JP5884497B2 - Cooling device, image forming apparatus - Google Patents

Description

  The present invention relates to a cooling device that cools a printed recording medium and an image forming apparatus that includes the cooling device.

  Conventionally, in printing by an electrophotographic image forming apparatus, a toner image is first formed on a recording medium, and then an unfixed toner image formed on the recording medium is heated and fixed. The recording medium after the fixing is at a high temperature, and toner blocking occurs if the recording medium is left as it is. Therefore, a cooling device for cooling the recording medium after fixing is provided in a path from the fixing unit to the paper discharge tray. The cooling device described in Patent Document 1 discloses a technique in which a heat pipe for cooling a recording medium conveyed by a conveyance belt is provided. The cooling device described in Patent Document 2 is provided with a pair of heat pipes, and discloses a technique for cooling the recording medium by sandwiching the recording medium from the upper and lower surfaces with the heat pipes. In the cooling device described in Patent Document 3, a heat pipe is provided so as to rotate, and a technique is disclosed in which the recording medium is conveyed by friction between the rotating heat pipe and the recording medium. In the cooling device described in Patent Document 4, a technique is disclosed in which two pairs of heat pipes and a conveyor belt are provided facing each other.

  However, assuming the use of thicker paper, in the conventional cooling device described above, the roller diameter is increased to increase the nip amount in order to increase the cooling efficiency, the belt is increased in the area where the heat pipe is wound, etc. However, in this case, problems such as an increase in the size of the apparatus, an increase in the bent portion of the transport path, and an increase in stress on the paper occur. In addition, when it is assumed that the conveyance path for performing cooling due to downsizing of the image forming apparatus is shortened, the recording medium can be cooled more efficiently besides means such as changing the size of the cooling apparatus itself. There was a need for a cooling device.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a cooling device capable of efficiently cooling a recording medium.

In order to solve the above-described problems and achieve the object, the present invention is a cooling device that cools a recording medium on which a toner image is fixed, and a conveying unit that conveys the recording medium along a conveying path; A first cooling unit that cools the recording medium by contacting one surface of the recording medium that is transported; and the other of the recording medium that is transported downstream of the first cooling unit in the transport path. A second cooling means for cooling the recording medium by contacting the surface of the recording medium, and contacting the one surface of the recording medium to be transported downstream of the second cooling means in the transport path. A third cooling unit that cools the recording medium, and is provided on the transport path from when the recording medium has been cooled by the first cooling unit to when cooling by the second cooling unit is started. The distance along the The distance from the first cooling means to the third cooling is set to be smaller than the distance along the transport path from the end of the cooling by the second cooling means to the start of the cooling by the third cooling means. The recording medium is cooled without heating the one surface and the other surface in the transport path to the means .

  According to the present invention, there is an effect that the recording medium can be efficiently cooled.

FIG. 1 is a longitudinal sectional view showing an example of the configuration of the image forming apparatus according to the embodiment. Drawing 2 is a mimetic diagram showing the composition of the cooling device of an embodiment. FIG. 3 is a perspective view illustrating a cooling unit and a transport unit used in the cooling device according to the embodiment. FIG. 4 is a schematic diagram illustrating the positional relationship of the cooling units used in the cooling device according to the embodiment. FIG. 5 is a graph showing the temperature transition of the recording paper due to the cooling of the cooling device. FIG. 6 is a block diagram illustrating a hardware configuration of the system of the image forming apparatus according to the embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the cooling device according to the present invention will be described below in detail with reference to the accompanying drawings.

  In this embodiment, a tandem color printer is described as an example of an image forming apparatus provided with a cooling device, but the present invention is not limited to this. For example, the present invention can be applied to a copying machine or a printer using an electrophotographic system, or a multifunction machine having at least a copy function or a printer function among a copy function, a printer function, a scanner function, and a facsimile function.

  First, the configuration of the image forming apparatus according to the present embodiment will be described.

