JP2013186130A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which: when an exhaust port is provided on a rear face and exhaust air is directed downward than horizontal to prevent a user from being blown by the exhaust air, the exhaust air flows around a bottom face of an apparatus and an intake port sucks a part of the exhaust air, and therefore, temperature of a body cannot be effectively decreased.SOLUTION: A shielding member is provided closer to a rear face side from the center of the front face of a body and a rear face of a body.

Description

  The present invention relates to an electrophotographic image forming apparatus such as a printer or a multifunction peripheral.

  2. Description of the Related Art There is known an electrophotographic image forming apparatus that forms a toner image formed on a recording material and fixes the toner image on the recording material by heating. In this configuration, when the toner melts (softens) in the container that contains the toner, the toner aggregates, which may cause image defects. For this reason, it is desired to cool the container for storing the toner.

  On the other hand, there is a conventional method of sucking (introducing) air into the machine with a fan from outside the machine, applying it to the object to be cooled, and discharging the air whose temperature has risen due to the removal of heat outside the machine. It has been. For example, Patent Document 1 discloses a configuration in which outside air is sucked from the surface of the apparatus and air after cooling is discharged from the back to the outside of the apparatus.

  On the other hand, an image forming apparatus including a caster that can slide the installation surface and an adjuster that can be adjusted in height on the bottom surface of the image forming apparatus has been commercialized. In recent years, such image forming apparatuses are often installed near walls.

JP-A-10-149081

  Here, when the wall is brought close to the back surface of the image forming apparatus provided with the exhaust port on the back surface, the following situation occurs.

  Specifically, when the wall and the back surface of the apparatus are close to each other, the air (exhaust gas) discharged from the exhaust port to the outside of the apparatus travels downward between the back surface and the wall surface of the apparatus. Then, the exhaust gas that has moved downward along the wall surface enters the gap between the bottom surface and the installation surface, and then slowly moves to the left and right side surfaces and the front surface along the bottom surface.

  For this reason, even if an intake port is provided in the front of the apparatus, the exhaust gas that has entered the intake port is mixed, and cooling efficiency inside the machine is reduced.

  Therefore, an object of the present invention is to prevent the cooling efficiency of the apparatus from being lowered due to the exhaust gas mixed in the intake port even when the apparatus configured to exhaust from the back is installed near the wall.

  Therefore, the image forming apparatus of the present invention is “a container for storing toner for developing an electrostatic image formed on an image carrier, a casing for storing the container, a bottom surface of the casing, Support means for contacting and supporting the housing, an exhaust port provided on the rear surface of the housing for exhausting air that has cooled the container, and provided on the front surface of the housing for taking outside air into the container And the gap between the bottom surface of the housing and the installation surface is shielded in the width direction of the bottom surface of the housing from the center of the bottom surface of the housing to the back side. And a shielding member.

  In the configuration of exhausting downward from the back surface, it is possible to suppress the intake of exhaust gas from the intake port and to suppress the cooling efficiency in the apparatus from being reduced.

1 is a schematic image configuration diagram of an image forming apparatus. FIG. 3 is a diagram for explaining an installation state of the image forming apparatus according to the first embodiment. 1 is a front view and a rear view of an image forming apparatus according to Embodiment 1. FIG. 1 is a perspective view of an image forming apparatus according to Embodiment 1. FIG. FIG. 6 is a perspective view of an image forming apparatus according to a second embodiment and a perspective view of a shielding member. FIG. 10 is a perspective view of an image forming apparatus according to a third embodiment and a perspective view of a shielding member. FIG. 6 is a diagram for explaining airflow in an installed state of an image forming apparatus according to a comparative example.

  Hereinafter, the image forming apparatus will be described in detail with reference to the drawings. Note that dimensions, materials, shapes, relative positions, and the like are not intended to be limited only to the configuration unless otherwise specified.

  This embodiment will be described. First, a schematic configuration of a unit related to image formation of the printer 100 as an image forming apparatus will be described. Then, the external appearance of the printer 100 and the configuration of the intake and exhaust ports will be described in detail.

