JP2009157319A - Cooling device for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device for an image forming apparatus capable of suppressing noise of a fan when forming a monochrome image. <P>SOLUTION: The cooling device 18 for the image forming apparatus 11 equipped with: a plurality of processing units 14 necessary for image formation; a plurality of branch ducts 19 extended from the processing units 14; main ducts 21a and 21b communicating with the plurality of branch ducts 19; and a fan 22 disposed in the main ducts 21a and 21b and discharging heat inside the apparatus to the outside is equipped with: a plurality of shutters 20 turning between an opening position where the branch ducts 19 communicate with the main ducts 21a and 21b and a closing position where the communication between the branch ducts 19 and the main ducts 21a and 21b is interrupted; and a shutter control means 38 controlling the opening/shutting and also opening/closing angles of the shutters 20 when forming a monochrome image and when forming a color image. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooling device for an image forming apparatus including a fan, a duct, and a shutter.

  Generally, in an image forming apparatus, it is necessary to exhaust heat generated from a developing device of a process unit to the outside of the apparatus main body.

  For example, Patent Document 1 describes a cooling device including two fans, a cooling fan and an exhaust fan.

  Patent Document 2 describes a cooling device including four exhaust fans arranged in an exhaust duct provided at the top of each color process cartridge.

  Further, Patent Document 3 describes a cooling device that includes an exhaust fan, an environment detection unit, and a use state detection unit, and switches an exhaust path according to an environmental state such as temperature and humidity and a use state of the image forming apparatus. Yes.

  However, since the cooling device described in any of the patent documents does not control the rotation speed of the fan regardless of whether a monochrome image or a color image is formed, the fan always rotates at full speed to suppress fan noise during monochrome image formation. There was a problem that I could not.

JP 2004-53973 A JP 2006-113344 A JP 2007-72110 A

  SUMMARY An advantage of some aspects of the invention is that it provides a cooling device for an image forming apparatus capable of suppressing fan noise during monochrome image formation.

  As means for solving the above-described problems, a cooling device for an image forming apparatus according to the present invention includes a plurality of process units necessary for image formation, a plurality of branch ducts extending from the process unit, and the plurality of branch ducts. In a cooling device for an image forming apparatus, comprising: a main duct that communicates with a fan that is disposed in the main duct and discharges heat inside the apparatus to the outside; and an opening position where the branch duct and the main duct communicate with each other A plurality of shutters that rotate between a closed position that blocks communication between the tributary duct and the main duct; a monochrome image that uses only the black process unit; and the plurality of process units that are used. And a shutter control means for controlling the opening / closing angle and the opening / closing angle of the shutter.

  Only the tributary duct that extends to the process unit that operates to generate heat is controlled by controlling the opening and closing angles of a plurality of shutters that rotate to connect each of the tributary ducts and the main duct, or block the communication. It can be communicated with the duct, and heat can be effectively conducted to the fan through the main duct.

  It is preferable that the cooling device of the image forming apparatus further includes fan control means for controlling the number of rotations of the fan during the monochrome image formation and the color image formation.

  Since the number of rotations of the fan can be changed as necessary to reduce the number of rotations between the monochrome image formation and the color image formation, the fan noise can be suppressed.

  As one specific means, at the time of forming the monochrome image, the shutter disposed in the tributary duct extending to the black process unit is located at the opening position and extends to the process unit other than the black. Preferably, the shutter disposed in the branch duct is located at the closed position, and the fan control means controls the fan so that the rotational speed of the fan is lower than a maximum value.

  During monochrome image formation, only the tributary duct extending to the operating black process unit communicates with the main duct, so that heat can be effectively conducted to the fan via the main duct, thereby suppressing the rotation speed of the fan. Fan noise can be suppressed.

  As another means, when the color image is formed, it is preferable that all of the shutters are located at the opening position, and the fan control means controls the fan so that the rotational speed of the fan becomes a maximum value.

  Further, when the color image is formed, the opening / closing angle of the individual shutters is increased in proportion to the distance from the fan, and the fan control means is configured so that the fan rotational speed is lower than the maximum value. Is preferably controlled.

  Since the opening and closing angles of the individual shutters increase in proportion to the distance from the fan, heat can be effectively conducted from each branch duct to the fan through the main duct, so that the fan rotation speed is suppressed. Fan noise can be suppressed.