  FIG. 1 is a longitudinal sectional view showing an example of the configuration of the image forming apparatus 1 of the present embodiment.

  In the image forming apparatus 1, a bottle storage unit 101 that stores a bottle is positioned above the image forming apparatus main body 10, and a paper feeding unit 12 that feeds the recording paper P is positioned below the image forming apparatus main body 10. An image forming unit 70 that forms an image on the recording paper P that is a recording medium is positioned between the storage unit 101 and the paper feeding unit 12. A fixing unit 20 that fixes an image on the recording paper P is positioned on the upper right side of the image forming apparatus main body 10, and a cooling device 25 that cools the recording paper P is positioned above the fixing unit 20 (downstream in the transport direction). .

  In the bottle accommodating portion 101, four toner bottles 102Y, 102M, 102C, and 102K corresponding to the respective colors of yellow, magenta, cyan, and black are detachably (replaceable).

  The image forming unit 70 includes an intermediate transfer belt 78, primary transfer bias rollers 79Y, 79M, 79C, and 79K, a secondary transfer backup roller 82, a cleaning backup roller 83, a tension roller 84, and an intermediate transfer cleaning unit 80. An intermediate transfer unit 85 is disposed. Image forming units 4Y, 4M, 4C, and 4K corresponding to the respective colors of yellow, magenta, cyan, and black are arranged in parallel so as to face the intermediate transfer belt 78 of the intermediate transfer unit 85.

  Photosensitive drums 5Y, 5M, 5C, and 5K are disposed in the image forming units 4Y, 4M, 4C, and 4K, respectively, and a charging unit 75 and a developing unit are provided around the photosensitive drums 5Y, 5M, 5C, and 5K, respectively. A unit 76, a cleaning unit 77, a charge removal unit (not shown), and the like are provided.

  Then, an image forming process (charging process, exposure process, developing process, transfer process, and cleaning process) is performed on each of the photoconductive drums 5Y, 5M, 5C, and 5K, thereby the photoconductive drums 5Y, 5M, and 5C. Images of each color are formed on 5K.

  In the charging step, the photoconductive drums 5Y, 5M, 5C, and 5K are each rotated clockwise by a drive motor (not shown), and the surface of the photoconductive drums 5Y, 5M, 5C, and 5K is positioned at the charging unit 75. Are uniformly charged.

  Subsequently, in the exposure process, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K reach the irradiation position of the laser beam emitted from the exposure unit 3, and the photosensitive drums 5Y, 5M, An electrostatic latent image corresponding to each color is formed on 5C and 5K.

  Subsequently, in the development process, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K reach a position facing the developing unit 76, and the electrostatic latent image is developed at this position, and the photosensitive drums 5Y, 5M, and 5C are developed. A toner image of each color is formed on 5K.

  Subsequently, in the transfer process, the surfaces of the photoconductor drums 5Y, 5M, 5C, and 5K reach the positions facing the intermediate transfer belt 78 and the primary transfer bias rollers 79Y, 79M, 79C, and 79K, and the photoconductors are in this position. The toner images on the drums 5Y, 5M, 5C, and 5K are transferred onto the intermediate transfer belt 78. However, a small amount of untransferred toner remains on the photosensitive drums 5Y, 5M, 5C, and 5K even after the transfer of the toner image.

  Subsequently, in the cleaning process, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K reach a position facing the cleaning unit 77, and the untransferred images remaining on the photosensitive drums 5Y, 5M, 5C, and 5K at this position. The toner is mechanically collected by the cleaning blade of the cleaning unit 77.

  Finally, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K reach a position facing a neutralization unit (not shown), and the residual potential on the photosensitive drums 5Y, 5M, 5C, and 5K is removed at this position. .

  Thus, a series of image forming processes performed on the photosensitive drums 5Y, 5M, 5C, and 5K is completed.

  Further, the toner images of the respective colors formed on the photosensitive drums 5Y, 5M, 5C, and 5K are transferred onto the intermediate transfer belt 78 by the transfer process performed on the intermediate transfer belt 78. A color image is formed.

