JP4608332B2 - Image forming apparatus - Google Patents

Description

The present invention relates to images forming device.

  As is well known, one of image forming methods is an electrophotographic method. In this method, when an electrostatic latent image formed on a photoconductor corresponding to a latent image carrier is subjected to visible image processing by receiving toner from a developing device, the toner image is applied to a recording medium such as recording paper. The transferred toner image is fixed by a melting / penetrating action using heat and pressure in a fixing device.

  By the way, the image forming apparatus includes a device serving as a heat source, such as the fixing device described above. Equipment that becomes a heat source is not limited to a fixing device, and includes electromagnetic equipment such as a motor and a clutch, and a microchip used for control. The heat from these heat sources is the atmosphere in the image forming apparatus. This may cause an increase in temperature and may have a thermal adverse effect on the equipped equipment.

  For example, since toner is used as a developer in the developing device, there is a possibility that the desired developer supply control cannot be performed due to the solidification of the toner due to the temperature rise in the developing device. In addition, in an optical system, since a resin material is frequently used as an optical lens such as an fθ lens, a regular imaging optical path is changed due to thermal deformation or the like, and a defective image such as a color shift is generated. Defects may occur.

  Therefore, conventionally, a configuration for discharging the heat generated in the fixing device to the outside has been adopted. As this configuration, it is a common configuration to arrange a heat exhaust fan near the fixing device (for example, Patent Document 1).

  Moreover, although it is not for exhaust heat, there is also a configuration in which ozone generated from the charging device is discharged using a fan (for example, Patent Document 2).

  Further, in order to prevent thermal deformation of the optical system parts, a configuration has been proposed in which each optical device is collectively provided with a duct that can be arranged in the airflow passage, and heat isolation and heat dissipation are performed using the duct (for example, Patent Documents). 3).

JP-A-11-231760 (paragraph "0009" column) Utility Model Registration No. 2554613 (page 2, left column, lines 22-32) JP 2001-22151 A (paragraph “0025” column)

  However, recent image forming apparatuses tend to be miniaturized. For this reason, the mounting density of devices and apparatuses inside is increasing, and in the case of performing forced exhaust heat using a fan, patent literature However, the air flow in the apparatus becomes a problem as disclosed. That is, there are cases where an air flow for efficient exhaust heat is not generated simply by installing a suction fan on the apparatus wall. For this reason, there is a problem that heat is trapped in the apparatus or ozone cannot be discharged well.

  In the patent document, in order to eliminate the above-described problems, a configuration is disclosed in which the number of fans is increased, a duct having a special structure is provided to configure an exhaust passage, or a plurality of ozone absorption filters are provided. ing. In addition, since the duct used as a heat countermeasure for the optical system parts needs to be arranged inside the optical writing devices together, the size of the duct becomes large, and an arrangement that does not hinder the airflow is required.

  However, in the case of such a configuration, an installation space for components in the apparatus is required, and there is a risk that the apparatus will be enlarged due to an increase in the installation space in the apparatus.

An object of the present invention is to provide an image forming apparatus provided with an exhaust heat structure that can favorably exhaust hot air accumulated in the apparatus while preventing an increase in the size of the apparatus in view of the above problems in the conventional exhaust heat structure. .

According to a first aspect of the present invention, there is provided an image forming unit, a transfer device that transfers a visible image formed by the image forming unit to a recording medium, and a fixing device that fixes the transferred visible image on the recording medium. An image forming apparatus comprising: a drive unit configured to drive the image forming unit or / and the fixing device, wherein the heat generation is caused by generating an air current in the vicinity of the fixing device and the drive unit constituting the heat generating unit. heat so as to discharge generated from parts, and opening in the support wall for extending direction one end for supporting the exhaust heat portion in the vicinity of the heat generating portion, the extension direction other end, discharge or cooling the recovered has been hot An exhaust heat duct disposed so as to be connected to forced intake / exhaust means for sucking in the working air, and inside the support wall to which an opening at one end in the extending direction of the exhaust heat duct is connected , before Along the longitudinal direction of the fixing device, said weir plate partitioning the image forming unit and the fixing device is provided, the space formed by the mechanism of the fixing device itself and weir plate, the exhaust heat duct This is characterized in that it is configured as a rectifying space for rectifying hot air toward the opening to which one end in the extending direction of the slab is connected .