  A plurality of process units necessary for image formation, a plurality of branch ducts extending from the process unit, a main duct communicating with the plurality of branch ducts, and the heat disposed in the main duct and exhausting the heat inside the apparatus to the outside A cooling unit for an image forming apparatus including a fan, wherein the vertical position is disposed only in a tributary duct extending from the black process unit and communicates only the main duct and the tributary duct extending to the black process unit. A shutter that rotates between the main duct and a horizontal position that communicates with all the tributary ducts, a monochrome image that uses only the black process unit, and a plurality of process units. Shutter control for controlling the opening / closing and opening / closing angle of the shutter during color image formation. It is preferred with a means.

  One shutter can rotate between a vertical position and a horizontal position, and can connect each branch duct and the main duct, or can block communication. Accordingly, only the branch duct extending to the process unit that operates to generate heat can be communicated with the main duct, and heat can be effectively led to the fan via the main duct.

  It is preferable that the cooling device of the image forming apparatus further includes fan control means for controlling the number of rotations of the fan during the monochrome image formation and the color image formation.

  As a specific means, when the monochrome image is formed, the shutter is positioned in the vertical position, and the fan control means controls the fan so that the rotational speed of the fan is lower than a maximum value. Is preferred.

  When a monochrome image is formed, only the tributary duct extending to the operating black process unit with the shutter positioned in the vertical position communicates with the main duct, so that heat can be effectively conducted to the fan via the main duct. Therefore, the fan noise can be suppressed by suppressing the rotational speed of the fan.

  As another means, when the color image is formed, it is preferable that the shutter is positioned at the horizontal position, and the fan control means controls the fan so that the rotation speed of the fan becomes a maximum value.

  According to the cooling device for an image forming apparatus according to the present invention, the rotational speed of the fan can be controlled according to the time of monochrome image formation or color image formation. Can be suppressed.

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

  FIG. 1 shows an image forming apparatus 11 according to an embodiment of the present invention. First, a schematic configuration of the image forming apparatus 11 will be described. The image forming apparatus 11 includes an intermediate transfer belt 12 as an image carrier at a substantially central portion inside thereof. The intermediate transfer belt 12 is supported by the outer peripheral portions of the rollers 13a and 13b and is driven to rotate in the direction of arrow A. The drive roller 13a is connected to a drive motor (not shown), and the driven roller 13b is driven to rotate as the drive roller 13a rotates. Under the lower horizontal portion of the intermediate transfer belt 12, there are four process units 14Y, 14M, 14C, and 14K corresponding to the respective colors of yellow (Y), magenta (M), cyan (C), and black (K). They are arranged along the intermediate transfer belt 12. Each process unit 14Y, 14M, 14C, 14K has a photosensitive drum 15Y, 15M, 15C, 15K and a developing device 16Y, 16M, 16C, 16K, respectively. Around the photosensitive drums 15Y, 15M, 15C, and 15K, primary transfer rollers 17Y, 17M, 17C, and 17K that face the photosensitive drums 15Y, 15M, 15C, and 15K with the intermediate transfer belt 12 interposed therebetween, respectively. Has been placed. Above the developing devices 16Y, 16M, 16C, and 16K, a cooling device 18 that cools the developing devices 16Y, 16M, 16C, and 16K and elements in the vicinity thereof is disposed. A portion of the intermediate transfer belt 12 supported by the drive roller 13 a is in contact with a secondary transfer roller (transfer roller) 23, and a nip portion between the secondary transfer roller 23 and the intermediate transfer belt 12 is a transfer portion 24. It has become. A fixing roller 26 and a pressure roller 27 are disposed further downstream of the sheet passing path 25a. The pressure contact portion is a fixing nip region 28.

  Under the image forming apparatus 1, four types of first, second, third, and fourth types of paper feeding units 29a, 29b, 29c, and 29d are provided. The first paper feeding unit 29a and the second paper feeding unit 29b is arranged up and down, and the third sheet feeding unit 29c and the fourth sheet feeding unit 29d are arranged on the left and right below the second sheet feeding unit 29b. The sheets S stacked and accommodated in each of the sheet feeding units 29a, 29b, 29c, and 29d are sent out one by one from the top to the sheet passing path 25b. A circulation path 31 is provided on the side of the image forming apparatus 11. The single-sided printed paper that is switched back by the paper discharge roller 32 is conveyed downward through the circulation path 31, and is again conveyed upward through the paper passage 25b with the unprinted surface facing the intermediate transfer belt 12. It has become so. A manual paper feeder 33 is provided below the circulation path 31. A sheet feeding roller 34 for feeding the sheet S is typically disposed in the sheet feeding path 25c from the manual sheet feeding device 33 and the sheet feeding units 29a, 29b, 29c, and 29d as shown in FIG. Has been. Reference numeral 35 denotes an exposure unit 35 that exposes the process units 14Y, 14M, 14C, and 14K based on image signals.

