JP6594058B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including an air flow generation unit that generates an air flow for discharging air inside the apparatus main body to the outside of the apparatus main body.

When a corona charger is used as a method for uniformly charging a photoconductor in an electrophotographic image forming apparatus, ozone or the like is generated as a by-product due to corona discharge.

Therefore, it is necessary to ventilate the corona charger by passing an air current through it. In this case, an air suction port is provided in the vicinity of the corona charger to suck the airflow discharged from the corona charger. Further, in order to suppress the temperature rise of the developer, air from outside the apparatus is sent to one end near the image forming unit, and in order to exhaust them, a suction port is provided at the other end near the image forming unit to suck the image forming unit. Some also ventilate.

  In the configuration in which the air in the vicinity of the image forming unit is sucked as described above, the developer carrier disposed in the developing unit, the photosensitive member, or the image carrier that transports the developed toner image to the recording material, etc. Toner may be released and scattered. Then, the air containing the scattered toner may be sucked. For this reason, generally, the airflow sucked from the vicinity of the image forming unit is collected by an exhaust duct or the like, and after removing these substances using a collecting means for collecting dust such as toner or ozone, the outside of the apparatus main body is removed. Is discharged.

  As the collecting means, a filter using mainly non-woven fabric or activated carbon is used, and many are arranged near the exhaust port of the image forming apparatus. These filters have a limited amount of collection and need to be replaced regularly. For this reason, when the filter replacement time is too long, the dust filter that collects dust such as toner may be clogged and the removal efficiency may be reduced.

  In order to cope with this, in order to detect the replacement time of the dustproof filter, there is provided a counter provided with a counter for counting the number of passing sheets or a detecting means for detecting the rotational speed of the fan as disclosed in Patent Document 1. There is one that detects the replacement time of the filter based on a change in the rotational speed.

JP 2003-316220 A

  However, when the dustproof filter is used for a long period of time after the replacement time of the dustproof filter is detected and until the dustproof filter is replaced, the dustproof filter removal efficiency is lowered. In this case, the dust discharged to the outside of the apparatus main body may increase slightly compared to the normal time.

  In view of the above circumstances, an object of the present invention is to provide an image forming apparatus capable of suppressing an increase in dust discharged outside the apparatus main body.

In order to achieve the above object, an image forming apparatus of the present invention is an image forming apparatus having an image forming section, and is provided inside the image forming apparatus , and a duct through which air that has passed through the image forming section passes. An air flow generating means for generating an air flow for exhausting air that has passed through the image forming unit from an outlet of the duct, and is provided upstream of the outlet in an exhaust path of air exhausted from the outlet. In addition, the air flow generating means, a filter provided between the image forming unit and the outlet in the exhaust path, for collecting dust, and exhausting air exhausted from the outlet to the outside of the image forming apparatus. The exhaust port is opposed to the exhaust port between the outlet and the exhaust port, and is spaced from both the outlet and the exhaust port. An air guide plate that is disposed at a position overlapping the outlet when looking at the mouth and changes the traveling direction of the air exhausted from the outlet, wherein the air exhausted from the outlet is formed from the exhaust outlet to form the image Before the air is exhausted to the outside of the apparatus, the air is diverted from the air guide plate in the space to generate a vortex, and the air guide plate separates the dust from the air in the space. To do.

  According to the present invention, an increase in dust discharged to the outside of the apparatus main body can be suppressed.

1 is a cross-sectional view of an image forming apparatus according to Embodiment 1. FIG. FIG. 3 is a schematic configuration diagram of the front side of the image forming unit in the apparatus main body. A sectional view of an image formation part is shown. FIG. 3 is a schematic configuration diagram of the rear side of the image forming unit in the apparatus main body. It is a perspective view near an exhaust port. It is sectional drawing which looked at the structure of FIG. 5 from the arrow J1 direction. It is sectional drawing which looked at the structure of FIG. 5 from the arrow J2 direction. FIG. 6 is a schematic diagram of a state of an air guide plate when an exhaust fan is stopped in an image forming apparatus according to a second embodiment. It is a schematic diagram of the state of a baffle plate when an exhaust fan is an operation state.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, since the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions, there is no specific description. As long as the scope of the invention is not limited to these, it is not intended. In addition, regarding the structure of a later Example, about the structure same as a previous Example, the code | symbol same as the previous Example is attached | subjected and the description in a previous Example shall be used.

  FIG. 1 is a cross-sectional view of the image forming apparatus 100 according to the first embodiment. The image forming apparatus 100 is an electrophotographic full color laser printer. The image forming apparatus 100 charges toner images of four colors having different colors depending on the first, second, third, and fourth image forming units Py, Pm, Pc, and Pb arranged in parallel in the apparatus main body 100A. A toner image is formed through the processes of exposure, development, and transfer.

