JP2021032958A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can prevent failure due to entry of a foreign substance.SOLUTION: An MFP comprises: a sub case 60 that is changeable in state from a stored state where it is stored in a main body case and an open state where it is located outside the main body case; an air blower; a duct that has an exhaust opening opened upward and an introduction opening opened downward in the open state of the sub case 60, receives air sent from the air blower from the introduction opening, and guides the air to the exhaust opening; and a partition member 75 that covers the exhaust opening and has air permeability.SELECTED DRAWING: Figure 3

Description

The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that forms an image using toner.

An image forming apparatus represented by an MFP (Multifunction Peripheral) often has a member that generates heat inside. For this reason, a blower that rotates the fan is used to circulate the air inside or discharge it to the outside to suppress the temperature rise inside the device.

For example, Japanese Patent Application Laid-Open No. 8-93530 describes a blower device provided in the image forming apparatus main body for sucking in external air or discharging internal air to the outside, and an image forming apparatus main body provided with the blowing device. In an image forming apparatus having a duct through which air to be sucked or discharged passes, and at least a part of the duct also serves as a handle portion of the image forming apparatus main body, between the handle portion and the blower portion. An image forming apparatus characterized by providing a partition member is described.

Japanese Unexamined Patent Publication No. 8-95330

In the MFP, the main body case can be partially opened and closed so that the user can take out the jammed paper in the transport path through which the paper passes inside the main body case in order to eliminate a failure such as a paper jam. There is. When this openable and closable part forms a part of the vertical ventilation path through which air passes, the ventilation path may be divided by opening the openable and closable part, and the ventilation path having an opening above may be exposed. is there. For this reason, there is a problem that foreign matter such as a clip may enter the ventilation path from the upper opening, and the foreign matter may cause a failure.

One of the objects of the present invention is to provide an image forming apparatus that prevents a failure due to the intrusion of a foreign substance.

According to a certain aspect of the present invention, the image forming apparatus has a sub-case that can change the state from the stored state housed in the main body case to the open state located outside the main body case, the air blowing means, and the sub-case. It has a discharge opening opened upward and an introduction opening opened downward in the state, and has a duct that receives the air sent from the blower means at the introduction opening and guides it to the discharge opening, and has air permeability that covers the discharge opening. It is provided with a partition member.

According to this aspect, the discharge opening of the duct is opened upward while the sub case is open, but since the discharge opening is covered with the partition member, foreign matter is prevented from entering through the discharge opening. Therefore, it is possible to prevent foreign matter from entering the ventilation means through the introduction opening that opens downward. As a result, it is possible to provide an image forming apparatus that prevents failure due to the entry of foreign matter.

Preferably, it further comprises a rotatable pressurizing member that is housed in the body case and forms a passage for the recording medium to and from the heating member, with the discharge opening below the pressurizing member when the subcase is in the stowed state. To position.

According to this aspect, since the discharge opening is located below the pressurizing member in the retracted state of the sub-case, the pressurizing member is cooled by the air blown by the blowing means. Therefore, since the pressurizing member is cooled from below, the image forming apparatus can be prevented from becoming large.

Preferably, when the sub-case is in the retracted state, the discharge opening is located below a predetermined range from each of both ends of the pressurizing member.

According to this aspect, the size of the passing portion differs depending on the size of the recording medium, but when the recording medium passes through the center of the pressurizing member regardless of the size of the recording medium, the passing portion is determined from the center of the pressurizing member. It is an area within the range. Therefore, since the discharge opening is located below the predetermined range from each of both ends of the pressurizing member, the temperature of the portion other than the passing portion can be prevented from rising.

Preferably, the changing means for changing the opening area of the discharge opening is further provided.

According to this aspect, the air can be blown to the portion of the pressurizing member other than the passing portion so that the air is blown to the portion other than the passing portion.

Preferably, the partition member covers the discharge opening regardless of the state of the subcase.

According to this aspect, the partition member covers the discharge opening regardless of whether the sub case is in the retracted state or the open state, so that the configuration of the sub case can be simplified.

Preferably, the partition member has a plurality of openings through which air can pass.

According to this aspect, since the partition member has a plurality of openings, it is possible to prevent the entry of foreign matter having a size larger than the size of the openings.

Preferably, the maximum length of each of the plurality of openings is equal to or less than the first threshold value L1.

According to this aspect, it is possible to prevent the entry of foreign matter having a minimum length of the first threshold value L1 or more.

Preferably, the maximum distance between each of the plurality of openings and the other adjacent openings is equal to or less than the second threshold value L2.

According to this aspect, since the maximum distance between the openings is the second threshold value L2 or less, the aperture ratio can be set to a predetermined value or more, and the air resistance can be set to a predetermined value or less.

