JP2006313294A - Heat-absorbing member, image forming apparatus and image forming unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently cool a process cartridge having a complicated shape, using a simple constitution. <P>SOLUTION: The heat-absorbing member 70, which is prepared by encapsulating a coolant 72 having heat-absorbing function into a sealing bag 71, is provided with a heat conducting plate 60 being an object conducting the heat transmitted from the heat-absorbing member 70; and a heat-dissipating means to dissipate the heat transmitted to the heat-conducting plate 60. Since the heat-absorbing member 70 is inserted in between a process cartridge 50 and the heat-conducting plate 60 and is brought into contact with the process cartridge 50 and the heat-conducting plate 60 coresponging to their shapes, a contact area can be increased, thereby the cooling efficiency is enhanced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat absorbing member for cooling a member to be cooled, an image forming apparatus such as a printer, a copying machine, and a facsimile, and an image forming unit.

  In recent years, due to the miniaturization of the apparatus, the distance between each unit or component is shortened, so that the temperature of each unit or the like is increased. In order to prevent this, there is a method of cooling with air, but a dedicated air path cannot be provided in a narrow space, and a sufficient cooling effect cannot be obtained. For this reason, what cools a to-be-cooled member along a to-be-cooled member is described using the elastic member comprised by the gel-like member with good heat conductivity, or silicone rubber with good heat conductivity, etc. (patent documents) 1).

  Japanese Patent Application Laid-Open No. H10-228561 describes a computer that cools a personal computer with a cooling member (heat-absorbing member) that is sealed at the bottom of the personal computer and seals a viscous fluid with good heat absorption.

  As described above, when the heat absorbing member in which the viscous fluid is sealed is used, it is possible to prevent the temperature rise of the unit or the like by arranging the deformed shape in a narrow space.

JP 2001-180800 A JP 2004-151943 A

  However, if the heat absorbing member as described above is arranged in a narrow space and the apparatus is operated for a long time, the temperature of the heat absorbing member itself also rises and the heat absorbing effect from the object is reduced. As a result, when the apparatus is used for a long time, the temperature of the apparatus itself increases.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a heat absorbing member, an image forming apparatus, and an image forming unit that can suppress the temperature rise of the entire apparatus even when the apparatus is used for a long time.

  The present invention relates to an endothermic member having an endothermic agent that absorbs heat and a sealing member that seals the endothermic agent in a deformable manner, and connects the endothermic agent in the sealing member and the outside of the sealing member. And a thermal conduction member that extends from the inside of the sealing member to the outside of the sealing member.

  According to the present invention, the endothermic property can be maintained by reducing the temperature rise of the endothermic member itself even when used for a long time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, what attached | subjected the same code | symbol in the same drawing or a different drawing performs the same structure or the same effect | action, The duplication description is abbreviate | omitted suitably about these.

<Embodiment 1>
FIG. 1 shows an image forming apparatus to which the present invention can be applied. The image forming apparatus shown in FIG. 4 is a four-color full-color image forming apparatus of an electrophotographic system or an intermediate transfer body system. The figure shows the image forming apparatus on the front side, that is, when operating the image forming apparatus. It is a schematic diagram equivalent to the longitudinal cross-sectional view seen from the side where a man is located. Examples of the image forming apparatus to which the present invention can be applied include a printer, a copying machine, a facsimile machine, and a complex machine of these.

  The image forming apparatus shown in FIG. 1 includes four image forming stations (image forming portions), that is, yellow (Y) images in order from the upstream side along the rotation direction of the intermediate transfer belt 10 as an intermediate transfer member. A forming station PY, a magenta (M) image forming station PM, a cyan (C) image forming station PC, and a black (Bk) image forming station PBk are provided.

  Since these four image forming stations have the same configuration and operation, a yellow image forming station PY will be described below as an example.

  As shown in FIG. 1, an image forming station PY includes a photosensitive drum 1 as an image carrier, a charger 2 that charges the photosensitive drum 1, and an exposure device that exposes the charged photosensitive drum 1 to form an electrostatic latent image. 3. Development unit 4 that develops the electrostatic latent image to form a toner image, transfer roller 5 that transfers the toner image on the photosensitive drum to a transfer material such as an intermediate transfer member or a recording material, and the photosensitive drum after the transfer A cleaning device 6 for cleaning toner and a toner cartridge 7 for storing toner for replenishing the developer are provided.

