Image forming device

Abstract

To solve the problem in which: in an exhaust configuration that merges a plurality of airflows with each other to exhaust the airflows, simultaneous interference between the plurality of airflows causes pressure drop, which reduces exhaust efficiency.SOLUTION: An image forming apparatus comprises: a first duct that forms a first airflow for exhausting air in the vicinity of a developing unit; a second duct that forms a second airflow for exhausting air in the vicinity of a recovery path; a third duct that forms a third airflow for exhausting air in the vicinity of an electrification unit; a first connection part that connects the first duct and the second duct with each other to merge the first airflow and the second airflow with each other; and a second connection part that connects the third duct and the first connection part with each other to merge the third airflow with the merged airflow of the first airflow and the second airflow.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to an electrophotographic image forming apparatus such as a copier, a printer, a facsimile, or a multifunction machine having a plurality of these functions. [Background technology]

[0002] Conventionally, image forming devices such as copiers, printers, facsimiles, and multifunction devices equipped with two or more of these functions have been configured to have fans to create airflow to suppress temperature increases inside the device and to collect ozone, toner, and the like inside the device.

[0003] For example, Patent Document 1 proposes a configuration in which a plurality of ventilation ducts corresponding to a plurality of photoconductors are provided, and the ducts are joined together and then exhausted to the outside of the image forming apparatus through a filter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-324687 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration of Patent Document 1 described above, multiple air flows join simultaneously at the joining point where multiple ventilation ducts join, so there is a risk of a decrease in exhaust efficiency from the exhaust duct after the joining.

[0006] SUMMARY OF THE PRESENTLY PREFERRED EMBODIMENTS An object of the present invention is to provide an image forming apparatus capable of suppressing a decrease in exhaust efficiency in an exhaust configuration in which a plurality of air flows are joined together and exhausted. [Means for solving the problem]

[0007] an exposure unit that forms an electrostatic latent image on the photoconductor charged by the charger; a development unit that develops the electrostatic latent image formed on the photoconductor with toner to form a toner image on the photoconductor; a transfer unit that transfers the toner image onto a sheet; a cleaning unit that cleans toner remaining on the photoconductor; a recovery unit having a recovery path that transports and recovers the toner recovered by the cleaning unit; a first duct that forms a first air flow for exhausting air in the vicinity of the development unit; a second duct that forms a second air flow for exhausting air in the vicinity of the recovery path; a third duct that forms a third air flow for exhausting air in the vicinity of the charging unit; a first connection portion that connects the first duct and the second duct to merge the first air flow and the second air flow; and a second connection portion that connects the third duct and the first connection portion to merge the third air flow into a merged air flow of the first air flow and the second air flow. an intake fan that takes in air into the first duct, the second duct, and the third duct, and an exhaust fan that exhausts air from the first duct, the second duct, and the third duct, and makes the pressure inside the first duct, the second duct, and the third duct negative relative to the outside of the device depending on the difference between the air volume of the intake fan and the air volume of the exhaust fan; It is characterized by: Effect of the Invention

[0008] According to the present invention, exhaust efficiency can be reduced in an exhaust configuration in which a plurality of air flows are joined together and exhausted. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of an image forming system including an image forming apparatus according to an embodiment of the present invention. [Diagram 2] 1 is a schematic cross-sectional view of an image forming unit of an image forming apparatus according to an embodiment of the present invention. [Diagram 3] 2 is a schematic cross-sectional view of a fixing and conveying unit of the image forming apparatus according to the embodiment. [Figure 4] FIG. 4 is a rear view of the airflow arrangement of the image forming apparatus according to the embodiment. [Diagram 5] FIG. 4 is a block diagram showing the fan airflow of the image forming apparatus according to the embodiment. [Figure 6]1A is a front view showing the appearance of an image forming apparatus according to an embodiment of the present invention, and FIG. [Figure 7] FIG. 2 is a rear perspective view of the duct unit according to the embodiment. [Figure 8] FIG. 2 is a front perspective view of the duct unit according to the embodiment. [Figure 9] FIG. 4 is an explanatory diagram showing an air flow in a development exhaust duct according to the embodiment. [Figure 10] 5A and 5B are explanatory diagrams showing the airflow of a development exhaust duct and the airflow of an ozone exhaust duct according to the embodiment; [Figure 11] 1A is a perspective view showing a state in which the developer exhaust duct and the ozone exhaust duct are joined together, and FIG. [Figure 12] 1A is a perspective view illustrating a joint portion of a developer exhaust duct and an ozone exhaust duct, and FIG. [Figure 13] FIG. 4 is a perspective view of the vicinity of a joint on the ozone exhaust duct side. [Figure 14] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in the following embodiments may be changed as appropriate depending on the configuration of the device to which the present invention is applied and various conditions, and are not intended to limit the scope of the present invention to only those.

[0011] <Embodiment 1> (Image forming system) Fig. 1 is a schematic cross-sectional view of an image forming system 100 including an image forming apparatus 101 according to an embodiment of the present invention. The image forming apparatus 101 shown in Fig. 1 is composed of an image forming unit 102 that transfers a toner image onto a fed sheet S, and a fixing and conveying unit 103 that fixes the transferred toner image onto the sheet S. The image forming unit 102 and the fixing and conveying unit 103 are each independent housings, and are movable by a plurality of casters provided on each. With this configuration, even a large device can be packaged and transported in a separated state for each housing, improving the workability during distribution up to installation.

[0012] An original reading device 104 for reading an original image and an original feeding device 105 for feeding a plurality of stacked originals to the original reading device 104 one by one are selectively connected to the upper portion of the image forming unit 102 .

[0013] Any one of a large-capacity feeding device 106 having a plurality of sheet storage units, a manual feeding device (not shown), or a long-length feeding device (not shown) capable of accommodating long sheets can be selectively connected to the upstream side of the image forming unit 102 in the sheet conveying direction. Any one of a large-capacity feeding device, a manual feeding device, and a long-length feeding device (not shown) can be selectively connected in a multiple-unit fashion to the further upstream side of the large-capacity feeding device 106.

[0014] A sensing device 107 is selectively connected to the downstream side of the fixing and conveying section 103 in the sheet conveying direction for reading the fixed toner image formed on one or both sides of the sheet S, detecting the image density and image position deviation, and performing feedback correction on the image signal transmitted to the image forming section 102.

[0015] Further downstream of the fixing and conveying section 103 or the sensing device 107, various sheet processing devices (not shown), such as an inserter, puncher, case binder, large-capacity stacker, folder, finisher, trimmer, etc., can be selectively connected, either individually or in combination.

[0016] As described above, the image forming apparatus 101 of this embodiment is selectively connected to various optional devices upstream and downstream in the sheet conveying direction, making it possible to in-line output of products that have been subjected to various post-processing processes for various materials, thereby providing an image forming system 100 that is highly productive, has high image quality, is highly stable, and is highly functional. Note that in this embodiment, the direction of the arrow X shown in the figure is the width direction (left-right direction) of the image forming system 100, the direction of the arrow Y is the front-rear direction, and the direction of the arrow Z is the vertical direction (up-down direction).

[0017] (Image forming apparatus: image forming unit 102) Fig. 2 is a schematic cross-sectional view of the image forming unit 102 in the image forming apparatus 101 of this embodiment. The image forming unit 102 shown in Fig. 2 includes a plurality of image forming stations 200 that form different toner images for each color, namely, yellow (Y), magenta (M), cyan (C), and black (K). Fig. 2(a) is a schematic cross-sectional view of the entire image forming unit 102. Fig. 2(b) is a schematic cross-sectional view of the image forming stations 200Y, M, and C. Fig. 2(c) is a schematic cross-sectional view of the image forming station 200K.