  The control unit 19 includes a CPU and a memory such as a ROM or a RAM. When the control unit 19 receives a print command signal output from an external interface 22 such as a host computer, the control unit 19 sequentially operates the image forming units Py, Pm, Pc, and Pb in accordance with an image forming control sequence stored in the memory. The image forming unit Py uses yellow toner, the image forming unit Pm uses magenta toner, the image forming unit Pc uses cyan toner, and the image forming unit Pb uses black toner.

  Each of the image forming units Py, Pm, Pc, and Pb includes a photosensitive drum 1 as an image carrier, a charger 2, an exposure device 3, a developing device 4, and a drum cleaner 5. The surface of the photosensitive drum 1 is uniformly charged by the charger 2, an electrostatic image is formed by the exposure device 3, and developed with toner (developer) by the developing device 4 to form a toner image.

  An intermediate transfer belt 7 is disposed below the image forming portions Py to Pb. The intermediate transfer belt 7 is suspended from a driving roller 6a, a driven roller 6b, and a tension roller 6c. A primary transfer roller 8 (transfer member) is disposed at a position facing the photosensitive drum 1 with the intermediate transfer belt 7 interposed therebetween. The toner image on the surface of each photosensitive drum 1 is transferred to the intermediate transfer belt 7 by the primary transfer roller 8 and superimposed. The transfer residual toner remaining on the surface of the photosensitive drum 1 is removed by the drum cleaner 5.

  On the other hand, the recording material P is accommodated in the feeding cassette 10. When the recording material P passes through the feeding roller 11 and the registration roller 13 and passes through the secondary transfer nip Tn between the driven roller 6b and the secondary transfer roller 14, the toner image is secondarily transferred. The transfer residual toner remaining on the surface of the intermediate transfer belt 7 is removed by the belt cleaner 9.

  The recording material P onto which the toner image has been secondarily transferred is fixed by the fixing device 15 and discharged to the discharge tray 18 by the discharge roller 17.

  An air supply port 212 is provided at the upper part of the image forming apparatus 100, and cooling air is introduced into the image forming units Py, Pm, Pc, and Pb by an air supply fan 211 as indicated by an arrow 210. The air that has cooled the image forming portions Py, Pm, Pc, and Pb cools the intermediate transfer belt 7, the belt cleaner 9, and the like, further cools the fixing device 15, and exhausts air from an exhaust port (not shown) by an exhaust fan 213. It is discharged out of the image forming apparatus 100. Next, an outline of ventilation of ozone and the like generated in the charger 2 and ventilation of the lower part of the developing device 4 will be described.

  FIG. 2 is a schematic configuration diagram of the front side of the image forming units Py, Pm, Pc, and Pb in the apparatus main body 100A. As shown in FIG. 2, an air supply port 222 for sending air to the charger 2 is disposed at the upper part of the image forming apparatus 100, and is taken into the apparatus main body 100 </ b> A by an air supply fan 221. The taken-in air flows in the air supply duct 223 in the direction of the arrow 220, and is sent to the image forming units Py, Pm, Pc, and Pb.

  FIG. 3 is a cross-sectional view of the image forming unit. Air sent from the air supply duct 223 to the image forming units Py, Pm, Pc, and Pb is sent to the upper duct 230 on the charger 2. The fed air flows in the upper duct 230 in the direction of the arrow 236, and is rectified so that the wind speed in the direction of the arrow 237 in the longitudinal region in the charger 2 is substantially uniform.

  The rectified air flows through the charger 2 from the top to the bottom, flows in the direction of arrow 238 together with ozone generated by the charger 2, and is discharged out of the charger 2 through the gap between the electrode plates of the charger 2. The The air discharged to the outside of the charger 2 is sucked into the exhaust duct 232 from the suction port 231 provided in the exhaust duct 232 and flows in the direction of the arrow 239 and the arrow 240.

  On the other hand, a lower suction port 233 is also provided below the developing device 4, and the temperature around the developing device 4 is suppressed by ventilating the periphery of the developing device 4. Air sucked from the lower suction port 233 flows in the direction of the arrow 242 and passes through the exhaust duct 234 provided on the rear side of the image forming apparatus 100 of the developing device 4 and the air exhausted from the charger 2 at the junction 235. Join.

  FIG. 4 is a schematic configuration diagram of the rear side of the image forming units Py, Pm, Pc, and Pb in the apparatus main body 100A. The exhaust from the charger 2 and the air sucked from the lower part of the developing device 4 are merged at the junction 235 of the exhaust duct 232, and the exhaust duct 224 provided on the rear side of the apparatus main body 100A, which is an exhaust means, is directed in the direction of arrow 225. Flowing into.