  The photosensitive drum 1 is configured by providing a photosensitive layer on the surface of a conductive drum base. The photosensitive drum 1 is rotationally driven at a predetermined process speed (weekly speed) counterclockwise in the figure (in the direction of arrow R1 in FIG. 2) by a driving means (not shown).

  A charging bias is applied to the charger 2 by a charging bias application power source (not shown). As a result, the surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity (for example, minus) and potential (for example, −600 V).

  An electrostatic latent image is formed on the surface of the charged photosensitive drum 1 by a scanner unit as the exposure device 3. The scanner unit emits a laser beam by a laser emitting unit 3a based on image information sent from a controller (not shown) that controls image information sent from an image reading unit, a PC, a server, etc. (all not shown). L is ON / OFF controlled. The laser beam L is scanned horizontally by a polygon mirror (not shown) that rotates and deflects the laser, and is further irradiated along a predetermined generatrix of the photosensitive drum 1 by a folding mirror 3b. On the surface of the photosensitive drum 1 after charging, the charge of the portion irradiated with the laser beam L is removed, and an electrostatic latent image is formed. The potential of the exposure part in this embodiment is -150V.

  This electrostatic latent image is developed by the developing device 4. The developing device 4 contains a two-component developer mainly composed of a carrier and toner. The developing device 4 attaches positively charged yellow toner to the exposed portion based on the image information of the electrostatic latent image, and develops the electrostatic latent image as a yellow toner image. Although some toners are positively charged, in this embodiment, negatively charged toner is used.

  Thus, the yellow toner image formed on the photosensitive drum 1 is transferred onto the intermediate transfer belt 10 as an intermediate transfer member by the transfer roller 5. The intermediate transfer belt 10 is stretched around a tension roller 11, a drive roller 12, and a secondary transfer counter roller 13, and is driven to rotate in the direction of arrow R <b> 10 by the rotation of the drive roller 12. The yellow toner image on the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 10 by applying a transfer bias to the transfer roller 5.

  At this time, the untransferred toner remaining on the photosensitive drum 1 without being primarily transferred is removed and collected by the cleaning device 6 and conveyed to a waste toner container (not shown).

  The same operation as that of the yellow image forming station PY described above is performed in the same manner for the remaining three colors, that is, magenta, cyan, and black image forming stations PM, PC, and PBk. The four color toner images are superimposed. A sensor (patch detection sensor) 16 for detecting color misregistration of the toner images superimposed on the intermediate transfer belt 10 faces the surface of the intermediate transfer belt 10 immediately downstream of the black image forming station PBk. It is arranged to do.

  The four color toner images superimposed on the intermediate transfer belt 10 are transferred onto the recording material P (for example, paper, transparent film) by the secondary transfer roller 14. The recording material P is conveyed by the feeding / conveying means 20. The feeding / conveying means 20 includes a sheet feeding cassette 21 disposed below the intermediate transfer belt 10. The paper feed cassette 21 stores a plurality of recording materials P in a stacked state and is detachably attached to the image forming apparatus main body M. The uppermost recording material P in the paper feed cassette 21 is fed by the paper feed roller 22 and is separated and conveyed one by one by the retard roller 23. The conveyed recording material P is temporarily stopped by a registration roller 24 disposed on the upstream side of the secondary transfer roller 14, and in synchronization with the toner image on the intermediate transfer belt 10, It is supplied to a secondary transfer portion between the secondary transfer roller 14. At this time, a secondary transfer bias is applied to the secondary transfer roller 14. As a result, the four color toner images on the intermediate transfer belt 10 are secondarily transferred onto the recording material P all at once. At the time of the secondary transfer, the transfer residual toner that is not transferred to the recording material P and remains on the intermediate transfer belt 10 is removed and collected by the belt cleaner 15 and conveyed to a waste toner container (not shown).