Preferably, the partition member has a mesh portion of a mesh structure forming a plurality of openings, and the mesh portion has a plurality of wires intersecting with each other.

According to this aspect, the configuration of the partition member can be simplified.

Preferably, each of the plurality of wires is welded at the intersection with the other wires.

According to this aspect, the strength of the partition member can be improved and the opening of the opening can be prevented from being deformed by an external force.

Preferably, the partition member has a mesh portion of a mesh structure forming a plurality of openings, and the mesh portion is formed of a heat-resistant resin.

According to this aspect, since the mesh portion is formed of resin, it is easy to manufacture.

It is a 1st perspective view which shows the appearance of the MFP in one of the Embodiments of this invention. It is sectional drawing which shows an example of the internal structure of the MFP schematically. It is a figure which shows the transport path of a paper. It is the figure which looked at the image formation path of the MFP from the left side side direction. It is a perspective view of a cooling device. It is a figure which shows the internal structure of a duct. It is a perspective view which shows the appearance of a sub case. It is a perspective view of a partition member. It is a top view of the partition member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Their names and functions are the same. Therefore, detailed explanations about them will not be repeated.

FIG. 1 is a first perspective view showing the appearance of the MFP in one of the embodiments of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of the internal configuration of the MFP. Hereinafter, for the sake of explanation, the left-right direction in FIG. 2 is referred to as a left-right direction, and the front-back direction is referred to as a depth direction. The direction from left to right in the left-right direction is called the right side direction, and the direction from right to left is called the left side direction. The direction from the front to the back in the depth direction is called the front direction, and the direction from the back to the front is called the back direction. With reference to FIGS. 1 and 2, the MFP 100 is an example of an image forming apparatus, an image forming unit 140 that forms an image on paper based on image data, and a paper feeding unit that supplies paper to the image forming unit 140. Includes 150 and.

The image forming unit 140 includes yellow, magenta, cyan, and black image forming units 20Y, 20M, 20C, and 20K, respectively. Here, "Y", "M", "C" and "K" represent yellow, magenta, cyan and black, respectively. An image is formed by driving at least one of the image forming units 20Y, 20M, 20C, and 20K. When all of the image forming units 20Y, 20M, 20C, and 20K are driven, a full-color image is formed. Printing data of yellow, magenta, cyan, and black are input to the image forming units 20Y, 20M, 20C, and 20K, respectively. Since the image forming units 20Y, 20M, 20C, and 20K differ only in the colors of the toners they handle, the image forming unit 20Y for forming a yellow image will be described here.

The image forming unit 20Y includes an exposure device 21Y into which yellow printing data is input, a photoconductor drum 23Y which is an image carrier, and a charging roller 22Y for uniformly charging the surface of the photoconductor drum 23Y. The developer 24Y, the primary transfer roller 25Y for transferring the toner image formed on the photoconductor drum 23Y onto the intermediate transfer belt 30 which is an image carrier by the action of electric field force, and the photoconductor drum 23Y. A drum cleaning blade 27Y, a toner bottle 41Y, and a toner hopper 42Y are provided to remove transfer residual toner.

The toner bottle 41Y contains yellow toner. The toner bottle 41Y rotates using the toner bottle motor as a drive source and discharges the toner to the outside. The toner discharged from the toner bottle 41Y is supplied to the toner hopper 42Y. The toner hopper 42Y supplies toner to the developing device 24Y when the remaining amount of toner contained in the developing device 24Y becomes equal to or less than a predetermined lower limit value.

A charging roller 22Y, an exposure device 21Y, a developing device 24Y, a primary transfer roller 25Y, and a drum cleaning blade 27Y are arranged in order around the photoconductor drum 23Y along the rotation direction of the photoconductor drum 23Y.

The photoconductor drum 23Y is charged by the charging roller 22Y and then irradiated with the laser beam emitted by the exposure device 21Y. The exposure device 21Y exposes the image-corresponding portion on the surface of the photoconductor drum 23Y to form an electrostatic latent image. As a result, an electrostatic latent image is formed on the photoconductor drum 23Y. Subsequently, the developer 24Y develops the electrostatic latent image formed on the photoconductor drum 23Y with the charged toner. Specifically, the toner image is formed on the photoconductor drum 23Y by placing the toner on the electrostatic latent image formed on the photoconductor drum 23Y by the action of the electric field force. The toner image formed on the photoconductor drum 23Y is transferred by the action of an electric field force on the intermediate transfer belt 30 which is an image carrier by the primary transfer roller 25Y. The toner remaining on the photoconductor drum 23Y without being transferred is removed from the photoconductor drum 23Y by the drum cleaning blade 27Y.

