JP2005292564A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate two tandem type image forming apparatuses and isolate the heat transfer between the chassis.
Therefore, only a portion where an unfixed image is formed is provided in the first chassis, and a fixing device that causes heat generation is provided in the second chassis. An air flow means for preventing heat from coming and going is provided in the opening constituting the recording material conveyance path between the chassis.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile using an electrophotographic system.

  In recent years, an image forming apparatus is required to output an image with higher image quality due to higher resolution and development of color technology, and various methods have been proposed.

  As one of the methods for achieving high-quality image output, it is important to reduce the difference in gloss value (reflectance) between the recording material surface and the printing portion.

  In order to reduce the difference in gloss, it is preferable to improve the fixing property between the toner and the recording material.

  In order to solve this problem, a configuration has been conventionally proposed in which a plurality of fixing devices are placed in a recording material conveyance path as shown in FIG. Patent Document 1).

  Further, in the conventional apparatus shown in FIG. 7, a unit equipped with the second fixing device is mounted on the side of the image forming unit equipped with the first fixing device, and the recording material passes only through the first fixing device. The recording material conveyance path and the recording material conveyance path for allowing the recording material to pass through both the first fixing device and the second fixing device can be switched. It is described that such a recording material conveyance path can be appropriately switched according to a mode such as a single-sided recording mode or a double-sided recording mode for a recording material (Patent Document 2).

Furthermore, in recent years, there has been a great demand for speeding up image formation, and an image forming apparatus having a plurality of (for example, four) image forming stations has attracted attention. As described above, in an apparatus having a plurality of image forming stations, the apparatus tends to be enlarged due to an increase in the length of the intermediate transfer belt.
JP-A-6-258970 JP 2003-5545 A

However, when the above-described configuration is mounted in one image forming apparatus main body, the following problems occur.
(1) Since the number of built-in items increases, the size of the main body of the image forming apparatus increases, and in a situation where the manufactured image forming apparatus is delivered and installed to the user, the vehicle for transportation must be increased in size. In some cases, problems may arise during transportation, such as being unable to be placed on an elevator during transportation. In addition, there has been a problem that the packaging material for packing the device has to be reinforced to increase the weight of the device, resulting in an increase in cost.
(2) Since the mounting density of various devices in the main body of the apparatus increases due to having a plurality of image forming stations, the fixing device and the image forming device are closer than before, and the low melting point toner having a small particle size is melted before fixing. Prone to problems such as wearing.

The present invention includes an image forming unit that forms an unfixed image on a recording material, and a fixing unit that thermally fixes an unfixed image on the recording material, and includes a first casing and a second casing. In the image forming apparatus configured to be separable,
The image forming unit is arranged in the first casing, and the fixing unit is arranged in the second casing.

  According to the present invention, the influence of heat on the image forming unit can be suppressed. Furthermore, it is possible to solve the problem during transportation of the image forming apparatus while suppressing the influence of heat on the image forming means.

  An embodiment of an electrophotographic image forming apparatus to which the present invention is applied will be specifically described with reference to FIGS.

  FIG. 1 is a cross-sectional explanatory view schematically showing a schematic configuration of an image forming apparatus that combines a first chassis unit and a second chassis unit according to the present invention to form a final form.

  In the image forming apparatus of the present example, a plurality of (four) image forming stations, which will be described later, are juxtaposed along the moving direction on the intermediate transfer member, so that the image forming speed can be increased. .

  Next, one of the plurality of image forming stations will be described in detail with reference to FIG. 1, but the configuration of each image forming station is substantially the same.

  The image forming apparatus of this example is configured to be separable into a first chassis 1 as a first casing and a second chassis 2 as a second casing.

  In this way, by having a configuration in which large-sized image forming apparatuses are separably connected, in a situation where the image forming apparatus is delivered and installed to a user, it can be divided and placed in an elevator. Since the weight of the chassis can be reduced, the transportation efficiency can be improved and the cost for reinforcing the packing material can be prevented.

The image forming station disposed in the first chassis is charged to a desired potential that forms part of the image forming unit, the electrophotographic photosensitive member (image carrier) 3 that forms part of the image forming unit. An exposure unit 5 that forms an electrostatic image by exposing the surface of the photoconductor 3 based on image information desired to be printed, and a developer to the electrostatic image formed on the photoconductor that forms part of the image forming unit The developing device 4 that visualizes the toner by adhering the toner, and the developed image that has been visualized on the photosensitive member that constitutes a part of the image forming means, is a recording material (resin recording represented by paper and OHP). Transfer means 7 for transferring to a material or the like.
Reference numeral 6 denotes a hopper that stores developer supplied to the developing device.
Reference numeral 8 denotes an exhaust device as suppression means for exhausting the interior of the first chassis using a fan.
9 is a recording material feeding section for feeding the recording material, 10 is a first belt conveying means for conveying the recording material after transfer to the second chassis side, and 11 is an unfixed image transferred on the first chassis unit side. It is a second belt conveyance unit that conveys a recording material on which an image is placed to the second chassis side.