  The recording material P onto which the toner image has been secondarily transferred is conveyed to a fixing device 30 where it is heated and pressed by a fixing roller 31 and a pressure roller 32 to fix the toner image on the surface. The recording material P after the toner image is fixed is discharged onto the paper discharge tray 26 via the paper discharge unit 25. Thereby, the four-color full-color image formation on one side of one recording material P is completed.

  When the toner image is formed on both surfaces of the recording material P, the recording material P after the toner image is fixed is not conveyed to the paper discharge unit 25 but is guided to the reversing path 27 where the front and back are reversed. Thereafter, the paper is guided to the re-feed path 28 and is supplied again to the secondary transfer unit via the registration roller 24 from here.

  Each of the image forming stations PY, PM, PC, and PBk described above is provided with a toner cartridge 7 that accumulates toner of each color and sends a predetermined amount to the developing device 4. The toner cartridge 7 is detachable from the image forming apparatus main body M.

  FIG. 2 is an enlarged vertical cross-sectional view of a process cartridge 50 that is an image forming unit that is detachably attached to the yellow image forming station PY and can be integrally removed from the image forming apparatus as a heat-absorbing object. Show.

  In the present embodiment, the process cartridge 50 includes the photosensitive drum 1, the charger 2, the developing device 4, and the cleaning device 6 that are integrally incorporated in a cartridge container (cartridge outer shell) 51. It consists of The cartridge container 51 is formed of a synthetic resin. Further, the cartridge container 51 rotatably supports the photosensitive drum 1, the charging roller 2 a of the charger 2, the developing sleeve 4 a of the developing device 4, and the conveying screw 6 b of the cleaning device 6. The charging roller 2a is disposed in contact with the photosensitive drum 1, and uniformly charges the surface of the photosensitive drum 1 when a charging bias is applied. The developing sleeve 4a carries a developer on the surface thereof, and develops the toner by attaching the toner to the electrostatic latent image on the photosensitive drum 1 by applying a developing bias. Further, the conveying screw 6b conveys the transfer residual toner scraped off by the cleaning blade 6a attached to the cartridge container 51 to a waste toner container (not shown). Note that a window portion 51 a is provided on the upper portion of the cartridge container 51 in order to allow the exposure laser beam L to pass therethrough.

  Further, a heat absorbing member 70 is in contact with the outer peripheral frame of the cartridge container 51. The cartridge container 51 is provided with an arrangement space which is an attachment portion for arranging the heat absorbing member 70.

  Here, the heat absorbing member 70 will be described. FIG. 3A is a cross-sectional view. The heat absorbing member 70 includes an enclosing bag (encapsulating member) 71 and an endothermic agent (viscous fluid in the present embodiment) 72 filled in the enclosing bag 71. The encapsulating bag 71 is configured by adhering or vapor-depositing a film having high thermal conductivity such as aluminum or copper on the surface of a resin base material made of polyethylene terephthalate or polyamide having a thickness of t = 50 to 100 μm. On the other hand, as the endothermic agent 72, for example, a high molecular weight hiddle gel that is a viscous fluid, is deformable, and has endothermic properties (for example, a sodium salt cross-linked product of isobutylene / maleic anhydride copolymer) can be used. The heat conductive plate (heat conductive member) 60 is preferably a metal member having high heat conductivity, and in the present embodiment, it is an aluminum plate having a thickness of 0.5 to 1 mm which is easily deformed. As shown in the longitudinal view of FIG. 3 (b), the aluminum plate has a structure in which the end portion of the aluminum plate is out of the encapsulating bag and can exchange heat with the outside. In order to reduce the temperature unevenness in the longitudinal direction in the polymer hiddle gel, the entire length of the encapsulating bag 71 is configured in the longitudinal direction. Note that at least one side of the metal member only needs to protrude to the outside, and heat exchange with the outside can be improved, so that the heat of the internal polymer hiddle gel can be released to the outside. In that case, the metal plate is preferably provided over the entire heat absorbing member 70 or at least in one direction.

