JP5482144B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  As a conventional image forming apparatus, a charger having a pair of charging wires for charging the surface of a photosensitive drum, a supply duct for supplying air to the pair of charging wires in the charger, and a suction duct for sucking air (For example, refer to Patent Document 1).

  In such an image forming apparatus, a larger amount of air is blown to the charging wire far from the suction duct that sucks air out of the pair of charging wires from the supply duct, thereby generating ozone or nitrogen generated in the charger during discharge. This prevents discharge products such as oxide from staying around the charging wire on the side far from the suction duct.

JP 2006-91327 A

  An object of the present invention is to provide an image forming apparatus capable of sufficiently removing unnecessary substances such as ozone and toner cloud staying around a plurality of charging members as compared with the case without this configuration.

  In order to achieve the above object, one embodiment of the present invention provides the following image forming apparatus.

[1] an image carrier;
First and second charging members respectively disposed at first and second positions for charging the surface of the image carrier;
A cleaning mechanism having a cleaning member for cleaning the first and second charging members, and a driving member for driving the cleaning member;
A blower passage forming member that has a blower port on the downstream side, changes the direction of external air from the air inflow side to the air outflow side, and forms a blower passage that leads to the blower port;
Arranged on the downstream side of the blower flow path forming member, the cleaning mechanism and the first and second charging members are accommodated, and the first and second charging members are provided downstream of the driving member as a branching portion. A housing member having an air intake port on the upstream side of the first and second branch passages branching toward the head and the drive member;
An exhaust passage forming member that is disposed closer to the second position than the first position and forms an exhaust passage for exhausting the external air blown to the first and second charging members to the outside; With
The blower flow path forming member has the first branch path side as the air inflow side of the external air with respect to the second branch path , and the blower opening has the first branch path as compared with the second branch path. An image forming apparatus in which the amount of air blown to the first branch path is larger than the amount of air blown to the second branch path by being arranged eccentrically on the branch path side.

[2] The air flow passage forming member, an image forming apparatus according to the end face of the second branch path side before Symbol blower opening are arranged substantially straight above the drive member [1].

[ 3 ] Cleaning the image carrier, first and second charging members disposed at first and second positions for charging the surface of the image carrier, and the first and second charging members, respectively. A cleaning mechanism having a cleaning member to be driven and a driving member for driving the cleaning member, and a blower flow having a blower port on the downstream side, redirecting external air from the air inflow side to the air outflow side and leading to the air blower port An air flow path forming member that forms a path, and disposed downstream of the air flow path forming member, houses the cleaning mechanism and the first and second charging members, and uses the drive member as a branching portion downstream thereof. The first and second branch paths branching toward the first and second charging members on the side, the housing member having an air intake port on the upstream side of the drive member, and the first position. The first and second charging units disposed on the second position side An exhaust passage forming member that forms an exhaust passage that exhausts the external air that is blown to the outside, and the air passage forming member is disposed on the second branch path side with respect to the first branch path. An image forming apparatus in which the amount of air blown to the first branch path is larger than the amount of air blown to the second branch path by using the air inflow side of external air.

According to the first and second aspects of the invention, the amount of air blown to the first branch passage is made larger than the amount of air blown to the second branch passage due to the shape of the blower passage forming member. And unnecessary substances such as ozone and toner cloud staying around the plurality of charging members can be sufficiently removed.

According to the third aspect of the present invention, the air flow passage forming member is blown to the first branch passage by setting the second branch passage side to the air inflow side of the external air rather than the first branch passage. The amount of air to be supplied can be made larger than the amount of air blown to the second branch path.

FIG. 1 is a front view showing a schematic configuration of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view showing the appearance of the back surface of the image forming apparatus according to the first embodiment of the present invention. FIG. 3 is a plan view for explaining the entire intake path in the image forming apparatus according to the first embodiment of the present invention. 4A and 4B show the dust removing device in the image forming apparatus according to the first embodiment of the present invention. FIG. 4A is a perspective view showing the inside, and FIG. 4B is a perspective view showing the appearance. . FIG. 5 is a cross-sectional view for explaining the dust removing device of the image forming apparatus according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining the wire cleaning device of the image forming apparatus according to the first embodiment of the present invention. 7A and 7B show the air duct of the image forming apparatus according to the first embodiment of the present invention. FIG. 7A is a sectional view and FIG. 7B is a perspective view. 8A and 8B show the disposal duct of the image forming apparatus according to the first embodiment of the present invention. FIG. 8A is a perspective view showing the front portion, and FIG. 8B is a perspective view showing the back portion. It is. FIG. 9 is a cross-sectional view for explaining the opening position of the disposal duct in the image forming apparatus according to the first embodiment of the present invention. FIG. 10 is a cross-sectional view showing a wire cleaning device according to a second embodiment of the present invention. 11A and 11B are diagrams for explaining the ozone removal performance of the comparative example. FIG. 11A is a cross-sectional view showing a schematic configuration of the air duct of the comparative example, and FIG. The figure which shows a measurement result, (c) is a figure which shows the measurement result of the wind speed near the charging wire by the increase in the air volume of the air blower shown in FIG. FIG. 12 is a diagram showing the relationship between the wind speed near the charging wire and the ozone concentration. FIG. 13 is a diagram for explaining the ozone removal performance of Example 1 corresponding to the first embodiment, (a) is a diagram showing a measurement result of ozone concentration in the vicinity of the charging wire, and (b). These are figures which show the measurement result of the wind speed near the charging wire by the increase in the air volume of the air blower shown in FIG.

[First Embodiment]
FIG. 1 shows a schematic configuration of an image forming apparatus according to a first embodiment of the present invention. The image forming apparatus 1 is applied to, for example, a color printer including a main unit 2, a paper feeding unit 3, a fixing unit 4, and filter units 5 and 6 (both shown in FIG. 2 described later). Are movably arranged via casters C, C,. Then, the image forming apparatus 1 performs image processing on image data transmitted from a host device such as a personal computer by an image processing unit (not shown), so that yellow (Y), magenta (M), cyan (C), After conversion into image data of each color of black (K), X ₁ , X ₂ , a paper P as a recording medium is used as a color image based on the image data of each color of Y, M, C, K, X ₁ , X ₂ It is comprised so that it may form.

X ₁ and X ₂ are colors other than Y, M, C, and K colors. For example, an intermediate color or special black is used. As the recording medium, in addition to the paper P, a resin sheet such as an OHP (overhead projector) sheet may be used.

