JP4006958B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic image forming apparatus used for a copying machine, a printer, or the like, and more particularly, to an image forming apparatus to which a fan unit for sucking or exhausting air is attached.
[0002]
[Prior art]
Conventionally, as an electrophotographic image forming apparatus used for a copying machine or a printer, an electrostatic latent image is formed by irradiating a charged photosensitive drum with exposure light scanned using an optical system. The electrostatic latent image on the photoconductive drum is developed with toner to form a toner image, and the toner image on the photoconductive drum is directly or once transferred to a recording medium via an intermediate transfer medium and then on the recording medium. A system in which a fixed image is formed by heating and pressing a non-fixed toner image with a fixing device is widely used.
[0003]
The image forming apparatus incorporates a heat source such as a fixing device, a power source, and a motor as described above, and also incorporates a number of temperature sensitive devices such as a transfer device and a developing device. A cooling fan unit is provided so that the internal temperature does not become too high, and the cooling fan unit is rotated at a high speed to exhaust the internal air or to suck the external air to cool the internal heat.
[0004]
The cooling fan unit has an intake surface that intakes air and an exhaust surface that discharges air, and if the intake surface and the exhaust surface are mistakenly mounted, for example, outside air is sucked in at the position where the inside air should be exhausted. Therefore, circulation of inside air and outside air is impaired. For example, in an image forming apparatus that considers the circulation of air such that the inside air is exhausted in the vicinity of the heat source and the outside air is sucked in the vicinity of the temperature-sensitive device, the outside air is sucked in the vicinity of the heat source and the temperature-sensitive device If circulation is performed to exhaust the inside air in the vicinity, the vicinity of the temperature-sensitive device is heated by the high-temperature inside air, so that not only the original function of the cooling fan unit cannot be performed, but also the cause of the failure of the image forming apparatus. It can be.
[0005]
Therefore, in order not to mix up the intake surface and the exhaust surface of the cooling fan unit, a rib is provided in the mounting portion of the cooling fan unit, and the rib is inserted into the notch portion of the fan case for routing the harness. If the surface and the exhaust surface are mistaken, the fan case is prevented from fitting exactly in the mounting part of the cooling fan unit.
[0006]
However, since the position and shape of the notch portion of the fan case may differ depending on the manufacturer, the method of providing the rib to be inserted into the notch portion in the mounting portion of the cooling fan unit is to procure cooling fan units from a plurality of manufacturers. In some cases, different measures are required for each manufacturer, which is rather complicated.
[0007]
[Problems to be solved by the invention]
In the present invention, in view of the above circumstances, even when a cooling fan unit procured from a plurality of manufacturers is attached to an image forming apparatus, there is a so-called erroneous assembly in which the intake surface and the exhaust surface of the cooling fan unit are attached incorrectly. An object of the present invention is to provide an image forming apparatus capable of preventing the above.
[0008]
[Means for Solving the Problems]
The image forming apparatus of the present invention that achieves the above object forms an image composed of a fixed toner image on a recording medium by forming a toner image and finally transferring and fixing the toner image on the recording medium. In a forming apparatus, a fan unit comprising a blade rotating in a predetermined direction, and a fan case that supports the blade and has an intake surface and an exhaust surface on both sides, and a side surface having an asymmetric recess between the intake surface side and the exhaust surface side And an attachment portion to which the fan unit is attached, having a protrusion that fits into the recess.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0010]
FIG. 1 is a schematic configuration diagram showing an embodiment of a color printer to which the image forming apparatus of the present invention is applied.
[0011]
The color printer shown in FIG. 1 includes an image processing unit 1 that performs predetermined image processing on input image data, a control unit 3 that controls the entire color printer, and an image processing unit and control that form an image on recording paper. There are an image forming unit other than the image forming unit, and an image processing unit 1, a control unit 3, and a housing 31 that houses the image forming unit.