  The attachment of the heat absorbing member 70 to the cartridge container 51 will be described. The cartridge container 51 is provided with a recess mounting portion along the size of the heat absorbing member 70 on the outer frame of the cartridge container 51. By fitting the heat absorbing member into the recess, the mounting position of the heat absorbing member 70 is set. Can be stabilized. The shape of the heat absorbing member 70 can be easily deformed, and the heat absorbing member 70 is deformed and attached along the contact surface with the cartridge container 51. Further, the metal plate inside can be similarly deformed, and is attached to the cartridge container 51 by performing deformation as close as possible to the deformation of the heat absorbing member 70. In addition, there is a method of using a fixing plate for fixing the heat absorbing member 70 to the cartridge container 51 when there is enough space. The fixing plate may be fixed to the cartridge container 51 with a fixing tool such as a screw so that the heat absorbing member 70 is sandwiched between the cartridge container 51 and the fixing plate.

  In the present embodiment, a heat radiating fin (solid heat sink, heat radiating means) 61 is fixed to one end of the heat conducting plate 60 by screws, rivets, press-fit pins, or the like. It should be noted that the heat conduction effect is obtained by applying silicon grease or the like having good thermal conductivity to the contact portion between the heat conductive plate 60 and the heat radiating fins 61 or the heat absorbing member 70 or the contact portion between the heat absorbing member 70 and the cartridge container 51. You may make it raise.

  The heat dissipating fins can be inserted into a part of the air path for discharging the air inside the image forming apparatus to the outside, and can easily dissipate heat by the air flow in the air path.

  Further, the image forming apparatus main body M may be configured to be provided with an exhaust fan for exhausting the heat radiated by the heat radiating fins 61 to the outside of the image forming apparatus main body M.

  In the present exemplary embodiment, the image forming unit is attached to the process cartridge 50. However, the same effect can be obtained by attaching the image forming unit to the developing unit or the like for which the temperature rise is desired to be prevented.

  As described above, by attaching the heat-absorbing member of the present invention to the image forming unit, it is possible to prevent the heat-absorbing member itself from being heated by the heat conducting member even if the image forming apparatus is used for a long time, and to increase the temperature of the image-forming unit. Can be prevented.

<Embodiment 2>
Another embodiment is shown as a method of attaching the heat absorbing member to the object. Since the configuration is the same as that of the first embodiment except for the configuration of the heat absorbing member and the mounting portion of the process cartridge that is the image forming unit to which the heat absorbing member is attached, the description in the present embodiment is omitted.

  In the first embodiment, the metal plate that is the heat conducting member 60 is provided inside the heat absorbing member 70. However, in this embodiment, the heat conducting member 600 is provided outside the heat absorbing member 700. It is what. That is, it is the structure provided in FIG.

  The heat absorbing member 700 includes an enclosing bag (encapsulating member) 710 and an endothermic agent (viscous fluid) 720 filled in the enclosing bag 710. The encapsulating bag 710 is configured by adhering or vapor-depositing a film having high thermal conductivity such as aluminum or copper on the surface of a resin base material made of polyethylene terephthalate or polyamide having a thickness of about t = 50 to 100 μm. On the other hand, as the endothermic agent 720, for example, an endothermic polymer hiddle gel (for example, a sodium salt cross-linked product of an isobutylene / maleic anhydride copolymer) can be used. Further, the heat absorbing member 700 shown in FIG. 4 is made of a high molecular polymer and extends substantially diagonally to the upper right of the cartridge container 51 from the lower left end in the drawing to the window 51a. Here, if the endothermic agent 720 is impregnated with a resin in a fibrous form, the handling thereof can be simplified. Moreover, you may make it comprise the enclosure bag 710 with a heat conductive silicone sheet.