(Configuration of main unit 2)
The main unit 2 includes an image forming unit 2A that forms an image on the paper P, a paper supply unit 2B that supplies the paper P to the image forming unit 2A, and a device main body that houses the paper supply unit 2B and the image forming unit 2A. The first housing 2C is disposed between the paper feeding unit 3 and the fixing unit 4.

The image forming unit _{2A, Y, M, C, K} , X 1, Y Multiple (this embodiment to form an image of each color of _{X 2, M, C, K} , corresponding to each color of X 1, _{X 2} The photosensitive drums 20Y, 20M, 20C, 20K as image carriers on which toner images of the respective colors Y, M, C, K, X ₁ and X ₂ are formed. 20X _1, and 20X _2, these chargers 21Y to charge the photosensitive drum _{20Y~20X 2, 21M, 21C, 21K} , 21X 1, and 21X _2, the photosensitive drum 20Y charged by these chargers 21Y～21X ₂ exposure unit 22Y as an exposure unit for exposing a _{~20X 2, 22M, 22C, 22K} , 22X 1, and 22X _2, an electrostatic latent on the photosensitive drum 20Y～20X ₂ formed by these exposer 22Y～22X ₂ Y, M, Includes _K, developing devices 23Y as a developing unit for developing with toner images of respective colors of _{X 1, X 2, 23M,} 23C, 23K, and a 23X 1, 23X _2.

Photoreceptor drums _{20Y, 20M, 20C, 20K,} 20X 1, 20X 2 , each having a photosensitive layer on the surface, are rotatably disposed in the direction of arrow R in the first housing 2C.

Chargers _{21Y, 21M, 21C, 21K,} 21X 1, 21X 2 are arranged photosensitive drums 20Y, each corresponding, 20M, 20C, _20K, around 20X 1, 20X _2, the pre-exposure the photosensitive drum 20Y It is configured to charge the ~20X _2.

Exposure unit _{22Y, 22M, 22C, 22K,} 22X 1, 22X 2 are disposed the photosensitive drums 20Y, each corresponding, 20M, 20C, _20K, above the 20X 1, 20X _2. The exposing unit 22Y～22X _2, each color electrostatic latent image of the photosensitive drum 20Y～20X ₂ is irradiated with modulated exposure light based on the image data of each color Y~X ₂ Y~X ₂ Is formed.

The developing units 23Y, 23M, 23C, 23K, 23X ₁ and 23X ₂ are arranged around the corresponding photosensitive drums 20Y, 20M, 20C, 20K, 20X ₁ and 20X ₂ , respectively.

Further, the image forming unit 2A, the photosensitive drums 20Y, 20M, 20C, _20K, the intermediate transfer belt 24 in contact with the surface of the 20X 1, 20X _2, photoreceptor drums _{20Y, 20M, 20C, 20K,} 20X 1, 20X Y respectively formed on the _{second surface, M, C, K, X} 1, X 2 of each color toner image the intermediate transfer belt 24 in the primary transfer to the primary transfer device _{25Y, 25M, 25C, 25K,} 25X 1, 25X ₂ , a drive roll 26 that drives the intermediate transfer belt 24, support rolls 27 </ b> A to 27 </ b> D that rotatably support the intermediate transfer belt 24 with a predetermined tension, and a toner image transferred to the intermediate transfer belt 24 on the paper P A secondary transfer device 28 for secondary transfer. The intermediate transfer belt 24, the primary transfer devices 25Y, 25M, 25C, 25K, 25X ₁ and 25X ₂ , the secondary transfer device 28, and the like are the same as those of the photosensitive drums 20Y, 20M, 20C, 20K, 20X ₁ and 20X ₂ . A transfer unit is configured to transfer the toner image formed on the surface onto the paper P.

Above the image forming portion 2A, Y, M, C, K, toner bottles 29Y as a toner supply unit that accommodates the toner of each color of _{X 1, X 2, 29M,} 29C, 29K, 29X 1, 29X 2 is Has been placed. Thus, each color of toner Y～X ₂ is supplied to the developing device 23Y～23X ₂ from the toner bottle 29Y~29X _2.

The intermediate transfer belt 24 is made of an endless belt, interposed first transfer device _{25Y, 25M, 25C, 25K,} 25X 1, 25X 2 and the photosensitive drum 20Y, 20M, 20C, _20K, between the 20X 1, 20X ₂ And is stretched over the drive roll 26 and the support rolls 27A to 27D. The intermediate transfer belt 24 is configured to circulate and move in the direction of arrow a by the drive roll 26. The drum contact side of the intermediate transfer belt 24, the photosensitive drums _{20Y, 20M, 20C, 20K,} 20X 1, the static eliminator 30Y which neutralizes _{20X 2, 30M, 30C, 30K} , 30X 1, 30X 2, and after the primary transfer of the photosensitive drum _{20Y, 20M, 20C, 20K,} 20X 1, 20X 2 in the drum cleaning device 31Y as an image carrier cleaning section for removing residual toner _{remaining, 31M, 31C, 31K, 31X} 1, 31X 2 are placed Has been. The residual toner removed by the drum cleaning device 31Y～31X ₂ is collected outside the first housing 2C via the toner recovery route (not shown).

The primary transfer devices 25Y, 25M, 25C, 25K, 25X ₁ and 25X ₂ respectively perform primary transfer in which the intermediate transfer belt 24 is pressed against the surface of the corresponding photosensitive drum 20Y, 20M, 20C, 20K, 20X ₁ and 20X _2. It is composed of a roll and is rotatably disposed inside the intermediate transfer belt 24. The primary transfer device 25Y～25X ₂ is constituted of the toner image on the photosensitive drum 20Y～20X ₂ to primarily transfer to the intermediate transfer belt 24.

  The drive roll 26 is rotatably disposed inside the intermediate transfer belt 24. The drive roll 26 is configured to circulate and move the intermediate transfer belt 24 in the direction of arrow a by rotation in the direction of arrow Q.

  The support rolls 27 </ b> A to 27 </ b> D are driven rolls, and are arranged rotatably inside the intermediate transfer belt 24, similarly to the drive roll 26. Among the support rolls 27A to 27D, the support rolls 27A and 27B function as primary transfer surface forming rolls, the support roll 27C functions as a tension roll, and the support roll 27D functions as a backup roll of the secondary transfer device 28, respectively.

