Image forming apparatus
The image forming apparatus addresses miniaturization and noise reduction by using the housings as ducts for vertical exhaust paths and soundproofing, effectively reducing noise and maintaining a compact design.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- CANON KK
- Filing Date
- 2022-03-30
- Publication Date
- 2026-06-01
Smart Images
Figure 0007867837000001 
Figure 0007867837000002 
Figure 0007867837000003
Abstract
Description
Technical Field
[0001] The present invention relates to an image forming apparatus such as a printer, a copier, a facsimile machine or a multifunction machine.
Background Art
[0002] An image forming apparatus includes an exhaust fan for exhausting air inside the housing in order to collect, for example, ozone generated by charging a photosensitive drum and toner scattered inside the machine with a filter, and to discharge heat generated by driving to the outside of the machine, and a cylindrical exhaust duct. The exhaust duct connects various devices such as a corona charger where ozone is generated, a developing device where scattered toner is generated, a power supply that becomes hot, etc. and the exhaust fan, and forms an air passage through which the airflow generated by the operation of the exhaust fan passes. However, the exhaust sound from the exhaust duct is a noisy sound for the user. Therefore, in order to reduce the noise caused by exhaust, an apparatus provided with an exhaust duct that discharges downward from the bottom surface of the apparatus toward an installation surface such as a floor (for example, the floor) has been proposed (Patent Document 1, Patent Document 2).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] Recently, image forming apparatuses for commercial printing that can form toner images on more recording materials in a shorter time have come into use. These apparatuses are larger than those for home use, for example, in terms of power supply equipment and process units, and also require larger exhaust fans and exhaust ducts, resulting in a larger overall size. However, since further miniaturization is desired even for image forming apparatuses for commercial printing, it is difficult to install an exhaust duct inside the image forming apparatus as described in Patent Document 1 due to space limitations. Also, installing an exhaust treatment device for downward exhaust separately from the main body of the image forming apparatus, as described in Patent Document 2, is contrary to miniaturization and is therefore difficult to adopt. Thus, there has been a long-standing desire for an apparatus that can achieve both miniaturization of the image forming apparatus and suppression of noise caused by exhaust, but such an apparatus has not yet been proposed.
[0005] This invention has been made in view of the above problems, and aims to provide an image forming apparatus that can achieve both miniaturization of the image forming apparatus and reduction of noise caused by exhaust. [Means for solving the problem]
[0006] An image forming apparatus according to one embodiment of the present invention comprises: an image forming unit that forms a toner image on a recording material; a first housing that houses the image forming unit; an exhaust fan provided in the first housing that exhausts air from inside the first housing through an exhaust port formed in the first housing; and a second housing that is positioned opposite the exhaust port of the first housing with a gap in between, and forms an exhaust path between itself and the first housing that guides the air exhausted from the exhaust port at least vertically downward. The first housing has an opposing portion that faces the second housing in the horizontal direction and forms a gap between it and the second housing, the exhaust port is formed in the opposing portion, and the gap forms the exhaust path. It is characterized by the following: Furthermore, an image forming apparatus according to one embodiment of the present invention comprises: an image forming unit that forms a toner image on a recording material; a first housing that houses the image forming unit; an exhaust fan provided in the first housing that exhausts air from inside the first housing through an exhaust port formed in the first housing; and a second housing that is positioned opposite the exhaust port of the first housing with a gap in between, and forms an exhaust path between itself and the first housing that guides the air exhausted from the exhaust port at least downward in the vertical direction, wherein the first housing faces the second housing in the horizontal direction and forms a first gap between itself and the second housing, and on the upper side in the vertical direction The device has a second opposing portion provided opposite to the second housing, which communicates with the first gap and forms the exhaust path between the second housing and the second opposing portion, the second opposing portion being provided with the exhaust port and a plurality of exhaust fans arranged in parallel in the width direction intersecting the vertical direction, a duct arranged in the second gap that guides the air exhausted from the exhaust port to the first gap, and partition members formed inside the duct that divide the inside of the duct into a plurality of spaces along the width direction and partition the air exhausted from the plurality of exhaust fans so that it does not move back and forth between the divided spaces. [Effects of the Invention]
[0007] According to the present invention, it is possible to achieve both miniaturization of the image forming apparatus and reduction of noise caused by exhaust with a simple configuration. [Brief explanation of the drawing]
[0008] [Figure 1] A schematic diagram showing an image forming system equipped with the image forming apparatus of this embodiment. [Figure 2] A cross-sectional view showing the configuration of an image forming and transfer apparatus. [Figure 3] A top view showing the image forming system. [Figure 4] A side view showing the image forming and transfer apparatus and power supply unit. [Figure 5] A schematic diagram showing the exhaust configuration of an image forming and transfer apparatus. [Figure 6] A cross-sectional view showing the exhaust configuration of this embodiment. [Figure 7] A top view showing the partition members inside the lower duct. [Figure 8] Rear view showing the partition members inside the lower duct. [Figure 9] A cross-sectional view showing the exhaust configuration when no bottom duct is provided. [Figure 10] A graph showing the experimental results of exhaust noise measurement. [Figure 11] A cross-sectional view showing another embodiment of the exhaust configuration. [Modes for carrying out the invention]
[0009] [First Embodiment] <Image Forming System> The following describes this embodiment. First, the image forming system equipped with the image forming apparatus of this embodiment will be described using Figures 1 to 4. The image forming system 1X shown in Figure 1 includes an image forming apparatus 101, a recording material supply device 106, and a recording material loading device 107. The recording material supply device 106 and the recording material loading device 107 are connected to the image forming apparatus 101 so as to be able to transport recording material S. The recording material supply device 106 is a device that supplies recording material S to the image forming apparatus 101, and the recording material loading device 107 is a device that loads the recording material S discharged from the image forming apparatus 101. Regarding the transport direction of the recording material S by the recording material supply device 106 (from right to left in Figure 1), the recording material loading device 107 is located downstream of the image forming apparatus 101.