On the other hand, the intermediate transfer belt 30 is suspended by the driving roller 33 and the driven roller 34 so as not to be loosened. When the drive roller 33 rotates counterclockwise in FIG. 2, the intermediate transfer belt 30 rotates counterclockwise in FIG. 2 at a predetermined speed. As the intermediate transfer belt 30 rotates, the driven roller 34 rotates counterclockwise.

As a result, the image forming units 20Y, 20M, 20C, and 20K transfer the toner image onto the intermediate transfer belt 30 in order. The timing at which the image forming units 20Y, 20M, 20C, and 20K each transfer the toner image onto the intermediate transfer belt 30 is adjusted by detecting the reference mark attached to the intermediate transfer belt 30. As a result, yellow, magenta, cyan, and black toner images are superimposed on the intermediate transfer belt 30.

The toner image formed on the intermediate transfer belt 30 is transferred to the paper by the action of an electric field force by the secondary transfer roller 26 which is a transfer member. The paper conveyed by the timing roller 31 is conveyed to the nip portion where the intermediate transfer belt 30 and the secondary transfer roller 26 are in contact with each other. The paper on which the toner image is transferred is conveyed to the fixing device 50, and is heated and pressurized. As a result, the toner is melted and fixed on the paper. After that, the paper is ejected to the output tray 39.

A belt cleaning blade 28 is provided upstream of the image forming unit 20Y of the intermediate transfer belt 30. The belt cleaning blade 28 removes the toner remaining on the intermediate transfer belt 30 without being transferred to the paper.

The MFP 100 drives all of the image forming units 20Y, 20M, 20C, and 20K when forming a full-color image, but any one of the image forming units 20Y, 20M, 20C, and 20K when forming a monochrome image. Drive one. Further, an image can be formed by combining two or more image forming units 20Y, 20M, 20C, and 20K. Here, an example in which the MFP 100 adopts a tandem system including image forming units 20Y, 20M, 20C, and 20K for forming toners of four colors on paper will be described, but one photoconductor drum has four colors. A 4-cycle method may be adopted in which the toners of the above are transferred to the paper in order.

A plurality of sheets of paper are set in the paper feed cassette 35. The paper contained in the paper cassette 35 is sequentially supplied to the transport path one by one by the take-out roller 36 attached to the paper cassette 35, and is sent to the timing roller 31 by the paper feed roller 37. Further, when one or more sheets of paper are set in the manual difference cassette 35A, the one or more sheets set in the manual difference cassette 35A are sequentially arranged one by one by the take-out roller 36A attached to the manual difference cassette 35A. It is supplied to the transport path and sent to the timing roller 31 by the paper feed roller 37.

FIG. 3 is a diagram showing a paper transport path. With reference to FIG. 3, the paper transport path includes an image forming path 45, a first transport path 46, a second transport path 47, and a front-back reversal path 48. The image forming path 45 is a path from the timing roller 31 to the path switching gate 49, and the secondary transfer roller 26 and the fixing device 50 are arranged in order from the timing roller 31. The timing roller 31 feeds the paper conveyed from the paper feed cassette 35 or the manual feed cassette 35A to the image forming path 45. The timing roller 31 starts conveying the paper so that the paper reaches the secondary transfer roller 26 at the timing when the toner image formed on the intermediate transfer belt 30 reaches the secondary transfer roller 26. The paper conveyed by the timing roller 31 is pressed against the intermediate transfer belt 30 by the secondary transfer roller 26, and the yellow, magenta, cyan, and black toner images formed on the intermediate transfer belt 30 are superimposed on the paper. Transferred.

The paper conveyed from the secondary transfer roller 26 is conveyed to the fixing device 50. The fixing device 50 heats the toner transferred to the paper and pressurizes the paper. As a result, the toner is fixed on the paper. After that, the paper is conveyed to either the first transfer path 46 or the second transfer path 47 by the route switching gate 49.

The first transport path 46 is a path from the route switching gate 49 to the paper ejection roller 43. The paper conveyed to the first transfer path 46 is ejected to the output tray 39 by the output roller 43.

The second transport path 47 is a path from the path switching gate 49 to the reversing roller 44. The second transport path 47 is connected to the image forming path 45 and the front-back reversal path 48 at the route switching gate 49. The paper entering the second transfer path 47 from the path switching gate 49 is conveyed to the reversing roller 44. The reversing roller 44 performs three operations: a standby operation, a reversing operation, and a paper ejection operation. When the reversing roller 44 is in the standby operation, the reversing roller 44 rotates in the forward direction and stops after a predetermined time has elapsed after the timing roller 31 is driven. As a result, the reversing roller 44 holds the paper entering from the path switching gate 49 in a state where the rear end has passed through the path switching gate 49. The reversing roller 44 performs a reversing operation after the standby operation. When the reversing roller 44 performs the reversing operation, the reversing roller 44 rotates in the reverse direction and conveys the held paper to the path switching gate 49 side. As a result, the paper is conveyed through the second transfer path 47 by the reversing roller 44, and is guided to the front and back reversing path 48 by the path switching gate 49. Further, when the reversing roller 44 performs the ejection operation, the reversing roller 44 rotates in the forward direction to eject the paper to the output tray 39.