  The intermediate transfer belt 78 is stretched and supported by a secondary transfer backup roller 82, a cleaning backup roller 83, and a tension roller 84.

  The primary transfer bias rollers 79Y, 79M, 79C, and 79K form a primary transfer nip by sandwiching the intermediate transfer belt 78 between the photosensitive drums 5Y, 5M, 5C, and 5K, respectively. Similarly, the secondary transfer backup roller 82 forms a secondary transfer nip by sandwiching the intermediate transfer belt 78 with the secondary transfer roller 89. A transfer bias reverse to the polarity of the toner is applied to the primary transfer bias rollers 79Y, 79M, 79C, and 79K.

  Then, the intermediate transfer belt 78 is moved endlessly in the direction of the arrow 87 by the rotational drive of the secondary transfer backup roller 82, and sequentially passes through the primary transfer nips of the primary transfer bias rollers 79Y, 79M, 79C, and 79K. In this way, the toner images of the respective colors on the photosensitive drums 5Y, 5M, 5C, and 5K are primarily transferred while being superimposed on the intermediate transfer belt 78.

  Subsequently, the intermediate transfer belt 78 onto which the toner images of the respective colors are transferred in an overlapping manner reaches a position facing the secondary transfer roller 89, and the four color toner images formed on the intermediate transfer belt 78 at this position are The image is transferred onto the recording paper P conveyed to the position of the secondary transfer nip. However, the untransferred toner that has not been transferred to the recording paper P remains on the intermediate transfer belt 78 even after the transfer of the toner image.

  Subsequently, the intermediate transfer belt 78 reaches the position of the intermediate transfer cleaning unit 80, and untransferred toner on the intermediate transfer belt 78 is collected at this position.

  Thus, a series of transfer processes performed on the intermediate transfer belt 78 is completed.

  Note that the recording paper P conveyed to the position of the secondary transfer nip is conveyed from the paper supply unit 12 via the paper supply roller 97, the registration roller pair 98, and the like.

  A plurality of recording papers P such as transfer paper are stored in the paper supply unit 12, and when the paper supply roller 97 is driven to rotate counterclockwise, the uppermost recording paper P is positioned between the rollers of the registration roller pair 98. It is sent toward.

  The recording paper P conveyed to the registration roller pair 98 is temporarily stopped at the position of the roller nip of the registration roller pair 98 that has stopped rotating. Then, the registration roller pair 98 is rotated in synchronization with the color image on the intermediate transfer belt 78, and the recording paper P is conveyed toward the secondary transfer nip. Thus, a desired color image is transferred onto the recording paper P.

  Subsequently, the recording paper P on which the color image has been transferred at the position of the secondary transfer nip is conveyed to the position of the fixing unit 20. At this position, the surface on which the color image of the recording paper P is transferred (formed) is heated by the heating member 21, and the opposite surface is pressed by the pressing member 31, whereby the color image is placed on the recording paper P. Let it settle.

  Thereafter, the recording paper P is cooled by the cooling device 25, and then discharged between the rollers of the paper discharge roller pair 99 and out of the device. The recording paper P discharged outside the apparatus by the paper discharge roller pair 99 is sequentially stacked on the stack unit 100 as an output image.

  Thus, a series of image forming processes in the image forming apparatus is completed.

  Next, a detailed configuration of the cooling device 25 will be described. FIG. 2 is a schematic diagram illustrating the configuration of the cooling device 25. FIG. 2 is a diagram schematically showing the configuration after passing through the fixing unit 20, so the direction in FIG. 1 and the direction in FIG. 2 do not match in the drawing, but the right side in FIG. The part 20 side and the left side are the stack part 100 side.

