JP4086175B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus having a cleaning device for removing toner adhering to an object to be cleaned.
[0002]
[Prior art]
An image forming apparatus configured as an electronic copying machine, a printer, a facsimile machine, or a multifunction machine having at least two of these functions is provided with a cleaning device that removes toner adhered to a member to be cleaned. For example, a cleaning device that forms a toner image on an image carrier with a developing device and removes transfer residual toner adhering to the surface of the image carrier after the toner image is transferred to a transfer material is an example. In this case, the image carrier constitutes the member to be cleaned.
[0003]
On the other hand, a device that generates a large amount of heat, for example, a fixing device, is provided in the main body of this type of image forming apparatus. For this reason, the temperature in the image forming apparatus main body rises, and accordingly, the temperature in the cleaning apparatus also rises. In particular, when a device that generates heat is provided in the vicinity of the cleaning device, the temperature inside the cleaning device increases significantly. When the temperature in the cleaning device rises excessively in this way, the toner in the inside of the cleaning device is fused, and for example, the normal operation of the toner discharge device that discharges the toner in the casing of the cleaning device is hindered. Function may be harmed.
[0004]
In order to eliminate the above problems, air is blown from the outside to the casing outer wall of the cleaning device by a fan to cool the cleaning device or to provide a heat insulating plate between the device that generates heat and the cleaning device. Measures such as suppressing the temperature rise inside the cleaning device have been taken, but such measures alone cannot effectively suppress the temperature rise inside the cleaning device, and reliably prevent the occurrence of the above-mentioned problems. It is difficult.
[0005]
[Problems to be solved by the invention]
The present invention has been made on the basis of the above-described novel recognition, and an object of the present invention is to provide an image forming apparatus that can more effectively suppress the temperature rise inside the cleaning device than in the past. is there.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a casing, a brush roller that is provided inside the casing and that contacts the surface of the object to be cleaned, and a moving direction of the surface of the object to be cleaned. And a cleaning blade that is in contact with the surface of the object to be cleaned in a state where the gap between the casing and the object to be cleaned is closed, and the cleaning blade and the brush roller An image forming apparatus comprising a cleaning device that removes toner adhering to the object to be cleaned, the air permeable filter disposed in the exhaust opening formed in the casing of the cleaning device, and the interior of the casing. The casing is sucked from the gap between the casing and the object to be cleaned. The inlet air is proposed an image forming apparatus characterized by comprising an exhaust fan for discharging the image forming apparatus outside the body through the filter within (claim 1).
[0008]
The image forming apparatus according to claim 1, further comprising a cooling unit that supplies cold air to the cleaning blade of the cleaning device, and the air after cooling the cleaning blade is exhausted by the exhaust unit. It is advantageous to configure so as to discharge outside (claim 2).
[0009]
The image forming apparatus according to claim 2, wherein the cooling unit includes a suction fan that sucks air outside the image forming apparatus main body, and an air intake duct that guides the air to the cleaning blade. It is advantageous (claim 3).
[0010]
The image forming apparatus according to any one of claims 1 to 3, wherein at least a part of the casing of the cleaning device includes a plurality of walls that are spaced apart from each other. It is advantageous that the air is exhausted out of the image forming apparatus main body by the exhaust fan.
[0011]
5. The image forming apparatus according to claim 4, further comprising: a fixing device that fixes at least the toner image formed on the transfer material by heat, wherein a casing portion of the cleaning device facing the fixing device includes the plurality of walls. It is advantageous if it is constituted by (Claim 5).
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0013]
FIG. 1 is a schematic vertical sectional view showing an example of an electrophotographic image forming apparatus. The image forming apparatus shown here is configured as an electronic copying machine. The image forming apparatus main body 1 includes an image reading unit 2 that reads an original image, an image forming unit 3 that forms an image on a transfer material, and a paper feeding unit 4 that supplies the transfer material to the image forming unit 3. Is provided.
[0014]
The image reading unit 2 includes a light source 7 that illuminates a document 6 placed on a contact glass 5 fixed to the upper part of the image forming apparatus main body, first to third mirrors 8, 9, and 10, and an image reading unit 11. The image reading means 11 includes an image sensor made of, for example, a CCD for reading a reflected light image from the document 6, and an imaging lens. Illustration of the image sensor and the imaging lens is omitted.