The front-back reversal path 48 is a path connecting the path switching gate 49 and the timing roller 31 in the image forming path 45. The paper that enters the front-back reversal path 48 from the path switching gate 49 is conveyed to the timing roller 31 by the transfer roller 38. Therefore, an image is formed on the front surface of the paper while the paper first passes through the image forming path 45, and an image is formed on the back surface of the paper while the paper passes through the image forming path 45 again via the front-back inversion path 48. Is formed. The paper on which the image is formed on the back surface is guided to the first transport path 46 by the path switching gate 49 and is discharged to the paper output tray 39.

The fixing device 50 includes a heating unit 51 and a pressurizing roller 59. The heating unit 51 includes a heating roller 53, a pad member 55, and an endless fixing belt 57. The heating roller 53 is a hollow columnar member, and has a heat source built therein. The heat source is, for example, a halogen heater. The heat source is not limited to the halogen heater, and a resistance heating element or IH (Induction Heating) may be used. The thermistor is arranged on the outside of the heating roller 53 in a non-contact state with the heating roller 53. The surface temperature of the heating roller 53 is detected by this thermistor, and the temperature of the heating roller 53 is controlled.

The fixing belt 57 is suspended by the heating roller 53 and the pad member 55 so as not to loosen. The rotation shaft of the heating roller 53 is pivotally supported by the main body case 10. The heating roller 53 is rotated at a predetermined rotation speed by a motor. As a result, the fixing belt 57 rotates. A sliding sheet is fixed to the nip portion side of the pad member 55, and the fixing belt 57 slides on the sliding sheet. The fixing belt 57 is heated to a predetermined temperature while in contact with the heating roller 53.

The pressure roller 59 is arranged at a position facing the pad member 55. The pressure roller 59 is a cylindrical member. The rotation shaft of the pressure roller 59 is pivotally supported by the main body case 10. The rotating shaft of the pressure roller 59 is urged toward the pad member 55 by an elastic body such as a spring, and a nip portion is formed between the pressure roller 59 and the pad member 55. The nip portion is a portion where the pressure roller 59 comes into contact with the fixing belt. The pressure roller 59 is driven and rotated by friction with the fixing belt 57. The pressurizing roller 59 may be rotated by a motor. In this case, the heating roller 53 may or may not be driven by the motor. When the heating roller 53 is not driven by the motor, the fixing belt 57 is driven to rotate due to friction with the pressurizing roller 59. The rotation of the fixing belt 57 causes the heating roller 53 to rotate in a driven manner.

The paper conveyed from the secondary transfer roller 26 is pressed against the fixing belt 57 at the nip portion between the pad member 55 and the pressure roller 59. The rotation axis of the pressurizing roller 59 and the rotation axis of the heating roller 53 are parallel to the depth direction and intersect the paper transport direction perpendicularly. The toner transferred to the paper is heated by the fixing belt 57 and is pressed between the pad member 55 and the pressure roller 59. As a result, the toner melted by heat is pressure-bonded to the paper.

The length of the fixing device 50 in the depth direction is determined according to the paper having the largest size in the horizontal direction perpendicular to the transport direction among the papers capable of forming an image by the MFP 100. Therefore, when an image is formed on paper whose size in the horizontal direction is smaller than the maximum size, the entire fixing device 50 is not used, but the vicinity of the center in the depth direction is used. Therefore, the paper does not pass through both end portions of the fixing device 50.

In the following description, the portion of the nip portion where the pressure roller 59 contacts the fixing belt 57 through which the paper passes is referred to as a passing portion, and the portion other than the passing portion is referred to as a non-passing portion. If the size of the paper in the horizontal direction is different, the length of the passing portion in the depth direction is different. The passing portion is formed between the pressure roller 59 and the pad member 55. Since heat is taken by the paper while the fixing belt 57 comes into contact with the paper at the passing portion, the heating roller 53 is heated by the heat source so that the temperature of the fixing belt 57 does not decrease. Since the passing portion includes the central portion of the fixing belt 57 in the depth direction, the temperature of the heating roller 53 is adjusted with reference to the temperature near the central portion in the depth direction. Therefore, the temperature of the portion of the fixing belt 57 that does not come into contact with the paper continues to rise because heat is not taken from the paper.