  The secondary transfer device 28 includes a transfer belt device, and is disposed outside the intermediate transfer belt 24. The secondary transfer device 28 is configured to secondarily transfer the toner image on the intermediate transfer belt 24 onto the paper P. On the paper transport side of the secondary transfer device 28, transport units 32 to 34 are arranged in parallel along the transport direction of the paper P. Of the transport units 32 to 34, the transport units 32 and 33 serve as a transport belt conveyor that transports the paper P in the main body unit 2 in the direction of the arrow b, and the transport unit 34 straddles between the main body unit 2 and the fixing unit 4. Each functions as a conveyor belt conveyor that conveys the paper P in the direction of arrow b.

  The paper supply unit 2B includes paper stackers 35 and 35 that store the paper P therein, and a pair of paper rolls 36 and 36 that roll the paper P stored in the paper stackers 35 and 35 one by one. It is disposed below the image forming unit 2A. On the downstream side of the sheet supply unit 2B, a pair of registration rolls 37 and 37 driven in synchronization with the timing of image formation, and the sheet P from the pair of registration rolls 37 and 37 toward the secondary transfer device 28. Conveying rolls 38, 38,... For conveying in the direction of arrow c are arranged. Details of the first housing 2C will be described later.

(Configuration of paper feed unit 3)
The paper feed unit 3 includes a paper supply unit 3A that supplies the paper P to the image forming unit 2A of the main unit 2 and a second housing 3B that accommodates the paper supply unit 3A therein. It is arranged on the side (left side in FIG. 1).

  The paper supply unit 3A has paper feed trays 39, 39 for stacking the paper P therein, and a pair of paper rolls 40, 40 for picking up the paper P delivered from the paper feed trays 39, 39 one by one. doing. A pair of registration rolls 41 and 41 that are driven in synchronism with the timing of image formation are disposed on the downstream side of the sheet supply unit 3A.

  The second housing 3B has a conveyance path 30B from the paper supply unit 3A toward the main body unit 2, and is movably disposed on the floor surface FL via casters C, C,.

(Configuration of the fixing unit 4)
The fixing unit 4 includes a fixing unit 4A that heats and fixes the toner image transferred to the sheet P, a cooling unit 4B that cools the sheet P fixed by the fixing unit 4A, and the cooling unit 4B and the fixing unit 4A. Is disposed on the other side of the main unit 2 (the right side in FIG. 1).

  The fixing unit 4A includes a heating roll 42 and a pressure roll 43, and is disposed between the transport unit 34 and the cooling unit 4B.

  The cooling unit 4B includes transport units 44 and 45 that transport the paper in the direction of arrow d, and a cooler 46 that cools the paper P transported by the transport units 44 and 45, and is disposed downstream of the fixing unit 4A. Has been. Discharging rolls 47 and 47 for discharging the paper P in the fixing unit 4 to the outside of the fixing unit 4 are disposed on the downstream side of the cooling unit 4B.

  The third housing 4C has a conveyance path 40C from the conveyance unit 34 to the discharge rollers 47, 47 via the fixing unit 4A and the cooling unit 4B, and is formed on the floor FL via casters C, C,. It is arranged to be movable.

  FIG. 2 shows the back side of the image forming apparatus 1.

In the first housing 2C, a suction port 52 that sucks external air into the interior, and a discharge port 53 that discharges the external air sucked from the suction port 52 to the outside after cooling each image forming unit in the image forming unit 2A, Discharge ports 50Y, 50M, 50C, 50K, 50X ₁ and 50X ₂ for releasing internal heat generation are provided. The suction port 52 is opened on a side surface on one side (paper feed unit 3 side) of the first housing 2C, and the discharge port 53 is opened on the upper surface of the other side (fixing unit 4 side) of the first housing 2C. .

  The filter unit 5 has a filter storage box 48 and is disposed on the back side of the main unit 2.

  The filter housing box 48 has suction ports 48a and 49Y to 49K for sucking outside air into the inside and a discharge port 48b for discharging the inside air to the outside, and is movable on the floor surface FL via casters C, C,. Is arranged. The suction ports 48 a and 49 Y to 49 K are opened on the back side of the filter housing box 48, and the discharge port 48 b is opened on the ceiling surface side of the filter housing box 48.

The filter storage box 48 has a cloud filter that captures a toner cloud as a waste object generated by driving the image forming unit 2A (shown in FIG. 1), and a waste object generated by driving the image forming unit 2A. An ozone filter (both not shown) that captures and decomposes ozone (O ₃ ) is incorporated. Further, the filter housing box 48 is provided with a discharge port (not shown) for discharging the internal air after passing through the cloud filter and the ozone filter to the outside. The discharge port is opened on the bottom side of the filter storage box 48.

  On the other hand, the filter unit 6 has a filter housing box 50 and is arranged on the back side of the main unit 2 in parallel with the side of the filter unit 5.

The filter storage box 50 has suction ports 50a, 51X ₁ , 51X ₂ for sucking external air into the inside, and discharge ports 50b for discharging the internal air to the outside, and is provided on the floor surface FL via casters C, C,. It is arranged to be movable. The suction ports 50a, 51X ₁ and 51X ₂ are opened on the back side of the filter housing box 50, and the discharge port 50b is opened on the ceiling surface side of the filter housing box 50, respectively.

The filter storage box 50 has a cloud filter that captures a toner cloud as a waste object generated by driving the image forming unit 2A (shown in FIG. 1), and a waste object generated by driving the image forming unit 2A. An ozone filter (both not shown) that captures and decomposes ozone (O ₃ ) is incorporated. Further, the filter storage box 50 is provided with a discharge port (not shown) for discharging the internal air after passing through the cloud filter and the ozone filter to the outside. The discharge port is opened on the bottom side of the filter storage box 50.

  FIG. 3 shows the inside of the first housing and the filter storage box. The first housing 2C has an accommodation space 200C inside, and accommodates the image forming unit 2A, the paper supply unit 2B (both shown in FIG. 1), and the like in the accommodation space 200C.

In the storage space 200C of the first housing 2C, dust removing devices 54Y, 54M, 54C, 54K as dust removing units for removing dust sent together with external air toward the image forming unit 2A (shown in FIG. 1). 54X _1, 54X _2, and ozone remaining in the periphery of the charging wire 71 charging wire 71 while cleaning a wire cleaning apparatus for removing unnecessary substances such as toner cloud _{55Y, 55M, 55C, 55K,} 55X 1, 55X 2 is Contained.

Dust removing device 54Y～54X ₂ is inlet _49Y~49K, 51X _1, 51X ₂ in the intake duct 56Y～56X _2, via the 57Y～57X _2, also wire cleaning device 55Y～55X ₂ is dust removing device They are respectively connected to 54Y~54X _2.