[0015]
When the image forming operation is started, the light source 7 and the first mirror 8 and the second and third mirrors 9 and 10 move to the right in FIG. The original 6 is illuminated. The reflected light image from the document 6 is reflected by the first to third mirrors 8, 9, and 10, passes through the imaging lens of the image reading means 11, reaches the image sensor, and the reflected light image from the document 6 is read.
[0016]
The image forming unit 3 includes a drum-shaped photoreceptor 12 which is an example of an image carrier, a charging device 13, a developing device 14, a transfer device 15, a cleaning device 16 for the photoreceptor, In addition to the lamp 17, the apparatus includes an exposure device 18, a registration roller pair 19, a fixing device 20, and the like. The transfer device 15 illustrated here includes an endless transfer belt 23 wound around a plurality of rollers 21 and 22 and driven in the direction of arrow A, and a transfer roller 24 disposed on the back side of the transfer belt 23. And a cleaning device 25 for the transfer belt.
[0017]
With the start of the image forming operation, the photoconductor 12 is rotationally driven in the direction of arrow B, and at this time, the surface of the photoconductor is charged to, for example, −900 V by the charging device 13. The exposure device 18 emits laser light L that is light-modulated in accordance with the image signal read by the image reading means 11, and the surface of the photosensitive member charged with the laser light L is exposed to perform optical writing. Is called. As a result, an electrostatic latent image is formed on the surface of the photosensitive member, and this electrostatic latent image is visualized as a toner image by the powdery developer D when passing through the developing device 14.
[0018]
On the other hand, the paper feed unit 4 includes, for example, a plurality of paper feed cassettes 26, 27, and 28 each containing various sizes of transfer material P made of transfer paper, and one uppermost transfer material P in each paper feed cassette. The sheet feeding rollers 29, 30, and 31 are fed out one by one, and the transfer material in the selected sheet feeding cassette is fed out by the rotation of the sheet feeding roller.
[0019]
The transferred transfer material P is sent to the nip portion between the photosensitive member 12 and the transfer belt 23 in contact with the photosensitive member 12 at a predetermined timing by the rotation of the registration roller pair 19. At this time, a transfer voltage is applied to the transfer roller 24, whereby the toner image on the photoreceptor is transferred onto the transfer material. Next, the transfer material is conveyed to the fixing device 20 by the transfer belt 23. When the transfer material passes through the fixing device 20, the toner image transferred onto the transfer material is fixed onto the transfer material at least by the action of heat. Is done. The transfer material after the toner image is fixed is discharged onto a paper discharge tray 33 via a paper discharge roller pair 32.
[0020]
On the other hand, untransferred toner adhering to the photoconductor after the toner image is transferred is removed by the photoconductor cleaning device 16. The surface of the photosensitive member whose surface has been cleaned by the cleaning device 16 is irradiated with light from the charge eliminating lamp 17, and the potential of the surface is initialized.
[0021]
The toner adhering to the transfer belt 23 is removed from the belt 23 by the transfer belt cleaning device 25. The cleaning device 25 includes a cleaning roller 34 which is an example of a cleaning member. The roller 34 is rotatably supported by a casing 35 and electrostatically sucks toner adhering to the transfer belt 23 to transfer the transfer belt 23. 23 surface is cleaned. A cleaning member composed of a cleaning blade or the like can also be used.
[0022]
The fixing device 20 illustrated in FIG. 1 includes a fixing roller 37 that is heated by an internal heater 36 and a pressure roller 38 that is in pressure contact with the fixing roller 37. These rollers 37 and 38 are each in the direction of arrow C. When the transfer material passes between them, heat and pressure are applied to the toner image transferred to the transfer material, and the toner image is fixed on the transfer material.
[0023]
Furthermore, the exposure apparatus 18 includes a laser light source 39, a rotary polygon mirror 40 that reflects the laser light emitted from the laser light source 39, an f-θ lens 41 for scanning imaging, mirrors 42, 43, 44, and the like. The laser beam L reflected by the mirror 44 exposes the charged surface of the photosensitive member, whereby an electrostatic latent image is formed on the photosensitive member as described above.
[0024]
In the illustrated image forming apparatus, as shown in FIG. 2, the photosensitive member 12, the cleaning device 16, the charging device 13 including a charging charger, the charge eliminating lamp 17, and the like are integrally assembled on the support. The photoconductor unit 45 is configured.
