JP2006215307A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prolong a lifetime of a filter for catching volatile organic compounds generated from resin components used in an image forming apparatus by efficiently using the filter. <P>SOLUTION: The image forming apparatus has an exhaust fan 54 for exhausting air from the interior of the apparatus to the outside thereof, and the filter 58 through which the airstream generated by the exhaust fan 54 passes and in which the filter 58 captures the volatile organic compounds in the air. The apparatus is characterized in that an amount of air passing the filter 58 is controlled by the exhaust fan 54 according to the information concerned with a temperature within the apparatus. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus using an electrophotographic method, and more particularly to an image forming apparatus having a function of collecting a volatile organic compound generated in the apparatus.

  2. Description of the Related Art Conventionally, as an image forming apparatus using an electrophotographic system, a plurality of image forming units are provided, toner images of different colors are formed in each image forming unit, and the same recording material carried and conveyed by a recording material carrier An image forming apparatus for forming a color image by sequentially superimposing and transferring the respective color toner images thereon, and transferring each color toner image by sequentially superimposing and transferring the color toner image onto the intermediate transfer member. Various proposals have been made for an image forming apparatus that forms a color image by batch-transferring toner images onto a recording material.

  A color image forming apparatus including a plurality of such image forming units is called a tandem type, and has a general color image forming apparatus configuration because the recording speed can be set high.

  However, in recent years, the printing speed of the above-described color image forming apparatus has been further increased, and heat generated from an electric unit such as a motor and a power source, a fixing device, etc., which is a heat generation source in the apparatus, has been developed. The total amount is increasing.

  For this purpose, the image forming apparatus is provided with an intake and exhaust fan and duct for cooling the inside of the apparatus. As the air flow inside the device by the intake and exhaust fans and ducts, the air taken from outside the device is sent to the above-mentioned heat sources (electrical units such as motors, power supplies, etc.) and the heat is taken away. Air is exhausted outside the equipment.

  Further, in the above-described color image forming apparatus, when recording is performed on both sides of the recording material, the recording material on which one side is recorded again passes through a high-temperature fixing device and has heat. It passes through the above-described image forming unit. As a result, the temperature of the image forming unit is raised, but air is also sent to the image forming unit using the fan and duct described above, and the air deprived of heat is exhausted outside the apparatus in the same manner as described above. I have to.

Japanese Patent Laid-Open No. 2003-186324

  As described above, when air is exhausted for cooling the inside of the apparatus, substances generated in the apparatus are also exhausted. In recent years, the discharge amount of substances generated in the apparatus has been regulated from an environmental standpoint.

  Japanese Patent Application Laid-Open No. 2003-186324 (Patent Document 1) discloses an image forming apparatus in which a fixing unit as a heating unit is provided with a member that adsorbs formaldehyde generated from toner or oil. Some devices have a dust collection filter attached to the exhaust port so that toner particles are not discharged outside the device.

  As the discharge amount of substances generated in the apparatus is regulated in this way, a trace amount of volatile organic compounds generated from resin parts used in the image forming apparatus are also concerned. It is coming. Specifically, there are standards such as the BAM standard, the UL standard, and the TUV standard that regulate the emission amount of the volatile organic compounds described above, and the necessity of satisfying these standards has arisen also in the image forming apparatus.

  Conventionally, a lot of resin has been used for the components constituting the image forming apparatus as described above. The reason why the resin is used for the parts constituting the image forming apparatus is that it has a higher degree of freedom in shape and lighter than metal. Actually, resin such as ABS, PS, PC + ABS, PPE, and POM is used for about 50% to 80% of the total number of parts in the apparatus, such as an exterior cover, a sheet guide, and a gear.

  A part of the volatile organic compounds whose emission amount is regulated in the aforementioned standard is generated from resin parts made of ABS, PS, PC + ABS, PPE, etc. used in the image forming apparatus. These resin parts are resin components by being exposed to heat generated by the drive motor, power supply, fixing device, or temperature rise in the apparatus due to the passing of heated recording material during double-sided recording. Chemical substances such as styrene (boiling point: 145.2 ° C.) and benzene (boiling point: 80.1 ° C.) reach the boiling point, become gas and are exhausted outside the device through the fan and duct provided in the device.

  As described above, in recent years, the speed of image forming apparatuses and the standardization of double-sided recording have progressed, the amount of heat generated in the apparatus has increased, and the resin parts disposed in the apparatus have been exposed to more heat than ever. . As a result, the amount of volatile organic compounds generated from the resin parts is also an amount that cannot be ignored.