[0012]
The image forming unit includes four photosensitive drums 10 on which toner images of each color of C (cyan), M (magenta), Y (yellow), and K (black) are formed. On the left side are an exposure device 12 that irradiates exposure light and an optical system 11 that scans the exposure light. Around each photosensitive drum 10, there are a charging device 13 for charging the photosensitive drum 10, a developing device 14 for developing the photosensitive drum with each color developer of C, M, Y, and K, and on the photosensitive drum 10 after transfer. A cleaner 16 is provided to remove excess toner remaining in the toner. Each developing device 14 is connected to a developer storage unit 15 that supplies each color developer by a pipe. A first-stage intermediate transfer body 17 to which the C and M color toner images are transferred is disposed at a position close to the photosensitive drum 10 where the C and M color toner images are formed. A first-stage intermediate transfer member 18 to which Y and K color toner images are transferred is disposed at a position close to the photosensitive drum 10 to be formed. The image forming unit is further close to both the first stage intermediate transfer body 17 to which the C and M color toner images are transferred and the first stage intermediate transfer body 18 to which the Y and K color toner images are transferred. A second-stage intermediate transfer body 19 to which the toner images of the first-stage intermediate transfer bodies 17 and 18 are transferred is disposed at the position where the toner image is transferred. Each of the intermediate transfer members 17, 18, and 19 is provided with a cleaner 20 that contacts the respective intermediate transfer members and cleans the toner remaining after the transfer. Further, the image forming unit has a paper feed cassette 22 for storing recording paper at the lower part of the control unit 3 and the image processing unit 1, and the paper drawn from the paper feed cassette 22 is a second stage intermediate transfer member. Each color on the intermediate transfer body 19 in the second stage is transferred by the transfer device 21 that is conveyed along the first conveyance path 23 toward the position 19 and is opposed to the intermediate transfer body 19 in the second stage with the first conveyance path 23 in between. The toner image is transferred to the recording paper. The first conveyance path further reaches the fixing device 27 and the discharge roll 28 of the image forming unit. The image forming unit further includes a second conveyance path 24 that conveys the recording paper that is manually fed from the right side surface of the color printer. The second conveyance path 24 is located in front of the transfer device 21 and the first conveyance path 23. To join. Further, there is a third transport path 25 that reverses and reversely feeds the recording paper having an image formed on one side from the fixing device 26 and the discharge roll 28 and joins the first transport path together with the second transport path 24. The third transport path 25 is used for duplex printing.
[0013]
The recording paper on which the color toner images on the second-stage intermediate transfer body 19 are transferred by the transfer device 21 is conveyed through the first conveyance path 23 to the fixing device 26, and the unfixed toner image is transferred to the fixing device 26. By being heated and pressurized by this, it is fixed on the recording paper. After the fixing, the recording paper is further conveyed through the first conveyance path 23 to reach the discharge roller 28 and is discharged outside the color printer.
Since the fixing device 26, the exposure device 12, and the power supply unit (not shown) of the image forming unit generate heat and the surroundings become high temperature, the heat generated by the fixing device 26 and the exposure device 12 is discharged outside the color printer to form an image. A cooling fan 30 is provided to prevent the inside of the apparatus from becoming high temperature.
The color printer is accommodated in a casing 31 configured to be able to open a predetermined portion, and a concave portion 32 for stacking the recording sheets discharged from the discharge roll is provided on the upper portion of the casing 31.
[0014]
When image data is input, the image processing unit 1 performs predetermined image processing and sends it to the image forming unit.