[0010] On the upstream side of the image forming apparatus 101 in the recording material conveyance direction, instead of the recording material supply device 106, a manual feeding device (not shown), a long sheet feeding device capable of accommodating a long recording material, etc. may be selectively connected. Further, although not shown, between the image forming apparatus 101 and the recording material stacking device 107 in the recording material conveyance direction, one or a plurality of various post-processing devices such as an inserter, a puncher, a bookbinding machine, a folding machine, a finisher, a trimmer, etc. can be selectively connected in combination. In this way, by selectively connecting various optional devices upstream and downstream of the image forming apparatus 101, it becomes possible to output in-line the products obtained by performing various post-processing on the recording material S of various materials, and an image forming system 1X with high productivity, high image quality, high stability, and high functionality can be provided.
[0011] In this specification, the side where the user stands when operating the operation unit 80 described later is referred to as "front (or forward)", and the opposite side is referred to as "back (or rear)". Also, the left when viewed from the front is referred to as "left", and the right when viewed from the front is referred to as "right". Therefore, FIG. 1 shows the image forming system 1X when viewed from the front.
[0012] <Image forming apparatus> The image forming apparatus 101 is roughly divided into an image forming transfer apparatus 500, a fixing conveyance apparatus 600, and a power supply apparatus 700 (see FIG. 3) which are configured separately. The image forming transfer apparatus 500 has a housing 500A as a first housing, and an image forming unit 800 etc. that realize the steps until the recording material S is conveyed and the toner image is transferred are accommodated in the housing 500A. The fixing conveyance apparatus 600 has a housing 600A, and a fixing device 8, a cooler 302, etc. that realize the step of conveying the recording material S and fixing the toner image are accommodated in the housing 600A.
[0013] <Image forming transfer apparatus> The configuration of the above-described image forming and transferring apparatus 500 will be described with reference to FIG. 2. As shown in FIG. 2, the image forming and transferring apparatus 500 is an intermediate transfer type apparatus in which image forming units 200Y, 200M, 200C, and 200K for forming yellow, magenta, cyan, and black toner images, respectively, accommodated in a housing 500A (inside the housing), are arranged facing an intermediate transfer belt 208. The image forming and transferring apparatus 500 forms a toner image on a recording material S in accordance with image data from an original reading apparatus provided above the housing 500A or an external device (not shown) such as a personal computer. Examples of the recording material S include sheet materials such as paper, plastic film, and cloth.
[0014] The conveyance process of the recording material S in the image forming and transferring apparatus 500 will be described. The recording material S is supplied one by one from a recording material supply device 106 in accordance with the image forming timing. The supplied recording material S is conveyed to a registration roller 213 disposed in the middle of a conveyance path 250. Then, skew correction and timing correction of the recording material S are performed by the registration roller 213, and the recording material S is sent to a secondary transfer unit ST. The secondary transfer unit ST is formed by a secondary transfer inner roller 214 and a secondary transfer outer roller 215 facing each other across the intermediate transfer belt 208, and is a nip portion that transfers the toner image from the intermediate transfer belt 208 onto the recording material S by applying a predetermined pressure and a secondary transfer voltage.
[0015] The formation process of an image that is sent to the secondary transfer unit ST at the same timing as the conveyance process of the recording material S up to the above-described secondary transfer unit ST will be described. First, the image forming units 200Y to 200K will be described. However, since the image forming units 200Y to 200K of each color are basically the same except for the color of the toner, hereinafter, the black image forming unit 200K will be described as a representative example.
[0016] The image forming unit 200K includes a photosensitive drum 201K, a charger 202K, a laser scanner 203K, a developer 204K, and the like. The surface of the rotating photosensitive drum 201K is uniformly pre-charged by the charger 202K, and then an electrostatic latent image is formed by the laser scanner 203K, which is driven based on the image data. Next, the developer 204K develops the electrostatic latent image formed on the photosensitive drum 201K with toner contained in the developer, and a toner image is formed on the photosensitive drum 201K.
[0017] Subsequently, a predetermined pressure and primary transfer voltage are applied by the primary transfer roller 207K, which is positioned opposite the image forming unit 200K and the intermediate transfer belt 208, and the toner image formed on the photosensitive drum 201K is primary transferred onto the intermediate transfer belt 208. Any remaining primary transfer toner on the photosensitive drum 201K after the primary transfer is removed by the drum cleaner 209K.