[0018] As shown in Fig. 2(a), the surface of the photosensitive drum 201 in each image creating station 200 is uniformly charged by a primary charger 202, and then an electrostatic latent image is formed on the photosensitive drum 201 by a laser scanner 203 driven based on a signal of transmitted image information. The latent image formed here is developed into a toner image by a developing device 204. In this embodiment, the photosensitive drum 201 is an example of a photosensitive body, the laser scanner 203 is an example of an exposure unit, and the developing device 204 is an example of a developing unit.

[0019] The toner consumed in the development is appropriately replenished to each developing device 204 from a toner bottle 205 via a toner replenishment path 206. The imaging stations 200Y, M, and C have a common configuration, except for the color of toner they use. In the following description, the reference characters Y, M, C, and K are omitted for the common configuration. Note that the imaging station 200K has a configuration with a part having a different function from the imaging stations 200Y, M, and C, and the differences will be described later.

[0020] The toner image on the photosensitive drum 201 is sequentially transferred onto the intermediate transfer belt 208 by the primary transfer roller 207, with a predetermined pressure and an electrostatic load bias being applied thereto. Here, the intermediate transfer belt 208 in this embodiment is an example of a transfer unit. A small amount of residual toner remaining on the photosensitive drum 201 after transfer is removed by a photosensitive drum cleaner 209 in preparation for the next image formation. The removed residual toner is collected in a recovered toner container 211 via a toner recovery path 210. Here, the photosensitive drum cleaner 209 is an example of a cleaning unit for cleaning the residual toner on the photosensitive drum 201, and the recovered toner container 211 is an example of a recovery unit.

[0021] Meanwhile, sheets S fed one by one from a sheet storage unit 212 inside the image forming unit 102 or from any of the above-mentioned sheet feeding devices connected externally to the image forming apparatus 101 are subjected to skew correction by forming a loop by making the leading edge follow the nip portion of the registration rollers 213. Thereafter, the registration rollers 213 convey the sheet S to the secondary transfer unit in synchronization with the toner image on the intermediate transfer belt 208.

[0022] The toner image on the intermediate transfer belt 208 is transferred to the sheet S by applying a predetermined pressure and electrostatic load bias at a secondary transfer nip consisting of a secondary transfer inner roller 214 and a secondary transfer outer roller 215. After transfer, a small amount of residual toner remaining on the intermediate transfer belt 208 is removed by an intermediate transfer belt cleaner 216 in preparation for the next image formation. The removed residual toner is collected in a recovered toner container 211 via a toner recovery path 210. The sheet S onto which the toner image has been transferred is transported to the downstream fixing transport section 103 by pre-fixing transport belts 217a, b.

[0023] (Image forming device: black and white image formation) The image forming apparatus 101 of this embodiment can form full-color images using all the image forming stations 200 for Y, M, C, and K described above, as well as black-and-white images using only the K image forming station 200K.

[0024] During black-and-white image formation, the primary transfer roller 207, the primary transfer auxiliary roller 218, and the intermediate transfer belt 208 are displaced to the positions indicated by the dashed lines in Fig. 2(a) by a spacing mechanism (not shown). This spacing mechanism allows the Y, M, and C image forming stations 200Y, 200M, and 750 separated from the intermediate transfer belt 208 to stop rotating. That is, unnecessary wear of parts due to unnecessary rotational driving can be prevented in the Y, M, and C image forming stations 200Y, 200M, and 750, and the lifespan can be extended.

[0025] On the other hand, the photosensitive drum 201K is configured with a larger diameter suitable for a longer life than the photosensitive drums 201Y, 201M, and 201C. Also, as shown in Fig. 2(c), the primary charger 202K is configured with a non-contact type using a corona charger suitable for a longer life than the contact type using roller chargers of the primary chargers 202Y, 202M, and 202C. Furthermore, the toner bottle 205K is configured with a larger capacity suitable for a longer life than the toner bottles 205Y, 205M, and 205C.

[0026] With the above configuration, even for a user who frequently uses black and white image formation, the maintenance interval of the frequently used K imaging station 200K can be prevented from becoming shorter than that of the less frequently used Y, M and C imaging stations 200Y, 200M and 750.

[0027] In addition, the large diameter drum configuration using corona charger 202K has a wider charging width and is more suitable for high speeds than the small diameter drum configuration using roller chargers 202Y, 202M, and 202C, and therefore can improve productivity when forming black and white images.

[0028] In the image forming unit 102 having different conditions between the image forming stations 200, the toner charge amount on the photosensitive drum 201 may differ due to differences in shape and wear. If the toner charge amount differs, the toner image may not be transferred uniformly to the sheet S in the secondary transfer process, resulting in a defective image. Therefore, the K photosensitive drum 201K is provided with a pre-transfer charger 219 consisting of a corona charger for equalizing the toner charge amount with the Y, M, and C photosensitive drums 201Y, 201M, and 201C. Here, the pre-transfer charger 219 is an example of another charging unit provided between the developer 204K and the photosensitive drum cleaner 209K in the rotation direction of the photosensitive drum 201.

[0029] As described above, according to the configuration of this embodiment, it is possible to provide an image forming apparatus 101 that is excellent in terms of high productivity, high image quality, high stability, and long life not only in full-color image formation but also in black-and-white image formation.

[0030] (Image forming apparatus: fixing conveying section 103) 3 is a schematic cross-sectional view of the fixing and conveying section 103 in the image forming apparatus 101 of this embodiment. The fixing unit 301 shown in FIG. 3 fixes a toner image on the sheet S conveyed by the image forming section 102 onto the sheet S by applying heat and pressure to the sheet S.

[0031] In this embodiment, the fixing unit 301 has a heating roller 301a heated by a heater (not shown) on the vertical upper side, and a pressure roller 301b that presses the sheet against the heating roller 301a on the vertical lower side. The sheet S on which a toner image is formed is heated and pressed in a fixing nip formed by the heating roller 301a and the pressure roller 301b, so that the toner image is fixed. The heating roller 301a and the pressure roller 301b pinch and convey the sheet downstream in the sheet conveying direction while heating and pressurizing the sheet. Here, the fixing unit 301 made of a pair of rollers has been described as an example, but the fixing unit 301 may be one in which a fixing nip is formed by a conveying belt.

[0032] The sheet S heated by the fixing unit 301 is transported by the transport belts 302a, b while being cooled by the heat absorption of the heat sink 303 in contact with the inner surface of the transport belt 30a of the cooling unit 302, and is discharged via the discharge transport path 304 to the sensing device 107 mentioned above or a post-processing device not shown.

[0033] When the sheet S is to be discharged upside down, the sheet S is switched back and conveyed in a discharge / reversal unit 305, and the sheet S is discharged through a discharge / conveyance path 304 in an upside-down state with the leading and trailing ends thereof swapped.

[0034] When forming images on both sides of the sheet S, the sheet S on which the image on the first side has been formed is switched back and conveyed in a duplex inversion section 306, and the leading and trailing ends of the sheet S are swapped and conveyed in an inverted state to a duplex conveying path 307. Thereafter, the sheet S is rejoined by the registration rollers 213 in synchronization with the succeeding sheet S fed from the sheet storage section 212 inside the image forming section 102 or any of the above-mentioned externally connected sheet feeding devices, and an image is formed on the second side in the same process as the first side, and the sheet is discharged via a discharge conveying path 304.