  According to the present invention, a barrier plate that partitions the image forming unit and the fixing device along the longitudinal direction of the fixing device is provided, and a space constituted by the barrier plate and the mechanism portion of the fixing device itself is Since it is configured as a rectifying space for rectifying hot air toward the opening of the exhaust heat duct, a part of the fixing device that is an existing structural member, in other words, a structure part of the heat generating part itself is used as the rectifying part. Therefore, it is not necessary to add a member constituting a new exhaust heat passage, and further, it is possible to suppress the intrusion of hot air in the vicinity of the fixing device by being thermally isolated by a barrier plate used in the rectifying space.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  FIG. 1 is an external view of an image forming apparatus 1 using an exhaust heat structure according to an embodiment of the present invention. The image forming apparatus 1 shown in FIG. 1 is a color printer having the configuration of the image forming processing unit shown in FIG. However, the present invention includes not only a color printer but also a facsimile device and a printing machine.

  In the image forming apparatus 1, the upper document scanning device 20 is disposed across the image forming unit shown in FIG. 2 in the vertical direction, and the paper feeding device 21 having a plurality of paper feeding trays 21 </ b> A and 21 </ b> B is disposed at the lower portion. In addition, the upper surface of the housing below the document scanning device 20 is provided with a paper discharge tray 1A that forms an in-body paper discharge portion, thereby eliminating the need for a paper discharge space outside the device. An operation panel 20 </ b> A is provided on the front surface of the document scanning device 20.

  Covers 22 and 23 that can be opened and closed are provided on the side surface of the apparatus housing on the upper portion of the paper feed cassette 21A and on the wall surface in a direction perpendicular to this position, and are opened when the image forming unit described later is replaced or maintained. It can be done.

  FIG. 2 is a diagram showing the configuration of the image forming processing unit, in which the document scanning device 20 located at the top and the paper feeding device 21 located at the bottom are omitted.

  In FIG. 2, the image forming processing unit 2 is provided with an image forming unit 2 capable of forming an image for each color separation (for convenience, initials Y, M, C, and B meaning yellow, magenta, cyan, and black are attached to reference numeral 2. Are displayed side by side, and the exposure unit 3 is disposed below the image forming units 2Y, 2M, 2C, and 2B.

Each of the image forming units 2Y, 2M, 2C, and 2B has the same configuration and is hand-woven. Now, the configuration of the unit that forms a yellow image will be described as follows.
The image forming unit 2Y is provided with a photosensitive drum 4Y that is a latent image carrier. Around the photosensitive drum 4Y, a charging device 5Y for performing an image forming process along the direction of the arrow shown in the figure. An incident portion 6Y for writing light from the exposure unit 3, a developing device 7Y, a transfer device 8, and a cleaning device 9Y are arranged.

  In FIG. 2, the developing device 7Y in the color printer uses a two-component developer including toner and carrier. In addition to supplying toner for correcting the developer concentration, the carrier is also supplied to remove the old developer. A trickle development system that allows the developer to be discharged and replaced is adopted.

  In FIG. 2, the transfer device 8 includes a transfer belt 8A that can move while facing and facing the photosensitive drum of each image forming unit, and is positioned at a position facing the photosensitive drum 4Y across the transfer belt 8A. A transfer roller 8Y capable of applying a transfer bias is provided.

  The transfer device 8 in the present embodiment is superposed on the primary transfer process in which the visible images carried on the photosensitive drums in the image forming units 2Y, 2M, 2C, and 2B are sequentially superimposed and transferred onto the transfer belt 8A. The secondary transfer process is performed in which the transferred image is collectively transferred to a recording sheet or the like fed out from the paper feeding device 10. For this reason, a secondary transfer device 11 including a transfer roller to which a transfer bias can be applied is disposed at a position where the secondary transfer process can be performed.

The paper feeding device 10 is provided with a paper feeding cassette 10A for storing recording paper and a registration roller 10B disposed in the feeding path. The registration roller 10B is introduced from a manual paper feeding tray 10C. The conveyance path of the recording paper to be recorded is provided at a position where it merges with the conveyance path from the paper feed cassette 10A.
In FIG. 2, reference numeral 12 denotes a cleaning device for the transfer belt 10A, and reference numeral 13 denotes a static elimination device for the transfer belt 10A.

  In the color printer 1 shown in FIG. 2, the color images formed in the image forming units 2Y, 2M, 2C, and 2B are sequentially superimposed and transferred to the transfer belt 8A of the transfer device 8 by the primary transfer process, and the superimposed images are formed. The recording paper batch-transferred onto the recording paper in the secondary transfer process moves to the fixing device 14 to fix the image, and as shown in FIG. It is designed to be discharged on 1A.