[0025]
Here, as shown in FIG. 2, the cleaning device 16 for the photosensitive member is rotatably supported by a casing 46, a cleaning blade 47 supported by the casing 46, and the casing 46 rotatably. The brush roller 48 and a recovery coil 49 which is an example of a toner discharge device disposed in the casing 46 are provided. The cleaning blade 47 and the brush roller 48 constitute a cleaning member that comes into contact with the surface of the photoconductor 12 and scrapes and removes transfer residual toner attached to the surface. The brush roller 48 is provided inside the casing 46, and the cleaning blade 47 is located on the downstream side of the brush roller 48 with respect to the movement direction of the surface of the photoconductor 12 and between the casing 46 and the photoconductor 12. It is in contact with the surface of the photoconductor 12 with the gap closed.
[0026]
The transfer residual toner removed from the surface of the photoreceptor by the cleaning blade 47 and the brush roller 48 is discharged out of the casing by a recovery coil 49 provided at the bottom of the casing 46 and driven to rotate. The toner discharged out of the casing 46 is accommodated in a waste toner container (not shown) or conveyed to the developing device 14 shown in FIG. Reused for visualization of images.
[0027]
As described above, the toner adhering to the photoconductor 12 is removed by the cleaning device 16. Therefore, in this example, the photoconductor 12 constitutes a cleaning target to be cleaned by the cleaning device 16.
[0028]
As described above, the electrophotographic image forming apparatus of this example includes a developing device that forms a toner image on an image carrier, a transfer device that transfers the toner image to a transfer material, and a transfer device on the image carrier after transfer. A cleaning device that removes the remaining toner and a fixing device that fixes the toner image transferred onto the transfer material by heat are provided. A large amount of heat is released from the fixing device 20. Since the photoconductor cleaning device 16 is provided in the vicinity of the fixing device 20, in this type of conventional image forming apparatus, the temperature inside the cleaning device may be excessively increased. If the temperature inside the cleaning device rises excessively in this way, the toner in the casing is fused and a large load is applied to the recovery coil that discharges the toner, and the smooth rotation of the recovery coil is hindered. In some cases, the recovery coil or a gear driving the recovery coil may be locked or damaged, which may impair the function of the cleaning device.
[0029]
In addition, when the toner collected by the cleaning device is transported to the developing device and reused, the toner deteriorates due to the temperature rise inside the cleaning device, and the toner is If it is used for visualization, an abnormal image may occur.
[0030]
In view of this, the image forming apparatus of this example is provided with exhaust means for discharging the air inside the cleaning device 16 to the outside of the image forming apparatus main body 1 in order to prevent the above-described problems. The specific configuration is as follows.
[0031]
FIG. 3 is a perspective view showing the image forming apparatus main body 1, the photoconductor unit 45, the photoconductor 12, an exhaust duct 50, which will be described later, and an intake duct 51 in a transparent state. As shown in FIG. 2, an opening 52 for exhaust is formed in the upper part of the casing 46 of the cleaning device 16, and an air permeable filter 53 for preventing toner scattering is provided therein, and the inside of the casing 46 is The filter 53 communicates with the air discharge path 54. The outlet of the air exhaust path 54 is connected to the inlet end of the exhaust duct 50 described above, and an exhaust fan 55 is provided at the outlet end of the exhaust duct 50 as shown in FIG. An ozone filter 56 is provided at the inlet end of the exhaust duct 50.
[0032]
By the operation of the exhaust fan 55 described above, the inside of the casing of the cleaning device 16 is sucked, and the air outside the casing 46 is taken into the casing 46 from the gap G between the lower portion of the casing and the photoreceptor 12 as indicated by the arrow F1. Is taken in. The air passes through the filter 53, the air discharge path 54 and the ozone filter 56 as indicated by arrows F 2 and F 3, flows into the exhaust duct 50, flows through the exhaust duct 50, and further passes through the exhaust fan 55 to form the image forming apparatus. It is discharged outside the main body 1. Thus, the air that has flowed into the casing of the cleaning device 16 by the action of the exhaust fan 55 is discharged out of the main body of the image forming apparatus through the filter 53, so that the heat inside the cleaning device 16 is taken away with the air. An excessive rise in the temperature of the cleaning device 16 is prevented, and the occurrence of the above-described conventional problems can be prevented.