The pressure roller 59 conducts heat from the fixing belt 57 at the nip portion while the paper is not conveyed. During the transfer of the paper, the pressure roller 59 conducts the heat of the fixing belt 57 through the paper at the passing portion and the heat from the fixing belt 57 at the non-passing portion. Therefore, in the pressure roller 59, the temperature of the portion that comes into contact with the paper is higher than the temperature of the portion that does not come into contact with the paper while the paper is being conveyed. Therefore, in the pressurizing roller 59 and the fixing belt 57 of the fixing device 50, the temperature of both ends that do not come into contact with the paper may continue to rise. The fixing device 50 may be damaged when the temperature exceeds a predetermined temperature.

Therefore, the MFP 100 in the present embodiment includes cooling devices 70A and 70B below the pressurizing roller 59. The cooling devices 70A and 70B cool both ends of the pressurizing roller 59 through which the paper does not pass with air.

The MFP 100 in the present embodiment is provided with a front-back inversion path 48 in order to form an image on both sides of the paper. Therefore, the cooling devices 70A and 70B are arranged between the image forming path 45 and the front-back inversion path 48. Since the cooling devices 70A and 70B are arranged between the image forming path 45 and the front-back inversion path 48, the space for arranging the cooling devices 70A and 70B can be arranged below the pressure roller 59, and the MFP100 can be arranged. Can be prevented from becoming large. An image forming apparatus that does not have a function of forming an image on both sides of the paper does not have a front-back inversion path 48. Therefore, the cooling device 70A may be arranged below the pressurizing roller 59. Even in this case, the MFP 100 can be prevented from becoming large.

FIG. 4 is a view of the image formation path of the MFP as viewed from the left side surface direction. With reference to FIGS. 3 and 4, the cooling device 70A is arranged below the front end of the pressure roller 59, and the cooling device 70B is arranged below the rear end of the pressure roller 59. Will be done. The rectifying member 59A is arranged around the end portion on the front side of the pressure roller 59, and the rectifying member 59B is arranged around the end portion on the back surface side of the pressure roller 59. Each of the rectifying members 59A and 59B forms an air flow path with the pressurizing roller 59.

The cooling device 70A discharges air upward. The air discharged from the cooling device 70A is guided to the portion where the rectifying member 59A of the pressurizing roller 59 is arranged along the air flow path shown by the dotted line. The air guided to the portion of the pressurizing roller 59 where the rectifying member 59A is arranged is guided to the periphery of the pressurizing roller 59 by the rectifying member 59A. The air that has passed through the rectifying member 59A is sent out from the back surface of the main body of the MFP 100 to the outside of the main body by the discharge fan 80 provided above the pressurizing roller 59. Similarly, the cooling device 70B discharges air upward. The air discharged from the cooling device 70B is guided to the portion where the rectifying member 59B of the pressurizing roller 59 is arranged along the air flow path shown by the dotted line. The air guided to the portion of the pressurizing roller 59 where the rectifying member 59B is arranged is guided to the periphery of the pressurizing roller 59 by the rectifying member 59B. The air that has passed through the rectifying member 59B is sent out from the back surface of the main body of the MFP 100 by the discharge fan 80 provided above the pressurizing roller 59.

FIG. 5 is a perspective view of the cooling device. With reference to FIG. 5A, the cooling device 70A includes a blower 71 including a fan and a motor for rotating the fan, a duct 73A, and a partition member 75. The duct 73A guides the air sent from the blower 71 to the partition member 75. The partition member 75 is breathable. Therefore, the air sent from the blower 71 is discharged upward from the partition member 75. With reference to FIG. 5B, the cooling device 70B includes a blower 71, a duct 73B, and a partition member 75. The duct 73B guides the air sent from the blower 71 to the partition member 75. The partition member 75 is breathable. Therefore, the air sent from the blower 71 is discharged upward from the partition member 75.

FIG. 6 is a diagram showing the internal configuration of the duct. FIG. 6 is a view of the ducts 73A and 73B as viewed from the left side surface direction. With reference to FIGS. 4 and 6, the duct 73A of the cooling device 70A arranged on the front side has a discharge opening 78A opened upward and an introduction opening 77A opened downward. The duct 73A receives the air sent from the blower 71 at the introduction opening 77A and guides it to the discharge opening 78A. The duct 73A includes a plurality of rectifying plates 81A, 82A, 83A. As a result, the first flow path sandwiched between the outer wall of the duct 73A and the rectifying plate 81A, the second flow path sandwiched between the rectifying plate 81A and the rectifying plate 82A, and the rectifying plate 82A and the rectifying plate 83A are sandwiched. A third flow path is formed, and a fourth flow path sandwiched between the rectifying plate 83A and the outer wall of the duct 73A is formed. The shapes and sizes of the rectifying plates 81A, 82A, and 83A are determined so that the amounts of air flowing through the first to fourth flow paths are the same.