  Further, a heat conduction plate (heat conductor) 600 made of a metal plate such as an aluminum plate having a thickness of 1 to 3 mm for attaching the heat absorbing member 700 to the cartridge container 51 is attached. The heat conduction plate 600 is formed in a shape that substantially follows the shape from the lower left end to the window portion 51a in the cartridge container 51 in FIG. It is installed. As shown in the perspective view of FIG. 6, the cartridge container 51 has convex portions 54 and 55 in the vicinity of both end portions in the longitudinal direction (the direction along the axis of the photosensitive drum 1). It arrange | positions so that it may fit in the recessed part between the parts 54 and 55. FIG. The heat conduction plate 600 is fixed to the convex portions 54 and 55 of the cartridge container 51 by screws 620 at almost the vicinity of both ends in the longitudinal direction. At this time, the heat absorbing member 700 may be temporarily fastened to the cartridge container 51 or the heat conducting plate 600 with a double-sided tape or an adhesive. Further, instead of the screw 62 as shown in FIG. 5, an urging member such as a plate spring or a torsion spring and a positioning means such as a pin fitting may be used in combination.

  Further, a heat radiating fin (solid heat sink, heat radiating means) 610 is fixed to one end portion of the heat conducting plate 600 by screws, rivets, press-fit pins, or the like. It should be noted that the heat conduction effect is obtained by applying silicon grease or the like having good thermal conductivity to the contact portion between the heat conduction plate 600 and the heat radiation fins 610 or the heat absorption member 700 or the contact portion between the heat absorption member 700 and the cartridge container 51. You may make it raise.

  As shown in FIG. 5, the process cartridge 50 is provided with a coupling 52 for transmitting driving from the image forming apparatus main body M side. Further, a coupling 53 that can be engaged with and disengaged from the coupling 52 is provided on the image forming apparatus main body M side. When the process cartridge 50 is mounted at a predetermined position of the image forming apparatus main body M, the couplings 52 and 53 are engaged. A driving force from the image forming apparatus main body M side is transmitted to the process cartridge 50 side through the couplings 52 and 53 in the engaged state. As a result, the photosensitive drum 1, the charging roller 2a, the developing sleeve 4a, and the conveying screw 6b in the process cartridge 50 are rotated.

  The image forming apparatus main body M is provided with an exhaust fan (not shown) for exhausting the heat radiated by the heat radiating fins 610 to the outside of the image forming apparatus main body M.

  FIG. 7 shows the process cartridge 50 of the yellow image forming station PY and the process cartridge of the magenta image forming station PM. A heat conductive plate 630 that covers both the magenta side of the yellow process cartridge 50 (the right side in the figure) and the yellow side (the left side in the figure) of the magenta process cartridge 50 is integrally configured. A heat absorbing member 730 is sandwiched between the heat conductive plate 630 and the yellow process cartridge 50, and between the heat conductive plate 630 and the magenta process cartridge 50, the same as the heat conductive plate 700 described above. Is sandwiched between them. According to this example, the number of parts can be reduced and the number of assembly steps can be reduced. Thus, a common heat conduction plate 630 can be attached between the process cartridges 50 and 50 adjacent to each other.

  In the above description, the example in which the heat dissipating fins 610 are provided at one end portion of the heat conducting plate 600 to dissipate heat from this is described. Instead, as shown in FIG. 8, a part of the heat conducting plate 800 is provided. May be extended upward, and the radiation fins 820 may be provided here. For example, if the heat dissipating fins 820 are configured to be positioned in the vicinity of the upper surface of the image forming apparatus main body M, the heat dissipated from the heat dissipating fins 820 can be discharged directly to the outside of the image forming apparatus main body M.

  It should be noted that the heat conduction plate 600 or the heat conduction plate 800 is subjected to heat insulation treatment on the outer peripheral portion other than the portions contacting the heat absorbing members 700 and 730 and the heat radiation fins 610 and 820, and other heat sources such as a control board and a fixing device. It is preferable that heat from the vessel 30 is not transferred.

<Embodiment 3>
In the first and second embodiments, the heat absorbing member is attached to the image forming unit. However, in the present embodiment, the intermediate transfer of the intermediate transfer unit, which is an image forming unit for forming the image of FIG. The belt 10 is attached to a part of the belt cleaner 15 for cleaning the belt 10. Since the belt cleaner 15 is disposed in the vicinity of the fixing device 30, the temperature rises. When the temperature of the belt cleaner increases, the waste toner collected in the belt cleaner may soften and harden, so it is necessary to prevent the temperature of the belt cleaner as much as possible. Therefore, when the heat absorbing member is attached to the belt cleaner 15, the same effect as the above embodiment can be obtained. Further, in this embodiment, in addition to the method of attaching to the belt cleaner, the attachment portion for attaching the metal plate such as an aluminum plate for releasing the heat of the heat absorbing member in contact with the heat absorbing member is provided in advance in the image forming apparatus. It is also possible to use this method.