(Dust removal device)
Then, per the dust removing device 54Y～54X _2, 3, FIG. 4 (a), described with reference to (b) and 5. 4A and 4B show the inside and appearance of the storage case. FIG. 5 shows the inside of the dust removing device. FIG. 4A shows a state where the upper portions of the intake duct 57K and the storage case 58K are removed.

As shown in FIG. 3, the dust removing device 54Y～54X ₂ is accommodating case 58Y～58X ₂ functioning as the intermediate duct, a charger as a filter 59Y～59X _2, and the blower target unit to capture dust 21Y～21X ₂ comprising a blower 60Y～60X ₂ for blowing air (shown in FIG. 1) is disposed in the first housing 2C.

As shown in FIGS. 4A and 4B, the storage cases 58Y to 58X ₂ (only the storage case 58K are shown) each open on the air suction side and the first opening 61 that opens on the air suction side. a second opening 62, the intervening disposed between the intake duct 57Y～57X ₂ (intake duct 57K only shown) and blower duct 70Y～70X ₂ (shown only blast duct 70K). First opening 61 is the intake duct 57Y～57X ₂ side, and the second opening portion 62 is opened, respectively the air duct 70Y～70X ₂ side.

Each of the filters 59Y to 59X ₂ (only the filter 59K is shown) is installed in the housing cases 58Y to 59X ₂ by closing the entire opening surface of the first opening 61 on the entire filter surface. The filter 59Y～59X ₂ is configured to capture dust sucked together with external air in the accommodating case 58Y～58X ₂ side through the first opening 61.

The blowers 60Y to 60X ₂ (only the blower 60K is shown) are each an impeller 63 (shown in FIG. 5) that is rotated by a drive motor (not shown), and casings 64Y, 64M that house the impeller 63 therein. It consists of a sirocco fan having 64C, 64K, 64X ₁ , 64X ₂ (only the casing 64K is shown), and is disposed in the housing cases 58Y to 58X ₂ . Then, the blower 60Y～60X _2, like for blowing external air through the charging device 21Y～21X ₂ as cleaned portion (only the blast duct 70K) air duct 70Y～70X ₂ (shown in FIG. 1), etc. It is configured.

The casings 64Y to 64X ₂ (only the casing 64K is illustrated) receive air flows generated by the rotation of the air intake 65 and the impeller 63 that take in external air that has passed through the filters 59Y to 59X ₂ , respectively, and the air ducts 70Y to 70X _2. an air outlet 66 for taking out the side, and is connected to the air duct 70Y～70X ₂ by inserting the portion in the second opening 62.

The air intake 65 is opened on the side opposite to the installation side of the filters 59Y to 59X ₂ (only the filter 59K is shown). Accordingly, the whole surface of the filter 59Y～59X ₂ can be used as the effective filter area, it is possible to suppress the occurrence of clogging in the filter 59Y～59X ₂ as compared with the case where the inlet 65 air intake and installation side .

In addition, as shown in FIG. 5, the casings 64Y to 64X ₂ (only the casing 64K is shown) have a dimension Sf between the filters 59Y to 59X ₂ (only the filter 59K is shown) and are arranged on the opening surface of the air intake 65. Sr and Sr are Sf <Sr, preferably Sr / Sf> 1.1, and more preferably Sr, where Sr is a dimension between the inner surface 67 of the opposing storage cases 58Y to 58X ₂ (only the storage case 58K is shown). The dimension is set to satisfy /Sf>1.5. Thus, compared to the case where Sf and Sr is set to Sf ≧ Sr, filter 59Y～59X ₂ and the casing from the space portion _{G 1} is formed between the casing 64Y~64X ₂ 64Y~64X ₂ and the inner surface 67 The external air flows smoothly into the space G2 formed between the _two .

(Wire cleaning device)
Then, per wire cleaning device 55Y～55X _2, will be described with reference to Figs. FIG. 6 shows a wire cleaning device. FIGS. 7A and 7B show the air duct. FIGS. 8A and 8B show a waste duct. FIG. 9 shows the opening position of the waste duct.

Dust wire cleaning device 55Y～55X ₂ comprises contacting the wire cleaning member to a charging wire of a pair of the charging member, by moving in the axial direction along the wire cleaning member to a charging wire, attached to the charging wire, It removes toner powder and charged products such as ozone.

As shown in FIG. 6, the wire cleaning devices 55Y to 55X ₂ (only the wire cleaning device 55K is shown) include wire cleaning mechanisms 68Y, 68M, 68C, 68K, 68X ₁ and 68X ₂ (only the wire cleaning mechanism 68K is shown), accommodation of the member casing _{69Y, 69M, 69C, 69K,} 69X 1, 69X 2 ( housing case 69K only shown) and blower duct 70Y as air flow passage forming _{member, 70M, 70C, 70K, 70X} 1, 70X 2 ( blast It has a duct 70K only) and is arranged around the photosensitive drums 20Y, 20M, 20C, 20K, 20X ₁ and 20X ₂ (only the photosensitive drum 20K is shown).

The wire cleaning mechanisms 68Y to 68X ₂ (only the wire cleaning mechanism 68K is shown) are arranged at first and second positions that charge the surfaces of the photosensitive drums 20Y to 20X ₂ (only the photosensitive drum 20K is shown), respectively. As a pair of upper and lower wire cleaning members 72, 72, 73, 73 for cleaning the first and second charging wires 71 </ b> A, 71 </ b> B, and a drive member for driving the upper and lower pair of wire cleaning members 72, 72, 73, 73. The lead screw 74 is housed in the housing cases 69Y to 69X ₂ (only the housing case 69K is shown) together with the first and second charging wires 71A and 71B.

The upper wire cleaning members 72, 72 are swingably disposed on the moving member 75 in the storage cases 69Y to 69X ₂ (only the storage case 69K is shown) via a swing member 76. The upper wire cleaning members 72 and 72 come into contact with the first and second charging wires 71A and 71B by the swinging of the swinging member 76 when the moving member 75 moves from the home position and the wire is cleaned. When 75 is located at the home position (when the wire is not cleaned), the swinging member 76 is returned to the swinging position so as to be separated from the first and second charging wires 71A and 71B.

  The lower wire cleaning members 73 and 73 are disposed on the moving member 75 via the support member 77 below the upper wire cleaning members 72 and 72.