Similarly, the duct 73B of the cooling device 70B arranged on the back side has a discharge opening 78B opened to the outside and an introduction opening 77B opened downward. The duct 73B receives the air sent from the blower 71 at the introduction opening 77B and guides it to the discharge opening 78B. The duct 73B includes a plurality of rectifying plates 81B, 82B, 83B. As a result, the first flow path sandwiched between the outer wall of the duct 73B and the rectifying plate 81B, the second flow path sandwiched between the rectifying plate 81B and the rectifying plate 82B, and the rectifying plate 82B and the rectifying plate 83B are sandwiched. A third flow path is formed, and a fourth flow path sandwiched between the rectifying plate 83B and the outer wall of the duct 73B is formed. The shapes and sizes of the rectifying plates 81B, 82B, and 83B are determined so that the amounts of air flowing through the first to fourth flow paths are the same.

As shown in FIG. 4, the discharge opening 78A of the cooling device 70A on the front side is located below a predetermined range from the end on the front side of the pressurizing roller 59. Further, the discharge opening 78B of the cooling device 70B on the back surface side is located below a predetermined range from the end portion on the back surface side of the pressure roller 59. The predetermined range is determined by the size of the paper having the smallest lateral size of the paper on which the MFP 100 can form an image. Therefore, when the MFP 100 forms an image on the paper having the smallest lateral size of the paper on which the image can be formed, the portion of the pressure roller 59 that does not come into contact with the paper can be cooled.

The cooling device 70A includes a windbreak plate 86A that can move in the depth direction. As the windbreak plate 86A moves in the depth direction, the cross-sectional area of the flow path of the duct 73A fluctuates. In other words, as the windbreak plate 86A moves in the depth direction, the opening area of the discharge opening 78A fluctuates. The windbreak plate 86A has a first position where it is located outside the duct 73A, a second position where the tip is located below the rectifying plate 81A, a third position where the tip is located below the rectifying plate 82A, and a tip. It can be moved to a fourth position located below the rectifying plate 83A. When the windbreak plate 86A is in the first position, the first flow path, the second flow path, the third flow path, and the fourth flow path are not blocked. The windbreak plate 86A blocks the first flow path at the second position, blocks the first flow path and the second flow path at the third position, and blocks the first flow path, the second flow path and the third flow path at the fourth position. Block the flow path. In FIG. 6, a case where the windbreak plate 86A exists at the fourth position is shown as an example. The windbreak plate 86A is connected to a rack 87A with teeth cut on the lower surface.

Similarly, the cooling device 70B includes a windbreak plate 86B that can be moved in the horizontal direction. As the windbreak plate 86B moves in the depth direction, the cross-sectional area of the flow path of the duct 73B fluctuates. In other words, as the windbreak plate 86B moves in the depth direction, the opening area of the discharge opening 78B fluctuates. The windbreak plate 86B has a first position where it is located outside the duct 73B, a second position where the tip is located below the rectifying plate 81B, a third position where the tip is located below the rectifying plate 82B, and a tip. It can be moved to a fourth position located below the rectifying plate 83B. When the windbreak plate 86B is in the first position, the first flow path, the second flow path, the third flow path, and the fourth flow path are not blocked. The windbreak plate 86B blocks the first flow path at the second position, blocks the first flow path and the second flow path at the third position, and blocks the first flow path, the second flow path and the third flow path at the fourth position. Block the flow path. In FIG. 6, a case where the windbreak plate 86B exists at the fourth position is shown as an example. The windbreak plate 86B is connected to a rack 87B with teeth cut on the upper surface.

The pinion gear 85 meshes with the teeth of the rack 87A and the teeth of the rack 87B. By rotating the pinion gear 85, the windbreak plate 86A moves in the horizontal direction and the windbreak plate 86A moves in the opposite direction to the windbreak plate 86A. As a result, the opening areas of the discharge opening 78A and the discharge opening 78B are changed. Specifically, the pinion gear 85 is driven by a motor to rotate, and simultaneously moves the windbreak plate 86A and the windbreak plate 86B in the opposite directions in the depth direction. By adjusting the rotation speed of the pinion gear 85, the windbreak plate 86A and the windbreak plate 86B can be moved from the first position to any of the fourth positions. As a result, the cooling portion of the pressure roller 59 is changed to one of the portions determined by the distance of four steps from both ends. Therefore, it is possible to prevent the temperature of the non-passing portion that does not come into contact with the paper of the pressure roller 59 from rising. The number of stages is not limited to four, and may be less or more.

As shown in FIG. 2, the MFP 100 in this embodiment includes an outer cover 90 and a sub-case 60. The outer cover 90 and the sub case 60 can be changed between a stored state housed in the main body case 10 and an open state located outside the main body case 10. The sub case 60 changes its state from the stored state to the open state while maintaining the vertical direction.