[0018] The intermediate transfer belt 208 is an endless belt that is stretched by multiple tension rollers and secondary transfer internal rollers 214, and is moved by a motor (not shown) at a speed corresponding to the rotation speed of the photosensitive drums 201Y to 201K. The image formation process for each color, which is processed in parallel by the image forming units 200Y to 200K described above, is performed at the timing when the toner images of the colors that were first transferred upstream in the direction of movement are sequentially superimposed on the intermediate transfer belt 208. As a result, a full-color toner image is ultimately formed on the intermediate transfer belt 208 and transported to the secondary transfer unit ST. The secondary transfer residue toner remaining on the intermediate transfer belt 208 after passing through the secondary transfer unit ST is recovered from the intermediate transfer belt 208 by a belt cleaner device 216.
[0019] Through the above transport and image formation processes, the timing of the recording material S and the toner image are synchronized in the secondary transfer section ST, and a secondary transfer is performed in which the toner image is transferred from the intermediate transfer belt 208 to the recording material S. Subsequently, the recording material S is transported to the fixing transport device 600 by the pre-fixing transport belts 217a and 217b, and the fixing transport device 600 fixes the toner image to the recording material S.
[0020] <Fusing and conveying device> Returning to Figure 1, the fixing and transport device 600 will be described. As shown in Figure 1, the fixing and transport device 600 has a fixing unit 8 and a cooler 302. The fixing unit 8 has a fixing roller 8a that is heated by a heater (not shown) and a pressure roller 8b that pressurizes the recording material S against the fixing roller 8a. The recording material S, on which a toner image has been formed, is transported from the image forming transfer device 500 and heated and pressurized while being held and transported in a fixing nip section N1 formed by the fixing roller 8a and the pressure roller 8b. As a result, the toner image is fixed to the recording material S.
[0021] The recording material S, heated by the fuser 8, is conveyed towards the cooler 302. The cooler 302 has cooling belts 302a and 302b and a heat sink 303. The cooling belts 302a and 302b are in contact with each other to form a cooling nip section N2 that grips and conveys the recording material S. The heat sink 303 is in contact with the inner circumferential surface of the cooling belt 302a, and the heat sink 303 cools the cooling belt 302a. As a result, the recording material S, heated by the fuser 8, is cooled when it is gripped and conveyed in the cooling nip section N2.
[0022] The recording material S, cooled by the cooler 302, is held by the cooling outlet roller 601 and transported. In the single-sided mode, where a toner image is formed on only one side of the recording material S, the recording material S, cooled by the cooler 302, is guided to the discharge transport path 304 and discharged from the housing 600A toward the recording material loading device 107. On the other hand, in the double-sided mode, where a toner image is formed on both sides of the recording material S, the recording material S, cooled by the cooler 302, is inverted in the inversion transport path 305 and then returned to the image forming transfer device 500 via the double-sided transport path 306. Thereafter, the recording material S undergoes the same process as in the single-sided mode to form a toner image on the other side of the recording material S, undergoes fixing by the fuser 8 and cooling by the cooler 302, and is then guided to the discharge transport path 304 and finally discharged from the housing 600A toward the recording material loading device 107.
[0023] As shown in Figure 3, in the image forming apparatus 101, a power supply unit 700 is detachably mounted on the back of the image forming transfer apparatus 500. The power supply unit 700 has a second housing 700A, and inside housing 700A are a power supply 701 and a power supply board (not shown) that controls the power supply 701, in order to supply power to and operate the image forming unit 800 in housing 500A, the fuser 8 and cooler 302 in housing 600A, etc. Note that the recording material supply device 106 and the recording material loading device 107 are each provided with their own dedicated power supplies (not shown).
[0024] As shown in Figure 4, the image forming transfer apparatus 500 and the power supply unit 700 are connected via a power cable 90 to enable power supply, and power is supplied from the power supply unit 700 to the image forming transfer apparatus 500 via the power cable 90. Since there is sufficient length in the power cable 90, the power supply unit 700 can move in the front-rear direction relative to the image forming transfer apparatus 500 without disconnecting the power cable 90. Therefore, maintenance work on components such as the drive unit of the image forming section 200K and the control board that controls power, which are located on the rear side of the image forming transfer apparatus 500, can be performed by a service technician while the image forming transfer apparatus 500 is in operation.
[0025] With the image forming and transfer apparatus 500 and the power supply unit 700 connected, a gap W1 is formed between the housing 500A and the housing 700A in the front-to-back direction, communicating with the installation surface such as the floor. In this embodiment, as will be described in detail later, the gap W1 forms an exhaust path that guides the air exhausted from the housing 500A at least downward in the vertical direction.