§1. {About the outline of the image forming apparatus}
Hereinafter, a part (image forming engine unit) related to image formation of the printer 100 will be briefly described.

■ (About the overall configuration of the entire device)
FIG. 1A is a diagram for explaining a schematic configuration of a printer 100 as an image forming apparatus. The printer 100 as an image forming apparatus includes first to fourth stations S (Bk to Y), and forms images with different toners on the respective photosensitive drums. FIG. 1B is an enlarged detailed view of a station as an image forming unit. Each station is substantially the same except for the type (spectral characteristics) of the toner for developing the electrostatic image formed on the photosensitive drum, and therefore, the first station (Bk) will be described as a representative.

  A station S (Bk) as an image forming unit includes a photosensitive drum D as an image carrier and a corona charger 10 as a charging device for charging the photosensitive drum D. After the photosensitive drum D is charged by the corona charger 10, an electrostatic image is formed on the photosensitive drum by exposure L from the laser scanner LS. The electrostatic image formed on the photosensitive drum D (on the image carrier) is developed into a toner image with black toner stored in the developing device 20. The toner image developed on the photosensitive drum D is transferred to an intermediate transfer belt ITB as an intermediate transfer member by a transfer roller 30 as a transfer member. Untransferred toner adhering to the photosensitive drum D without being transferred to the intermediate transfer belt is cleaned and removed by a cleaning device 40 having a cleaning blade. Incidentally, a corona charger, a developing device, etc. involved in forming a toner image on the photosensitive drum D (on the photosensitive member) are referred to as an image forming unit. In this embodiment, a corona charger has been described as an example of a charging device, but is not limited to a corona charging method.

  As described above, the toner images transferred in the order of yellow (Y), magenta (M), cyan (C), and black (Bk) from the photosensitive drum D provided in each station are superimposed on the intermediate transfer belt. The superimposed toner images are transferred to the recording material conveyed from the cassette C in the secondary transfer portion ST. The toner remaining on the intermediate transfer belt without being transferred to the recording material in the secondary transfer portion ST is cleaned by a belt cleaner (not shown). In this embodiment, a polyester resin is used as the binder resin for the toner, and when the developing device is heated to about 45 ° C., the fluidity of the toner is remarkably deteriorated. In this embodiment, the developing device functions as a container for storing toner, and charges the toner by stirring the toner stored in the container. The toner in the developing device is consumed by developing the electrostatic image. The consumed toner is replenished to the developing device from a toner bottle (not shown) in which replenishment toner is accommodated.

  The toner image transferred onto the recording material comes into contact with the toner and is fixed to the recording material by a fixing device F that heats and melts the toner and heat-fixes it on the recording material. Discharged. Further, the printer 100 includes a frame as a housing (not shown) that accommodates and supports the above configuration. The above is the schematic configuration of the entire apparatus.

§2. {Apparatus appearance and intake / exhaust configuration}
Hereinafter, the appearance and the intake / exhaust configuration of the printer 100 as the image forming apparatus will be described.

■ (About the appearance of the device)
FIG. 2A is a view for explaining the appearance of the apparatus in a state where the printer 100 is installed on the installation surface A. FIG. The printer 100 includes a front plate 60 on the side where the operation panel P is provided, and a rear plate 70 facing the wall surface B on the opposite side of the front plate 60. Here, the front side plate 60 side of the printer 100 is referred to as a front side (Front Side), and the rear side plate 70 side is referred to as a back side (Back Side). In addition, when the printer 100 and the wall surface B are installed up to a distance of about 50 mm to 300 mm between the rear side plate 70 and the wall surface B, it is said that the apparatus is installed in the vicinity of the wall surface. In this embodiment, the distance between the rear side plate 70 and the wall surface B is 200 mm.

  Next, the bottom surface of the printer 100 will be described. As shown in FIG. 2A, the bottom plate 90 of the printer is provided with casters 91 as a plurality of supporting members (supporting means) for easily sliding the printer 100. The caster 91 includes a lock mechanism, and the printer 100 is difficult to slide on the installation surface A in the locked state. In addition, the printer 100 includes an adjuster as a leg that can be adjusted in height to make it difficult to move from a predetermined position. In addition, a shielding member 80 is provided below the rear plate 70 of the printer 100 to suppress exhaust air blown downward from the back of the apparatus from entering the bottom plate 90. The shielding member is disposed so as to suppress exhaust gas from flowing between the bottom surface and the installation surface from the right end side (one end side) to the left end side (the other end side) of the back surface of the apparatus.