[0035] (Image forming device: Air flow arrangement) 4 is a diagram showing an airflow arrangement in the image forming apparatus 101 of this embodiment, as viewed from the rear side of the image forming apparatus 101. Here, the front side of the image forming apparatus 101 refers to the side from which the sheet storage unit 212 is pulled out relative to the image forming apparatus 101 when refilling the sheet storage unit 212 with sheets, and is the position where a user who operates the image forming apparatus 101 stands. The rear side of the image forming apparatus 101 refers to the side opposite to the front side in the front-rear direction (the insertion / removal direction of the sheet storage unit 212).

[0036] 4, the image forming apparatus 101 includes an imaging airflow 401, a pre-fixing transport airflow 402, and a power supply airflow 403. The fixing transport section 103 includes a fixing airflow 404, a cooling unit airflow 405, a power supply airflow 406, and an electrical equipment airflow 407.

[0037] The imaging air flow 401 of the image forming unit 102 includes a primary charger intake fan 408 , developing unit intake fans 409 Y, 409 M, and 409 C, and an imaging exhaust fan 410 .

[0038] The primary charger intake fan 408 supplies outside air for ventilation to the primary charger 202K of the image forming station 200K. A primary charger intake filter 411 is disposed upstream of the primary charger intake fan 408 to collect dust floating in the outside air and supply purified air to the K primary charger 202K.

[0039] The developing unit intake fans 409Y, 409M, and 409C supply outside air to the developing units 204Y, 204M, and 204C for cooling.

[0040] The imaging exhaust fan 410 exhausts ozone emitted by the K primary charger 202K and the pre-transfer charger 219 due to corona discharge from the K imaging station 200K. The imaging exhaust fan 410 also exhausts heat emitted by each developing device 204 due to friction during rotation from each imaging station 200. The imaging exhaust fan 410 also exhausts heat accumulated inside from the toner recovery path 210. Furthermore, the imaging exhaust fan 410 exhausts a small amount of floating toner emitted in each process of toner image formation from each imaging station 200. An imaging exhaust filter 412 is disposed upstream of the imaging exhaust fan 410 to collect ozone and toner-containing dust exhausted from each imaging station 200 and exhaust the purified air to the outside of the device 101.

[0041] According to the configuration of the imaging air flow 401 described above, the ozone, heat, and dust emitted during the imaging process can be efficiently exhausted without being retained in each imaging station 200, and can be collected by the imaging exhaust filter 412.

[0042] In other words, it is possible to prevent charging image defects such as uneven charging caused by ozone or dust adhering to the photosensitive drum 201 or the primary charger 202, developed image defects caused by the toner overheating and deteriorating fluidity, operational malfunctions such as clogging of the toner transport path, and transferred image defects caused by ozone or dust adhering to the pre-transfer charger 219.

[0043] Therefore, it is possible to provide an image forming apparatus 101 that is excellent in image quality, stability, and life span. Also, it is possible to provide an image forming apparatus 101 that is excellent in environmental consideration by reducing the amount of ozone and dust discharged to the outside of the image forming apparatus 101. The detailed configuration of the imaging air flow 401 will be described later.

[0044] Further, a pre-fixing conveying suction fan 413 is provided on the inner periphery of the pre-fixing conveying belts 217a, b to suction the sheet S to the outer periphery of the pre-fixing conveying belts 217a, b through a suction port (not shown) provided on the pre-fixing conveying belts 217a, b. A total of four pre-fixing conveying suction fans 413 are provided, two on the front and two on the back of each of the fixing conveying belts 217a, b. In this manner, the pre-fixing conveying air flow 402 of the image forming unit 102 is formed by the pre-fixing conveying suction fans 413.

[0045] The pre-fixing transport suction fan 413 is adjusted to an optimal air volume according to the material and shape of the transported sheet S by a control circuit (not shown). With this configuration, it is possible to stably transport a variety of materials without disturbing the unfixed toner image on the sheet S. Therefore, it is possible to provide an image forming apparatus 101 that is excellent in high image quality, high stability, and high functionality.

[0046] Note that the pre-fixing transport suction fan 413 may suck in heat, VOCs, dust, and UFPs emitted from the adjacent fixing unit 301. Therefore, the pre-fixing transport air flow 402 collects VOCs, dust, and UFPs using a fixing lower exhaust filter 422 (described later) and exhausts the purified air to the outside of the apparatus 101. With this configuration, it is possible to provide an image forming apparatus 101 that is environmentally friendly and reduces the amount of VOCs, dust, and UFPs discharged to the outside of the apparatus 101.

[0047] The power supply airflow 403 of the image forming unit 102 includes a power supply exhaust fan 415 that exhausts heat emitted by the power supply board 414 to the outside of the image forming apparatus 101. As the power supply exhaust fan 415 exhausts heat, outside air for cooling is supplied from the power supply intake port 416, and the power supply board 424 can be efficiently cooled. This configuration makes it possible to prevent malfunctions and breakdowns of the image forming apparatus 101 caused by a drop in output due to an overheating of the power supply board 414. Therefore, it is possible to provide an image forming apparatus 101 that is excellent in terms of high productivity, high stability, and long life.

[0048] The fixing air flow 404 of the fixing transport unit 103 includes a fixing heat exhaust fan 417 , a fixing pressurized intake fan 418 , a fixing pressurized exhaust fan 419 , and a moisture exhaust fan 420 .

[0049] Fixing heat exhaust fan 417 mainly exhausts heat emitted from the upper part, which is the heated side, of fixing unit 301 to the outside of device 101. When the components constituting fixing unit 301 or the release agent (wax) contained in toner are heated, VOCs, dust, UFPs, etc. may be emitted along with the heat. Therefore, on the downstream side of the airflow generated by fixing heat exhaust fan 417, fixing upper exhaust filter 421 for collecting VOCs, dust, and UFPs is provided.

[0050] The fixing pressurization intake fan 418 supplies outside air for cooling to the lower part, which is the pressurized side, of the fixing unit 301. The fixing pressurization exhaust fan 419 exhausts heat emitted from the lower part, which is the pressurized side, of the fixing unit 301 to the outside of the image forming apparatus 101. The moisture exhaust fan 420 exhausts water vapor emitted from the sheet S heated by the fixing unit 301 to the outside of the apparatus 101.

[0051] A fixing lower exhaust filter 422 is disposed downstream of the airflow generated by the fixing pressurization exhaust fan 419, the moisture exhaust fan 420, and the pre-fixing transport suction fan 413 described above, for collecting VOCs, dust, and UFPs emitted along with heat and water vapor.

[0052] According to the configuration of fixing air flow 404 described above, the heat, moisture, VOCs, dust, and UFPs released in the heating process can be efficiently discharged without accumulating inside image forming apparatus 101. In other words, it is possible to prevent image defects and operational defects caused by heat accumulating in image forming apparatus 101 and excessive temperature rise of toner and parts of each unit.

[0053] Also, it is possible to prevent defective fixed images and defective sheet transport such as defective fixation and separation caused by excessive heat given to the toner in the fixing process due to the pressure side of the fixing unit 301 rising too high. It is also possible to prevent condensation on the transport guide caused by water vapor adhering, and defective transport and defective images caused by condensed water droplets adhering to the sheet S during transport. Furthermore, it is possible to prevent malfunctions and defective sheet transport caused by the release agent (wax) vaporized by heating solidifying again and adhering to parts, etc. Therefore, it is possible to provide an image forming apparatus 101 that is excellent in high image quality, high stability and long life. It is also possible to provide an image forming apparatus 101 that is excellent in environmental consideration by reducing the amount of VOC, dust and UFP discharged to the outside of the image forming apparatus 101.