The outer cover 90 exposes the front-back inversion path 48 to the outside in the open state. The sub-case 60 constitutes a part of the image forming path 45 and a part of the front-back inversion path 48 in the stored state. The sub-case 60 exposes the image forming path 45 to the outside in the open state. When the outer cover 90 is opened when the paper is jammed in the front / back inversion path 48, the front / back inversion path 48 is exposed to the outside, so that the user can remove the paper from the front / back inversion path 48. When the outer cover 90 and the sub-case 60 are opened when the paper is jammed in the image forming path 45, the image forming path 45 is exposed to the outside, so that the user can remove the paper from the image forming path 45. The cooling devices 70A and 70B are arranged in the sub-case 60.

FIG. 7 is a perspective view showing the appearance of the sub case. With reference to FIG. 7, the discharge opening 78A of the duct 73A and the discharge opening 78B of the duct 73B are arranged on the upper surface of the sub case 60. Each of the discharge opening 78A and the discharge opening 78B is covered with the partition member 75. Therefore, the configuration of the sub-case 60 is simplified, and the manufacturing is easy.

In the sub-case 60, a part of the front-back inversion path 48 is formed on the surface viewed from the left side surface direction in the stored state, and a part of the image forming path 45 is formed on the surface viewed from the right side surface direction. The sub-case 60 has an opening / closing shaft 63 extending in the vertical direction in the vicinity of the back surface side in the stored state. In the sub case 60, the opening / closing shaft 63 is attached to the bearing of the main body case 10 of the MFP 100. The sub case 60 changes its state between the stored state and the open state by rotating around the opening / closing shaft 63 with respect to the main body case 10.

When the sub-case 60 is in the open state, the discharge opening 78A of the duct 73 and the discharge opening 78B of the duct 73B provided on the upper surface of the sub-case 60 are opened upward. Each of the discharge opening 78A and the duct 73B is covered with a partition member 75. Therefore, even when the user drops a foreign matter such as a clip onto the upper surface of the sub-case 60, the foreign matter is received by the partition member 75, and the foreign matter is received from the discharge opening 78A or the discharge opening 78B to the duct 73A or the duct 73B. No foreign matter can enter. Further, even if the user does not notice that the foreign matter has been dropped, the partition member 75 can prevent the foreign matter from entering the ducts 73A and 73B.

If the partition member 75 is not provided, foreign matter enters the ducts 73A and 73B. When foreign matter enters the duct 73A or the duct 73B, the foreign matter may enter the blower 71 through the introduction opening 77A of the duct 73A or the introduction opening 77B of the duct 73B, and the blower 71 may be damaged by the foreign matter. Therefore, it is necessary to remove foreign matter from the cooling devices 70A and 70B, but the size of the discharge opening of the ducts 73A and 73B is too small for the user to enter the ducts 73A and 73B. Further, the sub-case 60 must be removed from the main body, and the sub-case 60 must be turned upside down to discharge foreign matter from the cooling devices 70A and 70B, which complicates the work.

In the MFP 100 of the present embodiment, since the partition member 75 blocks the entry of foreign matter into the ducts 73A and 73B, it is possible to prevent the blower 71 from being damaged by the foreign matter.

FIG. 8 is a perspective view of the partition member. FIG. 9 is a plan view of the partition member. With reference to FIGS. 8 and 9, the partition member 75 has a plurality of openings through which air can pass. Further, the maximum length of each of the plurality of openings is equal to or less than the first threshold value L1. The first threshold value L1 may be set to a value equal to or greater than the minimum length of the foreign matter. Therefore, it is possible to prevent the entry of foreign matter having a minimum length larger than the first threshold value L1. For example, in the case of a clip, it is preferable that the first threshold value L1 is about 5 mm.

Further, the maximum distance between each of the plurality of openings and the other adjacent openings is equal to or less than the second threshold value L2. The aperture ratio of the partition member 75 is determined by the second threshold value L2 and the areas of the plurality of openings. The higher the aperture ratio, the lower the air resistance. Preferably, the aperture ratio is 85% or more. The aperture ratio is the ratio of the total area of the plurality of openings to the area of the openings of the partition member 75.