  2B is an enlarged view of the vicinity of the bottom plate 90 of the printer 100. FIG. As shown in FIG. 2B, when the distance between the lowest surface of the bottom plate 90 and the installation surface A is X (50 mm) and the distance between the installation surface A and the shielding member 80 is Y (5 mm). Y is narrower. In this embodiment, the distance between the apparatus bottom surface and the installation surface can be adjusted by an adjuster between 40 and 60 mm (55 mm in this embodiment). The shielding member 80 will be described in detail later.

■ (Intake and exhaust configuration)
Next, the intake and exhaust configurations will be described. 3A is a front view of the printer 100, and FIG. 3B is a rear view of the printer 100. The printer 100 of this embodiment includes an intake port 61 on the front surface and exhaust ports 71, 72, and 73 on the back surface. Further, an intake port 62 is also provided on the right side surface of the apparatus (see FIG. 2A). In this embodiment, the front surface refers to the side surface on which the operation panel P is provided, and the back surface refers to the surface facing the front surface. In addition, the exhaust port was provided with a louver or a hole, and adopted a configuration for exhausting horizontally or downward from the horizontal.

  The front plate 60 of the printer 100 is provided with an intake port 61 for taking outside air into the apparatus. The intake port is configured such that outside air below the horizontal direction is guided into the aircraft. Specifically, a louver is provided to suck in air below the horizontal direction. It should be noted that even the outside air above the gravitational direction need not be sucked, and the horizontal air may be sucked by a plurality of pinholes instead of the louvers. Further, the rear plate 70 of the printer 100 is provided with a discharge port for discharging the air cooled in the apparatus to the outside. The exhaust port 71 and the exhaust port 72 provided below the center in the height direction of the apparatus are provided with louvers that guide the exhaust toward a direction lower than the horizontal. Note that the air (exhaust) sent by the fan provided in the apparatus is changed by the louver provided at the exhaust port, and exhausted downward from the horizontal. On the other hand, an exhaust port 73 provided above the center of the apparatus in the height direction of the rear plate 70 is a uniform small-diameter hole, and the exhaust is exhausted in a substantially horizontal direction. Here, when forming a louver with a resin material, it is conceivable that an angle (elevation angle) formed by a surface that guides air in the exhaust direction and a horizontal plane is directed upward by about 1 degree in order to remove the louver from the mold. However, when the angle formed by the plane that guides the air below the exhaust direction of the louver and the horizontal plane (the depression angle) is sufficiently large (about 15 degrees or more), the exhaust direction is dominant in the lower direction. Therefore, even if the upper guide surface of the louver in the gravity direction is substantially horizontal, it is said that if the depression angle is sufficiently large, the exhaust is guided downward in the horizontal direction.

■ (Intake / exhaust port and air passage in the device)
Next, the correspondence between the intake / exhaust port and the part to be cooled (the air path inside the apparatus) will be briefly described. There are roughly two places where it is desirable to keep the temperature below a predetermined temperature in the apparatus. One is a fixing device and a recording material fixed by the fixing device, and the other is a developing device that accommodates toner. The sheet heated for fixing by the fixing device is preferably discharged after cooling. Further, when the toner stored in the developing device exceeds a predetermined temperature, the fluidity deteriorates. If the toner is difficult to flow in the developing device, the electrostatic image on the photosensitive member becomes difficult to be developed with the toner, and an image defect may occur. Therefore, it is desirable to cool so as to maintain a predetermined temperature (45 ° C. or lower in this embodiment).

  Therefore, in this embodiment, a configuration is adopted in which the outside air taken in from the air inlet 61 provided on the front surface of the apparatus is guided to the periphery of the fixing device and the periphery of the developing device, respectively. The air after cooling the periphery of the fixing device F is guided to an exhaust port 71 provided on the back surface of the device. Further, the air after the periphery of the developing device 20 is cooled is guided to an exhaust port 72 provided on the back surface of the apparatus. Note that the air that has cooled the periphery of the fixing device F has a higher temperature than the air that has cooled the periphery of the developing device 20.