  In order to collect the volatile organic compounds generated from these resin parts, it is effective to use a collection filter mainly composed of activated carbon. This type of filter collects volatile organic compounds by physically adsorbing gaseous substances in fine pores called pores. This collection filter collects a certain amount of volatile organic compounds contained in the exhaust air by an amount corresponding to the wind speed of the fan rotating at a constant speed.

  However, in general, the resin part is molded, and the molded resin part generates a volatile organic compound although it is a small amount immediately after molding, and the amount decreases as time passes. There is a tendency to do. Therefore, even in an image forming apparatus in which many of these resin parts are used, the amount of volatile organic compounds generated from the resin parts tends to decrease as time passes from the initial use. That is, the amount of the volatile organic compound generated from the image forming apparatus using many resin parts is not constant.

  For this reason, when the volatile organic compounds generated from many resin parts used in the image forming apparatus exceed the collection amount of the filter by the fan rotating at the constant speed, the various standards described above are prescribed. The amount of volatile organic compounds exceeding the value may be exhausted outside the apparatus.

  On the other hand, even if the amount of volatile organic compounds generated at the initial stage of use does not exceed the amount collected by the filter, the amount collected by the filter is constant as long as the fan rotates at a constant speed. A certain amount of volatile organic compounds in the exhaust air is always collected. That is, even if the volatile organic compound decreases below the specified value with time, the volatile organic compound in the air exhausted from the inside of the apparatus to the outside of the apparatus is collected more than necessary. By collecting more volatile organic compounds in this way, the period during which the filter can be collected decreases, and as a result, the lifetime of the filter that collects the volatile organic compounds is shortened. There is a problem that the volatile organic compound cannot be efficiently collected by the filter.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent volatile organic compounds generated from resin parts used in an image forming apparatus from being discharged out of the apparatus in an amount exceeding the specified values of various standards. It is.

  Another object of the present invention is to enable efficient collection of volatile organic compounds by the filter and extend the life of the filter.

  A typical configuration of the present invention for achieving the above object has an exhaust means for exhausting air from the inside of the apparatus to the outside of the apparatus, and a filter through which an air flow generated by the exhaust means passes, In the image forming apparatus that collects volatile organic compounds in the air, the filter controls the amount of air that passes through the filter by the exhaust unit based on information on the temperature in the apparatus.

  According to the present invention, it is possible to prevent the volatile organic compound generated from the resin component used in the image forming apparatus from being discharged out of the apparatus in an amount exceeding the specified values of various standards. Further, the volatile organic compound can be efficiently collected by the filter, and the life of the filter can be extended.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
The image forming apparatus according to the first embodiment of the present invention will be described in detail with reference to FIGS.

  First, the overall configuration of the image forming apparatus will be outlined with reference to FIG. FIG. 1 is a longitudinal sectional view showing the overall configuration of a full-color laser beam printer 100 which is an aspect of the image forming apparatus.

  An image forming apparatus 100 shown in the figure includes four photosensitive drums 1a, 1b, 1c, and 1d arranged in parallel in the vertical direction. A photosensitive drum 1 (1a, 1b, 1c, 1d) as an image carrier is rotationally driven counterclockwise in the drawing by a driving means (not shown). A charging device 2 (2a, 2b, 2c, 2d) for uniformly charging the surface of the photosensitive drum 1 in order according to the rotation direction, and a toner attached to the electrostatic latent image around the photosensitive drum 1 A developing device 4 (4a, 4b, 4c, 4d) for developing as an image, a cleaning device 6 (6a, 6b, 6c, 6d) for removing transfer residual toner remaining on the surface of the photosensitive drum 1 after transfer, and the like are provided. Has been. 3 (3 a, 3 b, 3 c, 3 d) is a scanner unit 5 that forms an electrostatic latent image on the photosensitive drum 1 by irradiating a laser beam between the charging device 2 and the developing device 4 based on image information. This is an electrostatic transfer unit as a transfer unit that faces a plurality of photosensitive drums 1a, 1b, 1c, and 1d and transfers a toner image on the photosensitive drum 1 to a sheet S as a recording material.

  Here, the photosensitive drum 1 and the charging device 2, the developing device 4, and the cleaning device 6 as process means that act on the photosensitive drum 1 are integrally formed into a cartridge that is detachable from the image forming apparatus main body 100. Process cartridges 7 (7a, 7b, 7c, 7d) are formed. The process cartridge 7 and the electrostatic transfer unit 5 constitute an image forming unit that forms an image on a sheet.