[0054] The cooling unit airflow 405 of the fixing and conveying section 103 includes a cooling unit exhaust fan 423 for discharging heat emitted by a heat sink 303 disposed inside the cooling unit 302 to the outside of the apparatus 101. The heat sink 303 of the cooling unit 302 is a heat exchanger that absorbs heat from the fixed sheet S via the conveying belt 302a and releases the absorbed heat. With this configuration, the sheet S heated by the fixing unit 301 can be efficiently cooled, and the amount of heat released from the sheet S in the downstream conveying path can be reduced.

[0055] That is, it is possible to prevent image defects and operational defects caused by the toner in the image forming unit 102 overheating due to heat radiation from the sheet S during double-sided image formation. It is also possible to prevent toner images from sticking between the sheets S when a large amount of products are stacked in the post-processing device. Therefore, it is possible to provide an image forming apparatus 101 that is excellent in high image quality and high stability.

[0056] The power supply airflow 406 of the fixing conveying unit 103 includes power supply exhaust fans 425 and 426 that exhaust heat emitted from the power supply board 424 to the outside. As the power supply exhaust fans 425 and 426 exhaust air, air for cooling is supplied from the power supply intake port 427, and the power supply board 424 can be efficiently cooled. This configuration makes it possible to prevent malfunctions and breakdowns caused by the power supply board 424 overheating and reducing its output. Therefore, it is possible to provide an image forming apparatus 101 that is excellent in terms of high productivity and high stability.

[0057] The electrical airflow 407 of the fixing and conveying section 103 includes an electrical exhaust fan 430 that exhausts heat emitted by the electrical boards 428 and 429 to the outside. As the electrical exhaust fan 430 exhausts air, air for cooling is supplied from the electrical intake port 431, and the electrical boards 428 and 429 can be efficiently cooled. This configuration makes it possible to prevent malfunctions and breakdowns caused by the electrical boards 428 and 429 overheating and reducing their output. Therefore, it is possible to provide an image forming apparatus 101 that is excellent in terms of high productivity and high stability.

[0058] (Image forming equipment: Air flow balance) 5 is a block diagram showing the air volume of the intake and exhaust fans in the image forming apparatus 101 of this embodiment, where (a) shows the air volume of each fan in the image forming unit 102, and (b) shows the air volume of each fan in the fixing and conveying unit 103. The numerical values ​​shown in FIG. 5 indicate, as an example, the air volume of each fan when forming an image on thick paper.

[0059] The dashed lines in FIG. 5(a) indicate the total range of the intake fan total air volume Q1 and the exhaust fan total air volume Q2 acting on the inside of the image forming unit 102 of the image forming apparatus 101. Here, the power supply air flow 403 is configured with an independent air passage that does not communicate with the inside of the image forming unit 102 and the fixing and conveying unit 103, and is configured to directly intake and exhaust the outside air. Therefore, the power supply air flow 403 is excluded from the total value because it does not affect the air flow inside the image forming unit 102. Here, the intake fan is a fan that takes in air from outside the image forming apparatus 101 into the inside of the apparatus, and among the fans provided in the image forming unit 102, the primary charger intake fan 408 and the three developer intake fans 409C, M, and Y correspond to this. An exhaust fan is a fan for discharging air inside the image forming apparatus 101 to the outside of the apparatus, and among the fans provided in the image forming unit 102, the image creation exhaust fan 410 and the four pre-fixing transport suction fans 413 correspond to this.

[0060] In this embodiment, the image forming apparatus 101 is configured such that the total air volume Q2 of the exhaust fans is larger than the total air volume Q1 of the intake fans of the image forming unit 102 as described below.

[0061] Q1: 0.60m 3 / min <Q2:2.13m 3 / min According to this configuration, the inside of the image forming unit 102 can be kept at a negative pressure relative to the outside air. Therefore, it is possible to prevent ozone and dust inside the image forming unit 102 from leaking out of the image forming apparatus 101 through minute gaps such as the seams of the exterior cover. That is, the imaging exhaust filter 412 provided at the airflow exhaust port of the image forming unit 102 reliably captures ozone and dust inside the image forming apparatus 101, and it is possible to provide an image forming apparatus 101 that is excellent in environmental consideration.

[0062] The dashed line in Fig. 5(b) indicates the total range of the total air volume Q3 of the intake fans and the total air volume Q4 of the exhaust fans acting inside the fixing and conveying section 103 of the image forming apparatus 101. Here, the intake fan is a fan for taking in the air outside the image forming apparatus 101 into the inside of the apparatus, and corresponds to the fixing pressurization intake fan 418 among the fans provided in the fixing and conveying section 103. Also, the exhaust fan is a fan for discharging the air inside the image forming apparatus 101 to the outside of the apparatus, and corresponds to the three fixing exhaust heat fans 417, the fixing pressurization exhaust fan 419, the moisture exhaust fan 420, the cooling unit exhaust fan 423, the power supply exhaust fans 425 and 426, and the electrical equipment exhaust fan 430 among the fans provided in the fixing and conveying section 103.

[0063] In this embodiment, the total air volume Q4 of the exhaust fans is configured to be larger than the total air volume Q3 of the intake fans.

[0064] Q3: 1.74m 3 / min <Q4:9.77m 3 / min According to this configuration, the inside of the fixing and conveying section 103 can be kept at a negative pressure relative to the outside air. This makes it possible to prevent VOCs, dust, and UFPs inside the fixing and conveying section 103 from leaking out of the image forming apparatus 101 through minute gaps such as the seams of the exterior cover. That is, the upper fixing exhaust filter 421 and the lower fixing exhaust filter 422 provided at the airflow exhaust port of the fixing and conveying section 103 reliably collect VOCs, dust, and UFPs inside the image forming apparatus 101, making it possible to provide an image forming apparatus 101 that is excellent in environmental consideration.

[0065] Furthermore, in this embodiment, the differential air volume between the total air volume Q4 of the exhaust fans and the total air volume Q3 of the intake fans in the fixing and conveying unit 103 is configured to be larger than the differential air volume between the total air volume Q2 of the exhaust fans and the total air volume Q1 of the intake fans in the image forming unit 102.

[0066] (Q2-Q1): 1.53m 3 / min<(Q4-Q3):8.03m 3 / min According to this configuration, the inside of the fixing and conveying section 103 can be kept at a relatively more negative pressure than the inside of the image forming section 102. Therefore, it is possible to prevent the heat, VOCs, dust, UFPs, and water vapor emitted inside the fixing and conveying section 103 from flowing into the inside of the image forming section 102 through the communication section between the image forming section 102 and the fixing and conveying section 103. In other words, it is possible to prevent the heat, VOCs, dust, UFPs, and water vapor that are likely to be generated near the fixing unit 301 from flowing into the inside of the housing of the image forming section 102 disposed adjacent to the fixing and conveying section 103.

[0067] This makes it possible to prevent image defects and operational malfunctions caused by heat from the fixing unit 301 flowing into the image forming section 102 and deteriorating the fluidity of the toner, image defects, transport defects and operational malfunctions caused by VOCs, dust or UFPs flowing in and adhering to components, and image defects and transport defects caused by water vapor flowing in and condensing on components.