The lead screw 74 is a male screw arranged parallel to the longitudinal direction of the first and second charging wires 71A and 71B, and is arranged rotatably in the accommodation cases 69Y to 69X ₂ (only the accommodation case 69K is shown). Has been. The lead screw 74 is rotated by a drive motor (not shown), and a moving member 75 attached to the lead screw 74 by a female screw is reciprocated along the first and second charging wires 71A and 71B. The wire cleaning members 72 and 72 and the lower wire cleaning members 73 and 73 are driven.

The storage cases 69Y to 69X ₂ (only the storage case 69K is shown) are opened to the upstream side of the first and second branch passages 78 and 79, each branching on the downstream side with the lead screw 74 as a branching portion. And an air intake port 81 that circulates through the branch passages 78 and 79, and is disposed in the vicinity of the photosensitive drums 20Y to 20X ₂ (only the photosensitive drum 20K is shown). ing.

The air ducts 70Y to 70X ₂ (only the air duct 70K is illustrated) are first and second via the air intake port 70a through which air flows from the air blowers 60Y to 60X ₂ and the first and second branch paths 78 and 79. The air outlet 82 for blowing external air to the charging wires 71A and 71B, and a curved path 83 as a flow passage that changes the direction of the air flow by the external air from the air inflow side to the air outflow side and circulates to the air outlet 82. Are disposed upstream of the housing cases 69Y to 69X ₂ (only the housing case 69K is shown).

The opening 82a of the air outlet 82 is eccentrically arranged on the first branch path 78 side near the air inflow side of the curved path 83 among the first and second branch paths 78 and 79. That is, a pair of opening surfaces 78a of the housing case 69Y～69X _2, the opening surface 78a of the air inflow side of the inner curved path 83 78a are disposed opposite the opening surface 82a of the air duct 70Y~70X _2. In addition, the air outlet 82 has an outer end surface 82 b that forms a part of the opening end surface thereof, which is disposed almost directly above the lead screw 74. Thus, the external air blown downstream from the air blowing port 82 is branched by the lead screw 74 so that the first charging wire 71A side has a higher wind speed than the second charging wire 71B side. And the second branch passages 78 and 79 are flown along the axial direction of the second branch passages 78 and 79 with little speed unevenness, and then blown to the charging wires 71A and 71B through the branch passages 78 and 79, and around the charging wires 71A and 71B. Unnecessary matter staying in the gas is discharged to the outside through the introduction ducts 95 and 96. The pair of opening surfaces 78a of the housing case 69Y～69X _2, a portion of the opening surface 78a and the other opening face 78a of the air inflow side of the inner curved path 83 78a is the opening surface 82a of the air duct 70Y～70X ₂ You may arrange | position facing.

Curved path 83 has a passage 83a which respective axes are orthogonal to each other, 83 b, and both these passages 83a, having a flow channel 83c interposed between 83 b, it is disposed on the air outflow side of the air duct 70Y～70X ₂ Yes. The flow path 83a is opened to the straight path 84 (shown in FIG. 7A), and the flow path 83b is opened to the outside via the air blowing port 82. In the channel 83c, the inner and outer two road surfaces 830c and 831c are formed with curved surfaces having different curvatures.

Further, as shown in FIG. 7 (a), the air duct 70Y~70X ₂ (shown only blast duct 70K) has a straight path 84, each of which flows into the flow path 83a of the curved path 83, the blower 60Y～60X ₂ It is connected to the air intake 66 (shown in FIG. 5) of the casings 64Y to 64X ₂ (shown in FIG. 3) in (shown in FIG. 3). As shown in FIG. 7B, the air ducts 70 </ b> Y to 70 </ b> X ₂ are integrally provided with a reinforcing portion 85 that protrudes from the curved path 83 to the opposite side of the straight path 84.

Straight path 84 is disposed on the air inflow side of the air duct 70Y～70X ₂ (shown only blast duct 70K), and the blower 60Y～60X ₂ casing 64Y~64X in (3) ₂ (3) An air outlet 66 is connected. In the straight path 84, a plurality of guide members 86, 87, 88 for guiding external air to the air blowing port 82 are arranged in parallel in the axial direction of a pair of first and second charging wires 71A, 71B (shown in FIG. 6). Are arranged. In this case, the plurality of guide members 86, 87, 88 have an air flow in which the air flow from the straight path 84 to the curved path 83 does not have uneven wind speed along the axial direction of the first and second charging wires 71 </ b> A, 71 </ b> B. It is preferable that it is formed so that. In the present embodiment, the straight path 84 includes guide members 86A and 86B disposed at both ends, and straight portions 87a disposed inside the guide members 86A and 86B and extending along the axial direction of the charging wires 71A and 71B. A guiding member (first guiding member) 87A to 87E composed of a curved portion 87b having a shape curved toward the curved path 83 from the straight portion 87a and a guiding member having a curved shape is disposed between the guiding members 87A to 87E. Members (second guide members) 88A to 88E are provided.

  With the configuration of the guide members 86, 87, 88, the air flow by the external air is branched into three by the guide members 87A, 87B on the inlet side of the guide members 87A-87E, and the branch flow on one end side is guided. The member 88A is guided to the curved path 83, the central branch flow is guided to the curved path 83 by the guide members 87C, 88B, 88C, and the other branch flow is curved by the guide members 87D, 87E, 88D, 88E. 83. For this reason, external air can be blown from the straight path 84 to the curved path 83 along the axial direction of the charging wires 71A and 71B with little speed unevenness.

In the vicinity of the wire cleaning devices 55Y to 55X ₂ (only the wire cleaning device 55K is shown in FIG. 6), disposal ducts 90Y, 90M, 90C, 90K, 90X ₁ and 90X ₂ (FIG. 8) as discharge members shown in FIG. (Only the disposal duct 90K is shown in (a) and (b)).

Waste duct 90Y～90X ₂ has first to fourth openings 91 to 94 as shown in FIG. 8 (a) and (b), first, second and third openings 91 to 93, Each circulates in the fourth opening 94. The fourth opening 94 is connected to a disposal pipe (not shown) with a bellows pipe in the filter storage boxes 5 and 6 (shown in FIG. 2). A blower for flowing the internal air to the outside is provided inside the disposal pipe. Then, waste objects such as toner cloud and ozone generated in the image forming unit 2A (shown in FIG. 6) are discharged from the internal air through a waste duct 90Y to 90X ₂ and a waste pipe with a bellows pipe by a blower. When it is discharged, it is captured by cloud filter and ozone filter.