[0033]
As described above, the exhaust unit of the present example sucks the air in the cleaning device to be discharged out of the image forming apparatus main body and discharges the air to the outside of the image forming apparatus main body, and the air is discharged into the exhaust fan. The exhaust duct 50 led to 55 is provided, and the air in the cleaning device is surely discharged out of the main body of the image forming apparatus by the exhaust means having such a simple configuration, and the temperature rise of the cleaning device is effectively suppressed. Can do.
[0034]
2 and 3, the image forming apparatus of this example includes a suction fan 57 for taking in air outside the main body of the image forming apparatus, and the intake duct 51 described above. In the image forming apparatus main body, it is branched into two duct portions 51A and 51B. As shown by an arrow F4 in FIG. 3, cool air outside the image forming apparatus main body is taken into the intake duct 51 by the suction fan 57, and the cool air is divided into the duct portions 51A and 51B of the intake duct 51, respectively. The air flowing into one duct portion 51A flows into the inside of the photoconductor 12 from one end in the longitudinal direction of the photoconductor 12, and is discharged out of the photoconductor from the other end as indicated by an arrow F5. In this way, the photoreceptor 12 is cooled by the cold air. As shown by an arrow F6, the air flowing into the other duct portion 51B passes through the air inflow path 58, passes through the case 59 of the charging device 13 made of a charger, and enters the photoconductor unit 45. FIG. As shown by an arrow F7, it flows along the peripheral surface of the photosensitive member 12 and reaches the cleaning member comprising the cleaning blade 47, where the cleaning blade 47 and its vicinity are cooled. This air flow not only supplies fresh air to the charging device 13, but also serves to carry ozone generated by the charging device 13.
[0035]
The air after cooling the cleaning blade 47 is drawn by the exhaust fan 55 and flows into the air discharge path 54 as indicated by the arrow F8, where the air discharged from the casing 46 of the cleaning device 16 and The air flows through the ozone filter 56, the exhaust duct 50, and the exhaust fan 55, and is discharged out of the image forming apparatus main body. When the air passes through the ozone filter 56, ozone contained in the air is removed.
[0036]
The cleaning blade 47 is made of an elastic body such as rubber, for example. If the temperature of the blade 47 rises excessively, abnormal noise is generated due to sliding friction between the blade 47 and the surface of the photoreceptor, or the cleaning blade 47. However, in the image forming apparatus of this example, since the cleaning blade 47 is cooled with cold as described above, the occurrence of the above-described problems can be prevented. When the cleaning member is made of a material other than the cleaning blade, the cleaning member can be cooled in the same manner as described above.
[0037]
As described above, the image forming apparatus of the present example has cooling means for supplying the cooling air taken from outside the image forming apparatus main body to the cleaning member of the cleaning device 16 and cooling the cleaning member. The cooling unit includes a suction fan 57 that sucks air outside the image forming apparatus main body, and an intake duct 51 that guides the air to the cleaning member. The air after cooling the cleaning member is discharged out of the image forming apparatus main body by the above-described exhaust means. For this reason, an exhaust device dedicated to the cooling means can be eliminated, and the configuration can be simplified.
[0038]
In addition, as shown in FIG. 2, at least a part of the casing 46 of the cleaning device 16 is constituted by a plurality of walls 60 and 61 that are spaced apart from each other, and in the illustrated example, an air layer is interposed therebetween. A double wall is constituted by the outer wall 60 and the inner wall 61 positioned so as to be. When the casing 46 has such a multi-wall structure, the heat insulating property is improved, and the temperature rise inside the casing 46 can be more reliably suppressed.
[0039]
At this time, if the air between the walls 60 and 61 is discharged to the outside of the main body of the image forming apparatus by the above-described exhaust means, an air flow is generated between the walls 60 and 61. 61 can be cooled, and the heat insulation effect can be further enhanced. Specifically, the above-described air-permeable filter 53 is disposed in the upper openings 62 of both walls 60 and 61, and the air between the walls 60 and 61 is sucked by the exhaust fan 55. As a result, the air between the walls 60 and 61 is discharged out of the image forming apparatus main body through the filter 53, the air discharge path 54, the ozone filter 56, the exhaust duct 50, and the exhaust fan 55 as indicated by an arrow F9. The
[0040]
As described above, if the casing 46 has a multiple wall structure, the heat insulating effect of the casing can be enhanced if it is used in at least a part of the casing. However, as shown in FIGS. If the casing portion of the cleaning device 16 that opposes the fixing device 20 that fixes the toner image at least by the action of heat is constituted by a plurality of walls 60 and 61, the cleaning device is caused by a large amount of heat released from the fixing device 20. It can suppress effectively that the temperature inside 16 is raised.