[0068] As described above, heat released inside the fixing and conveying section 103 is efficiently discharged from the airflow exhaust port of the fixing and conveying section 103 without remaining inside the image forming section 102, and VOCs, dust and UFPs are reliably captured by the upper fixing exhaust filter 421 and the lower fixing exhaust filter 422 provided at the exhaust port, making it possible to provide an image forming apparatus 101 that excels in high image quality, high stability, long life, and environmental friendliness.

[0069] (Image forming section: Imaging airflow 401) Next, a detailed configuration of the imaging air flow 401 will be described. In this embodiment, the imaging air flow 401 is provided in order to prevent charging image defects such as charging unevenness caused by ozone or dust adhering to the photosensitive drum 201 or the primary charger 202 as described above, developed image defects caused by toner overheating and deteriorating fluidity, operational defects such as clogging of the collection path 210, and transferred image defects caused by ozone or dust adhering to the pre-transfer charger 219.

[0070] In this embodiment, polyester resin is used as the binder resin for the toner, and if the temperature in the vicinity of the developing device 204 becomes 40° C. or higher, there is a risk of image defects occurring, and if the temperature in the vicinity of the collection path 210 becomes 45° C. or higher, there is a risk of toner clogging. Therefore, in the imaging air flow 401 of this embodiment, intake and exhaust are performed so that the temperature in the vicinity of the developing device 204 becomes 40° C. or lower and the temperature in the vicinity of the collection path 210 becomes 45° C. or lower.

[0071] 6A and 6B are diagrams showing the external appearance of the image forming unit 102 of the image forming apparatus 101, where (a) is a front view and (b) is a right side view.

[0072] As shown in Fig. 6(a), a front cover 60a provided on the front side of the image forming unit 102 is provided with an intake port 61. As shown in Fig. 6(b), a side cover 60b provided on the right side of the image forming unit 102 is provided with an intake port 62.

[0073] The aforementioned developing intake fans 409Y, M, and C are fans that draw air from outside the image forming unit 102 through the intake port 61 of the front cover 60a in order to cool each developing device 204 and keep it at or below a predetermined temperature.

[0074] The primary charger intake fan 408 is a fan for blowing the air outside the image forming unit 102, which is sucked in through the intake port 62, from above the primary charger 202K toward the photosensitive drum 201K.

[0075] 7 shows a duct unit 700 constituting the imaging airflow 401. The duct unit 700 in this embodiment is a duct unit that merges multiple airflows, such as an airflow for cooling the developing devices 204, an airflow for collecting ozone released by corona discharge of the primary charger 202K and the pre-transfer charger 219, and an airflow for discharging heat retained in the toner recovery path 210, and exhausts the air from one exhaust port. In other words, it is a duct unit that takes in air from multiple intake ports, merges the airflows, and then exhausts the air to the outside of the image forming unit 102.

[0076] In this way, when multiple air flows are joined together, if the joining points of the multiple air flows overlap and pressure loss increases, there is a risk of the overall exhaust efficiency decreasing. Therefore, the duct unit 700 of this embodiment provides a configuration that suppresses the decrease in exhaust efficiency while joining multiple air flows. The duct unit 700 will be described in detail below with reference to Figs. 7 to 10.

[0077] As shown in FIG. 7, the duct unit 700 is fixed to a rear plate 501 and a bottom plate 502 which are parts of the support frame of the image forming unit 102. Here, the support frame of the image forming unit 102 is composed of a plurality of support columns (not shown) fixed to the bottom plate 502 and extending in the vertical direction, a front plate (not shown) fixed to the support columns on the front side of the image forming apparatus 101, a rear plate 501 fixed to the bottom plate 502 on the rear side of the image forming apparatus 101, and a plurality of stays connecting each support column and the rear plate 501. Each unit such as the imaging station 200 described above is supported by the front plate and the rear plate 501 (not shown). The bottom plate 502 is a portion to which a plurality of casters of the image forming unit 102 described above are attached, and is a plate-like member facing the installation surface of the image forming apparatus 101.

[0078] 7, the duct unit 700 is located on the rear side of the rear plate 501 in the image forming section 102. In other words, the duct unit 700 is attached to the surface (rear side) of the rear plate 501 opposite to the surface (front side) on which the imaging units are located.

[0079] In this embodiment, the duct unit 700 includes a development exhaust duct 701, an ozone exhaust duct 702, an imaging exhaust duct 703, and an outside exhaust duct 704. The airflow formed by each duct will be described below.

[0080] Fig. 8 is a perspective view of the duct unit 700 as viewed from the front side. Note that the rear side plate 501 is omitted in Fig. 8. Fig. 9 is a cross-sectional view of the duct unit 700 as viewed from the rear side, showing the airflow of the developer exhaust duct 701. Fig. 10 is a cross-sectional view of the duct unit 700 as viewed from the right side, showing the airflow of the developer exhaust duct 701 and the airflow of the ozone exhaust duct 703.

[0081] As shown in FIG. 8, the developer exhaust duct 701 is provided with a developer exhaust section 701a and a cooling exhaust section 701b, which are integrally made of resin. The developer exhaust section 701a is provided with developer exhaust ports 71Y,M,C. These developer exhaust ports 71Y,M,C are provided at positions corresponding to the respective developers 204Y,M,C so as to exhaust the air that is sucked in by the developer intake fans 409Y,M,C and passes near the developers 204Y,M,C. In addition, the rear side plate 501 is provided with openings corresponding to the developer exhaust ports 71Y,M,C, and the developer exhaust duct 701 exhausts the air near the developers 204Y,M,C from the developer exhaust ports 71Y,M,C through the openings. In this embodiment, the vicinity of the developers 204Y,M,C refers to the area around the developers 204Y,M,C through which the airflow formed by the intake of the developer intake fans 409Y,M,C flows. This makes it possible to suppress the occurrence of defective developed images caused by the toner in the developing device overheating and the toner fluidity deteriorating due to the ambient temperature of each developing device 204Y, M, C exceeding a predetermined temperature.

[0082] Inside the developer exhaust portion 701a of the developer exhaust duct 701, the airflow of the air sucked in from the developer exhaust port 71Y, the airflow of the air sucked in from the developer exhaust port 71M, and the airflow of the air sucked in from the developer exhaust port 71C join together.

[0083] Here, inside the developer exhaust section 701a of the developer exhaust duct 701, the confluence point of the air flow sucked in from the developer exhaust port 71Y and the air flow sucked in from the developer intake port 71M is located upstream of the confluence point with the air flow sucked in from the developer intake port 71C.

[0084] In other words, in the developer exhaust section 701a of the developer exhaust duct 701, from the upstream side of the airflow, first the airflow of air sucked in from the developer exhaust port 71Y and the airflow of air sucked in from the developer exhaust port 71M join together, and then downstream the airflow of air sucked in from the developer exhaust port 71C joins together.

[0085] This configuration can suppress airflow loss more effectively than a configuration in which the airflows are simultaneously merged. The airflow W1 in the developer exhaust duct 701 where the air sucked in from each of the developer intake ports 71Y, M, and C merge is shown in Fig. 9. Here, the developer intake port 71Y is an example of a first intake port, the developer intake port 71M is an example of a second intake port, and the airflow W1 is an example of a first airflow.