  Each developing device 4a, 4b, 4c, 4d in each process cartridge 7 is composed of a developing unit that stores toner of each color of yellow, magenta, cyan, and black, respectively. There is a toner container for storing toner in the developing device, and the LED light is transmitted through the toner container to detect the transmission time and to detect the remaining amount of toner.

  The electrostatic transfer unit 5 has an electrostatic transfer belt 11 as a sheet carrier for carrying and conveying a sheet. The electrostatic transfer belt 11 is supported in the vertical direction by four rollers including a driving roller 13, driven rollers 14a and 14b, and a tension roller 15. The sheet S is circulated so as to contact the body drum 1. Further, transfer rollers 12 (12a, 12b, 12c, 12d) are arranged in parallel at positions facing the inside of the electrostatic transfer belt 11 and facing the four photosensitive drums 1a, 1b, 1c, 1d. As a result, the sheet S is conveyed to each transfer position by the electrostatic transfer belt 11, and the toner image on each photosensitive drum 1 is transferred by each transfer roller 12.

  The feeding unit 16 feeds the sheet S to the image forming unit, and a plurality of sheets S are stored in the cassette 17. At the time of image formation, the feeding roller 18 (half-moon roller) feeds the uppermost sheet S on the cassette 17, the leading edge of the sheet S abuts against the registration roller pair 19, temporarily stops, forms a loop, and then the electrostatic transfer belt 11. The rotation and the image writing position are synchronized, and the sheet is fed to the electrostatic transfer belt 11 by the registration roller pair 19.

  The fixing unit 20 as a fixing unit fixes the toner images of a plurality of colors transferred to the sheet S, and includes a rotating heating roller 21a and a pressure roller that presses and applies heat and pressure to the sheet S. 21b. Downstream of this, there is a pair of discharge rollers 23 for discharging the sheet S out of the apparatus main body.

  In addition, a discharge sensor (not shown) is disposed between the fixing roller pair 21 and the discharge roller pair 23 to check whether the sheet S has been reliably discharged out of the apparatus or is not wound around the fixing roller pair 21. Monitoring.

  In addition, a double-sided path used when image recording is performed on both sides of the sheet S is formed on the back surface of the electrostatic transfer belt unit 5. A switching flapper 24 for switching whether to discharge a sheet to the discharge unit 31 or to guide the sheet to the duplex path, and a sheet guided to the duplex path by the switching flapper 24 are switched back to the entrance of the duplex path. A pair of possible transport rollers 25 and a transport roller pair 26 for transporting the switchback transported sheet into the double-sided path are arranged to transport the sheet S downward in the figure. A U-turn path 30 is provided at the lowest point of the double-sided path to change the sheet conveyance direction, and the sheet S guided to the U-turn path 30 is re-fed to the registration roller pair 19.

  As an image forming operation, the process cartridges 7a, 7b, 7c, and 7d are sequentially driven in accordance with the recording timing, and the photosensitive drums 1a, 1b, 1c, and 1d are rotated counterclockwise in accordance with the drive. Driven. Then, the scanner units 3 corresponding to the respective process cartridges 7 are sequentially driven. By this driving, the charging roller 2 imparts a uniform charge to the circumferential surface of the photosensitive drum 1, and the scanner unit 3 exposes the circumferential surface of the photosensitive drum 1 according to the image signal to perform photosensitive drum 1. An electrostatic latent image is formed on the peripheral surface. The developing roller in the developing device 4 transfers (transfers) the toner to the electrostatic latent image and forms (develops) the toner image on the circumferential surface of the photosensitive drum 1.

  At the timing when the leading edge of the toner image on the circumferential surface of the photosensitive drum 1 that is the most upstream is rotated and conveyed to a point facing the electrostatic transfer belt 11, the recording start position of the sheet S coincides with that point. Then, the registration roller pair 19 starts to rotate and feeds the sheet S to the electrostatic transfer belt 11.

  The sheet S is pressed against the outer periphery of the electrostatic transfer belt 11 so as to be sandwiched between the electrostatic adsorption roller 22 and the electrostatic transfer belt 11, and a voltage is applied between the electrostatic transfer belt 11 and the electrostatic adsorption roller 22. By doing so, the sheet S is configured to be electrostatically attracted to the outer periphery of the electrostatic transfer belt 11. As a result, the sheet S is stably adsorbed to the electrostatic transfer belt 11 and conveyed to the most downstream transfer unit.