  Reference numeral 12 arranged in the second chassis is a first fixing device that forms a part of the fixing means and fixes an image (developer image) on the recording material on which the image is transferred in the first chassis to the recording material. is there. The first fixing device 12 is configured to be freely drawn out of the second chassis in consideration of maintenance and replacement.

  Reference numeral 13 denotes an exhaust duct for mainly exhausting heat from the fixing device in the second chassis unit. Reference numeral 14 denotes a conveyance path connecting the first fixing and the second fixing.

  Reference numeral 15 arranged in the second chassis is a second fixing device which constitutes a part of the fixing means and achieves high image quality by gloss control. The second fixing device 15 is configured to be drawn out of the second chassis in consideration of maintenance and replacement. The first fixing device and the second fixing device can be independently pulled out of the second chassis.

  Reference numeral 16 denotes a refeeding conveyance path for conveying and guiding the recording material to the image forming unit again when images are formed on both sides of the recording material, 17 is a reversing path for reversing the refeeding recording material, and 18 This is a double-sided path for conveying the reversed recording material to the developing device.

  A bottle 19 stores waste toner from a developing device and a cleaning device that cleans the photosensitive member and the intermediate transfer member. By disposing the above-described waste toner bottle in a space further below the double-sided conveyance unit below the fixing device in the second chassis, it is possible to effectively use the empty space and increase the waste toner bottle capacity. In addition, since the fixing unit space is blocked by the double-sided conveyance guide, it is possible to prevent waste toner conveyance failure due to melting of the waste toner by heat. Reference numeral 20 denotes an external paper discharge roller for discharging the recording material on which image formation has been completed to the outside of the apparatus, and 21 denotes a caster.

  As described above, in this example, the image forming station for performing image formation is arranged in the first chassis, while the two fixing devices for heat-fixing the toner images are arranged in the second chassis. The heat generated by the fixing device is prevented from entering the first chassis. As a result, the image forming station can always form a high-quality image without being affected by heat.

  In addition, as will be described below, in this example, a further contrivance is provided to suppress the passage of heat between the first chassis and the second chassis.

  FIG. 2 is a diagram for explaining the details of the belt conveying unit described above. 11a is a suction fan, and in this embodiment, a centrifugal fan (hereinafter referred to as a sirocco fan) is used, and 11b is an exhaust of the suction fan obliquely downward. An exhaust duct for exhausting air. 11c is a conveyance belt having a plurality of suction holes (not shown), 11d is a belt conveyance unit frame, 11e is a belt drive roller, and 10f is a belt drive motor.

  FIG. FIG. 6 is a diagram for explaining the flow of air (exhaust heat) around the openings of the first chassis unit and the second chassis unit, where 30 is a column of the first chassis, 31 is a column of the second chassis, and 32 is a second chassis. It is a welded partition plate member. Reference numeral 33 denotes a fixed guide for delivering the recording material from the double-sided conveyance of the second chassis unit to the double-sided conveyance of the first chassis unit, and 34 denotes a partition plate member welded to the first chassis. Although 35 is not shown in detail, 35 is a drawer unit showing a schematic shape with a two-point difference line, and the left side of the registration roller, the pre-registration conveyance unit, the second transfer roller and the first chassis unit on both sides is mounted on the same frame. Shows what

  In this embodiment, an air flow is formed as indicated by the arrows shown in FIG. 3, and the exhaust duct 11b described in FIG. 2 has a shape for returning the hot air that has circulated from the second chassis side back to the second chassis side. have.

  In addition, an exhaust device 9 of the first chassis unit is disposed further upstream of the first chassis unit and above the belt conveyance path in the vicinity of the opening so that the intake air is directly discharged from the rear side to the outside of the machine. It is configured. As can be seen from the figure, this exhaust device is configured to be useful for suction of floating toner generated in the transfer portion by using a filter (not shown).

  The two airflow means described above block the heat intrusion from the second chassis unit to the first chassis unit in the belt conveyance unit opening.

  Further, the suction fan 11a of the second belt conveyance unit is controlled so as to be driven in order to prevent hot air from flowing in from the second chassis unit even when the image forming apparatus is in a standby state.

  In this embodiment, the belt conveyance unit is divided into the first and second, so that the suction fan of the belt conveyance unit can be as close as possible to the connection portion of the opening of the first and second chassis. It is more effective to prevent the hot air from wrapping around than a single belt conveyance unit.

  Further, by welding the partition plate 32 to the second chassis side, it can be used up to the inside of the second chassis as a JAM processing space on the transport path connected by the belt transport unit, and the exhaust heat duct 9 is connected to the second chassis. It becomes possible to make it closer to the two chassis side.

  Since hot air rises in the second chassis unit, an exhaust duct attached to the unit top plate is arranged on each fixing device, and hot air is sucked from the back by a fan and discharged outside the apparatus. By arranging two fixing devices in the same chassis, it is possible to configure so that only one duct member is required as shown in FIG. By adopting a shape that allows efficient intake, it is possible to achieve the function with a single exhaust fan.

  FIG. 4 is a schematic view of the second chassis side as viewed from the first chassis side. The exhaust heat duct 13 is attached to the second chassis top plate 2a, and the recording path JAM is formed at the back hinge. It shows that there is a portion where the shape of the duct is inclined in order to open and close during processing. In the figure, reference numeral 40 denotes an exhaust fan.