[0086] Next, the air flow in the cooling exhaust section 701b of the development exhaust duct 701 will be described. The cooling exhaust section 701b of the development exhaust duct 701 has a pre-transfer charging exhaust port 72 and an imaging cooling port 73 as shown in FIG. 8. The pre-transfer charging exhaust port 72 is an intake port for sucking air containing ozone, which is a discharge material generated by the pre-transfer charger 219, from the vicinity of the pre-transfer charger 219 into the inside of the cooling exhaust section 701b of the development exhaust duct 701. The imaging cooling port 73 is an intake port for supplying air in the vicinity of the toner recovery path 210 into the inside of the cooling exhaust section 701b of the development exhaust duct 701. Here, in this embodiment, the cooling exhaust port 73 is an example of a first opening for introducing air in the vicinity of the toner recovery path 210 into the inside of the cooling exhaust section 701b. The pre-transfer charging exhaust port 72 is an example of a second opening for introducing air in the vicinity of the pre-transfer charger 219 into the inside of the cooling exhaust section 701b.

[0087] In this embodiment, an air flow is formed by the imaging exhaust fan 410 so as to suck air from the pre-transfer charging exhaust port 72 and the imaging cooling port 73. Here, in this embodiment, the vicinity of the pre-transfer charger 219 refers to the area around the pre-transfer charger 219 where air is sucked in by the imaging exhaust fan 410, and the vicinity of the toner recovery path 210 refers to the area around the toner recovery path 210 where air is sucked in by the imaging exhaust fan 410.

[0088] As a result, the air containing ozone generated by the pre-transfer charger 219 can be sucked in by the airflow formed inside the cooling exhaust section 701b of the development exhaust duct 701, and collected by the imaging exhaust filter 412 described later. In addition, the airflow formed inside the cooling exhaust section 701b of the development exhaust duct 701 can release heat accumulated inside the toner recovery path 210.

[0089] 9, the cooling exhaust section 701b of the development exhaust duct 701 is provided with the pre-transfer charging exhaust port 72 upstream of the imaging cooling port 73 in the airflow. Therefore, when the imaging exhaust fan 40 rotates, the airflow W2 formed by the air sucked from the pre-transfer charging exhaust port 72 merges with the airflow W3 formed by the air sucked from the imaging cooling port 73 at the position where the imaging cooling port 73 is provided, and becomes the airflow W23 downstream of the imaging cooling port 73. Here, the airflow W23 is an example of the second airflow.

[0090] As shown in FIG. 10, the cooling exhaust portion 701b of the development exhaust duct 701 has guide shape portions 701bR1 and 702bR2 so that the airflow sucked in from the pre-transfer charging exhaust port 72 and the imaging cooling port 73 flows smoothly downward in the vertical direction.

[0091] Here, the guide shape portion 701bR1 guides the airflow W2 of the air sucked in from the pre-transfer charging exhaust port 72 vertically downward and causes it to merge with the airflow W3.

[0092] The airflow W23 is sucked by the imaging exhaust fan 240 and flows along the rear side of the cooling exhaust portion 701b of the development exhaust duct 701. That is, the airflow W23 flows vertically downward along the curved shape of the guiding shape portion 702R2.

[0093] In this embodiment, the pre-transfer charger exhaust port 72 is located higher than the imaging cooling port 73 in order to exhaust the air around the pre-transfer charger 219. However, it may be an intake port for exhausting air other than that of the pre-transfer charger 219. Even if the pre-transfer charger exhaust port 72 is located lower than the imaging cooling port 72, it may have a similar merging configuration.

[0094] 9, in the development exhaust duct 701, the airflow W1 of the development exhaust section 701a and the airflow W23 of the cooling exhaust section 701b join together to form an airflow W123. Here, the position where the imaging cooling port 73, which is the joining point of the airflow W2 and the airflow W3, is provided is provided upstream of the joining point of the airflow W1 and the airflow W23. This prevents the airflows W1, W2, and W3 from joining together at the same time, thereby suppressing the pressure loss of the airflows when the airflows W1, W2, and W3 are joined together.

[0095] In addition, a downward guide shape portion 701aR is provided in the developer exhaust portion 791a of the developer exhaust duct 701 so that the airflow W1 of the developer exhaust duct 701 smoothly changes from a horizontal direction (arrow -X direction) to a vertical downward direction (arrow -Z direction). In addition, a lower end portion 701aRl of the downward guide shape portion 701aR of the developer exhaust portion 701a is disposed below a lower surface 701al of the left-right crossing portion of the developer exhaust duct 701. In addition, the airflow W1 and the airflow W23 are blocked by a shielding wall 701c, and a lower end portion 701cl of the shielding wall 701c is disposed vertically below a lower end portion 701aRl of the downward guide shape portion 701aR, so that the airflow W1 is deflected downward before being merged with the airflow W23.

[0096] That is, the airflow W23 joins with the airflow W1 downstream of the position where the airflow W23 is guided vertically downward along the curved surface of the guiding shape portion 702bR2 as described above. Therefore, the developer exhaust duct 701 is formed so that the airflow W1 and the airflow W23 are oriented vertically downward at the joining point of the airflow W1 and the airflow W23. This makes it possible to suppress an increase in pressure loss compared to a configuration in which the airflow W1 of the developer exhaust portion 701a of the developer exhaust duct 701 joins with the airflow W23 in a state where the airflow W1 is oriented in the horizontal direction (in the direction of the arrow -X).

[0097] Here, the developer exhaust section 701a of the developer exhaust duct 701 is an example of a first duct, and the cooling exhaust section 701b is an example of a second duct. Also, a region in the developer exhaust duct 701 where the airflow W1 and the airflow W23 join together to form the airflow W123 is an example of a first connecting section. That is, in the developer exhaust duct 701, a portion downstream of the airflow from the lower end 701cl of the shielding wall 701c is an example of the first connecting section.

[0098] Next, a description will be given of a confluence configuration of the air flow W123 in the development exhaust duct 701 and the air flow W4 in the ozone exhaust duct 702. As shown in Figures 8 and 10, the charger exhaust port 74 is provided at the topmost position in the vertical direction, and sucks air near the primary charger 202K, including ozone generated by the primary charger 202K, into the ozone exhaust duct 702.

[0099] In this embodiment, an air flow is formed by the imaging exhaust fan 410 so as to draw in air from the charging exhaust port 74. Here, the vicinity of the primary charger 202K in this embodiment refers to the area around the primary charger 202K where air is drawn in by the imaging exhaust fan 410.

[0100] The air containing ozone generated by the primary charger 202K can be sucked in by the air flow formed inside the ozone exhaust duct 702 and collected by the imaging exhaust filter 412 described later.

[0101] The air sucked into the primary charger 202K of the image forming station 200K by the primary charger intake fan 408 described above is exhausted to the outside of the image forming unit 102 through this ozone exhaust duct 703 and the image forming exhaust filter 412.

[0102] Here, the ozone exhaust duct 702 is provided on the rear side of the development exhaust duct 701 in the image forming apparatus 101 of this embodiment. Therefore, the air flow W4 formed inside the ozone exhaust duct 702 passes through the rear side of the image forming apparatus as shown in Fig. 10 and merges with the above-mentioned air flow W123 to become the merged air flow Wt. Here, the air flow W4 in this embodiment is an example of a third air flow.

[0103] Like the other duct shapes, the ozone exhaust duct 702 also has a guide shape portion 702R that is curved so that the airflow direction is vertically downward. As a result, the airflow W4 becomes a vertically downward airflow like the airflow W123 before merging with the airflow W123. This makes it possible to suppress an increase in pressure loss.

[0104] Further, the airflow W4 of the ozone exhaust duct 702 is configured to merge with the airflow W123 downstream of the merging point of the airflow W1 and the airflow W23 by the lower end 702l of the ozone exhaust duct. In other words, the intersection point between the guiding shape portion 701bR2 and the ozone exhaust duct 702 is disposed vertically below the lower end 701cl of the shielding wall 701c.