  As shown in FIG. 2, the cooling device 25 includes a conveyance path 110 for the recording paper P, a first cooling unit 120 a, and a first conveyance unit that is provided facing the first cooling unit 120 a and the conveyance path 110. Part 130a, second cooling part 120b, second cooling part 120b and second transport part 130b provided opposite to each other across transport path 110, third cooling part 120c, third cooling part 120c and transport A third transport unit 130c provided facing the path 110, a fourth cooling unit 120d, a fourth transport unit 130d provided facing the fourth cooling unit 120d and the transport path 110, It has.

  The first cooling unit 120a and the third cooling unit 120c cool the recording paper P from the upper side (the first surface side of the recording paper P) in the drawing, and the second cooling unit 120b and the fourth cooling unit 120d are The recording paper P is cooled from the lower side (the second surface side of the recording paper P) in the drawing. Therefore, the recording paper P is cooled from both sides. FIG. 3A is a perspective view illustrating the configuration of each of the cooling units 120a to 120d. As shown in FIG. 3, the cooling units 120 a to 120 d have cooling heat pipes 121 that are in contact with the recording paper P. The heat pipe 121 is rotatably provided, and a plurality of sets (three sets in this embodiment) of radiating fins 122-1, 2, 3 are attached to the end of the heat pipe 121, A plurality of cooling fans 123-1, 2, 3 are provided facing the heat radiating fins 122. The heat dissipating means is constituted by the radiation fins 122-1, 2, 3 and the cooling fans 123-1, 2, 3. The cooling fan 123 may be operated at all times during printing, or may be provided with a temperature sensor that acquires the temperature of the heat pipe 121 and driven when the value of the temperature sensor exceeds a predetermined value. . Since these cooling units 120a to 120d are also rotatably provided, the cooling units 120a to 120d convey the recording paper P by contacting the recording paper P.

  FIG. 3B is a perspective view showing the configuration of each transport unit. Conveying sections (contact means) 130a to 130d are composed of a belt 131 made of an elastic body and a driving roller 132 that supports the belt 131 by two axes and drives the belt by rotating, and corresponds to the conveying means. To do. In addition, you may employ | adopt the structure which combined the driving roller and the driven roller. Further, the conveyance units 130a to 130d are provided so as to press the recording paper P against the cooling units 120a to 120d facing each other during conveyance, and the recording paper P is cooled by the conveyance units 130a to 130d. Cooling is performed more efficiently by being brought into contact with 120d. As the conveyance units 130a to 130d, ones made of other members may be used. For example, when the recording paper P comes into contact with the recording paper P, such as a rubber rotating roller, the friction coefficient is high. Any material may be used as long as the transportability does not deteriorate.

  As shown in FIG. 2, a pair of pressure rollers 140 (pressure means) for pressing the recording paper P from both sides are provided between the second cooling part 120b and the third cooling part 120c in the transport path 110. It has been. Even when the recording paper P is pressed by the pressure roller 140 and formed to have a large thickness, the heat transfer path in the thickness direction is shortened by the pressing, so the thickness of the recording paper P is reduced. The amount of heat existing in the center in the direction can easily move to the surface side, and the heat inside the paper can be made more uniform in the thickness direction of the recording paper P.

  Next, the positional relationship between the cooling units 120a to 120d will be described. In FIG. 2, the distance from the position at which the first cooling unit 120a stops contacting with the recording paper P and the cooling ends to the position at which the second cooling unit 120b starts to contact the recording paper P and starts cooling is a distance a. It is defined as Similarly, the distance from the position at which the second cooling unit 120b is no longer in contact with the recording paper P and the cooling is finished to the position at which the third cooling unit 120c starts to contact the recording paper P and starts cooling is defined as a distance b. Defined.

  In the present embodiment, the cooling units 120a to 120d are arranged so that the relationship of distance a <distance b is satisfied. The distance a and the distance b are linearly shown in the figure, but are originally defined as distances along the transport path 110. The distance a is set as small as possible. Immediately after the cooling of the recording paper P by the first cooling unit 120a is finished, the respective cooling is performed in a positional relationship where the cooling of the recording paper P by the second cooling unit 120b is started. The parts 120a and 120b are provided. Further, the second cooling unit 120b and the third cooling unit 120c are provided with a certain distance apart.