  Next, a schematic operation of the image forming apparatus 11 having the above configuration will be described.

  Color print data obtained by reading an image with the image reading unit 36 or image data output from a personal computer or the like is subjected to predetermined signal processing by the exposure unit 35, and then yellow (Y), magenta (M ), Cyan (C), and black (K) image signals are supplied to the process units 14Y, 14M, 14C, and 14K. In each of the process units 14Y, 14M, 14C, and 14K, a laser beam modulated with an image signal is projected onto each photosensitive drum 15 (15Y, 15M, 15C, and 15K) to form an image latent image. Yellow, magenta, cyan, and black toner images are formed on the photosensitive drums 15Y, 15M, 15C, and 15K. The formed yellow, magenta, cyan, and black toner images are primarily transferred onto the moving intermediate transfer belt 12 in sequence by the action of the primary transfer rollers 17Y, 17M, 17C, and 17K. The superimposed toner image formed on the intermediate transfer belt 12 in this way reaches the transfer unit 24 as the intermediate transfer belt 12 moves. In this transfer unit 24, the superimposed toner images are collectively applied to the paper S supplied from the paper feed units 29 a, 29 b, 29 c, 29 d or the manual paper feeder 33 by the action of the secondary transfer roller 23. Next transferred. Next, the sheet S on which the toner image is secondarily transferred reaches the fixing nip region 28. In the fixing nip region 28, the toner image is fixed on the paper S by the action of the fixing roller 26 and the pressure roller 27. The sheet S on which the toner image is fixed is discharged to a discharge tray 37 via a discharge roller 32.

  Next, the cooling device 18 according to the present invention will be described. As shown in FIG. 1, the cooling device 18 disposed above each of the process units 14Y, 14M, 14C, and 14K includes a plurality of tributary ducts that extend upward from the process unit 14 (14Y, 14M, 14C, and 14K). 19 (19Y, 19M, 19C, 19K), first to fourth shutters 20a, 20b, 20c, 20d rotatably disposed at the upper end of the tributary duct 19 and the tributary duct 19 are connected horizontally. The main duct 21a extends in the direction, and is arranged at the end of the main duct 21a. The fan 22 communicates with the outside and exhausts the heat inside the image forming apparatus 11 to the outside.

  As shown in FIG. 2, the four tributary ducts 19Y, 19M, 19C, and 19K are arranged behind the process units 14Y, 14M, 14C, and 14K of the respective colors, and the lower ends thereof are arranged at the process units 14Y, 14M, 14C, and It opens in the vicinity of 14K.

  The first shutter 20a is installed at the upper end of a tributary duct 19Y extending from the rear of the yellow process unit 14Y. The second shutter 20b is installed at the upper end of a branch duct 19M extending from the rear of the magenta process unit 14M. The third shutter 20c is installed at the upper end of a tributary duct 19C extending from the rear of the cyan process unit 14C. The fourth shutter 20d is installed at the upper end of a tributary duct 19K extending from the rear of the black process unit 14K. As shown in FIG. 3, each shutter 20 (20 a, 20 b, 20 c, 20 d) is closed to block the communication between the branch duct 19 and the main duct 21 a and the opening position where the branch duct 19 and the main duct 21 a communicate with each other. It can be rotated around the axis 41 between positions. As shown in FIG. 4, each shutter 20 is connected to a motor 42 (42a, 42b, 42c, 42d) whose rotation is controlled by a control unit 38. The shutter 20 is made of resin, for example, but the shape and material thereof are not particularly limited as long as heat can be blocked.

  Instead of connecting each shutter 20 individually to the motor 42 as shown in FIG. 4, the first to third shutters 20a, 20b, 20c are connected to one motor 42 as shown in FIG. 3, and the fourth shutter 20d is connected. May be connected to another motor 42. The shutter 20 is connected to an opening / closing worm wheel 44 via a shaft 41. The open / close worm wheel 44 meshes with an open / close worm 46 connected to a shaft 45 extending along the main duct 21a. The opening / closing worms 46 of the first shutter 20a, the second shutter 20b, and the third shutter 20c are connected to a coaxial shaft 45, and a gear 47 is connected to an end of the shaft 45. The gear 47 meshes with a motor gear 48 connected to the motor 42.

  As shown in FIG. 2, the main duct 21 a communicates with the upper end of the branch duct 19 via the shutter 20 and extends in the image forming apparatus 11 in the horizontal direction.

  The fan 22 is attached to the end portion of the main duct 21a via, for example, a screw (not shown) or by a claw stop. However, the shape of the fan 22 is not particularly limited as long as the heat in the main duct 21a is discharged to the outside of the image forming apparatus 11.