[0105] This allows the air flows W1 to W4 to merge one by one without merging at the same time, thereby reducing losses due to air flow interference and making the most of the performance of the imaging exhaust fan 410.

[0106] Thereafter, the combined air flow Wt passes through an imaging exhaust filter 412 provided inside an imaging exhaust duct 703 , and is exhausted from an exhaust port provided in the bottom plate 502 through an external exhaust duct 704 .

[0107] In this way, the ozone and toner contained in the air sucked in inside the image forming unit 102 in the imaging air flow 401 is captured by the imaging exhaust filter 412, so that the amount of ozone and toner discharged to the outside of the image forming apparatus 101 can be reduced, and an image forming apparatus 101 with excellent environmental friendliness can be provided.

[0108] In addition, by forming the imaging air flow 401 using the duct unit 700, the objects to be collected, such as toner, ozone, etc., can be collected by the imaging exhaust filter 412 after being collected into one air flow as the merged air flow Wt, so that the number of filters can be reduced compared to a configuration in which a filter is provided for each air flow.

[0109] Next, the coupling structure between the development exhaust duct 701 and the ozone exhaust duct 702 will be described with reference to FIGS.

[0110] Fig. 11 is a perspective view showing the relationship between the developer exhaust duct 701, the sealing sheet 260, and the ozone exhaust duct 702. Fig. 11(a) is a perspective view showing a state in which the developer exhaust duct 701 and the ozone exhaust duct 702 are joined, and Fig. 11(b) is a perspective view showing a state in which the developer exhaust duct 701 and the ozone exhaust duct 702 are disassembled.

[0111] 11A, a hole-shaped portion 750 having an opening width Lb is provided on the contact surface between the developer exhaust duct 701 and the ozone exhaust duct 702. The start position of the hole shape 750 is the intersection point between the guide shape portion 701bR2 and the ozone exhaust duct 702.

[0112] The airflow W123 described above flows along the guide portion 701bR2 until it reaches the hole portion 750, and after reaching the hole portion 750, flows as airflow Wt along the outer shape (the wall on the rear side) of the ozone exhaust duct 703.

[0113] By removing a part of the wall of the guide shape portion 701bR2, the opening cross-sectional area can be increased by the thickness of the duct for this airflow Wt. This makes it possible to reduce the loss of air volume by not reducing the duct cross-sectional area of ​​the curved shape portion, which has a large loss. This configuration is more effective when the positional relationship between the two ducts to be joined results in a curved shape with a small radius, or when the distance between the two ducts is short and the intersection with the opposing duct is located near the start of the curved shape even if the radius of the curved shape is large.

[0114] In this embodiment, the ozone exhaust duct 702 is an example of a third duct, and a portion in the duct unit 700 where the air flows W1 to W4 join together to form the joined air flow Wt is an example of a second connecting portion. That is, the position in the duct unit 700 where the hole-shaped portion 750 is provided is an example of a second connecting portion.

[0115] Next, the configuration of the sealing seal 260 will be described. Fig. 12(a) is a perspective view showing the joint between the ozone exhaust duct 702 and the developer exhaust duct 701, and is a perspective view of Fig. 11(b) seen from a different angle. Fig. 12(b) is a perspective view showing the vicinity of the hole-shaped portion 750. Fig. 13 is a perspective view of the vicinity of the joint on the ozone exhaust duct 702 side. Fig. 14 is a cross-sectional view of the vicinity of the hole-shaped portion 750. In Fig. 14, the hatched portion represents the sealing sheet 260.

[0116] The sealing sheet 260 is provided so as to fill the gap between the hole 750 provided in the development exhaust duct 701 and the ozone exhaust duct 702. This is to prevent an increase in airflow loss caused by the exhaust fan 240 sucking air from the gap at the joint of the ducts.

[0117] In this embodiment, the sealing sheet 260 is used by being crushed between the hole shaped portion 750 of the developer exhaust duct 70 and the ozone exhaust duct 702. The sealing sheet 260 is desirably made of a material that is not easily deteriorated by ozone, and for example, a foamed sealing material mainly composed of EPDM rubber is assumed.

[0118] The sealing sheet 260 is attached to the ozone exhaust duct 702 side with an adhesive tape (not shown). The sealing sheet 260 is attached without any gaps based on the lower end of the ozone exhaust duct 702, and has a gate-like shape that seals the outside of the hole shape 750 of the development exhaust duct 701.

[0119] Here, the relationship between the distance La between the sealing sheets 260 and the dimension Lb of the cutout portion of the development exhaust duct 701 is La≧Lb. If this relationship is Lb>La, the sealing sheet 260 protruding from the development exhaust duct 701 side will block part of the air path. In addition, the airflow W123 flows along the outer side surface of the development exhaust duct 701, and if there is a protruding portion of the sealing sheet 260, it will interfere with the airflow W4 of the ozone exhaust duct, causing a pressure loss.

[0120] From the above, the edge shape 702b is provided to attach the sealing seal 260 to both ends forming the opening on the ozone exhaust duct 702 side so that the distance La between the sealing sheets 260 and the cutout dimension Lb of the developer exhaust duct 701 have a relationship of La≧Lb. In this embodiment, the edge shape 702b is provided because the ozone exhaust duct outer width Lw is smaller than the size considering the width 2Lt of the two double-sided tapes and the tolerance (component and sheet attachment) α of the opening width Lb on the developer exhaust duct side. Therefore, the condition for the edge shape 702b is Lb+2Lt+α≧Lw. The edge width may be Lb+2Lt+α-Lw or more. In this case, it is possible to increase the entire ozone duct width Lw, but providing the edge shape 702b is preferable from the viewpoint of space and material costs.

[0121] Ribs 70b are provided on both sides of the developer exhaust duct 701, and the claw shapes 70a provided on the side of the edge 702b of the ozone exhaust duct 702 are hooked onto these shapes. There is a small gap between the claw shapes 70a and the ribs 70b in consideration of component tolerances, but this gap is closed by the reaction force of the sealing sheet 260 crushed between the developer exhaust duct 701 and the ozone exhaust duct 702. While the side portions of the duct unit 700 are held down by claw shapes, it is difficult to provide a holding shape such as a claw in the center from the viewpoint of molding, so two sealing ribs 750d extending in the left-right direction (arrow X direction) are provided. The sealing sheet 260 is doubly crushed by these two sealing ribs 750d, improving the sealing performance of the gap provided in the duct unit 700.

[0122] By configuring the duct unit 700 in this manner, it is possible to suppress a decrease in exhaust efficiency due to pressure loss caused by simultaneous interference between multiple air flows in an exhaust configuration in which multiple air flows are joined together and exhausted, thereby preventing the exhaust efficiency from decreasing.

[0123] <Other embodiments> In the above-described embodiment, both the pre-transfer charging exhaust port 72 and the imaging cooling port 73 are provided in the cooling exhaust portion 701b of the development exhaust duct 701, but the pre-transfer charging exhaust port 72 and the imaging cooling port 73 do not necessarily need to be provided in the same duct. For example, only the imaging cooling port 73 may be provided in the cooling exhaust portion 701b of the development exhaust duct 701, and the air sucked in from the imaging cooling port 73 may be merged with the air flow W1. In this case, when the air sucked in from the pre-transfer charging exhaust port 72 is merged with the other air flows W1 to W3, it is sufficient that the air is merged at a position that does not overlap with the merging point of the other air flows as described above.