  While being conveyed in this way, the toner images on the photosensitive drums 1 are sequentially transferred to the sheets S by an electric field formed between the photosensitive drums 1 and the transfer rollers 12.

  The sheet S to which the four color toner images are transferred is separated from the electrostatic transfer belt 11 by the curvature of the belt driving roller 13 and is carried into the fixing unit 20. After the toner image is thermally fixed by the fixing unit 20, the sheet S is discharged out of the apparatus by the discharge roller pair 23 with the image surface facing down to the discharge unit 31.

  The operation of double-sided recording will be described. When the printer main body receives the duplex recording signal, the switching flapper 24 guides the sheet S to the conveyance roller pair 25 and detects that the sheet S has passed through the fixing roller pair 21 by the discharge sensor. Based on the detection signal, the conveying roller pair 25 rotates in the reverse direction and guides the sheet S to the conveying roller pair 26. The sheet S that has entered the double-sided path by the conveying roller pair 26 is conveyed by the conveying roller pair 28 and 29 to the registration roller pair 19 through the U-turn path 30. Thereafter, the back surface recording is completed in the same image forming process as the front surface recording, and the sheet S on which the images are recorded on the front and back surfaces is discharged to the discharge unit 31.

  The image forming apparatus 100 uses resin parts in many other locations such as an exterior cover, a sheet guide, and a user access unit. As materials for the resin parts, ABS (acrylonitrile / butadiene / styrene), PS (polystyrene), PC (polycarbonate), POM (polyacetal), and the like are properly used according to functions required for each part.

  Next, the airflow configuration in the image forming apparatus 100 will be described with reference to FIG. 2A and 2B are explanatory views showing an airflow configuration of the image forming apparatus, in which FIG. 2A is a top view of the image forming apparatus 100 and FIG. 2B is a perspective view of a filter.

  As shown in FIG. 2, an intake axial fan 51 is disposed on the left side surface portion of the image forming apparatus main body 100. The intake axial fan 51 is fixed directly to the left cover 52 with screws. The left cover 52 that is a part of the exterior cover that forms the exterior of the apparatus is formed of a resin such as ABS, and a louver 53 is integrally formed in the vicinity of the intake axial flow fan 51. The intake axial flow fan 51 rotates in a direction to take outside air into the apparatus main body. In order to suppress a temperature rise in the apparatus, air (such as an image forming unit or a fixing unit 20) is air ( Air).

  In addition, an exhaust axial flow fan 54 that constitutes an exhaust unit is disposed in the right rear portion of the image forming apparatus main body 100. The exhaust axial flow fan 54 rotates in a direction to discharge the air inside the apparatus to the outside of the apparatus, and blows air (air) that has taken away heat by blowing to an apparatus temperature rising part such as the image forming part or the fixing part 20. Discharged out of the device.

  The exhaust axial flow fan 54 is held by a fan holder 55 in which a duct portion is integrally formed. The fan holder 55 is formed of a resin such as ABS, and the exhaust axial flow fan 54 is fixed by a snap fit (not shown).

  One end of the fan holder 55 is engaged with a louver 57 that is formed integrally with a rear cover 56 that is a part of the exterior cover that forms the exterior of the apparatus. The other end of the fan holder 55 is disposed so as to face the image forming unit or the fixing unit 20 that is a temperature raising unit in the image forming apparatus 100. As a result, the axial fans 51 and 54 generate an air flow in the direction of the arrow in FIG. 2A, and the air taken from the outside of the apparatus into the apparatus is blown to the temperature raising portion in the apparatus, and the air is effectively supplied to the apparatus. Exhaust outside.

  The fan holder 55 holds the exhaust axial fan 54 and holds a filter 58 as a collecting member at a position close to the exhaust axial fan 54. The filter 58 is fixed by a snap fit (not shown) formed in the fan holder 55. The filter 58 of the present embodiment is an activated carbon filter through which an air flow generated by the exhaust means passes and which contains activated carbon to collect volatile organic compounds in the air.

  The filter 58 is arranged at a position away from the exhaust axial flow fan 54 by a predetermined distance (about 20 mm in this embodiment) so as not to generate wind noise of the exhaust axial flow fan 54. In general, the axial flow fan has a characteristic that the wind speed on the intake side is substantially uniform regardless of the position, and the wind speed varies depending on the position because the exhaust side exhibits radial wind power. Therefore, in the present embodiment, the filter 58 is disposed on the upstream side of the air flow with respect to the exhaust axial flow fan 54 so as to allow air to uniformly pass through the filter 58.