  The motors 42a, 42b, 42c for controlling the opening / closing or opening / closing angle of the first shutter 20a, the second shutter 20b, and the third shutter 20c, the motor 42d for controlling the opening / closing or opening / closing angle of the fourth shutter 20d, and the rotation of the fan 22 are controlled. The motor 42e is controlled by a control unit 38 which is a control unit for the shutter 20 and the fan 22.

  Next, the operation of the shutter 20 according to the present invention will be described with reference to FIG. As shown in FIG. 3A, for example, when the process unit 14 is operated from a state in which the shutters 20a, 20b, and 20c are closed, the motor gear 48 is moved in the B direction by driving the motor 42 as shown in FIG. Rotating, the gear 47 rotates in the C direction. When the gear 47 rotates in the C direction, the shaft 45 and the opening / closing worm 46 also rotate in the C direction. When the opening / closing worm 46 is rotated in the C direction, the opening / closing worm wheel 44 is rotated in the D direction, and at the same time, the shutters 20a, 20b, 20c are also rotated around the shaft 41 in the D direction and opened.

  Only the tributary duct 19 extending to the process unit 14 that generates heat by operating is controlled by controlling the opening and closing angles of the plurality of shutters 20 that communicate with each of the tributary ducts 19 and the main duct 21a. The main duct 21a can be communicated, and heat can be effectively conducted to the fan 22 via the main duct 21a.

  At the time of monochrome image formation using only the black process unit 14K, as shown in FIG. 4, since the fourth shutter 20d is opened and the tributary duct 19 and the main duct 21a communicate with each other, it is generated from the black developing device 16K. The heat reaches the fan 22 via the branch duct 19 and the main duct 21a, and is exhausted from the fan 22 to the outside. On the other hand, the first to third shutters 20a, 20b, and 20c are closed to block communication between the branch ducts 19Y, 19M, and 19C and the main duct 21a. Since the main duct 21a communicates only with the tributary duct 19, heat can be effectively conducted from the black developing device 16K to the fan 22 and the rotational speed of the fan 22 can be reduced. The number of rotations of the fan 22 can be reduced to, for example, ¼ at the time of color image formation. Therefore, noise caused by the fan 22 when forming a monochrome image can be suppressed.

  When forming a color image using the process units 14 of each color of yellow, magenta, cyan, and black, the first to third shutters 20a, 20b, and 20c are at the same angle and the fourth shutter 20d is more than that as shown in FIG. The branch duct 19 and the main duct 21a communicate with each other. Accordingly, the heat generated from the developing devices 16 (16Y, 16M, 16C, and 16K) for each color arrives at the fan 22 via the branch duct 19 and the main duct 21a, and travels outward from the fan 22 having the maximum rotation speed. Exhausted.

  Further, at the time of color image formation, as shown in FIG. 6, the opening / closing angle of the shutter 20 may be controlled to increase in proportion to the distance from the fan 22. The opening / closing angle θ1 of the first shutter 20a closest to the fan 22 is minimized, the opening / closing angles θ2 and θ3 of the second and third shutters 20b and 20c are sequentially increased, and the opening / closing angle θ4 of the fourth shutter 20d farthest from the fan 22 By maximizing this, heat can be effectively guided from each branch duct 19 to the fan 22 via the main duct 21a. For this reason, the rotation speed of the fan 22 can be lowered and the noise of the fan 22 can be suppressed.

  FIG. 7 shows a modification of the above embodiment, but the same elements as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted. In the modification of FIG. 7, the fan 22 is disposed on the right end of the main duct 21b opposite to the above-described embodiment, that is, on the black developing device 16K side. Only the fifth shutter 20e is connected to the upper end of the branch duct 19K extending from the black developing device 16K, and only the branch duct 19K communicates with the main duct 21b to communicate with the other branch ducts 19Y, 19M, 19C and the main duct 21b. The tributary ducts 19Y, 19M, 19C, and 19K are installed so as to be rotatable between a vertical position where they are blocked and a horizontal position where the branch ducts 19Y, 19M, 19C, and 19K communicate with the main duct 21b.

  Since the fifth shutter 20e can rotate between the vertical position and the horizontal position to connect the main ducts 21b to or from the main duct 21b, the fifth shutter 20e operates. Thus, only the tributary duct 19 extending to the process unit 14 that generates heat can be communicated with the main duct 21b, and heat can be effectively guided to the fan 22 via the main duct 21b.