  In addition, the printer 100 of this embodiment includes an air path that guides outside air to the corona charger. When charging the photoreceptor with a corona charger, discharge products are generated from the air. It is desirable to ventilate discharge products because they cause image flow. Therefore, the printer 100 according to the present embodiment blows outside air taken in from the intake port 62 from above the corona charger toward the photosensitive member. The air sent toward the photoconductor passes through a filter provided at an exhaust port 73 on the back of the main body from a duct provided on the downstream side in the rotation direction of the photoconductor, and is then exhausted outside the apparatus. Note that the temperature of the air after spraying on the corona charger 10 is lower than the temperature of the air after cooling the developing device 20.

  If the air path inside the printer is configured as described above, the exhaust from the exhaust port 71 having a high temperature is sandwiched between the exhaust from the corona charger and the exhaust from the developing device. As a result, the exhaust having a higher density than the exhaust from the exhaust port 71 is exhausted from 73, so that the air that has cooled the periphery of the fixing device F can hardly travel around the wall and enter the front of the device. In addition, by providing the exhaust port 72 below the gravitational direction, the exhaust from the exhaust port 71 can be made difficult to flow between the shielding member 80 and the installation surface B.

§3. {Explanation using a perspective view from the bottom side}
Next, the flow of the shielding member 80 and the exhaust gas will be described in detail using a perspective view of the printer 100 from the grounding surface A side.

■ (About the arrangement and configuration of shielding members)
FIG. 4 is a perspective view of the printer 100 from the grounding surface A side. As shown in FIG. 4, a plate-shaped shielding member 80 is bonded to the end of the bottom plate 90 on the rear plate side along the width direction of the device (a direction orthogonal to the front-back direction). Specifically, a polyurethane foam material having a thickness (in the front of the main body) of 25 mm, a width (in the main body width direction) of 650 mm, and a height (in the main body height direction) of 45 mm was used as the shielding member 80. The width of the printer 100 is 690 mm, and the gap between the bottom plate 90 and the installation surface A is 50 mm. Therefore, considering the projection area seen from the rear panel, with respect to a gap of ^{690mm × 50mm (= 34500mm 2)} , it will cover a 650mm × 45mm (= 29250mm ²⁾ in the shield member 80. That is, the shielding member 80 covers about 85% of the projected area of the space vacated between the bottom surface of the main body and the installation surface by the casters 91.

  In the present embodiment, the above dimensions are adopted. However, the thicker the shielding member, the wider the width, and the higher the height, the higher the exhaust shielding effect. In this configuration, if the shielding member shields 80% or more of the projected area, a sufficient improvement in cooling efficiency could be confirmed. Further, it is preferable to adopt a configuration in which the shielding member 80 has a mounting error (about 5 mm), a dimension that eliminates the gap with the installation surface as much as possible, and a narrow bottom gap in the casing width direction. The shielding member is not limited to the foam material, and a sheet material such as a PET sheet may be used.

  In addition, since it is more effective to shield the high-temperature air at a position as far as possible from the intake portion 61, the position of the shielding member 80 is the rear side plate rather than the center position (bottom surface center) between the front side plate 60 and the rear side plate 70. The position on the 70 side is preferred. In the present embodiment, since the shielding member 80 is located behind the center in the apparatus front-rear direction, the re-intake of exhaust gas can also be suppressed at the intake port 62 provided in front of the center of the right side plate.

  With the above configuration, even when the wall surface B is close to the rear plate 70, the high-temperature air exhausted obliquely downward from the exhaust unit 71 through the louver 72 is difficult to pass between the bottom plate 90 and the installation surface A. Become. Therefore, the amount of the exhausted high temperature air passing between the bottom surface of the main body and the installation surface A is reduced. As a result, it is possible to suppress an increase in the temperature of air sucked from an air inlet provided on a surface different from the back surface of the main body, and maintain the cooling efficiency in the machine.