As shown in FIG. 9, the first opening 91 has a photosensitive drum 20Y, 20M, 20C, 20K, and the like through a cloud introduction duct 95 and an ozone introduction duct 96 as an exhaust (disposal) flow path forming member. 20X ₁ , 20X ₂ (only the photosensitive drum 20K is shown), the second opening 92 is on the developing units 23Y, 23M, 23C, 23K, 23X ₁ , 23X ₂ (only the developing unit 23K is shown), and 3 opening portions 93 are respectively opened on the drum cleaning devices 31Y, 31M, 31C, 31K, 31X ₁ and 31X ₂ (only the drum cleaning device 31K is shown). The ozone introduction (disposal) duct 96 is disposed closer to the second position where the second charging wire 71B is disposed than the first position where the first charging wire 71A is disposed. The air flow rate with respect to the 1st thru | or 3rd opening parts 91-93 is set to the flow volume used as the distribution ratio of about 7: 5: 1, for example. That is, if the air flow rate to the third opening 93 is “1”, the air flow rate to the first opening 91 is “7”, and the air flow rate to the second opening 92 is “5”. It is said.

(Operation of Image Forming Apparatus 1)
Next, the operation of the image forming apparatus 1 shown in the first embodiment will be described with reference to FIGS. 1 to 3, 5, and 6.

  As shown in FIG. 1, when the paper P is supplied from the paper supply unit 2B of the main unit 2, the paper P stacked in the paper stackers 35 and 35 is separated one by one by a pickup roll (not shown). Then, the paper rolls 36 and 36 are sent to the stopped registration rolls 37 and 37.

  Next, the leading edge of the paper P is abutted against the registration rolls 37, 37, and the correction of the oblique feeding of the paper and the alignment of the leading edge of the paper are made to wait.

  Here, when the paper P is supplied from the paper supply unit 3A of the paper supply unit 3, the paper P stacked in the paper supply trays 39 and 39 is separated one by one by a pickup roll (not shown), The paper rolls 40, 40 are sent to the stopped registration rolls 41, 41.

  Next, the leading edge of the paper P is abutted against the registration rolls 41, 41, and correction of the oblique feeding of the paper and alignment of the leading edge of the paper are made to wait.

Then, the registration rollers 37 and 37 or the registration rollers 41 and 41 are rotated in synchronization with the image formation timing in the image forming unit 2A to feed the paper P to the secondary transfer device 28, and the photosensitive drums 20Y, 20M, 20C, After the toner images formed on 20K, 20X ₁ and 20X ₂ are primarily transferred to the intermediate transfer belt 24 by the primary transfer devices 25Y, 25M, 25C, 25K, 25X ₁ and 25X ₂ , the support roll 27D in the secondary transfer device 28 is used. The toner image is secondarily transferred to the paper P fed to the position.

  Thereafter, in the image forming apparatus 1, the fixing unit 4 A of the fixing unit 4 fixes the toner image onto the paper P, and then the paper P is cooled by the cooling unit 4 B and discharged out of the fixing unit 4 by the discharge rollers 47 and 47. To do.

At this time, as shown in FIG. 2, the filter housing box 48 and 50 outside of the external air inlet 49Y, 49M, 49C, _49K, 51X 1, the intake duct 51X in ₂ from the filter housing box 48 and 50 56Y, _56M, 56C, 56K, is sucked into the 56X 1, 56X ₂ (shown in FIG. 3).

External air sucked into the intake duct 56Y~56X _2, as shown in FIG. 3, the intake duct 57Y, 57M, 57C, _57K, after having flowed into the 57X 1, 57X _2, the filter 59Y, 59M, 59C, _59K, and flows 59x 1, 59x ₂ accommodated through the (filter 59K shown only in FIG. 5) case _58Y, 58M, 58C, 58K, the 58X 1, 58X _2.

In this case, when the dust with an external air intake duct 56Y~56X within ₂ is sucked, the dust is captured the entire filter 59Y～59X ₂ (shown only filter 59K) as a filter effective area.

The external air flowing into the housing case 58Y~58X in _2, as shown in FIG. 5, the blower _{60Y, 60M, 60C, 60K,} 60X 1, 60X 2 external air space by driving (only shown blower 60K) It is guided from G ₁ to the space G ₂ and taken into the casings 64Y, 64M, 64C, 64K, 64X ₁ and 64X ₂ (only the casing 64K is shown) from the air intake 65.

Taken was outside air into the casing 64Y～64X _2, rotary air intake and out the outlet 66 to the _second outer casing 64Y～64X by the action of centrifugal force due to the impeller 63, blown from the air inlet 70a ducts 70Y, 70M , 70C, _70K, and flows into the 70X 1, 70X ₂ (blast duct 70K only shown).

As shown in FIG. 6, the external air that has flowed into the air ducts 70 </ b> Y to 70 </ b> X ₂ is connected to the straight path 84 (FIG. 7 (FIG. 7A)) by guide members 86 </ b> A, 86 </ b> B, 87 </ b> A to 87 </ b> E, induced are shown in a)) from the air inflow side to the air outflow side, was further outflow from curved path 83 air blowing port 82 to flow into the outer air duct 70Y～70X _2, housing case 69Y, 69M, 69C, 69K , 69X ₁ , 69X ₂ (only the housing case 69K is shown) flows from the air intake port 80.

External air flowing into the housing case 69Y~69X in _2, the first and the person with the lead screw 74 of the first charging wire 71A side is branched so that the second charging wire 71B greater wind speed than the side After flowing in along the axial direction of the two branch passages 78 and 79 with less speed unevenness, the fluid flows through the first and second branch passages 78 and 79 to the first and second charging wires 71A and 71B. Each is blown. The external air blown to the first charging wire 71A becomes a strong flow toward the rotation direction of the photosensitive drum 20K due to the laminar flow due to the rotation of the photosensitive member and the suction of the ozone waste duct 96, and the surrounding air around the strong flow is strong. Since air has the property of being attracted to a strong flow and assimilating and flowing, the weak flow in the second charging wire 71B is insufficient compared to the first charging wire 71A due to the strong flow in the first charging wire 71A. It flows while being drawn to make up for it, and it blows without generating stagnation and vortices. By blowing air to the charging wires 71A and 71B, unnecessary substances such as ozone and toner cloud staying around the charging wires 71A and 71B, together with external air, a cloud introduction duct 95, an ozone introduction (disposal) duct 96, a dustproof filter, It is discharged outside through an ozone filter.

