan detector 78 provided in the controller 70 for detecting whether the filter has reached its pre-lifespan and provisional lifespan detects that the filter has reached its provisional lifespan. In this case, as shown in the upper part of
The predetermined rotation speed for the provisional lifespan in this case is set as a rotation speed corresponding to a timing at which the collection efficiency of the filter is predicted to decrease by about 20% from the initial value with reference to actual measurement results obtained from tests.
The determination of whether the filter has reached its provisional lifespan is performed similarly to the case of the determination of whether the filter has reached its pre-lifespan.
Finally, after the control period of the pre-lifespan collection mode, the collection efficiency of the filter serving as the collector 63 further decreases to approach the inherent lifespan of the filter. Therefore, as shown in
As shown in
In the particle collecting device 6, control is performed based on this lifespan-approaching collection mode so that particles are collected until the filter reaches its inherent lifespan while the decrease in the collection efficiency of the filter serving as the collector 63 is further compensated for.
In this particle collecting device 6, for example, a warning prompting the user to replace the collector 63 may be displayed on, for example, the operable unit 12 of the image forming apparatus 1 when the filter serving as the collector 63 reaches its provisional lifespan.
Modifications
The present disclosure is not limited to the contents described in the first exemplary embodiment and permits various modifications. For example, the present disclosure includes the following modifications.
With regard to the particle collecting device 6, a vent pipe of another type may be used as the vent pipe 61 (including the channel space 60), an air blower other than an axial fan may be used as the first air blower 62, an air blower other than a sirocco fan may be used as the second air blower 64, or another type of a filter may be used as the collector 63, so long as at least the relationship “P2<P1≤atmospheric pressure” may be maintained during the operation of the particle collecting device 6.
Moreover, the operation (including control operation) of the particle collecting device 6 is not limited to the operation example described in the first exemplary embodiment. The particle collecting device 6 may be configured to perform different operation.
For example, the vent pipe 61 may have, as the first channel space 60A, a channel space extending substantially linearly to the first air blower 62 and having a width equal to the length of the collector 63 in the longitudinal direction C. Moreover, the vent pipe 61 may be a vent pipe not having the front channel-space section 60C. Furthermore, the vent pipe 61 may have, as the aforementioned front channel-space section 60C, a front channel-space section whose inner wall surface facing the collector 63 in the longitudinal direction C of the collector 63 is separated from the collector 63 by the same distance entirely in the longitudinal direction C.
Furthermore, as shown in
As shown in
Furthermore, as indicated by a two-dot chain-line arrow in
The opening 80 shown in
Moreover, as shown in
Furthermore, the opening 80 is oriented in a direction substantially orthogonal to the exhaust direction at the terminal port 641c of the exhaust passage 641b of the sirocco fan.
In the image forming apparatus 1 including the particle collecting device 6 provided with the opening 80, when the particle collecting device 6 is actuated and causes the sirocco fan serving as the second air blower 64 to operate, the air discharged from the sirocco fan travels through the exhaust passage 641b and flows through an exhaust passage surrounded by the upper surface 61Ba of the vent pipe 61 and the exhaust guides 69a and 69b from the terminal port 641c as the air E5 having directivity substantially in the longitudinal direction of the exhaust passage, as shown in
As shown in
Accordingly, as shown in
As a result, in a case where the air E11 existing in the neighboring space section 18 includes excess heat, the air E11 including the heat may be easily discharged without providing a dedicated device, such as an exhaust device.
In the first exemplary embodiment, the particle collecting device 6 is used as a collecting device that collects particles generated in the fixing unit 5 of the image forming apparatus 1. Alternatively, the particle collecting device 6 may be used as a collecting device that collects particles generated from a component other than the fixing unit 5 of the image forming apparatus 1. Moreover, the particle collecting device 6 may be used in various types of apparatuses other than an image forming apparatus if particles have to be collected.
The image forming apparatus that uses the particle collecting device 6 is not limited to the type described in the first exemplary embodiment and may alternatively be of another type that utilizes electrophotography. As another alternative, the image forming apparatus that uses the particle collecting device 6 may be an image forming apparatus that employs an image forming method other than electrophotography (such as a liquid-droplet jet method or a print method).
The foregoing description of the exemplary embodiments of the present disclosure has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, thereby enabling others skilled in the art to understand the disclosure for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the following claims and their equivalents.
Number | Date | Country | Kind |
---|---|---|---|
2018-131223 | Jul 2018 | JP | national |
2018-165236 | Sep 2018 | JP | national |
Number | Name | Date | Kind |
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8116653 | Kondo et al. | Feb 2012 | B2 |
9671753 | Yamashita | Jun 2017 | B2 |
9977400 | Yamaguchi | May 2018 | B2 |
Number | Date | Country |
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2008216301 | Sep 2008 | JP |
2016162759 | Sep 2016 | JP |
Number | Date | Country | |
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20200019117 A1 | Jan 2020 | US |