  The double-sided conveyance unit on the second chassis side below the first fixing unit is configured to open and close the lower guide around a hinge (not shown) at the back during JAM processing.

  At this time, as in this embodiment, the partition plate member under the belt conveyance unit is welded to the first chassis, so that the second chassis recording material double-sided conveyance of the second shear recording material first chassis reaches the limit. The first chassis and the second chassis unit can be isolated without impairing the JAM processability by using the second chassis unit double-sided transport upper guide and the above-described partition plate.

  FIG. 5 is a cross-sectional view showing a caster mounting structure, 45 is a top plate of the bottom plate portion, and 43 is a step screw foot. The caster 21 is fastened by a step screw 43 and a nut 44 to a bracket 47 welded to the bottom plate portion with the elastic member 46 interposed therebetween. As the above-described elastic member, a vibration-isolating rubber is generally used in a high-quality machine.

  However, when the recording material moves between two chassis as in the present invention, if a step between the chassis occurs, the conveyance becomes unstable, which is not preferable. In addition, adjusting the height by adding an adjuster increases the cost.

  In particular, in the image forming apparatus as in this example, since the first chassis and the second chassis are transported in a separated state and the two are connected at the installation destination, the conventional first chassis is provided. In order to adjust the height at the time of connection by separately providing an adjusting means for adjusting the height of the second chassis, the installation work may take a long time.

  Therefore, in the present invention, the difference in the amount of the stain due to the difference in weight between the first chassis unit and the second chassis unit does not change the mounting height of the casters, and the first chassis unit and the second chassis unit each. Canceled by using elastic members of different hardness.

  That is, since the weight on the first chassis side is heavier than that on the second chassis side, the hardness of the elastic member on the first chassis side is harder than the hardness of the elastic member on the second chassis side in this example. It is configured. In this way, the amount of sinking due to the difference in weight between the first chassis and the second chassis can be achieved despite the fact that the bracket is an adjuster-less structure and the bracket member having a large mold investment is commonly used between the two chassis. The difference can be canceled satisfactorily.

  According to this example, since the amount of sinking of each chassis is automatically adjusted according to the hardness of the elastic member, the work time associated with installation can be shortened.

  With the configuration as described above, the image forming apparatus can be divided into the first chassis unit and the second chassis unit, so that the image forming apparatus can be transported separately before installation, and the packaging form is also provided. It is possible to make it large enough to withstand elevator transportation.

  As a modification of the present invention, when two transport belt units are not used, the same effect can be obtained by driving the exhaust device installed in the first chassis during standby.

  In addition, a configuration in which only one fixing device as a fixing unit is provided may be provided. In this case as well, the one fixing device is arranged on the second chassis side instead of the first chassis side, so that the first chassis side is arranged. It is possible to reduce as much as possible that the image forming apparatus is affected by heat from the fixing unit.

  In the case where a plurality of fixing devices are provided for high image quality and high image productivity, the problem of heat caused by the fixing device becomes significant. In this case, it is particularly preferable to install all the fixing devices on the second chassis side. It is valid.

1 is a schematic diagram of an image forming apparatus. It is the schematic of a belt conveyance unit. It is the schematic of the connection part vicinity of a 1st chassis and a 2nd chassis. It is a side view of a 2nd chassis. FIG. 3 is a schematic view of a caster attachment portion to the image forming apparatus main body. It is sectional drawing of the conventional image forming apparatus. It is sectional drawing of the conventional image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st chassis 2 2nd chassis 12 1st fixing device 15 2nd fixing device

Claims (8)

An image forming unit that forms an unfixed image on a recording material, and a fixing unit that thermally fixes an unfixed image on the recording material, and is configured to be separable into a first housing and a second housing In the image forming apparatus,
An image forming apparatus comprising: the image forming unit arranged in the first casing; and the fixing unit arranged in the second casing.   2. The image forming apparatus according to claim 1, wherein when the fixing unit includes a plurality of fixing devices, all the fixing devices are arranged in the second casing.   Each of the first casing and the second casing is provided with an opening that constitutes a recording material conveyance path on a surface facing each other, and heat generated in the second casing is generated by the first casing. The image forming apparatus according to claim 1, further comprising a suppressing unit that suppresses entry into the one housing.   The image forming apparatus according to claim 3, wherein the suppression unit includes an exhaust unit that exhausts air to an upper portion of the second casing.   The image forming apparatus according to claim 4, wherein the exhaust unit includes a duct for guiding air to an upper portion of the second casing.   The image forming apparatus includes a conveyance unit that is detachably attached to the image forming apparatus and that bridges between the first casing and the second casing and conveys a recording material carrying an unfixed image. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 3, wherein the suppression unit includes an exhaust unit that exhausts air to an upper portion of the first casing. In the image forming apparatus configured to be transportable by being separated into the first casing and the second casing,
The first housing and the second housing are installed via elastic materials, and the hardness of these elastic materials depends on the weight of the first housing and the second housing. An image forming apparatus characterized by being different from each other.

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