  The filter 58 has activated carbon as its material, has fine pores on its surface, and physically adsorbs volatile organic compounds such as styrene and benzene in the air passing through the filter 58. The ones that can be collected are used.

  Further, the filter 58 has a honeycomb structure as shown in FIG. 2B, and air can be evenly passed through the filter 58 without disturbing the air flow in the direction of the arrow in the figure. . In addition, since the filter 58 can maximize the surface area in contact with air, the performance of collecting volatile organic compounds in the air is improved.

  Next, the variable control of the exhaust axial flow fan 54 according to the temperature change in the apparatus will be described with reference to FIG.

  In the present embodiment, as the temperature in the image forming apparatus 100 rises, the rotational speed of the exhaust axial flow fan 54 is decreased so as to collect volatile organic compounds exceeding the specified value in the air by the filter 58. Control is in progress. The specified value here is a specified value of a standard such as a BAM standard, a UL standard, or a TUV standard that regulates the emission amount of the volatile organic compound.

  As described above, the image forming apparatus 100 is composed of many resin parts. The resin parts constantly discharge volatile organic compounds into the air.

  FIG. 3A shows the relationship between the internal temperature of the image forming apparatus 100 and the amount of volatile organic compounds generated from the resin parts used in the image forming apparatus 100.

  As can be seen from FIG. 3 (a), many resin parts generate many volatile organic compounds at high temperatures (about 80 ° C or higher), but at normal temperatures (about 25 ° C). It can be seen that the amount is decreasing. This is because the volatile organic compound is a compound such as styrene or benzene having a boiling point of 50 ° C. to 260 ° C., and is likely to volatilize as the temperature rises in the apparatus, and generates a lot of gas.

  Next, FIG. 3B shows the relationship between the wind speed of air passing through the filter 58 and the collection efficiency at which the filter 58 collects volatile organic compounds.

  As shown in FIG. 3B, it is generally known that the collection efficiency by the filter 58 is improved as the wind speed by the axial fan 54 is slower. Normally, the axial fan 54 arranged for suppressing the temperature rise in the apparatus is used at the maximum rotational speed (the chain line portion in FIG. 3B) so as to achieve the maximum wind speed of the fan. However, in the axial fan 54 rotated at the maximum rotational speed, the air speed at the surface of the filter 58 is higher than that at the rotational speed at which the wind speed is lower than that. Since the volatile organic compound cannot be adsorbed stably in the pores, the collection efficiency of the volatile organic compound is low, and the collection performance of the volatile organic compound by the filter 58 is not sufficiently exhibited.

  Therefore, in the present embodiment, as shown in FIG. 3A, it is generated by the exhaust axial flow fan 54 as shown in FIG. 3C in accordance with the amount of the volatile organic compound generated from the image forming apparatus. The collection efficiency by the filter 58 is optimized so as to change the wind speed, collect volatile organic compounds exceeding the specified value in the exhaust air, and extend the life of the filter 58.

  Specific control of the exhaust axial flow fan 54 in accordance with the amount of the volatile organic compound is shown in FIG. FIG. 3C shows the relationship between the apparatus internal temperature and the rotational speed of the exhaust axial flow fan 54. As shown in FIG. 3C, the exhaust axial flow fan 54 is configured such that the rotational speed is changed stepwise (five steps in this embodiment) and the wind speed is changed stepwise. ing. The exhaust axial flow fan 54 is controlled by a control means 60 (see FIG. 1) that controls each part of the entire image forming apparatus. At the initial stage of use of the apparatus in which the temperature inside the apparatus is at room temperature (about 25 ° C.), the volatile organic compound generated from the resin components inside the apparatus is less than the specified value of the above-mentioned standard. The number of rotations is set to the maximum number of rotations of a normal fan.

  Thereafter, when continuous paper feeding or frequent printout is performed, the internal temperature of the image forming apparatus 100 rises. Then, when the temperature inside the apparatus reaches a predetermined temperature t1 by the temperature detecting means 70 (see FIG. 2A) that detects the temperature inside the image forming apparatus 100, the amount of increase in the generation of volatile organic compounds is calculated from the temperature inside the apparatus. As shown in FIG. 3C, the rotational speed of the exhaust axial fan 54 is decreased by one level, that is, the wind speed and the air volume of the exhaust axial fan 54 are controlled to be reduced. Increases the collection efficiency.