[0124] In the above-described embodiment, the image forming apparatus 101 having a housing for the image forming unit 102 and a housing for the fixing and conveying unit 103 has been described as an example, but the present invention may be applied to an image forming apparatus having one housing or an image forming apparatus having three or more separate housings. Even in this case, by forming the imaging airflow 401 similar to that in the above-described embodiment by the duct unit 700, it is possible to prevent a decrease in exhaust efficiency in a configuration in which multiple airflows are joined together and exhausted. [Explanation of symbols]

[0125] 71 Developer exhaust vent 72 Pre-transfer charge exhaust vent 73 Imaging cooling port 74 Electrostatic exhaust vent 100 Image forming system 101 Image forming device 102 Image forming section 103 Fixing conveying section 200 Imaging Unit 202K Primary charger 204 Developer 219 Pre-transfer charger 401 Imaging Air Flow 410 Imaging exhaust fan 412 Imaging Exhaust Filter 700 Duct unit 701 Developer exhaust duct 702 Imaging exhaust duct 703 Ozone Exhaust Duct 704 Exhaust Duct 705 External Exhaust Duct

Claims

1. a charging unit for charging the photoconductor by corona discharge; an exposure unit for forming an electrostatic latent image on the photoconductor charged by the charging unit; a developing unit that develops the electrostatic latent image formed on the photoconductor with toner to form a toner image on the photoconductor; a transfer unit for transferring the toner image onto a sheet; a cleaning unit for cleaning the toner remaining on the photoconductor; a collection unit having a collection path for conveying and collecting the toner collected by the cleaning unit; a first duct forming a first air flow for exhausting air in the vicinity of the developing unit; a second duct that forms a second air flow for exhausting air in the vicinity of the recovery path; a third duct that forms a third air flow for exhausting air in the vicinity of the charging unit; a first connection portion that connects the first duct and the second duct so as to merge the first airflow and the second airflow; a second connecting portion connecting the third duct and the first connecting portion so that the third airflow is joined to a joined airflow of the first airflow and the second airflow; an intake fan that takes in air into the first duct, the second duct, and the third duct; an exhaust fan that exhausts air from the first duct, the second duct, and the third duct, a pressure inside the first duct, the second duct, and the third duct is made negative relative to the outside of the device by a difference between an air volume of the intake fan and an air volume of the exhaust fan; 1. An image forming apparatus comprising:

2. an exhaust port that exhausts the combined air flow, which is combined by the second connecting portion, to an outside of the image forming apparatus; a filter provided upstream of the exhaust port in the combined airflow; The image forming apparatus according to claim 1 , further comprising:

3. The invention further includes an exhaust fan provided between the filter and the exhaust port in the combined airflow.

3. The image forming apparatus according to claim 2,

4. Another photoreceptor different from the photoreceptor; a different developing unit for developing the electrostatic latent image on the different photoconductor with a toner of a different color from that of the developing unit; the first duct includes a first intake port for taking in air adjacent to the developing unit and a second intake port for taking in air adjacent to the other developing unit; the first duct has a first guide shape portion, which is located downstream of the first intake port and the second intake port in the first air flow and guides the first air flow vertically downward; 4. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

5. a charging unit different from the charging unit, the charging unit being provided between the cleaning unit and the developing unit in the rotation direction of the photoconductor, the charging unit charging the photoconductor by corona discharge; the second duct has a first opening for introducing air in the vicinity of the recovery path into the second duct, and a second opening for introducing air in the vicinity of the other charging unit into the second duct, The second opening is provided upstream of the first opening in the air flow inside the second duct.

5. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

6. the second duct has a second guide shape that guides the second airflow vertically downward on a downstream side of the second opening in the second airflow; 6. The image forming apparatus according to claim 5,

7. the third duct has a third intake port for taking in air in the vicinity of the charging unit, and a third guide shape portion downstream of the third intake port in a path of the third air flow for guiding the third air flow vertically downward; 7. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

8. The first duct, the second duct, and the first connecting portion are integrally formed of resin.

8. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

9. The image forming apparatus includes: a first housing having the charging unit, the exposure unit, the developing unit, the transfer unit, the cleaning unit, and the recovery unit; a second housing disposed adjacent to the first housing, the second housing having a fixing unit that heats the sheet onto which the toner image has been transferred by the transfer unit and fixes the toner image onto the sheet; the first duct, the second duct, and the third duct are provided in the first housing.

9. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

10. A sealing member is provided between the first duct and the second duct.

10. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

11. A charging unit for charging a photoconductor by corona discharge; an exposure unit for forming an electrostatic latent image on the photoconductor charged by the charging unit; a developing unit that develops the electrostatic latent image formed on the photoconductor with toner to form a toner image on the photoconductor; a transfer unit for transferring the toner image onto a sheet; a cleaning unit for cleaning the toner remaining on the photoconductor; a collection unit having a collection path for conveying and collecting the toner collected by the cleaning unit; a first duct forming a first air flow for exhausting air in the vicinity of the developing unit; a second duct that forms a second air flow for exhausting air in the vicinity of the recovery path; a third duct that forms a third air flow for exhausting air in the vicinity of the charging unit; a first connection portion that connects the first duct and the second duct so as to merge the first airflow and the second airflow; a second connecting portion connecting the third duct and the first connecting portion so that the third airflow is joined to a joined airflow of the first airflow and the second airflow; a charging unit different from the charging unit, the charging unit being provided between the cleaning unit and the developing unit in the rotation direction of the photoconductor, the charging unit charging the photoconductor by corona discharge; the second duct has a first opening for introducing air in the vicinity of the recovery path into the second duct, and a second opening for introducing air in the vicinity of the other charging unit into the second duct, The second opening is provided upstream of the first opening in the air flow inside the second duct.

1. An image forming apparatus comprising:

12. An exhaust port that exhausts the merged airflow merged by the second connecting portion to the outside of the image forming apparatus; a filter provided upstream of the exhaust port in the combined airflow; The image forming apparatus according to claim 11 , further comprising:

13. Further comprising an exhaust fan provided in the combined airflow between the filter and the exhaust port.

13. The image forming apparatus according to claim 12.

14. Another photoreceptor different from the photoreceptor; a different developing unit for developing the electrostatic latent image on the different photoconductor with a toner of a different color from that of the developing unit; the first duct includes a first intake port for taking in air adjacent to the developing unit and a second intake port for taking in air adjacent to the other developing unit; the first duct has a first guide shape portion, which guides the first airflow vertically downward, downstream of the first intake port and the second intake port in the first airflow; 14. The image forming apparatus according to claim 11,

15. The second duct has a second guiding shape that guides the second airflow vertically downward downstream of the second opening in the second airflow.

15. The image forming apparatus according to claim 11,

16. The third duct has a third intake port for drawing in air in the vicinity of the charging unit, and a third guide shape portion downstream of the third intake port in the path of the third airflow for guiding the third airflow vertically downward.

16. The image forming apparatus according to claim 11,

17. The first duct, the second duct, and the first connecting portion are integrally formed of resin.

17. The image forming apparatus according to claim 11,

18. The image forming apparatus comprises: a first housing having the charging unit, the exposure unit, the developing unit, the transfer unit, the cleaning unit, and the recovery unit; a second housing disposed adjacent to the first housing, the second housing having a fixing unit that heats the sheet onto which the toner image has been transferred by the transfer unit and fixes the toner image onto the sheet; the first duct, the second duct, and the third duct are provided in the first housing.

18. The image forming apparatus according to claim 11,

Images