Inside the color printer 1, in the upper space of each of the image forming units 2Y, 2M, 2C, and 2B, toner replenishing units 15Y, 15M, 15C, and 15B used for a trickle developing method (a method that can replace old and new developers) and A carrier replenishing unit 16 shared with each of these toner replenishing units is disposed.
In this embodiment, exhaust heat ducts 100 and 101 are provided as components capable of discharging hot air or introducing cooling air for each heat generating section in the image forming processing section.
In the present embodiment, the heat exhaust ducts 100 and 101 are provided with a fixing unit 14 (FIG. 2) in which a driving unit and a heater equipped with electromagnetic parts such as a driving motor corresponding to a heat generation unit in the image forming processing unit are arranged. Reference) is provided, and the configuration thereof is shown in the drawings after FIG.

  FIG. 3 is a front view of a support wall plate 1B provided to support the drive unit and the fixing device 14 in the apparatus housing. In FIG. 3, the support wall plate 1B includes a drive unit and a fixing device. Exhaust heat ducts 100 and 101 are provided, and the exhaust heat ducts 100 and 101 are both supported at the other end in the extension direction by a support substrate 102 provided perpendicular to the support wall plate 1B, and one end in the extension direction is shown in FIG. As shown in FIG. 3, the openings 1B1 and 1B2 formed in the vicinity of the fixing device and above the fixing device 14 are connected to face each other.

  As shown in FIGS. 1 and 3, a fan 103 capable of intake and exhaust is installed inside the other end in the extending direction of the exhaust heat ducts 100 and 101, and the hot air generated in the apparatus is exhausted or cooled to the outside. Air can be introduced. In the case of the present embodiment, the fan 103 is used for exhausting the hot air to the outside.

  As shown in FIG. 5, the exhaust heat duct 100 for the drive unit is located outside the opening located at one end in the extending direction, separately from the opening at one end in the extending direction connected to the opening provided in the support wall plate 1 </ b> B. A recovery port 100 </ b> A is provided for recovering hot air that has opened and has been raised from the drive motor M. FIG. 5B is an enlarged view of a part of the drive exhaust heat duct 100. The recovery port 100A described above in FIG. 5B is in the exhaust heat duct 100 bent toward the support wall plate 1B. The volume of the straight line portion is made larger than the volume of the portion communicating with the opening at one end in the extending direction, and the rising airflow from the drive motor M can be sucked using the difference in size (one point in FIG. 5B). A state indicated by a chain line arrow) is formed as a recovery port 100A in size.

  As shown in FIGS. 5B and 6, a developing device adjacent to the fixing device 14 is included in the support wall plate 1 </ b> B to which the opening at one end in the extending direction of the driving heat exhaust duct 100 is connected. As shown in FIG. 6 (for the sake of convenience, the fixing device 14 is omitted) between the image forming units, in particular, a toner replenishing portion (denoted by reference numerals 15Y, 15M, 15C, and 15B in FIG. 2). Alternatively, a weir plate 104 is provided vertically between the fixing device 14 and a position adjacent to the installation location of the carrier replenishing portion 16) shared with the toner replenishing portion. A space between the fixing device 14 and the fixing device 14 partitioned by the fan 104 is a space that rectifies the air flow when sucked by the fan 103, and further, this space is used as a heat isolation space with the toner replenishing unit. Going on. Therefore, the exhaust heat duct 100 for the drive unit not only collects hot air from the periphery of the drive motor but also generates hot air from the fixing device 14 side that reaches the toner replenishment unit through the opening connected to the support substrate 1B. It has a function that can be collected.

  In particular, as indicated by reference numeral 106 in FIGS. 5A and 5B (indicated by a two-dot chain line in FIG. 5A), between the toner replenishing portion and the developing device side above the drive motor M. A function of suppressing a thermal adverse effect caused by the hot air from the drive motor M, which is generated with respect to the toner supply tube connected to the motor, is provided. In this embodiment, by collecting the hot air generated from the drive motor M and the electronic components used in the drive circuit at the collection port 100A, it is possible to prevent toner deterioration in the toner supply tube 106. ing.

  In this embodiment, in order to suppress the thermal adverse effect on the toner supply tube 106, although not shown, the connection position of the opening located at one end in the extending direction of the driving heat exhaust duct 100 is the juxtaposition position of the toner supply unit. It is set to be the same level. Thus, the hot air staying around the toner replenishing portion can be collected together with the discharge of the hot air targeting the toner replenishing tube 106 itself.