[0026] The image forming and transfer apparatus 500, the fixing and transport apparatus 600, and the power supply unit 700 described above each have independent housings 500A, 600A, and 700A, and are therefore movable by casters provided on each. This makes it possible to pack and transport the image forming and transfer apparatus 500, the fixing and transport apparatus 600, and the power supply unit 700 separately, even if the image forming apparatus 101 is large, improving work efficiency up to installation. The top surface of housing 500A is equipped with an operation unit 80, etc. The operation unit 80 is positioned so that users performing normal printing operations can easily operate it, with a display (such as an LCD touch panel) capable of displaying various information and keys for inputting various information according to user operations located on the front side.
[0027] Furthermore, as shown in Figure 3, the recording material supply device 106, the image forming transfer device 500, the fixing and transport device 600, and the recording material loading device 107 are connected in such a way that they do not protrude further forward than the others. This is preferable because it provides an image forming system 1X without any protrusions on the front side, which does not interfere with the user when performing normal printing operations. The power supply device 700 is positioned behind the image forming transfer device 500 so that it does not overlap with the recording material supply device 106 or the fixing and transport device 600 when viewed from the left and right directions. This is to ensure that the air exhausted from the housing 500A, as will be described later, does not hit the walls of the recording material supply device 106 or the fixing and transport device 600, but is instead exhausted in the left and right directions.
[0028] <Exhaust System> Next, the exhaust configuration for exhausting the air inside the housing 500A to the outside in the image forming and transfer apparatus 500 will be explained with reference to Figures 2 and 4, and with reference to Figures 5 to 9. In Figure 5, as an example, an exhaust configuration for exhausting the air near the charger 202K and an exhaust configuration for exhausting the air near the developer 204K of the image forming unit 200K are shown.
[0029] Before explaining the exhaust configuration, we will briefly describe the air supply configuration for supplying air to the image forming unit 200K from the outside. As shown in Figure 5, in the image forming unit 200K, the electrostatic supply fan 105 supplies air from outside the housing 500A and blows it into the supply duct 102 via a dust filter (not shown). The dust filter is a fibrous filter that removes dust and dirt contained in the air supplied from outside the housing 500A.
[0030] The air supply duct 102 is a duct that guides the air Q1 supplied from the electrostatic fan 105 to the electrostatic unit 202K, and is connected to the electrostatic unit 202K on the downstream side in the direction of airflow within the air supply duct 102. The connection portion 103 between the air supply duct 102 and the electrostatic unit 202K is open along the longitudinal direction in order to uniformly supply air to the electrostatic unit 202K.
[0031] Air Q1 supplied from the charger supply fan 105 passes through the charger 202K and is used to discharge ozone and charge-generating products generated in the charger 202K. Air Q2 containing ozone and charge-generating products discharged from the charger 202K is drawn into the exhaust duct 112 through the exhaust duct opening 113 connected to the charger 202K as the charger exhaust fan 111 operates.
[0032] The exhaust duct 112 has an exhaust duct opening 113 that extends along its longitudinal direction to guide air uniformly from the longitudinal direction of the charger 202K to the charger exhaust fan 111 as the charger exhaust fan 111 operates. Inside the exhaust duct 112, an ozone filter 115 is positioned upstream of the charger supply fan 105 to filter the air, and ozone and charge products are recovered as they pass through the ozone filter 115. Therefore, air from which ozone and charge products have been removed from air Q2 is exhausted to the outside of the housing 500A. Note that by setting the airflow of air Q1 and air Q2 to "Q2 > Q1", ozone and charge products are removed from air Q2.
[0033] The developer unit 204K has a developing sleeve 2041 that carries and rotates the toner used for development in order to develop the electrostatic latent image on the photosensitive drum 201K into a toner image using a developer. In the developer unit 204K, due to the centrifugal force generated as the developing sleeve 2041 rotates, a small amount of toner that was not used for development may be scattered inside the unit, and such scattered toner may contaminate the inside of the unit. Therefore, a toner scattering recovery fan 121 and a toner scattering recovery duct 122 are provided to recover the scattered toner. The toner scattering recovery fan 121 draws air from the bottom of the developer unit 204K over its entire length from the toner scattering recovery duct opening 123 of the toner scattering recovery duct 122. The toner scattering recovery duct 122 guides the air inside the developer unit 204K to the toner scattering recovery fan 121 as the fan 121 operates.
[0034] Inside the toner collection duct 122, a toner filter 125 is positioned upstream of the toner collection fan 121. As air Q3 containing scattered toner passes through the toner collection duct 122, the scattered toner is removed by the toner filter 125. After toner removal, the air Q3 is exhausted outside the housing 500A by the toner collection fan 121. Even if the airflow of air Q3 is smaller than that of air Q1 and Q2, the toner can still be collected by being carried by the airflow. Therefore, the cross-sectional area of the toner collection duct 122 can be smaller than that of the exhaust duct 112 and the supply duct 102.