  In the curved path 83, the air flow Fin inside the road surface 830c follows the road surface 830c as shown by the solid line in FIG. 6 when the wind speed is relatively low, but as the wind speed increases, as shown by the broken line in FIG. The air flow F′in tends to leave the road surface 830c. On the other hand, even if the wind speed increases in the curved path 83, the angle α formed by the line connecting the center of the first and second charging wires 71A and 71B and the center of the lead screw 74 and the inner wall surface of the flow path 83c. Thus, the air flow Fout along the road surface 831c, which is the outer wall surface of the curved path 83, has a component Δf toward the inner road surface 830c. Therefore, this acts on the inner air flow F′in, and the first branch 78 The wind speed passing through the second branch path 79 can be made larger than the wind speed passing through the second branch path 79. Even if the wind speed changes in the curved path 83, the variation in the air volume between the first and second branch paths 78 and 79 is suppressed. The

[Second Embodiment]
FIG. 10 is a cross-sectional view showing a wire cleaning device according to a second embodiment of the present invention. Air duct 70Y～70X ₂ of the first embodiment, than the second branch path 79 of the wire cleaning mechanism 68Y～68X ₂ but the first branch path 78 side and the air inlet side of the external air, the The air ducts 70 </ b> Y to 70 </ b> X ₂ (only the air duct 70 </ b> K are illustrated) of the second embodiment are configured such that the second branch path 79 side of the first branch path 78 is the air inflow side of the external air. Further, the air duct 70Y～70X ₂ of the first embodiment has been arranged an air blowing port 82 eccentrically to the first branch passage 78 side, the blast duct 70Y～70X ₂ (blowing of the second embodiment The duct 70 </ b> K only is illustrated in a size corresponding to the air intake 80 of the storage cases 69 </ b> Y to 69 </ b> X <b> ₂ (only the storage case 69 </ b> K is illustrated) without the air outlet 82 being eccentric.

  According to the second embodiment, even when the air outlet 83 of the air duct is not eccentric to the first branch path 78, when the external air flowing into the air duct flows through the curved path 83, the outside ( Since the wind speed on the side with the larger radius of curvature is greater than that on the inner side, the flow velocity of the first branch path 78 is greater than that of the second branch path 79, as in the first embodiment. In the air duct of the second embodiment, the air outlet 82 may be eccentric to the first branch path 78 side.

  Even if the wind speed sent to the curved path 83 increases and the air flow is separated from the inner road surface 830c, the amount of air in the second branch path 79 on the exhaust side <the first branch path 78 on the opposite side to the exhaust side. It is possible to reduce the amount of air in the first branch 78 on the side opposite to the exhaust side, which tends to decrease the amount of air flowing in.

  An embodiment of the present invention will be described with reference to FIGS.

(Comparison example ozone removal performance)
11A and 11B are diagrams for explaining the ozone removal performance of the comparative example. FIG. 11A is a cross-sectional view showing a schematic configuration of the air duct of the comparative example, and FIG. 11B is a graph showing the ozone concentration in the vicinity of the charging wire. The figure which shows a measurement result, (c) is a figure which shows the measurement result of the wind speed near the charging wire by the increase in the air volume of the air blower 60K shown in FIG. 11B and 11C, IN1, IN2, CEN, OUT2, and OUT1 indicate the measurement positions in the longitudinal direction in the vicinity of the charging wires 71A and 71B. In FIGS. 6 and 9, IN1 is the innermost position. , OUT1 is the closest position, CEN is an intermediate position between IN1 and OUT1, IN2 is an intermediate position between IN1 and CEN, and OUT2 is an intermediate position between CEN and OUT1.

  FIG. 12 is a diagram showing the relationship between the wind speed near the charging wire and the ozone concentration. From the figure, it can be seen that the ozone concentration staying in the vicinity of the charging wire decreases as the wind speed in the vicinity of the charging wire increases. The target value is assumed to be 4.9 ppm.

  As shown in FIG. 11A, the air duct 70K of the comparative example has a size corresponding to the air intake port 80 of the housing case 69K without the air outlet 82 being eccentric to the first branch path side. .

  In the air duct 70K of the comparative example, as shown in FIG. 11B, the ozone concentration in the center between the first and second charging wires in the inner side IN1 greatly exceeds the target value (4.9 ppm). . From FIG. 11 (c), it can be seen that even if the duty ratio of the blower 60K shown in FIG. 5 is increased, the wind speed at IN1 does not increase so much and the ozone concentration cannot be made lower than the target value.

(Ozone removal performance of Example 1)
FIG. 13 is a diagram for explaining the ozone removal performance of Example 1 corresponding to the first embodiment, (a) is a diagram showing a measurement result of ozone concentration in the vicinity of the charging wire, and (b). These are figures which show the measurement result of the wind speed of the charging wire vicinity by the increase in the air volume of the air blower 60K shown in FIG. In FIGS. 13A and 13B, IN1, IN2, CEN, OUT2, and OUT1 indicate the measurement positions in the longitudinal direction in the vicinity of the charging wires 71A and 71B. In FIGS. 6 and 9, IN1 is the innermost position. , OUT1 is the closest position, CEN is an intermediate position between IN1 and OUT1, IN2 is an intermediate position between IN1 and CEN, and OUT2 is an intermediate position between CEN and OUT1.

  As shown in FIG. 13A, in the air duct 70K of Example 1, the ozone concentration became the target value (4.9 ppm) or less at any location in the longitudinal direction of the charging wire. From FIG. 12B, it can be seen that by increasing the duty of the blower 60K shown in FIG. 5, the wind speed in the vicinity of the charging wire can be increased at any location in the longitudinal direction of the charging wire. Therefore, as shown in FIG. 12, the ozone concentration can be further reduced by increasing the duty of the blower 60K.

  Although the image forming apparatus of the present invention has been described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

(1) In the above embodiment, the case where a pair of charging wires 71A and 71B is used for each image forming unit has been described. However, the present invention is not limited to this, and the number of wires may be three or more. Good.

(2) In the above embodiment, the case where the present invention is applied to a printer has been described. However, the present invention is not limited to this, and may be applied to a copying machine or a facsimile. The present invention may be applied to a multi-function machine that is a combination of at least two.

(3) In the above embodiment, the case where the image forming apparatus 1 is a color image forming apparatus using a plurality of photosensitive drums 20Y, 20M, 20C, 20K, 20X ₁ and 20X ₂ has been described. Is not limited thereto, and may be a monochrome image forming apparatus using a single photosensitive drum.

(4) The flow path structure in which the amount of air blown to the first branch path is larger than the amount of air blown to the second branch path is not limited to the first and second embodiments, and is housed. You may implement | achieve by changing the shape and position of components which comprise a wire cleaning apparatus like the shape of a case, arrangement | positioning of a lead screw, etc., or adding components.