  On the other hand, as shown in FIG. 4, the heat exhaust duct 101 for the fixing device is connected to the opening 1B2 formed above the installation position of the fixing device 14 in the support wall plate 1B by connecting the opening at one end in the extending direction. When hot air generated from the fixing device 14 rises, it can be sucked and discharged.

  Since the present embodiment is configured as described above, the exhaust heat ducts 100 and 101 are provided for each heat generating portion in the image forming apparatus. As a result, it is possible to collect the hot air at each heat generating part instead of collecting it individually, so that it is possible to efficiently suppress the temperature rise. The installation space can be reduced as compared with the accommodated duct structure.

  The hot air generated from the fixing device 14 is sucked into the exhaust heat duct 101 for the fixing device, and the hot air generated from the driving unit and the hot air staying between the fixing device 14 and the toner replenishing unit are driven exhaust heat duct 100. It is discharged to the outside by being sucked. In particular, in the exhaust heat duct 100 for the drive unit, a recovery port 100A that can recover hot air rising from the periphery of the drive motor M on the way to the connection position with the opening formed in the support wall plate 1B. Therefore, hot air from another position in two directions can be recovered by a single duct.

  On the other hand, a fixing device 14 and a toner replenishing portion disposed in the vicinity of the fixing wall 14B are connected by a weir plate 104 inside the support wall 1B to which the opening at one end in the extending direction of the exhaust heat duct 100 for the drive unit is connected. Since it is partitioned, not only can the hot air from the fixing device 14 inadvertently enter the toner replenishing portion, but also an air flow rectifying space is formed between the weir plate 104 and the fixing device 14. As a result, the airflow generated by suction by the fan 103 is rectified and conveyed. As a result, the heat retention phenomenon that occurs when turbulent flow occurs can be prevented and the hot air can be quickly recovered, and the adverse effect of the heat on the toner replenishing unit can be suppressed to prevent the replenishment toner from being altered. It becomes possible.

  In the above embodiment, since the fan 103 is a discharge fan, it has a function of discharging hot air staying in each heat generating portion to the outside, so it is necessary to take in outside air. Therefore, in this embodiment, as shown in FIG. 7, an outside air intake port 1C1 provided with a filter is formed in the cover member 1C of the apparatus housing located on the side opposite to the side where the exhaust heat ducts 100 and 101 are provided. The outside air inlet 1C1 is used as a hot air outlet when the fan 103 is a suction fan.

1 is an external view of an example of an image forming apparatus using an exhaust heat structure according to an embodiment of the present invention. FIG. 2 is a schematic diagram for explaining a configuration of an image formation processing unit in the image forming apparatus shown in FIG. 1. FIG. 2 is a front view of a support wall plate built in the image forming apparatus shown in FIG. 1. It is the figure seen from the inner side of the support wall board shown in FIG. It is a figure for demonstrating the structure of the exhaust heat duct for drive parts among the exhaust heat ducts shown in FIG. 3, (A) is a general view, (B) is a partial enlarged view. It is a figure for demonstrating the structure of the dam plate which comprises the space connected to the opening of the exhaust heat duct for a drive among the exhaust heat ducts shown in FIG. It is a figure which shows the structure of the wall surface on the opposite side to the side in which the extension direction other end of the heat exhaust duct in the main body housing | casing of an image forming apparatus is located.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1B Support wall board 2 Image forming unit 14 Fixing apparatus 15 Toner replenishment part 100 Heat exhaust duct for drive parts 100A Recovery port 101 Waste heat duct for fixing apparatus 103 Fan 104 Dam plate 105 Toner replenishment tube M Drive motor

Claims (1)

An image forming unit;
A transfer device for transferring a visible image formed by the image forming unit to a recording medium;
A fixing device for fixing the transferred visible image on a recording medium;
An image forming apparatus comprising: a drive unit for driving the image forming unit or / and the fixing device;
A support in which one end in the extension direction supports the exhaust heat part in the vicinity of the heat generating part so that an air flow is generated in the vicinity of the fixing device and the driving part constituting the heat generating part to discharge the heat generated from the heat generating part. open at the wall, the extension direction end is provided with a waste heat duct, which is arranged to be connected to the forced intake and exhaust means for the intake of exhaust or cooling air recovered by the hot air,
The inside of the exhaust heat duct extending direction end the support wall opening is connected to the, in the longitudinal direction of the fixing device, the sheathing board for partitioning between the fixing device and the image forming unit is provided The space formed by the barrier plate and the mechanism unit of the fixing device itself is configured as a rectifying space for rectifying hot air toward an opening to which one end in the extension direction of the exhaust heat duct is connected. A featured image forming apparatus.

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