  The reason why the second cooling unit 120b and the third cooling unit 120c are provided apart from each other is that the heat in the thickness direction of the recording paper P is dispersed and equalized after the cooling is finished and before the next cooling. This is to make it happen. Usually, when the recording paper P having a certain thickness is cooled, the temperature of the surface in contact with each of the cooling units 120a to 120d rapidly decreases, but the temperature at the center in the thickness direction is unlikely to decrease. When cooling with a cooling device having sufficient cooling capacity, the higher the temperature of the portion to be cooled, the better the cooling efficiency. Therefore, when the temperature of the recording paper P is equalized in the thickness direction, the heat in the thickness direction of the recording paper P moves to the surface side of the cooled recording paper P, and the cooling of the recording paper P is performed at the next cooling. The surface temperature to be applied can be made high.

  Next, the effect of the present embodiment will be described with reference to FIGS. FIG. 4 shows the positional relationship between the cooling units 120a to 120d, and the simulation is performed with the six types of positional relationships (i) to (f). In the figure, the position on the left side (horizontal axis: 0) is used as a reference, and the numbers indicate the distance (unit: mm) from the reference position. FIG. 5 is a graph showing the temperature transition of the recording paper P in the case of the positional relationships (A) to (F) shown in FIG.

The simulation setting conditions in FIG. 5 are as follows.
<Setting conditions>
The contact time between the cooling units 120a to 120d and the recording paper P is 0.03 seconds.
The contact surfaces of the transport units 130a to 130d with the recording paper P are formed of a heat insulating member.
-The heat radiation during the conveyance between the cooling units 120a to 120d is set under the conditions of a heat transfer coefficient of 5 [W / (m ² · ° C.)] and an air temperature (room temperature) of 32 ° C.

  In the configuration (a) of FIG. 4, the first cooling unit 120 a is 20 mm, the second cooling unit 120 b is 100 mm, the third cooling unit 120 c is 180 mm, and the fourth cooling unit 120 c is 260 mm. The state provided at each position is shown. The first cooling unit 120a, the second cooling unit 120b, the third cooling unit 120c, and the fourth cooling unit 120d are provided on the upper surface side of the recording paper P, respectively.

  In the configuration (b) of FIG. 4, the first cooling unit 120a is 20 mm, the second cooling unit 120b is 100 mm, the third cooling unit 120c is 180 mm, and the fourth cooling unit 120d is 260 mm. The state provided at each position is shown. The first cooling unit 120a and the third cooling unit 120c are provided on the upper surface side of the recording paper P, and the second cooling unit 120b and the fourth cooling unit 120d are provided on the lower surface side of the recording paper P, respectively.

  In the configuration (c) of FIG. 4, the first cooling unit 120 a is 20 mm, the second cooling unit 120 b is 40 mm, the third cooling unit 120 c is 180 mm, and the fourth cooling unit 120 d is 200 mm. The state provided at each position is shown. This positional relationship is the positional relationship of the present embodiment shown in FIG. 2, and the second cooling unit 120b is provided immediately after the first cooling unit 120a. Further, a distance for equalizing heat in the thickness direction of the recording paper P exists between the second cooling unit 120b and the third cooling unit 120c. The first cooling unit 120a and the third cooling unit 120c are provided on the upper surface side of the recording paper P, and the second cooling unit 120b and the fourth cooling unit 120d are provided on the lower surface side of the recording paper P, respectively.

  In the configuration (d) of FIG. 4, the first cooling unit 120 a is 20 mm, the second cooling unit 120 b is 40 mm, the third cooling unit 120 c is 100 mm, and the fourth cooling unit 120 d is 120 mm. The state provided at each position is shown. The first cooling unit 120a and the third cooling unit 120c are provided on the upper surface side of the recording paper P, and the second cooling unit 120b and the fourth cooling unit 120d are provided on the lower surface side of the recording paper P, respectively.