  Then, dust and toner are removed from the exhaust gas by the toner filter 244. Thereafter, the exhaust gas passes through an exhaust fan 247 as “air current generating means” that generates an air current that discharges air inside the apparatus main body 100A to the outside. Further, after the ozone and the like are removed by the ozone filter 249, the exhaust gas flows in the direction of the arrow 229 and is exhausted from the exhaust port of the apparatus main body 100A. This is the exhaust path.

  Here, the toner filter 244 and the ozone filter 249 are not necessarily required, and can be omitted mainly when there is little scattering of toner in the apparatus main body 100A or when exhausted from a place where ozone or the like is not generated. Next, the detailed structure of the exhaust means of the present embodiment will be described.

  5 is a perspective view of the vicinity of the exhaust port 251, FIG. 6 is a cross-sectional view of the configuration of FIG. 5 viewed from the direction of the arrow J1, and FIG. 7 is a cross-sectional view of the configuration of FIG. The exhaust duct 224 is composed of a plurality of ducts that are partly detachably attached. The toner filter 244 as the “collecting means” described above is disposed inside the exhaust duct 224 or upstream of the exhaust duct 224 in the direction of air flow, and collects dust. The exhaust duct 224 includes a toner filter 244 and an ozone filter 249.

  The exhaust duct 224 includes a toner filter holder 243 that is connected to the junction 235 and supports the toner filter 244 in a detachable manner. The exhaust duct 224 includes a connection duct 260 that is detachably attached when the toner filter 244 is replaced. The connecting duct 260 as a part of the “exhaust duct” that guides the air flow of the exhaust fan 247 constitutes a duct by combining the lower connecting duct 245 and the upper connecting duct 246, and connects the toner filter holder 243 and the exhaust fan 247. ing. Further, the exhaust duct 224 includes an ozone filter holder 248 that is disposed downstream of the exhaust fan 247 and detachably supports the ozone filter 249 in the downstream opening.

  Further, there is a space between the ozone filter 249 disposed at the outlet of the exhaust duct 224 and the exhaust port 251 that removes ozone and the like from the airflow flowing through the connection duct 260 and exhausts the ozone filter 249 through the space. 255 and an air guide plate 250 are provided. A space 255 as a “first region” is a region between the exhaust duct 224 and the exhaust port 251.

  The air guide plate 250 as the “airflow direction changing portion” is disposed inside the space 255 between the exhaust duct 224 and the exhaust port 251, and is disposed to face the end portion of the exhaust duct 224. The air guide plate 250 changes the direction of the airflow so that the airflow exhausted from the connecting duct 260 to the space 255 changes direction and then goes to the exhaust port 251. That is, the air guide plate 250 changes the wind direction of the exhaust so that the exhaust gas that has passed through the ozone filter 249 in the space 255 bypasses the exhaust port 251 and is bypassed and discharged to the outside of the apparatus main body 100A.

  The air guide plate 250 has a surface 250 a that spreads in a direction different from the direction orthogonal to the air flow traveling direction of the air flow exhausted from the connection duct 260. Since the air guide plate 250 is disposed so as to bypass the airflow exhausted from the exhaust duct 224, the exit of the exhaust duct 224 is not visible when the inside of the image forming apparatus 100 is viewed from the exhaust port 251.

  As a result, as shown in FIG. 6, the exhaust gas sent from the exhaust fan 247 in the direction of the arrow 252 in the exhaust duct 224 passes through the ozone filter 249 and then is converted in the direction of the arrow 253 by the baffle plate 250. Then, the exhaust gas further changes its direction in the vicinity of the end portion of the air guide plate 250 and is discharged from the exhaust port 251.

  A gap 270 as a “second region” is secured around the end portion of the exhaust duct 224. Therefore, when the exhaust gas exiting from the exhaust duct 224 changes direction, a part of the exhaust gas is diverted so as to spiral in the direction of the arrow 256 and flows toward the gap 270 (around the end of the exhaust duct 224). After slowly flowing through the space 255, the air is exhausted from the exhaust port 251. Exhaust gas that has not diverted in the direction of the arrow 256 is exhausted from the exhaust port 251 after the direction of the arrow 254 changes direction to reduce the wind speed.

  Further, as shown in FIG. 7, a gap 270 is also provided in the vertical direction of the exhaust duct 224. Thus, the exhaust gas flowing in the direction of the arrow 253 always flows while generating a shunt in the direction of the arrow 256. In this embodiment, as shown in FIG. 6, the exhaust fan 247 has an exhaust direction in the direction of the arrow 252. Therefore, the wind speed of the exhaust gas that has passed through the ozone filter 249 is larger on the upper side and smaller on the lower side.

  In the case of the exhaust duct 224 having such a wind speed distribution, the angle of the baffle plate 250 is adjusted so that the upper air stream having a high wind speed passes through a long path until it reaches the exhaust port 251, and most of the exhaust is indicated by an arrow. What is necessary is just to make it flow in 253 direction. By doing so, the substantial flow path from the exhaust duct 224 to the exhaust port 251 is extended, and it is possible to further increase the opportunities for the exhaust to divert.