§4. {Description of comparison with comparative example}
Below, after explaining a comparative example, the result compared with the composition of this example is shown.

■ (Explanation about comparative examples)
FIG. 7 is a diagram for explaining the intake / exhaust configuration and airflow of Comparative Example 1 and Comparative Example 2 compared with the present case. (A) of FIG. 7 is a structure which exhausts upwards rather than a horizontal direction from the exhaust port provided in the back side (comparative example 1). Similar to the present embodiment, the air inlet is provided with a louver so as to suck air below the horizontal direction. On the other hand, the louver is cut so that the exhaust port exhausts upward from the horizontal direction. The flow of air when the printer employing the configuration of Comparative Example 1 is arranged near the wall will be briefly described. The air exhausted upward from the back of the printer hits the wall near the back and is carried forward of the apparatus. Naturally, since the upper part is not a space surrounded by the apparatus and the wall surface, there is little wraparound of the exhaust in the front and left and right directions of the apparatus. However, the exhaust gas that hits the wall faces the user standing on the front side of the apparatus that can easily operate the operation panel P. It is assumed that many users do not feel comfortable that air warmer to some extent than the outside air (about 2 to 4 ° C. warmer than the outside air) hits the chest and face positions. If the exhaust is exhausted upward, but the distance between the back surface and the wall is small, a part of the exhaust will go downward in the apparatus. However, since there is no shielding member that shields the exhaust gas flowing downward along the back surface from flowing around the front of the apparatus, the cooling efficiency is somewhat lowered.

  Next, FIG. 7B shows a configuration in which exhaust is performed downward in the horizontal direction from an exhaust port provided on the back side (Comparative Example 2). When the printer is arranged near the wall surface, there is no exhaust space between the rear plate and the wall surface. Therefore, the exhausted air is guided to the bottom surface of the device. Exhaust gas that has passed through the air passage composed of the back surface and the wall surface flows to the bottom surface of the installation, and then flows into the gap between the caster 91 and the bottom surface. Then, the air flowing into the bottom surface of the printer travels along the bottom surface and moves to the three surfaces of the apparatus except the back surface. Exhaust gas that has traveled through the bottom surface is re-intaken at the intake section, and cooling efficiency decreases. Although it is conceivable that the intake port is directed upwards in order to make it difficult for the exhaust air that has entered from the back of the device to be sucked in, it is not preferable that foreign objects such as dust are easily inhaled when the intake port is directed upwards.

■ (Contrast of this example and Comparative Example 2)
Hereinafter, in the configuration of the present embodiment and the configuration of Comparative Example 2, the temperature of the air sucked in the intake portion on the front surface of the apparatus will be compared.

  Table 1 is a table showing the intake air temperature from the intake section 61. Table 1 is a table showing the results of measurement in a state in which image formation was continuously performed in an outside air temperature environment of 27.0 ° C. and the temperature inside the apparatus reached an equilibrium state. When the shielding member 80 is not provided (Comparative Example 2), the internal temperature can be suppressed to 27.6 ° C. in the configuration of the present embodiment, compared to 28.7 ° C.

  As described above, the developing device is cooled by the air introduced from the intake section 61 of this embodiment. For this reason, the difference in intake air temperature significantly affects the difference in toner temperature in the developing device. When the configuration of the present embodiment was adopted, the temperature of the toner in the developing device could be made lower than 45 ° C. even under an outside air environment of 30.0 ° C. Although it is conceivable to increase the diameter of the fan and increase the power supply in order to keep the toner having a low melting point at a low temperature in the apparatus, it is not preferable because it leads to an increase in the size of the apparatus and an increase in power consumption.

  This embodiment will be described below. In addition, about the same structure, the overlapping description is abbreviate | omitted suitably by attaching | subjecting the same code | symbol.

  FIG. 5A is an external view from the bottom of the printer 100 according to this embodiment. In this embodiment, the shielding member 80 is detachably attached to the main body. FIG. 5B is an enlarged view of the shielding member 80 that is detachable. The shielding member 80 is bonded and fixed to a sheet metal 81 having an L-shaped cross section, and the sheet metal 81 can be attached to the rear plate 70 with screws 83 and 84.