  In the configuration (e) of FIG. 4, the first cooling unit 120a is 20 mm, the second cooling unit 120b is 40 mm, the third cooling unit 120c is 100 mm, and the fourth cooling unit 120d is 180 mm. The state provided at each position is shown. The first cooling unit 120a and the third cooling unit 120c are provided on the upper surface side of the recording paper P, and the second cooling unit 120b and the fourth cooling unit 120d are provided on the lower surface side of the recording paper P, respectively.

  The configuration (f) in FIG. 4 is such that the first cooling unit 120a is 20 mm, the second cooling unit 120b is 40 mm, the third cooling unit 120c is 260 mm, and the fourth cooling unit 120d is 280 mm. The state provided at each position is shown. The first cooling unit 120a and the third cooling unit 120c are provided on the upper surface side of the recording paper P, and the second cooling unit 120b and the fourth cooling unit 120d are provided on the lower surface side of the recording paper P, respectively.

  Next, the temperature transition in the case of each positional relationship (configuration (A) to configuration (F)) described above will be described. FIG. 5A shows the transition of the average paper temperature of the recording paper P during about 700 ms, and FIG. 5B shows the enlarged part of the temperature transition between 560 ms and 680 ms. . As shown in FIG. 5 (a), when the configuration (A) and the configuration (B) are compared, the difference between the cooling units 120a to 120d is about 1.0 ° C. even though the cooling units 120a to 120d are at the same position. Thus, the cooling efficiency is higher when the upper and lower portions are alternately arranged.

  Further, when the configuration (b) and the configuration (c) are compared, the positions of the first cooling unit 120a and the third cooling unit 120c are both the same, but in the configuration (c), the second cooling unit 120b and the second cooling unit 120c are the same. Each of the four cooling parts 120d is provided immediately after the front cooling part. As a result, in the configuration (C), a temperature about 0.3 ° C. lower was measured, and when the temperature difference between both sides of the recording paper P was increased by cooling, the temperatures on both sides of the recording paper P were equal. A higher cooling effect can be obtained if the cooling is performed before the temperature of the non-cooled surface becomes low.

  Further, when the configurations (c) to (f) are compared, the average sheet temperature is measured lower than the other positional relationships in the configurations (c) and (f). This is because the heat at the center in the thickness direction of the recording paper P is equalized by allowing time to elapse between the time when both sides of the recording paper P are once cooled and the next cooling. Can be raised. Since each cooling part 120a-120d can cool more efficiently, so that the temperature of the part which contacts more is high, like 2nd cooling part 120b and 3rd cooling part 120c like composition (c) and composition (f), It is preferable to arrange the cooling units 120a to 120d so that there is a certain interval between them, at least a larger interval than between the first cooling unit 120a and the second cooling unit 120b. It should be noted that the temperature does not change in the positional relationship between the configuration (c) and the configuration (f) because the amount of heat in the recording paper P is dispersed and substantially equalized by the distance shown in FIG. This is because it is sufficient.

  The cooling device of the present embodiment described above can be realized by changing as follows. That is, in the embodiment, the four cooling units 120a to 120d are provided. However, considering the above effects, cooling units that cool at least the upper surface and the lower surface of the recording paper P are provided adjacent to each other. The cooling of the other surface may be performed immediately after the one surface is cooled.

  Further, although the image forming apparatus of the type in which the recording paper P is conveyed one by one is shown, the cooling device can be applied to an image forming apparatus that performs printing using continuous paper (continuous paper / web). In this case, the conveyance unit 130 provided to face the cooling unit 120 is not indispensable, and a conveyance unit that conveys the web between the cooling units 120 of the cooling device 25 or the downstream side of the cooling device 25 (for example, It is possible to adopt a configuration in which conveyance is performed by a conveyance roller pair).