  Thereafter, as shown in FIG. 3C, every time the temperature inside the apparatus rises and reaches the predetermined temperatures t2 and t3, the rotational speed of the exhaust axial flow fan 54 is decreased by one step to increase the wind speed and the air volume. Finally, at the peak of temperature rise in the apparatus (temperature t4 in FIG. 3C), the rotational speed of the exhaust axial flow fan 54 maximizes the collection efficiency of the volatile organic compound by the filter 58. Control is performed to achieve a low speed.

  As described above, in the present embodiment, the amount of air passing through the filter is controlled by the exhaust unit based on the information related to the temperature in the apparatus. In particular, in this embodiment, the number of rotations (rotational speed) per unit time of the exhaust fan is controlled based on information related to the temperature in the apparatus. When the temperature in the apparatus increases, the unit of the exhaust fan The number of revolutions per hour) decreases, and the speed of the air flow generated by the exhaust means decreases.

  The temperature inside the apparatus, which serves as a reference for changing the rotational speed of the exhaust axial flow fan, is experimentally determined, and the type, size, thickness, and resin of the resin used in the components constituting the image forming apparatus, It depends on the arrangement. For this reason, it is necessary to make an experiment and decide for each product.

  In this way, the amount of volatile organic compounds generated from the resin components used in the image forming apparatus is grasped in advance, and according to the amount of increase in the generation of volatile organic compounds that increases as the apparatus temperature rises, Control is performed to reduce the rotational speed of the exhaust axial flow fan 54 so that the volatile organic compounds in the air exhausted from the image forming apparatus are below a specified value, and the volatile organic compounds in the air are removed from the filter 58. I try to increase the amount collected.

  Thereby, it is possible to prevent the volatile organic compound generated from the resin parts used in the image forming apparatus from being discharged out of the apparatus in an amount exceeding the prescribed values of various standards. Further, since the volatile organic compound that increases as the temperature in the apparatus rises can be collected according to the increase amount, the volatile organic compound can be efficiently collected by the filter 58 and captured. The lifetime of the filter 58 having a predetermined total amount that can be collected can be extended.

  In addition, the life of the filter 58 can be set longer than the life of the apparatus, and it is not necessary to replace the filter 58 that has been performed by the user in the past, so that user maintenance can be improved.

  Furthermore, in consideration of the exchangeability by the user in the past, the arrangement of the filter 58 has been limited to the exhaust side of the exhaust axial flow fan 54 which is a place close to the outer cover, but according to the present embodiment, as described above. Since the life of the filter 58 can be set longer than the life of the apparatus, the degree of freedom in arranging the filter 58 is increased, and the exhaust axial flow fan 54 can be arranged on the intake side. Thereby, it becomes possible to allow uniform air to pass through the filter 58 due to the characteristics of the axial fan, and the collection efficiency of the volatile organic compound by the filter 58 can be further improved.

  Furthermore, by changing the rotational speed of the exhaust axial flow fan 54 as a cooling fan for suppressing the temperature rise in the apparatus according to the increase in the amount of volatile organic compounds that increases as the apparatus temperature rises, the filter Since the collection efficiency of the volatile organic compound by 58 is optimized, it is possible to collect the volatile organic compound stably over the product lifetime without increasing the product cost.

  In the present embodiment, the configuration in which the amount of volatile organic compounds collected by the filter 58 is changed by controlling the air velocity and the air volume of the exhaust axial flow fan 54 is described, but the present invention is not limited to this. For example, a movable shielding member (collection amount changing means) is provided on either one of the front and rear sides of the filter 58 so that the area through which the air of the filter 58 passes is increased or decreased by the shielding member. Control may be performed to increase the air passage area of the filter 58 in order to increase the amount of volatile organic compounds collected by the filter 58 as the temperature in the apparatus rises.

  That is, the position of the shielding member is controlled based on the information related to the temperature in the apparatus. When the temperature in the apparatus increases, the shielding member moves so as to expose the filter and is generated by the exhaust means. The area of the filter through which the air flow passes increases.

  Also with this configuration, the collection efficiency of the volatile organic compound by the filter 58 can be changed to optimize the collection efficiency.

[Second Embodiment]
In the first embodiment described above, the configuration is illustrated in which control is performed to reduce the rotational speed of the exhaust axial flow fan 54 in order to increase the amount of volatile organic compounds collected by the filter 58 as the apparatus temperature rises. In the second embodiment, the exhaust axial flow fan 54 is used to increase the amount of the volatile organic compound collected by the filter 58 using the information on the ambient temperature around the fixing unit 20 as in the first embodiment. The control is performed to reduce the rotation speed of the motor. Hereinafter, a second embodiment will be described. Since the schematic configuration of the image forming apparatus according to the second embodiment is the same as that of the above-described embodiment, the description thereof is omitted here, and the above-described description is used.