1 Image forming apparatus,
2 ... main unit, 2A ... image forming unit, 2B ... sheet supplying unit, 2C ... first housing, 20Y, 20M, 20C, 20K , 20X 1, 20X 2 ... photoconductor drum, 21Y, 21M, 21C, 21K , 21X ₁ , 21X ₂ ... charger, 22Y, 22M, 22C, 22K, 22X ₁ , 22X ₂ ... exposure unit, 23Y, 23M, 23C, 23K, 23X ₁ , 23X ₂ ... developer, 24 ... intermediate transfer belt, 25Y _{, 25M, 25C, 25K, 25X} 1, 25X 2 ... primary transfer belt, 26 ... driving roller, 27A to 27D ... supporting roll, 28 ... second transfer device, 29Y, 29M, 29C, 29K , 29X 1, 29X 2 ... toner bottles, 30Y, 30M, 30C, 30K , 30X 1, 30X 2 ... neutralizer, 31Y, 31M, 31C, 31K , 31X 1, 31 ₂ ... drum cleaning device, 32 to 34 ... transport unit, 35 ... sheet stacker, 36 ... handling roller, 37 ... register roller, 38 ... conveying rolls,
DESCRIPTION OF SYMBOLS 3 ... Paper feed unit, 3A ... Paper supply part, 3B ... 2nd housing | casing, 30B ... Conveyance path, 39 ... Paper feed tray, 40 ... Separation roll, 41 ... Registration roll,
DESCRIPTION OF SYMBOLS 4 ... Fixing unit, 4A ... Fixing part, 42 ... Heating roll, 43 ... Pressure roll, 4B ... Cooling part, 44, 45 ... Conveyance unit, 46 ... Cooler, 47 ... Discharge roll, 4C ... 3rd housing | casing, 40C ... conveyance path, 200C ... housing space, 52 ... inlet, 53 ... discharge port, 50Y, 50M, 50C, 50K , 50X 1, 50X 2 ... discharge port,
5 ... Filter housing box, 48a, 49Y, 49M, 49C, 49K ... Suction port, 48b ... Discharge port,
6 ... filter housing box, 50a, _51X 1, 51X 2 _... suction port, 50b ... discharge port,
54Y, 54M, 54C, 54K, 54X ₁ , 54X ₂ ... Dust removing device, 56Y, 56M, 56C, 56K, 56X ₁ , 56X ₂ ... Intake duct, 57Y, 57M, 57C, 57K, 57X ₁ , 57X ₂ ... intake duct, 58Y, 58M, 58C, 58K , 58X 1, 58X 2 ... housing case, 59Y, 59M, 59C, 59K , 59X 1, 59X 2 ... filter, 60Y, 60M, 60C, 60K , 60X 1, 60X 2 ... Blower, 61 ... first opening, 62 ... second opening, 63 ... impeller, 64Y, 64M, 64C, 64K, 64X ₁ , 64X ₂ ... casing, 65 ... air inlet, 66 ... air outlet, 67 ... Inside,
55Y, 55M, 55C, 55K, 55X 1, 55X 2 ... wire cleaning device, 68Y, 68M, 68C, 68K , 68X 1, 68X 2 ... wire cleaning mechanism, 69Y, 69M, 69C, 69K , 69X 1, 69X 2 ... housing case, 70Y, 70M, 70C, 70K , 70X 1, 70X 2 ... air duct, 70a ... air inlet, 71A ... first charging wire, 71B ... second charging wire, 72, 73 ... wire cleaning member, 74 ... lead screw 75 ... moving member 76 ... oscillating member 77 ... support member 78 ... first branch path 79 ... second branch path 80 ... air intake port 81 ... air intake port 82 ... Blower, 82a ... Open surface, 82b ... Outside open end face, 83 ... Curved path, 83a to 83c ... Flow path, 830c, 831c ... Road surface, 84 ... Straight path, 85 ... Reinforcement part, 86- 88,86A, 86B, 87A~87E, 88A~88E ... guide member, 90Y, 90M, 90C, 90K , 90X 1, 90X 2 ... waste duct, 91 to 94 ... opening, 95 ... cloud introduction duct, 96 ... Ozone introduction duct,
C ... Caster, FL ... Floor surface, P ... Paper

Claims (3)

An image carrier,
First and second charging members respectively disposed at first and second positions for charging the surface of the image carrier;
A cleaning mechanism having a cleaning member for cleaning the first and second charging members, and a driving member for driving the cleaning member;
A blower passage forming member that has a blower port on the downstream side, changes the direction of external air from the air inflow side to the air outflow side, and forms a blower passage that leads to the blower port;
Arranged on the downstream side of the blower flow path forming member, the cleaning mechanism and the first and second charging members are accommodated, and the first and second charging members are provided downstream of the driving member as a branching portion. A housing member having an air intake port on the upstream side of the first and second branch passages branching toward the head and the drive member;
An exhaust passage forming member that is disposed closer to the second position than the first position and forms an exhaust passage for exhausting the external air blown to the first and second charging members to the outside; With
The blower flow path forming member has the first branch path side as the air inflow side of the external air with respect to the second branch path , and the blower opening has the first branch path as compared with the second branch path. An image forming apparatus in which the amount of air blown to the first branch path is larger than the amount of air blown to the second branch path by being arranged eccentrically on the branch path side. Said air flow passage forming member, an image forming apparatus according to claim 1 which is arranged substantially right above the previous SL blower opening of the second branch path side of the end face said drive member. An image carrier,
First and second charging members respectively disposed at first and second positions for charging the surface of the image carrier;
A cleaning mechanism having a cleaning member for cleaning the first and second charging members, and a driving member for driving the cleaning member;
A blower passage forming member that has a blower port on the downstream side, changes the direction of external air from the air inflow side to the air outflow side, and forms a blower passage that leads to the blower port;
Arranged on the downstream side of the blower flow path forming member, the cleaning mechanism and the first and second charging members are accommodated, and the first and second charging members are provided downstream of the driving member as a branching portion. A housing member having an air intake port on the upstream side of the first and second branch passages branching toward the head and the drive member;
An exhaust passage forming member that is disposed closer to the second position than the first position and forms an exhaust passage for exhausting the external air blown to the first and second charging members to the outside; With
By setting the air flow passage forming member to be the air inflow side of the external air on the second branch path side from the first branch path, the amount of air blown to the first branch path is set to the second level. The image forming apparatus in which the amount of air blown to the branch path is increased.

Images