  Further, as long as a sufficient space is secured between the second cooling unit 120b and the third cooling unit 120c, the pressure roller need not be provided. The configuration of the pressure roller may be any as long as it can press the recording paper P from both sides.

  Further, due to the size restriction of the image forming apparatus, even when there is not enough space between the second cooling unit 120b and the third cooling unit 120c, at least the temperatures on both sides of the recording paper P are equalized. Thus, it is possible to obtain an effect of obtaining a higher cooling effect by performing the cooling before the temperature of the uncooled surface is lowered.

  Moreover, you may use structures other than the combination of the heat pipe as a cooling part, and a heat dissipation fin and a cooling fin as an exhaust heat means. For example, a Peltier element or the like may be provided between the heat pipe and the heat radiating fin so that the exhaust heat can be efficiently performed by generating a temperature difference.

  Although the present invention has been described with reference to an electrophotographic apparatus using toner, the present invention has a drying apparatus for drying ink formed on a recording medium, and the cooling apparatus of the present invention is installed downstream of the drying apparatus. By doing so, the present invention can also be applied to an ink jet apparatus.

  FIG. 6 is a block diagram illustrating an example of a hardware configuration of the image forming apparatus according to the present embodiment. As shown in the figure, the image forming apparatus 1 has a configuration in which a controller 210 and an engine unit (Engine) 260 are connected by a PCI (Peripheral Component Interface) bus. The controller 210 is a controller that controls the entire image forming apparatus 1 and controls drawing, communication, and input from an operation unit (not shown). The engine unit 260 is a printer engine that can be connected to a PCI bus, and is, for example, a monochrome plotter, a 1-drum color plotter, a 4-drum color plotter, a scanner, or a fax unit. The engine unit 260 includes an image processing unit such as error diffusion and gamma conversion in addition to a so-called engine unit such as a plotter.

  The controller 210 includes a CPU 211, a north bridge (NB) 213, a system memory (MEM-P) 212, a south bridge (SB) 214, a local memory (MEM-C) 217, and an ASIC (Application Specific Integrated Circuit). 216 and a hard disk drive (HDD) 218, and the North Bridge (NB) 213 and the ASIC 216 are connected by an AGP (Accelerated Graphics Port) bus 215. The MEM-P 212 further includes a ROM (Read Only Memory) 212a and a RAM (Random Access Memory) 212b.

  The CPU 211 performs overall control of the image forming apparatus 1 and includes a chip set including the NB 213, the MEM-P 212, and the SB 214, and is connected to other devices via the chip set.

  The NB 213 is a bridge for connecting the CPU 211 to the MEM-P 212, SB 214, and the AGP bus 215, and includes a memory controller that controls reading and writing to the MEM-P 212, a PCI master, and an AGP target.

  The MEM-P 212 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, a printer drawing memory, and the like, and includes a ROM 212a and a RAM 212b. The ROM 212a is a read-only memory used as a memory for storing programs and data, and the RAM 212b is a writable and readable memory used as a program / data development memory, a printer drawing memory, and the like.

  The SB 214 is a bridge for connecting the NB 213 to a PCI device and peripheral devices. The SB 214 is connected to the NB 213 via a PCI bus, and a network interface (I / F) unit and the like are also connected to the PCI bus.

  The ASIC 216 is an IC (Integrated Circuit) for image processing having hardware elements for image processing, and has a role of a bridge for connecting the AGP bus 215, the PCI bus, the HDD 218, and the MEM-C 217, respectively. The ASIC 216 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 216, a memory controller that controls the MEM-C 217, and a plurality of DMACs (Direct Memory) that rotate image data using hardware logic. (Access Controller) and a PCI unit that performs data transfer between the engine unit 260 via the PCI bus. The ASIC 216 is connected to an FCU (Facsimile Control Unit) 230, a USB (Universal Serial Bus) 240, and an IEEE 1394 (the Institute of Electrical and Electronics 13) interface via a PCI bus. The operation display unit 220 is directly connected to the ASIC 216.