  In the configuration of this embodiment, the clearance between the bottom plate 90 of the printer 100 and the installation surface A is 50 mm, and the clearance between the attached shielding member 80 and the installation surface A is 0 mm. This is because the shielding member 80 is attached after the printer 100 is installed, so that the shielding member wears off the installation surface as the apparatus slides, and does not take into consideration that it interferes with moving on the casters 91 by touching the installation surface. Because it is good. Of course, even if it is the structure which can attach or detach the shielding member 80, it may be the structure which can make a some clearance gap between the shielding member after installation, and an installation surface.

  This embodiment will be described below. In addition, about the same structure, the overlapping description is abbreviate | omitted suitably by attaching | subjecting the same code | symbol.

  FIG. 6A is an overview from the bottom of the printer 100 according to this embodiment. In the present embodiment, the exhaust part 93 is disposed on the bottom plate 90. Thereby, it is possible to reduce noise caused by exhaust while suppressing exhausted air from directly hitting a user standing in the vicinity of the apparatus.

  The shielding member 80 of the present embodiment is adhesively fixed to the attachment sheet metal 81 so as to be positioned between the bottom plate 90 and the installation surface A. FIG. 6B is an enlarged view of the shielding member 80 and the mounting sheet metal 81. A part of the attachment metal plate 81 is hooked and fixed to the bottom plate 90 by the hook portion 92 and is fixed to the rear side plate 70 by screws. Fixing with screws was not shown because it was the same as in Example 2. The shielding member 80 of this embodiment has a V shape when viewed from the bottom plate 90 side. In addition, the inlet 61 is comprised so that the air below a horizontal direction may be taken in similarly to Example 1,2.

  When the shielding member 80 is not provided in the configuration in which the exhaust port is provided on the bottom surface, continuous image formation is performed in an environment where the outside air temperature is 27.0 ° C., and the temperature inside the image forming apparatus rises to reach an equilibrium state. In the state, the temperature in the intake portion was 29.0 ° C. On the other hand, when the shielding member 80 is provided as in this embodiment, the temperature in the intake portion can be suppressed to 27.7 ° C. That is, the cooling efficiency can be improved while preventing the exhausted air from directly hitting a user in the vicinity of the image forming apparatus.

100 printer (image forming apparatus)
60 Front plate 61, 62 Air intake (intake part)
70 Rear side plate 71, 72, 73 Exhaust port (exhaust part)
80 shielding member 90 bottom plate 91 caster (supporting member)

Claims (6)

A container containing toner for developing an electrostatic image formed on the image carrier;
A housing containing the container;
A support means provided on a bottom surface of the housing and supporting the housing in contact with an installation surface;
An exhaust port provided on the rear surface of the housing for exhausting air that has cooled the container;
An intake port provided on the front surface of the housing, for taking outside air into the container;
A shielding member that is provided from one end to the other end side in the width direction of the bottom surface of the housing on the back side from the bottom center of the housing, and shields a gap between the bottom surface of the housing and the installation surface; An image forming apparatus.   The image forming apparatus according to claim 1, wherein the shielding member is attachable to the housing, and the shielding member is in contact with an installation surface on which the image forming apparatus is installed.   The image forming apparatus according to claim 1, wherein the exhaust port exhausts in a horizontal direction or downward below the horizontal direction, and the intake port takes outside air below the horizontal direction into the apparatus. A fixing device for heating and fixing a toner image on a recording material;
A second exhaust port provided on the rear surface of the housing for exhausting the air that has cooled the recording material heated by the fixing device downward from the horizontal,
The image forming apparatus according to claim 1, wherein the second exhaust port is disposed above the exhaust port in a direction of gravity.   The said shielding member shields the projection area of the clearance gap between the bottom face of the said housing | casing supported by the said support means, and an installation surface 80% or more, It is any one of Claim 1 thru | or 4 characterized by the above-mentioned. The image forming apparatus described. An operation panel for operating the image forming apparatus;
The image forming apparatus according to claim 1, wherein the operation panel is provided on a front side of the casing.

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