  Most of the temperature rise in the apparatus of the image forming apparatus is influenced by the amount of heat when the fixing unit 20 heats and fixes the sheet. For this reason, in this embodiment, rotation control of the exhaust axial flow fan 54 is performed based on the ambient temperature information around the fixing unit 20. When the fixing unit 20 is generating heat, the ambient temperature around the fixing unit 20 can be predicted from parameters such as the heat generation time and the rest time of the fixing unit 20 and the print job history. That is, the control unit 60 includes a detection unit for detecting information related to the temperature in the apparatus, and the detection unit can detect the heat generation time of the fixing unit 20 or the number of print jobs. And the apparatus is provided with a temperature prediction table for predicting the temperature based on the information obtained from the detection result of the detection means, referring to the temperature prediction table based on parameters such as the heat generation time and the number of jobs, Atmospheric temperature is predicted. Note that the ambient temperature around the fixing unit 20 is not limited to the prediction based on the above-described information. For example, a temperature detection unit such as a sensor for detecting the ambient temperature around the fixing unit 20 may be provided.

  When 1000 sheets or more are continuously passed, the resin parts around the fixing unit 20 may exceed 130 ° C. at the peak due to the heat generated by the fixing unit 20 exceeding 200 ° C. according to the experimental result of the temperature rise in the apparatus. all right.

  Moreover, when the resin temperature of the test piece of the PC-ABS material used around the fixing unit 20 was set to 130 ° C. and 25 ° C. and the volatile organic compound was measured, the discharge amount of the volatile organic compound was 25 ° C. In the case of 1, the temperature at 130 ° C. was 235 times or more. From this result, it was found that the discharge amount of the volatile organic compound is particularly affected by the resin parts that reach a high temperature such as around the fixing unit 20.

Measurement result of volatile organic compounds PC + ABS
25 degreeC state (2.5 g / 30 minute measurement): 45.8 ng / g
130 degreeC state (0.1 g / 30 minute measurement): 10800 ng / g

  From this result, in this embodiment, the information on the ambient temperature around the fixing unit 20 is used to increase the amount of volatile organic compounds collected by the filter 58 in the same manner as in the first embodiment described above. The control is performed to reduce the rotational speed of the fan 54.

  As a result, it is possible to prevent the volatile organic compound generated from the resin parts around the fixing unit 20 from being discharged outside the apparatus in an amount exceeding the prescribed values of various standards. Further, when the fixing unit 20 generates heat, the volatile organic compound that increases as the heating amount increases can be collected according to the increase amount. Therefore, it is possible to extend the life of the filter 58 whose total amount that can be collected is determined.

[Third Embodiment]
In the first embodiment described above, an example in which the collection efficiency of the volatile organic compound by the filter 58 is optimized by changing the wind speed and the air volume of the exhaust axial flow fan 54 according to the change in the apparatus temperature is shown. In the embodiment, when the apparatus has no internal temperature detection means and only includes an environment detection sensor 80 (see FIG. 1) capable of detecting the temperature and humidity of the usage environment as environmental information, the usage environment of the apparatus itself is used. The collection efficiency of the volatile organic compound by the filter 58 is optimized according to the temperature change.

  When the change in the temperature rise in the image forming apparatus was examined, the detection result of the environment detection sensor (environment detection means) 80 provided in the image forming apparatus showed the peak of the temperature rise in the apparatus according to the environment temperature when the apparatus was used. It was found that the temperature inside the apparatus was offset. Specifically, as shown in FIG. 4, when continuous printing (time: 60 minutes) of the apparatus was performed at an air temperature of 20 ° C., the peak temperature rise in the apparatus was about 37 ° C. When continuous printing was performed at an air temperature of 30 ° C., the peak temperature rise in the apparatus reached about 45 ° C. From the relationship between the temperature in the apparatus and the amount of volatile organic compounds generated as shown in FIG. 3A, the generation of volatile organic compounds increases as the apparatus temperature increases. By adding to this information the ambient temperature information around the fixing unit that can be predicted from the heat generation / rest time of the fixing device and the print job history shown in the second embodiment, the amount of volatile organic compounds generated can be known more accurately. It became possible.