[0035] As shown in Figure 6, the above-mentioned electrostatic discharge fan 111, dust collection fan 121, exhaust duct 112, dust collection duct 122, ozone filter 115, and toner filter 125 are provided on the protruding portion 5001 of the housing 500A. The protruding portion 5001, as the second opposing portion, extends vertically upward from the power supply unit 5, protruding toward the housing 700A side (housing side) from the vertical upper end of the main body portion 5002, which forms a gap W1 (first gap) between it and the housing 700A. In this embodiment, the power supply unit 700 is arranged such that the housing 700A faces the exhaust port 5003 of the housing 500A via a gap W1. In this case, the housing 500A has a main body portion 5002 as the first opposing portion, which faces the housing 700A in the front-rear direction (horizontal direction) and forms a gap W1 between it and the housing 700A. As will be described later, the gap W1 forms an exhaust path between itself and the housing 500A that guides the air exhausted from the exhaust port 5003 at least vertically downward.
[0036] The protruding portion 5001 is formed to have an exhaust port 5003 that opens vertically downward, connecting the inside and outside of the housing 500A. Air is exhausted from this exhaust port 5003 to the outside of the housing 500A in conjunction with the operation of the electrostatic exhaust fan 111 and the debris collection fan 121. In this embodiment, sirocco fans are used as the electrostatic exhaust fan 111 and the debris collection fan 121 because they can easily secure airflow even with high pressure loss. The protruding portion 5001 is also formed in a curved shape so that the exhaust direction from the electrostatic exhaust fan 111 and the debris collection fan 121 is directed towards the exhaust port 5003, and an exhaust duct 131 is provided as a guide duct connecting the electrostatic exhaust fan 111 and the debris collection fan 121 to the exhaust port 5003. Although a sirocco fan is used as an example in this embodiment, it is not limited to this, and exhaust noise is also generated by other fans such as axial flow fans, so this embodiment can be applied without being limited to the type of fan.
[0037] If the exhaust from the electrostatic discharge fan 111 and the airborne recovery fan 121 is directed towards the rear, the exhaust port will be located on the rear of the housing 500A, resulting in a loud exhaust noise that is easily heard by the user. Therefore, in this embodiment, the power supply unit 700 is positioned on the rear of the housing 500A such that the housing 700A forms an exhaust path (gap W1) between itself and the housing 500A that guides the air exhausted from the exhaust port 5003 vertically downward. The housing 700A is also positioned below the protruding portion 5001, with a gap W2 (second gap) between the lower surface of the protruding portion 5001 and the gap W1, and gap W2 and gap W1 communicate to form an exhaust path that guides the air exhausted from the exhaust port 5003 vertically downward. Furthermore, gaps W1 and W2 form an exhaust path between themselves and the housing 500A that guides the air exhausted from the exhaust port 5003 in the width direction (left-right direction) that intersects the vertical direction.
[0038] In this embodiment, as a soundproofing measure against exhaust noise from the charger exhaust fan 111 and the debris collection fan 121, as described above, a gap W1 serving as an exhaust path is provided between the housing 500A and the housing 700A, guiding the exhaust at least vertically downwards. That is, by passing the exhaust from the charger exhaust fan 111 and the debris collection fan 121 between the housing 500A and the housing 700A, the housing 700A itself acts as a soundproofing wall, making the exhaust noise less audible to the user. Therefore, in this embodiment, since the housings 500A and 700A themselves are used as ducts, there is no need to provide dedicated ducts, which reduces costs and allows for miniaturization of the image forming apparatus 101 with a simple configuration.
[0039] In this embodiment, as shown in Figure 6, a lower duct 132 is positioned in the gap W2 so that the exhaust gas exhausted by the exhaust duct 131 does not pass through the gap W2 to the rear side. The lower duct 132 guides the air exhausted from the exhaust port 5003 into the gap W1 by blocking the side of the gap W2 opposite to the main body 5002 in the front-rear direction. The lower duct 132 has a blocking portion 132a formed therein as a blocking member. That is, even if the air exhausted from the exhaust port 5003 flows to the side opposite to the main body 5002, i.e., the rear side, it is obstructed by the blocking portion 132a, so that it passes through the gap W2, hits the main body 5002, and flows downward along the gap W1 to be exhausted. In this way, by providing the lower duct 132, the exhaust gas can be passed between the housing 500A and the housing 700A, and the housing 700A itself can act as a sound barrier to block the exhaust noise.
[0040] As shown in Figure 7, one electrostatic exhaust fan 111Y~111K and one airborne recovery fan 121Y~121K are provided for each color. Multiple electrostatic exhaust fans 111Y~111K and airborne recovery fans 121Y~121K are arranged in parallel in the left-right direction on the aforementioned protruding section 5001.
[0041] When the electrostatic exhaust fans 111Y~111K and the scattered recovery fans 121Y~121K are sirocco fans, the airflow direction at the fan exhaust port tends to be tilted relative to the blocking portion 132a on average, as shown by the arrows in the figure, when viewed from above. Therefore, when the air exhausted from the exhaust port 5003 hits the blocking portion 132a and changes direction, the airflow direction tends to change to the direction in which the recording material S discharged from the housing 500A is transported (from right to left), as shown in Figure 8. In view of this, in this embodiment, a plurality of partition plates 132Y, 132M, 132C, and 132K are provided inside the lower duct 132 with the aim of ultimately forming a smooth downward airflow through the gap W1.