  At the time of monochrome image formation, as shown in FIG. 7A, the fifth shutter 20e is positioned in the vertical position. Since the main duct 21b communicates only with the tributary duct 19K disposed in the black developing device 16K, heat is effectively conducted from the black developing device 16K to the fan 22 to reduce the rotational speed of the fan 22. can do. Therefore, noise caused by the fan 22 when forming a monochrome image can be suppressed.

  At the time of color image formation, as shown in FIG. 7B, since the fifth shutter 20e is positioned at the horizontal position, the heat generated from the developing device 16 of each color is supplied to the fan through the branch duct 19 and the main duct 21b. Arrives up to 22 and is exhausted to the outside from the fan 22 having the maximum rotation speed.

1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention. (A) Top view of the cooling device according to the first embodiment of the present invention (b) Front view of the cooling device according to the first embodiment of the present invention. (A) The perspective view of the cooling device which concerns on 1st Embodiment of this invention at the time of monochrome image formation (b) The perspective view of the cooling device which concerns on 1st Embodiment of this invention at the time of color image formation. The side view of the cooling device which concerns on 1st Embodiment of this invention at the time of monochrome image formation. The side view of the cooling device which concerns on 1st Embodiment of this invention at the time of color image formation. The side view of the cooling device of the modification which concerns on 1st Embodiment of this invention at the time of color image formation. (A) Side view of a cooling device according to the second embodiment of the present invention during monochrome image formation (b) Side view of the cooling device according to the second embodiment of the present invention during color image formation.

Explanation of symbols

11 Image forming apparatus 14, 14Y, 14M, 14C, 14K Process unit 18 Cooling device 19, 19Y, 19M, 19C, 19K Tributary duct 20 Shutter 20a First shutter 20b Second shutter 20c Third shutter 20d Fourth shutter 20e Fifth Shutter 21a, 21b Main duct 22 Fan 38 Control section (shutter and fan control means)

Claims (9)

A plurality of process units necessary for image formation, a plurality of branch ducts extending from the process unit, a main duct communicating with the plurality of branch ducts, and the heat disposed in the main duct and exhausting the heat inside the apparatus to the outside A cooling device for an image forming apparatus including a fan,
A plurality of shutters rotating between an opening position where the branch duct and the main duct communicate with each other, and a closed position where communication between the branch duct and the main duct is blocked;
Shutter control means for controlling the opening / closing and opening / closing angle of the shutter during monochrome image formation using only the black process unit and during color image formation using the plurality of process units;
A cooling apparatus for an image forming apparatus. The cooling device of the image forming apparatus further includes
2. The cooling device for an image forming apparatus according to claim 1, further comprising fan control means for controlling the number of rotations of the fan during the monochrome image formation and the color image formation. When forming the monochrome image,
The shutter disposed in the tributary duct extending to the black process unit is located at the opening position;
The shutter disposed in the branch duct extending to the process unit other than the black is located in the closed position;
3. The cooling device for an image forming apparatus according to claim 2, wherein the fan control unit controls the fan so that the rotation speed of the fan is lower than a maximum value. During the color image formation,
All of the shutters are located at the opening position,
3. The cooling device for an image forming apparatus according to claim 2, wherein the fan control unit controls the fan so that the rotation speed of the fan becomes a maximum value. During the color image formation,
The opening and closing angles of the individual shutters increase in proportion to the distance from the fan,
3. The cooling device for an image forming apparatus according to claim 2, wherein the fan control unit controls the fan so that the rotational speed of the fan is lower than a maximum value. A plurality of process units necessary for image formation, a plurality of branch ducts extending from the process unit, a main duct communicating with the plurality of branch ducts, and the heat disposed in the main duct and exhausting the heat inside the apparatus to the outside A cooling device for an image forming apparatus including a fan,
A vertical position that is disposed only in the tributary duct extending from the black process unit and communicates only the main duct and the tributary duct extending to the black process unit, and communicates the main duct and all the tributary ducts. A shutter that rotates between a horizontal position;
Shutter control means for controlling the opening / closing and opening / closing angles of the shutter during monochrome image formation using only the black process unit and during color image formation using the plurality of process units;
A cooling apparatus for an image forming apparatus. The cooling device of the image forming apparatus further includes
7. The cooling device for an image forming apparatus according to claim 6, further comprising fan control means for controlling the number of rotations of the fan during the monochrome image formation and the color image formation. When forming the monochrome image,
The shutter is located in the vertical position;
8. The cooling device for an image forming apparatus according to claim 7, wherein the fan control unit controls the fan so that the rotational speed of the fan is lower than a maximum value. During the color image formation,
The shutter is located in the horizontal position;
8. The cooling device for an image forming apparatus according to claim 7, wherein the fan control unit controls the fan so that the rotation speed of the fan becomes a maximum value.

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