  Dusts such as toner tend to gather outside due to the influence of centrifugal force at locations where the airflow changes direction, and accumulate without getting on the airflow when the wind speed is low. In places where vortices are generated, there are many places where dust such as toner flows to the outside due to centrifugal force and places where dust such as toner accumulates due to a low wind speed. For this reason, dust such as toner is easily separated from the airflow. This makes it possible to provide more diversion points in the middle of the exhaust path and generate more vortices to separate more dust such as toner contained in the exhaust and reduce the dust contained in the exhaust. .

  As described above, a region for separating dust such as toner contained in the exhaust is provided immediately before exhausting from the apparatus main body 100A. This makes it possible to suppress the amount of dust such as toner discharged to the outside of the apparatus main body 100A even when using a dustproof filter whose removal efficiency has dropped beyond the replacement time.

  The basic configuration in the vicinity of the image forming apparatus 100, the exhaust duct 224, and the exhaust port 251 according to the present embodiment is the same. The feature of this embodiment is that the air guide plate 250 is made of a flexible material and is urged in a direction approaching the exhaust duct 224 when the exhaust fan 247 is stopped. . FIG. 8 is a schematic diagram of the state of the air guide plate 250 when the exhaust fan 247 is stopped, and FIG. 9 is a schematic diagram of the state of the air guide plate 250 when the exhaust fan 247 is in operation.

  When the exhaust fan 247 is stopped, the surface of the air guide plate 250 is arranged so as to spread in a direction orthogonal to the airflow traveling direction of the airflow exhausted from the exhaust duct 224. When the exhaust fan 247 is driven, the surface of the air guide plate 250 moves so as to spread in a direction different from the direction orthogonal to the airflow traveling direction of the airflow exhausted from the exhaust duct 224.

  By energizing the air guide plate 250 in the direction of the exhaust duct 224, when the exhaust fan 247 is stopped, the flow path near the outlet of the exhaust duct 224 becomes narrow. When the exhaust fan 247 is in an operating state, the air guide plate 250 is pushed by the air flow generated from the exhaust fan 247 and the deflection flow path becomes large. That is, the resistance of the exhaust flow path from the exhaust duct 224 to the exhaust port 251 is greater in the stopped state than in the operating state of the exhaust fan 247.

  The exhaust fan 247 has a moment when the wind speed increases at the time of start-up. At that time, there is a possibility that dust such as toner accumulated in the exhaust duct 224 will fly up and be carried on the airflow. However, with the configuration as in the present embodiment, it is possible to mitigate the instantaneous increase in wind speed when the exhaust fan 247 is started, and to suppress the rise of dust such as toner.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 100A Apparatus main body 224 Exhaust duct 247 Exhaust fan (air flow generation means)
250 Air guide plate (Airflow direction change part)
251 Exhaust port 255 space (first region)
270 gap (second region)

Claims (5)

An image forming apparatus having an image forming unit,
A duct provided inside the image forming apparatus , through which air that has passed through the image forming unit passes ,
An airflow generating means for generating an airflow for exhausting air that has passed through the image forming unit from an outlet of the duct, and is provided upstream of the outlet in an exhaust path of air exhausted from the outlet. The air flow generating means;
A filter that is provided between the image forming unit and the outlet in the exhaust path and collects dust;
An exhaust port for exhausting the air exhausted from the outlet to the outside of the image forming apparatus;
When facing the exhaust port between the outlet and the exhaust port and spaced from both the outlet and the exhaust port, and when viewing the outlet from the exhaust port, the outlet Is an air guide plate that changes the traveling direction of the air exhausted from the outlet, before the air exhausted from the outlet is exhausted from the exhaust port to the outside of the image forming apparatus. In addition, the air is diverted from the air guide plate in the space to generate a vortex, and the air guide plate is configured to separate dust from the air in the space;
An image forming apparatus comprising: a. The filter is a toner filter that collects toner contained in the air that has passed through the image forming unit, and the duct further includes an ozone filter that collects ozone contained in the air that has passed through the toner filter,
The image forming apparatus according to claim 1 wherein the ozone filter which is characterized in that provided in the duct so as to face the air guide plate. The image forming apparatus according to claim 1, wherein the filter is provided between the image forming unit and the duct in the exhaust path . Wherein the portions adjacent to the duct in a direction perpendicular to the direction to the air guide plate from the outlet is formed a space air whose traveling direction has been changed by the air guide plate being exhausted from the outlet flows the image forming apparatus according to any one of claims 1 to 3, characterized in that there. The air guide plate is made of a flexible material, and is located closer to the outlet when the air flow generation means is stopped than when the air flow generation means is driven. the image forming apparatus according to any of claims 1 to 4, characterized in that it is biased toward the outlet so.

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