  The MEM-C 217 is a local memory used as a copy image buffer and a code buffer, and an HDD (Hard Disk Drive) 218 is a storage for storing image data, programs, font data, and forms. It is.

  The AGP bus 215 is a bus interface for a graphics accelerator card proposed for speeding up graphics processing. The AGP bus 215 speeds up the graphics accelerator card by directly accessing the MEM-P 212 with high throughput. It is.

  In the above embodiment, the image forming apparatus of the present invention has been described by taking an example in which the image forming apparatus is applied to a multifunction machine having at least two functions among a copy function, a printer function, a scanner function, and a facsimile function. The present invention can be applied to any image forming apparatus such as a printer, a scanner apparatus, and a facsimile apparatus. The position of the cooling device can also be appropriately changed according to the shape and configuration of the image forming apparatus.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 3 Exposure part 4Y-4K Image forming part 5Y-5K Photosensitive drum 10 Image forming apparatus main body 12 Paper feed part 20 Fixing part 21 Heating member 25 Cooling device 31 Pressure member 70 Image forming part 75 Charging part 76 Development Section 77 Cleaning section 78 Intermediate transfer belt 79Y to 79K Primary transfer bias roller 80 Intermediate transfer cleaning section 82 Secondary transfer backup roller 83 Cleaning backup roller 84 Tension roller 85 Intermediate transfer unit 89 Secondary transfer roller 97 Paper feed roller 98 Registration roller Pair 99 Discharge roller pair 100 Stack unit 101 Bottle storage unit 102Y Toner bottle 110 Transport path 120a First cooling unit 120b Second cooling unit 120c Third cooling unit 120d Fourth cooling unit 121 Heat pipe 122 Heat radiation fin 123 Cooling fan 130a 1st conveyance part (contact means)
130b Second transport unit 130c Third transport unit 130d Fourth transport unit 131 Belt 132 Drive roller 140 Pressure roller P Recording paper

Japanese Patent Laid-Open No. 04-260065 JP-A-10-207155 Japanese Patent Laid-Open No. 2006-98917 Japanese Patent Application Laid-Open No. 2003-066744

Claims (5)

A cooling device for cooling a recording medium on which a toner image is fixed,
Conveying means for conveying the recording medium along a conveying path;
First cooling means for cooling the recording medium by contacting one surface of the recording medium being conveyed;
A second cooling means for cooling the recording medium by being in contact with the other surface of the recording medium to be conveyed on the downstream side of the conveying path from the first cooling means;
A third cooling means for cooling the recording medium by contacting the one surface of the recording medium to be transported on the downstream side of the transport path from the second cooling means ;
The distance along the transport path from the end of cooling of the recording medium by the first cooling means to the start of cooling by the second cooling means is that the recording medium is supplied by the second cooling means. It is set smaller than the distance along the transport path from the end of cooling until the cooling by the third cooling means is started,
A cooling apparatus, wherein the recording medium is cooled without heating the one surface and the other surface in a conveyance path from the first cooling device to the third cooling device. Further comprising a fourth cooling means for cooling the recording medium by contacting the other surface of the recording medium to be transported on the downstream side of the transport path from the third cooling means;
2. The cooling device according to claim 1, wherein an interval between the first cooling unit and the second cooling unit is the same as an interval between the third cooling unit and the fourth cooling unit. 3. The cooling according to claim 1, wherein an interval between the second cooling unit and the third cooling unit is not less than 7 times an interval between the first cooling unit and the second cooling unit. apparatus. The pressurizing means for applying pressure from both sides without heating the recording medium between the second cooling means and the third cooling means in the transport path. The cooling device as described in any one of 1-3 . The cooling device according to any one of claims 1 to 4 ,
Toner image forming means for forming a toner image on the recording medium;
Fixing means for heating and fixing an unfixed toner image formed on the recording medium;
An image forming apparatus.

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