[0015]
Based on the image data sent from the image processing unit 1, the image forming unit performs pulse modulation on the exposure device 12 for each color of Y (yellow), M (magenta), C (cyan), and K (black). Exposure light is emitted, and the exposure light forms an electrostatic latent image on the photosensitive drum 10 for each color via the optical system 11. The electrostatic latent image on each photosensitive drum 10 is developed with each color developer to become a color toner image, and the C and M toner images and the Y and K toner images are in the first stage. Transferred to the intermediate transfer members 17 and 18. The toner images for each of the two colors of the first-stage intermediate transfer bodies 17 and 18 are transferred to the second-stage intermediate transfer body 19, and each color toner image is formed on the second-stage intermediate transfer body 19. Each color toner image on the intermediate transfer member 19 in the second stage is extracted from the paper feed tray 22 and conveyed on the first conveyance path 23 or manually from the second conveyance path 24 to the first. The recording paper that is merged with the conveyance path 23 and conveyed, forms an image on one side, and is merged with the first conveyance path 23 via the third conveyance path 25 to form an image on the other side. The unfixed color toner image is transferred to a recording sheet to form an image, and the unfixed color toner image on the recording sheet is heated and pressed by the fixing device 27 to form an image. The recording paper on which the image is formed is discharged to the outside of the image forming apparatus by the discharge roll 28 and is stacked on the concave portion 32 provided on the upper portion of the housing 31.
[0016]
Exposure device 12 (optical system 11), photosensitive drum 10, developing device 14, developer storage unit 15, first and second stage intermediate transfer members 17, 18, 19, first, second and third transports The paths 23, 24, 25, the fixing device 27 and the like are driven directly by a motor (not shown) or indirectly by way of a gear and a belt (not shown). Further, since the fixing device 27, the exposure device 12, the power supply unit (not shown), etc. generate heat and the surroundings become hot, the cooling fan 30 is driven at a high speed so as to exhaust the hot air when printing is performed. Rotate.
[0017]
Here, the cooling fan is used to exhaust the inside air, but can also be used to take in the outside air.
[0018]
Although the image forming apparatus of the present embodiment has been described with respect to a color printer, the image forming apparatus need not be limited to a color printer, and can be applied to a monochrome printer or a copier.
[0019]
FIG. 2 is a front view of the cooling fan unit.
[0020]
As shown in FIG. 2, the cooling fan unit 30 includes a square fan case 40 and blades 41 that rotate in the direction of arrow A within the fan case 40. In the center of the fan case 40, there is a heart part 42 with a built-in brushless DC motor for rotating the blades 41. The heart part 42 is supported by the fan case 40 by ribs 45 extending in a diagonal direction. A harness 44 is connected to the heart portion 42, and a connector 43 is attached to the tip of the harness 44. The harness 44 can supply a direct current to the brushless DC motor, and can transmit a signal for controlling the number of revolutions, if necessary. The cooling fan unit 30 has an intake surface for sucking air (a back surface not shown) and an exhaust surface (a surface appearing in the diagram) for discharging air.
[0021]
FIG. 3 is a side view of the cooling fan unit.
[0022]
As shown in FIG. 3, the cooling fan unit 30 includes a fan case 40 and blades 41 that rotate within the fan case 40. The right side of the figure represents the intake surface for inhaling air, and the left side of the figure represents the exhaust surface for exhausting air.
[0023]
Air is drawn from the right side of the cooling fan unit 30 and discharged to the left side. The vane 41 is inclined from the intake surface side 46 toward the exhaust surface side 47 and has a structure for sending out air. The side surface of the cooling fan unit 30 is an asymmetric recess between the intake surface side 46 and the exhaust surface side 47. There are 48. The depression 48 on the side surface of the fan case 40 has a shape that is biased toward the intake surface side 46, and this tendency is caused by the inclination of the blades 41, so there is almost no difference between manufacturers.
[0024]
FIG. 4 is a schematic plan view showing an aspect of a mounting portion to which the cooling fan unit is attached.