  Moreover, the same effect can be obtained even when the image forming apparatus is attached to an electrical component for forming an image, an electric substrate, or the like.

  In addition, the present invention can be effectively used for cooling other complicated shapes.

1 is a longitudinal sectional view schematically showing a schematic configuration of an image forming apparatus to which the present invention can be applied. FIG. 3 is an enlarged longitudinal sectional view showing configurations of a process cartridge, a heat absorbing member, and a heat conduction plate according to the first embodiment. (A) is sectional drawing of a heat absorption member, (b) is a longitudinal direction figure of a heat absorption member. FIG. 6 is an enlarged vertical cross-sectional view illustrating the configuration of a process cartridge, a heat absorbing member, and a heat conduction plate according to Embodiment 2. It is a top view of a process cartridge and a heat conductive plate. It is a disassembled perspective view of a process cartridge, a heat absorption member, and a heat conductive plate. FIG. 4 is a longitudinal sectional view of the vicinity of a yellow process cartridge and a magenta process cartridge. It is a longitudinal cross-sectional view explaining the other structure of a heat conductive board and a radiation fin.

Explanation of symbols

50 Process cartridge (cooled member)
51 Cartridge container 60, 600, 630
Thermal conduction plate (thermal conductor)
61,610,820
Heat dissipation fin (solid heat sink, heat dissipation means)
70,700,730
Endothermic member 71, 710
Encapsulation bag (encapsulation member)
72,720
Endothermic agent (viscous fluid)
M Image forming device body

Claims (11)

In the heat absorbing member having a heat absorbing agent that absorbs heat and a sealing member that seals the heat absorbing agent in a deformable manner,
Forming a thermal path connecting the endothermic agent in the sealing member and the outside of the sealing member, and having a heat conductive member extending from the inside of the sealing member to the outside of the sealing member,
An endothermic member. The endothermic agent is a synthetic polymer hiddle gel;
The heat absorbing member according to claim 1. The heat conducting member is a metal plate.
The heat absorbing member according to claim 1, wherein the heat absorbing member is a heat absorbing member. The sealing member is composed of a sheet material obtained by coding aluminum on a flexible resin base layer, or a heat conductive silicone sheet.
The heat absorbing member according to claim 1, wherein the heat absorbing member is a heat absorbing member. The heat absorbing member according to any one of claims 1 to 4, further comprising a heat radiating unit that radiates heat of the heat conducting member. In an image forming apparatus that has an image forming unit for forming an image and forms an image on a recording material,
The image forming unit can be attached with the heat absorbing member according to any one of claims 1 to 5.
An image forming apparatus. An image forming apparatus main body having an arrangement space in which the heat conducting member protruding to the outside is arranged;
The image forming apparatus according to claim 6. The arrangement space is a part of an air path for exhausting air from the inside of the image forming apparatus main body toward the outside.
The image forming apparatus according to claim 7. In an image forming unit for forming an image, an endothermic member having heat absorbing agent that absorbs heat and a sealing member that seals the endothermic agent can be attached.
It has a heat radiating member that contacts a part of the heat absorbing member and radiates heat from the heat absorbing member, and has a mounting part for the heat radiating member
An image forming unit. A heat conducting member mounting portion is provided between the heat conducting member that conducts heat and the heat absorbing member is sandwiched between the heat conducting member and the heat conducting member.
The image forming unit according to claim 9. In an image forming apparatus having an image forming portion for forming an image, an endothermic member having a heat absorbing agent that absorbs heat and a sealing member that seals the endothermic agent can be attached.
Having a heat radiating member mounting portion that contacts a part of the heat absorbing member and radiates heat from the heat absorbing member;
An image forming apparatus.

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