[0042] The partition plates 132Y~132K, acting as partition members, divide the inside of the lower duct 132 (inside the duct) into multiple spaces along the left-right direction, and partition them so that the air exhausted from the multiple electrostatic exhaust fans 111Y~111K and the airborne recovery fans 121Y~121K does not move back and forth between the divided spaces. The electrostatic exhaust fans 111Y~111K and the airborne recovery fans 121Y~121K are arranged relatively close to each other. In this case, the exhaust from each fan may interfere with each other, making it easy for vortices to form, which may make it difficult for air to flow towards the main body 5002 that forms the gap W1.
[0043] Therefore, in this embodiment, partition plates 132Y, 132M, 132C, and 132K are provided between the charger exhaust fans 111Y~111K and the debris collection fans 121Y~121K, which are arranged relatively close together and of the same color. The air exhausted from the charger exhaust fans 111Y~111K and the debris collection fans 121Y~121K flows more easily toward the main body 5002 along the partition plates 132Y, 132M, 132C, and 132K. In addition, because the exhaust air hits the partition plates 132Y, 132M, 132C, and 132K, the exhaust air does not interfere with each other and vortices are less likely to be generated, so the exhausted air flows smoothly toward the main body 5002.
[0044] Furthermore, it is preferable that the area D of the opening in the lower duct 132 facing the main body 5002 of the housing 500A shown in Figure 7 be larger than the sum of the areas F of the exhaust ports of the charger exhaust fans 111Y~111K and the airborne recovery fans 121Y~121K shown in Figure 8. This allows the exhausted air to flow smoothly towards the main body 5002.
[0045] However, depending on the arrangement of the electrostatic exhaust fans 111Y~111K and the airborne recovery fans 121Y~121K, there may be cases where "the area D of the opening < the sum of the areas F of the fan exhaust ports," in which case the pressure loss will be high and it may not be possible to secure the required exhaust volume. In such cases, as shown in Figure 7, it is advisable to provide openings 132L and 132R on the side of the lower duct 132. However, when openings 132L and 132R are provided, the exhaust noise will be louder than when there are no openings on the side. In contrast, in this embodiment, as described above, partition plates 132Y, 132M, 132C, and 132K are used to allow more air to flow toward the main body 5002. As a result, the air velocity of the air exhausted from openings 132L and 132R decreases, and the exhaust noise from openings 132L and 132R is reduced.
[0046] Furthermore, in this embodiment, as a soundproofing measure against exhaust noise, as shown in Figure 6, a soundproofing sheet 134 is provided as a soundproofing member in the lower duct 132 at a position facing the exhaust port 5003. The soundproofing sheet 134 is provided to reduce the collision noise caused by the air exhausted from the exhaust port 5003 hitting the lower duct 132. In addition, in the curved exhaust duct 131, a soundproofing sheet 133 is provided as a soundproofing member at a position (curved portion) facing the fan exhaust ports of the charger exhaust fan 111 and the debris recovery fan 121. The soundproofing sheet 133 is provided to reduce the collision noise caused by the air exhausted from the fan exhaust ports hitting the exhaust duct 131. The soundproofing sheets 133 and 134 are formed from, for example, foam material and are bonded inside the exhaust duct 131 and the lower duct 132, respectively.
[0047] Furthermore, the same soundproofing material may also be provided on the main body 5002 of the housing 500A, which is hit by the air flowing through the gap W2. However, since the main body 5002 is located away from the exhaust port 5003, and the gap W2 is a large opening area that extends across the entire left-right direction of the housing 500A compared to the area of the fan exhaust port, the airflow velocity of the air flowing through the gap W2 will decrease before it reaches the main body 5002. Because the airflow velocity decreases, the impact noise when it hits the main body 5002 is small, so it is not necessary to provide a soundproofing material on the main body 5002.
[0048] In the embodiment described above, an example in which a lower duct 132 is provided was explained, but it is not necessary to provide the lower duct 132. As shown in Figure 9, if the lower duct 132 is not provided, the gap W2 between the lower surface of the protruding portion 5001 and the upper surface of the housing 700A functions as a duct. A blocking cover 136 is provided on the housing 700A to block the gap W2 opposite to the main body portion 5002 in the front-rear direction in order to guide the air exhausted from the exhaust port 5003 from gap W2 to gap W1. That is, even if the air exhausted from the exhaust port 5003 flows to the opposite side of the main body portion 5002, i.e., the rear side, it is obstructed by the blocking cover 136, so that it passes through gap W2, hits the main body portion 5002, and flows downward along gap W1 and is exhausted. The blocking cover 136 is fixed to the housing 700A so that it moves together with the power supply unit 700. Since the sealing cover 136 is a smaller component than the lower duct 132 (see Figure 6) mentioned above, it can be manufactured at a relatively low cost.
[0049] In this embodiment as well, as a soundproofing measure against exhaust noise, a soundproofing sheet 133 is provided in the exhaust duct 131 at a position (curved portion) facing the fan exhaust ports of the charger exhaust fan 111 and the debris collection fan 121. In addition, a soundproofing sheet 134 is provided on the upper surface of the housing 700A at a position facing the exhaust port 5003 through a gap W2. The soundproofing sheet 134 is provided to reduce the impact noise generated when the air exhausted from the exhaust port 5003 hits the housing 700A.