[0025]
The attachment portion 49 is a rectangular box, and a large number of holes 50 for circulating air are provided on the entire surface excluding the position where the cooling fan unit is attached. At the position parallel to the front surface of the mounting portion 49, two members 51, each of which has a U-shaped end M and an end N, sandwiching the side surface of the cooling fan unit, are mounted at intervals. It is. A hole 50 that circulates air inside two lines parallel to one side of the mounting portion 49 that connects the end portion M and the end portion N of each of the left member 51a and the right member 51b in the drawing. A protrusion 52 that fits into the recess of the fan case is provided at a position close to the line on the side where many are provided.
[0026]
The protruding portion 52 has a structure in which a part of the rectangular box of the mounting portion 49 is cut and raised, but is not necessarily limited to this structure, and two protrusions 52 parallel to one side of the mounting portion 49 are provided. If it is provided at a position near the line on the side where a large number of holes 50 for circulating air are provided, and is configured to fit into a recess on the side surface of the cooling fan unit, a screw It may be stopped.
[0027]
In this way, the mounting portion is provided with a protrusion that fits into the recess 48 of the fan case shaped close to the intake surface side 46, so that the intake surface side and the exhaust surface side can be prevented from being mistakenly attached. it can.
[0028]
FIG. 5 is a schematic front view showing one mode when the cooling fan unit is attached to the mounting portion.
[0029]
As shown in FIG. 5, the attachment portion 49, which is a rectangular box, is provided with a left member 51 a and a right member 51 b, and end portions M and N (end portions) of both members 51 a and 51 b. The fan case 40 is sandwiched and supported by the part N is hidden. The cooling fan unit 30 has a blade 41 that rotates in the fan case 40, and a heart portion 42 in which a brushless DC motor that rotates the blade 41 is built in the center of the fan case 40. The heart portion 42 is supported by the fan case 40 by ribs 45 extending in a diagonal direction, and a harness 44 is connected to the heart portion 42. In addition, a protrusion 52 that fits into a depression on the side surface of the cooling fan unit 30 is provided near the left member 51a of both the members 51a and 51b.
[0030]
【The invention's effect】
As described above, according to the image forming apparatus of the present invention, even when a cooling fan unit procured from a plurality of manufacturers is attached to the image forming apparatus, so-called misassembly is prepared as a separate part. Therefore, it is possible to prevent the cost from increasing and complicated work.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating an embodiment of a color printer to which an image forming apparatus of the present invention is applied.
FIG. 2 is a front view of a cooling fan unit.
FIG. 3 is a side view of a cooling fan unit.
FIG. 4 is a schematic plan view showing a mounting portion for mounting a cooling fan unit.
FIG. 5 is a schematic front view when a cooling fan unit is attached to a mounting portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image processing part 3 Control part 10 Photosensitive drum 11 Optical system 12 Exposure apparatus 13 Charger 14 Developing device 15 Developer storage part 16 Cleaner 17, 18 First stage intermediate transfer body 19 Second stage intermediate transfer body 21 Transfer Device 22 paper feed cassette 23 first transport path 24 second transport path 25 third transport path 26 detection sensor 27 fixing device 28 discharge roller 30 cooling fan unit 31 housing 32 recess 40 fan case 41 blade 42 heart part 43 connector 44 harness 45 Rib 46 Intake surface side 47 Exhaust surface side 48 Recess 49 Mounting portion 50 Hole 51 Member 51a Left member 51b Right member 52 Projection

Claims (1)

An image forming apparatus for forming an image composed of a fixed toner image on the recording medium by transferring and fixing the toner formed the toner image of the image on the record medium,
A fan that rotates in a predetermined direction, a fan that supports the blade, has an intake surface on one side and an exhaust surface on the other side, and has an asymmetric recess between the intake surface side and the exhaust surface side on the side surface A fan unit consisting of a case,
A protrusion provided at a position to be fitted into the recess when the intake surface is in a correct orientation of the image forming apparatus in a correct direction and a reverse direction, and the protrusion of the side surface of the fan case. An image forming apparatus comprising: an attachment portion to which a side surface on the side into which is inserted is attached.

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