Specifically, the partition member 75 has a mesh portion having a network structure that forms a plurality of openings. The mesh portion has a plurality of wires intersecting with each other. Since the mesh portion is made of a wire rod, the structure of the partition member 75 can be simplified and the manufacturing is easy. A rectangle in which a plurality of openings are separated by a wire rod. Since the plurality of openings are rectangular, the maximum length of the openings is the diagonal length of the openings. Here, since the first threshold value L1 is set to 5 mm, a plurality of wire rods are arranged in the partition member 75 so that the diagonal length, which is the maximum length of each of the plurality of openings, is 5 mm or less. Further, since the plurality of openings are divided by the wire rod, the distance between the plurality of openings is the diameter of the wire rod. Therefore, the diameter of the wire rod is equal to or less than the second threshold value L2. In order to secure an aperture ratio of 85% or more, the second threshold value L2 is 1 mm or less from the sum of the area of each of the plurality of openings and the length of the wire rod. Therefore, in the present embodiment, the diameter of the wire rod is set to 1 mm.

Further, it is preferable that each of the plurality of wire rods is welded at a portion intersecting with other wire rods. As a result, the partition member 75 can have a predetermined strength, and the plurality of openings can be less likely to be deformed by an external force. For example, the user can prevent the opening from being pushed open with a finger. The wire rod is preferably made of metal so that the partition member 75 has a predetermined strength.

Further, the partition member 75 has a mesh portion having a network structure for forming a plurality of openings, and the mesh portion may be formed of a heat-resistant resin. Since the mesh portion is made of resin, it is easy to manufacture.

In the present embodiment, the MFP 100 has been described as an example of the image forming apparatus, but a copying machine, a laser beam printer, a facsimile apparatus, or the like may be used.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

100 MFP, 20Y, 20M, 20C, 20K Roller Image Forming Unit, 21Y, 21M, 21C, 21K Exposure Device, 22Y, 22M, 22C, 22K Charging Roller, 23Y, 23M, 23C, 23K Photoreceptor Drum, 24Y, 24M, 24C, 24K Developer, 25Y, 25M, 25C, 25K Primary Transfer Roller, 26 Secondary Transfer Roller, 27Y, 27M, 27C, 27K Drum Cleaning Blade, 28 Belt Cleaning Blade, 30 Intermediate Transfer Belt, 31 Timing Roller, 33 Drive roller, 34 driven roller, 35 paper feed cassette, 36, 36A take-out roller, 37 paper feed roller, 39 paper discharge tray, 41Y, 41M, 41C, 41K toner bottle, 42Y, 42M, 42C, 42K toner hopper, 43 paper discharge Paper roller, 44 reversing roller, 45 image forming path, 46 first transfer path, 47 second transfer path, 48 front and back reversal path, 50 fixing device, 51 heating part, 53 heating roller, 55 pad member, 57 fixing belt, 59 Pressurizing roller, 59A, 59B rectifying member, 60 sub-case, 63 opening / closing shaft, 70A, 70B cooling device, 70A, 70B cooling device, 71 blower, 73A, 73B duct, 75 partition member, 75A, 75B duct, 80 discharge fan , 81A rectifying plate, 81A, 82A, 83A, 84A rectifying plate, 81B, 82B, 83B, 84B rectifying plate, 85 pinion gear, 86A windbreak plate, 86B windbreak plate, 90 outer cover.

Claims (11)

A sub-case that can change the state from the stored state stored in the main body case to the open state located outside the main body case,
Blower means and
The sub-case has a discharge opening opened upward and an introduction opening opened downward in the open state, and a duct that receives air sent from the blower means at the introduction opening and guides the air to the discharge opening. ,
An image forming apparatus including a breathable partition member that covers the discharge opening. A rotatable pressurizing member housed in the main body case and forming a passage portion through which the recording medium passes with the heating member is further provided.
The image forming apparatus according to claim 1, wherein the discharge opening is located below the pressurizing member when the sub-case is in the stored state. The image forming apparatus according to claim 2, wherein when the sub-case is in the stored state, the discharge opening is located below a predetermined range from each of both ends of the pressurizing member. The image forming apparatus according to claim 2 or 3, further comprising a changing means for changing the opening area of the discharge opening. The image forming apparatus according to any one of claims 1 to 4, wherein the partition member covers the discharge opening regardless of the state of the subcase. The image forming apparatus according to any one of claims 1 to 5, wherein the partition member has a plurality of openings through which air passes. The image forming apparatus according to claim 6, wherein the maximum length of each of the plurality of openings is equal to or less than the first threshold value L1. The image forming apparatus according to claim 6 or 7, wherein the maximum distance between each of the plurality of openings and the other adjacent openings is equal to or less than a second threshold value L2. The partition member has a mesh portion of a network structure forming the plurality of openings.
The image forming apparatus according to any one of claims 6 to 8, wherein the mesh portion has a plurality of wires intersecting with each other. The image forming apparatus according to claim 9, wherein each of the plurality of the wire rods is welded at a portion intersecting with the other wire rods. The partition member has a mesh portion of a network structure forming the plurality of openings.
The image forming apparatus according to any one of claims 6 to 8, wherein the mesh portion is formed of a heat-resistant resin.

Images