[0050] Next, Figure 10 shows the experimental results of measuring the exhaust noise at the back of housing 700A when housings 500A and 700A are arranged with gaps W1 and W2 as described above, and different soundproofing measures are applied. The soundproofing measures are as follows: Mode A: No bottom duct 132 and sealing cover 136 are provided, and only a soundproofing sheet 133 is provided on the exhaust duct 131; Mode B: No bottom duct 132 or sealing cover 136 are provided, and a soundproofing sheet 134 is provided on the top of housing 700A (see Figure 9); and Mode C: The bottom duct 132 and sealing cover 136 are provided, and soundproofing sheets 133 and 134 are also provided (see Figure 6). "Def" represents the case with no soundproofing measures applied. Note that the sound pressure level (dB) shown here is not an acoustic power level calculated by measuring in a semi-anechoic chamber, but rather a measurement result in a laboratory close to the actual usage environment. Furthermore, since the configuration, size, and fan output of the equipment vary, these measurement results cannot be uniquely reproduced.
[0051] As can be seen from Figure 10, even without providing the lower duct 132 and the sealing cover 136, the sound pressure level (dB) can be reduced compared to the untreated case (Def) by providing the soundproofing sheets 133 and 134 (Mode A, Mode B). In other words, it can be seen that soundproofing can be achieved by arranging the housing 500A and housing 700A with a gap W1 between them, exhausting air downwards through the gap between housing 500A and housing 700A, and providing soundproofing sheets in the airflow deflection section in the narrow space. This is because the collision sound of the air exhausted from the exhaust port 5003 is reduced by the soundproofing sheets, and a portion of the exhausted air is exhausted downwards through the gap W1 between housing 500A and housing 700A. In contrast, as in Mode C, by providing a bottom duct 132 and a blocking cover 136 to eliminate exhaust flowing out to the rear of the housing 700A, and by exhausting the exhaust downward through the gap W1 between the housing 500A and the housing 700A, a higher sound insulation effect can be obtained. In this embodiment, the gap W2 between the housing 500A and the housing 700A is set to, for example, "18 mm" to perform airflow deflection in a narrow space.
[0052] As described above, in this embodiment, the housing 500A and the housing 700A are arranged to face each other in the front-to-back direction (horizontal direction), forming a gap W1. The gap W1 forms an exhaust path between the housing 500A and the housing 700A that guides the air exhausted from the exhaust port 5003 at least downward in the vertical direction. The air exhausted from the exhaust port 5003 of the housing 500A is guided to the gap W1 by the lower duct 132 located in the gap W2. The lower duct 132 has a blocking portion 132a that closes the side opposite to the main body 5002, so even if the air exhausted from the exhaust port 5003 flows to the rear side, it is obstructed by the blocking portion 132a. As a result, it passes through the gap W2, hits the main body 5002, and flows downward along the gap W1 to be exhausted. In this way, by passing the exhaust air between the housing 500A and the housing 700A, the housing 700A itself acts as a sound barrier, blocking the exhaust noise. Therefore, miniaturization of the image forming apparatus 101 and reduction of noise caused by exhaust can be achieved with a simple configuration.
[0053] [Other embodiments] In the above-described embodiment, the case in which the housing 700A is positioned below the protruding portion 5001 was explained as an example, but the invention is not limited to this. For example, as shown in Figure 11, the housing 500A may not have a protruding portion 5001, and an axial flow fan, which is an exhaust fan 138, may be provided on the back of the housing 500A. The exhaust fan 138 performs exhaust, for example, to prevent the temperature inside the housing 500A from rising. In this case, the housing 500A has a main body portion 5004 that faces the housing 700A in the front-to-back direction (horizontal direction) and forms a gap W3 between it and the housing 700A, and an exhaust port 5005 is formed in the main body portion 5004 for exhausting from the inside to the outside of the housing 500A by the exhaust fan 138. In other words, the housing 700A is positioned to face the exhaust port 5005 of the housing 500A via the gap W3.
[0054] Furthermore, in order to guide the air exhausted from the exhaust port 5005 downward through the gap W3, a blocking cover 137 is provided on the housing 700A that blocks the vertically upper side of the gap W3. That is, even if the air exhausted from the exhaust port 5005 hits the main body 5004 and flows upward, it is obstructed by the blocking cover 137 and flows downward along the gap W3 and is exhausted. The blocking cover 137 is fixed to the housing 700A so that it moves together with the power supply unit 700.
[0055] Furthermore, in this embodiment, as a soundproofing measure against exhaust noise, a soundproofing member 139 is provided in the housing 700A at a position facing the exhaust port 5005. The soundproofing member 139 is provided to reduce the collision noise generated when the air exhausted from the exhaust port 5005 hits the housing 700A. The soundproofing member 139 is formed of, for example, a foam material and is bonded to the front side of the housing 700A.