[0041]
The example in which the present invention is applied to the cleaning device 16 that removes the transfer residual toner on the photoconductor 12 has been described above. However, the present invention is also applicable to a cleaning device that removes toner attached to a cleaning target other than the photoconductor. It can be widely applied. For example, in an image forming apparatus of a type in which a toner image formed on a photosensitive member is transferred to an intermediate transfer member and the toner image on the intermediate transfer member is transferred to a transfer material, the transfer residue adhering to the intermediate transfer member is transferred. A cleaning device that removes the toner is provided. In order to prevent the temperature in the cleaning device from rising excessively, the above-described configurations can be employed. Further, the above-described configurations can also be employed to prevent the temperature inside the cleaning device 25 for the transfer belt 23 shown in FIG. 1 from rising excessively.
[0042]
Further, the present invention can be widely applied to various image forming apparatuses other than electronic copying machines.
[0043]
【The invention's effect】
According to the first aspect of the present invention, since the air inside the cleaning device is discharged to the outside of the image forming apparatus main body and the cleaning device is cooled, it is possible to effectively prevent a problem that the temperature inside the cleaning device rises excessively. can do.
[0045]
According to the second aspect of the present invention, the cleaning blade of the cleaning device can be cooled by cold air, and the cooled air is discharged out of the image forming apparatus main body by the exhaust fan. An apparatus is unnecessary, and it can be prevented that the structure of the image forming apparatus is complicated.
[0046]
According to the invention which concerns on Claim 3, the cooling means of a simple structure can be provided.
[0047]
According to the invention which concerns on Claim 4, the heat insulation effect of the casing of a cleaning apparatus can be improved, and the temperature rise inside a cleaning apparatus can be suppressed more effectively.
[0048]
According to the fifth aspect of the present invention, since the heat released from the fixing device is blocked by the plurality of walls, the temperature rise inside the cleaning device can be more effectively suppressed.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view illustrating an example of an image forming apparatus.
FIG. 2 is a cross-sectional view showing a photoconductor and a configuration around the photoconductor.
FIG. 3 is a perspective view illustrating an exhaust unit, a cooling unit, and a state of airflow generated in these units.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 16 Cleaning device 20 Fixing device 25 Cleaning device 35 Casing 46 Casing 47 Cleaning blade 48 Brush roller 50 Exhaust duct 51 Intake duct 52 Opening 53 Filter 55 Exhaust fan 57 Suction fan 60 Wall 61 Wall G Gap

Claims (5)

A casing, a brush roller that is provided inside the casing and contacts the surface of the object to be cleaned, and is located downstream of the brush roller with respect to the moving direction of the surface of the object to be cleaned, and the casing A cleaning blade that contacts the surface of the object to be cleaned in a state where a gap between the object and the object to be cleaned is closed, and the toner attached to the object to be cleaned is removed by the cleaning blade and the brush roller. In the image forming apparatus provided with the cleaning device, the air permeable filter disposed in the exhaust opening formed in the casing of the cleaning device, the inside of the casing is sucked, and the casing and the object to be cleaned are Air that has flowed into the casing from the gap between the filter and the filter To the image forming apparatus characterized by comprising an exhaust fan for discharging to the outside of the image forming apparatus main body. The image forming apparatus according to claim 1, further comprising: a cooling unit that supplies cold air to the cleaning blade of the cleaning apparatus, and the air after cooling the cleaning blade is discharged out of the image forming apparatus main body by the exhaust fan. The image forming apparatus according to claim 2, wherein the cooling unit includes a suction fan that sucks air outside the image forming apparatus main body, and an air intake duct that guides the air to the cleaning blade. 4. The at least part of the casing of the cleaning device is constituted by a plurality of walls arranged at intervals, and the air between the walls is discharged out of the image forming apparatus main body by the exhaust fan. 5. The image forming apparatus according to any one of the above. The image forming apparatus according to claim 4, further comprising: a fixing device that fixes the toner image formed on the transfer material by at least heat, wherein a casing portion of the cleaning device facing the fixing device is configured by the plurality of walls. .

Images