  Therefore, by applying the same control as the control performed in the first embodiment to the in-machine temperature information to the exhaust axial flow fan, the optimum collection efficiency according to the amount of volatile organic compounds generated in the apparatus is obtained. By controlling the exhaust axial flow fan 54 as described above, the filter 58 can be used efficiently, and the life of the filter 58 can be extended. Further, it is possible to prevent the volatile organic compounds generated from the resin parts used in the image forming apparatus from being discharged out of the apparatus in an amount exceeding the prescribed values of various standards.

[Other Embodiments]
In the above-described embodiment, the control of changing the rotational speed of the exhaust fan constituting the exhaust means stepwise according to the amount of the volatile organic compound generated from the resin component used in the apparatus is exemplified. However, the present invention is not limited to this. For example, the control may be changed steplessly.

  In the embodiment described above, as a process cartridge that is detachable from the main body of the image forming apparatus, a photosensitive drum, a charging unit (charging device) as a process unit that acts on the photosensitive drum, and a developing unit (developing device). , The process cartridge integrally including the cleaning unit (cleaning device) is illustrated, but is not limited thereto, and any one of the charging unit, the developing unit, and the cleaning unit may be used in addition to the photosensitive drum. It may be a process cartridge integrally having one.

  In the above-described embodiment, the color image forming picture apparatus capable of forming a color image has been described as an example. However, the present invention is not limited to this, and may be a monochrome image forming apparatus capable of forming a monochrome image. .

  In the above-described embodiments, the printer is exemplified as the image forming apparatus. However, the present invention is not limited to this, and other image forming apparatuses such as a copying machine and a facsimile machine, or a combination of these functions. Other image forming apparatuses such as multifunction peripherals may also be used. Alternatively, an image forming apparatus that uses an intermediate transfer member, sequentially transfers the toner images of each color on the intermediate transfer member, and collectively transfers the toner images carried on the intermediate transfer member onto a sheet. The same effect can be obtained by applying the present invention to the image forming apparatus.

1 is a cross-sectional view illustrating an embodiment of an image forming apparatus according to the present invention. 2A and 2B are explanatory diagrams illustrating an airflow configuration in the image forming apparatus according to the present invention, in which FIG. 1A is a top view of the image forming apparatus, and FIG. (A) is a figure which shows the generation amount of a volatile organic compound, (b) is a figure which shows the relationship between the wind speed of the air which passes a filter, and collection efficiency, (c) is the rotation speed control of an exhaust axial flow fan. FIG. It is a figure which shows the change of the temperature rising in an apparatus by environmental temperature difference.

Explanation of symbols

51 ... Intake axial flow fan 54 ... Exhaust axial flow fan (exhaust means)
55 ... Fan holder 58 ... Filter 60 ... Control means 70 ... Temperature detection means 80 ... Environment detection means 100 ... Image forming apparatus main body

Claims (10)

An image forming apparatus that includes an exhaust unit for exhausting air from the inside of the apparatus to the outside of the apparatus and a filter through which an air flow generated by the exhaust unit passes, and the filter collects volatile organic compounds in the air. In the device
An image forming apparatus, wherein the amount of air passing through the filter is controlled by the exhaust unit based on information related to temperature in the apparatus.   2. The image forming apparatus according to claim 1, wherein when the temperature in the apparatus increases, the speed of the air flow generated by the exhaust unit decreases.   The image forming apparatus according to claim 1, wherein when the temperature in the apparatus increases, an area of a filter through which an air flow generated by the exhaust unit passes increases.   The image forming apparatus according to claim 1, wherein the exhaust unit is an exhaust fan, and the number of revolutions of the exhaust fan is controlled based on information related to a temperature in the apparatus.   The image forming apparatus according to claim 1, further comprising: a shielding member that shields an air flow generated by the exhaust unit, wherein the position of the shielding member is controlled based on information related to temperature in the apparatus. .   The image forming apparatus according to claim 1, further comprising a temperature detection unit configured to detect a temperature inside the apparatus.   The image forming apparatus according to claim 6, further comprising a fixing unit that heat-fixes an unfixed image on a recording material, wherein the temperature detecting unit detects a temperature around the fixing unit.   2. The image forming apparatus according to claim 1, further comprising a fixing unit that heat-fixes an unfixed image on a recording material, and the information related to the temperature in the apparatus is a heat generation time of the fixing unit.   The image forming apparatus according to claim 1, wherein the information related to the temperature in the apparatus is a number of print jobs.   The image forming apparatus according to claim 1, wherein the information related to the temperature in the apparatus is environmental information.

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