[0056] The above-described embodiment is not limited to electrophotographic image forming apparatuses that use a developer containing toner and a carrier to form a toner image on a recording material, but may also be applied to image forming apparatuses of other types. For example, it can be applied to inkjet image forming apparatuses that form an image by ejecting ink toward a recording material. [Explanation of Symbols]
[0057] 101...Image forming apparatus, 111Y~111K (121Y~121K, 138)...Exhaust fan (charger exhaust fan, scattering and recovery fan), 115...Filter (ozone filter), 125...Filter (toner filter), 131...Guidance duct (exhaust duct), 132...Duct (bottom duct), 132a...Blocking member (blocking part), 132Y~132K...Partition member (partition plate), 133 (134, 1 39)...Soundproofing material (soundproofing sheet), 136 (137)...Blocking material (blocking cover), 500A...First housing (housing), 700A...Second housing (housing), 701...Power supply, 800...Image forming unit, 5001...Second opposing part (protruding part), 5002 (5004)...First opposing part (opposing part, main body), 5003 (5005)...Exhaust port, W1 (W3)...First gap (gap), W2...Second gap (gap), S...Recording material
Claims
1. An image forming unit that forms a toner image on a recording material, A first housing housing the aforementioned image forming unit, An exhaust fan is provided in the first housing, which exhausts the air inside the first housing through an exhaust port formed in the first housing, The system comprises a second housing positioned opposite the exhaust port of the first housing with a gap in between, and forming an exhaust path between itself and the first housing that guides the air exhausted from the exhaust port at least vertically downward, The first housing has a facing portion that faces the second housing in the horizontal direction and forms a gap between it and the second housing, The exhaust port is formed in the opposing portion, The gap forms the exhaust path. An image forming apparatus characterized by the following:
2. The opposing portion is a first opposing portion that faces the second housing in the horizontal direction and forms a first gap between itself and the second housing. The first housing is provided so as to face the second housing on the vertically upper side, and has a second opposing portion that forms a second gap between itself and the second housing that communicates with the first gap. The exhaust port is formed in the second opposing portion, The first gap and the second gap form the exhaust path. The image forming apparatus according to feature 1.
3. The second gap is provided with a duct that guides the air exhausted from the exhaust port into the first gap, The image forming apparatus according to feature 2.
4. In the duct, a sound-insulating member is provided at a position opposite the exhaust port to reduce the noise level of the air exhausted from the exhaust port. The image forming apparatus according to feature 3.
5. The second gap is provided with a sealing member that closes the side opposite to the first opposing portion in the horizontal direction. The image forming apparatus according to feature 2.
6. In the second housing, a sound-insulating member is provided at a position facing the exhaust port through the second gap to reduce the noise level of the air exhausted from the exhaust port. The image forming apparatus according to feature 5.
7. The second opposing section is provided with a plurality of exhaust fans arranged in parallel in the width direction intersecting the vertical direction, Within the duct, partition members are formed that divide the duct into multiple spaces along the width direction, and prevent air exhausted from multiple exhaust fans from moving between the divided spaces. The image forming apparatus according to feature 3 or 4.
8. The second opposing section is provided with an exhaust fan, a guide duct that guides the air inside the first housing to the exhaust fan in accordance with the operation of the exhaust fan, and a filter that filters the air flowing through the guide duct. The image forming apparatus according to any one of claims 2 to 6.
9. A sealing member is provided to close the vertically upper side of the gap, The image forming apparatus according to feature 1.
10. In the second housing, a sound-insulating member is provided at a position facing the exhaust port through the gap, which reduces the noise level of the air exhausted from the exhaust port. The image forming apparatus according to feature 9.
11. The gap forms an exhaust path that guides the air exhausted from the exhaust port in a width direction intersecting the vertical direction between itself and the first housing. The image forming apparatus according to any one of claims 1 to 10.
12. The second housing houses a power supply that provides power to operate the image forming unit. The image forming apparatus according to any one of claims 1 to 11.
13. An image forming unit that forms a toner image on a recording material, A first housing housing the aforementioned image forming unit, An exhaust fan is provided in the first housing, which exhausts the air inside the first housing through an exhaust port formed in the first housing, The system comprises a second housing positioned opposite the exhaust port of the first housing with a gap in between, and forming an exhaust path between itself and the first housing that guides the air exhausted from the exhaust port at least vertically downward, The first housing has a first opposing portion that faces the second housing in the horizontal direction and forms a first gap between it and the second housing, and a second opposing portion that is provided to face the second housing on the upper vertical side and communicates with the first gap and forms a second gap between it and the second housing that forms the exhaust path. The second opposing section is provided with the exhaust port and a plurality of exhaust fans arranged in parallel in the width direction intersecting the vertical direction. A duct is placed in the second gap to guide the air exhausted from the exhaust port into the first gap. Within the duct, partition members are formed that divide the duct into multiple spaces along the width direction, and prevent air exhausted from multiple exhaust fans from moving between the divided spaces. An image forming apparatus characterized by the following:
14. In the duct, a sound-insulating member is provided at a position opposite to the exhaust port to reduce the noise level of the air exhausted from the exhaust port. The image forming apparatus according to feature 13.