JP6429439B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus that forms an image on a recording member, and more particularly to a cooling mechanism for electronic components such as an electrical board and a hard disk drive.

  In recent years, image forming apparatuses such as digital multi-function peripherals have been increased in color and speed, and the processing speed of electronic devices mounted on a main substrate that controls the apparatus has also been increased. As the processing speed of the electronic device increases, the power consumption increases, and as a result, the heat generation amount of the device also increases.

  On the other hand, in digital multi-function peripherals, a storage device such as a hard disk drive has been standardly installed in the device in order to digitize, store and reuse paper documents. Since paper documents are digitized and stored as images, image processing is required. For this reason, hard disk drives are often arranged and connected in the vicinity of an ASIC that performs image processing.

Further, as described above, an electronic device having a large amount of heat generation is mounted on the circuit board of the image forming apparatus, and the hard disk drive is affected by the heat. Hard disk drives have problems such as being susceptible to heat due to the mechanical parts and shortening their lifetime when exposed to high temperatures.
In order to solve such a problem, there is known a means for cooling by natural convection by providing a vertical air flow path between a vertical substrate frame equipped with a hard disk drive and the hard disk drive (Patent Document 1). However, since natural convection is used, the cooling capacity is not sufficient, and the system board mounted on the vertical board frame and facing the hard disk drive has the following restrictions on the arrangement of electrical components. In other words, it is necessary to dispose the electrical component that generates a large amount of heat upward in the vertical direction and the electrical component that has a large shape at a position that does not block the vertical air flow (Patent Document 1, paragraph).

  etc).

  Further, a means is known in which a hard disk drive is disposed above the electrical board by a support member, a blower fan is disposed between the hard disk drive and the electrical board, and the hard disk drive and the electronic device on the electrical board are simultaneously cooled. Patent Document 2).

JP 2007-8020 A JP 2009-69708 A

  However, although the hard disk drive is provided in the image forming apparatus, it is evaluated that the hard disk drive is disposed in the open space from the viewpoint of the air flow for cooling. For this reason, there has been a problem that heat generated from the hard disk drive cannot be efficiently exhausted by the air supply fan. There is also a problem that cooling cannot be performed efficiently depending on the relationship between the amount of heat generated from the hard disk drive and the amount of heat generated from the electrical board.

  The present invention has been made in view of the above-described problems, and in an image forming apparatus having a plurality of heat-generating components such as an electronic device on a hard disk drive and an electrical board, the plurality of components can be efficiently cooled. An object is to provide an image forming apparatus.

In order to achieve this object, the image forming apparatus of the present invention generates heat in accordance with the operation of the image forming apparatus, and surrounds the hard disk drive apparatus that stores data, an air inlet and an air A surrounding member having a discharge port; and a central processing unit that is provided outside the surrounding member and controls the image forming apparatus, wherein the amount of heat generated when the image forming apparatus generates heat is A central processing unit larger than the calorific value of the hard disk drive device, a heat sink that dissipates heat from the central processing unit, a circuit board that is provided outside the enclosing member and on which the central processing unit is mounted, The hard disk drive device and the heat sink attached to the air discharge port inside the enclosing member A cooling fan that generates an airflow for cooling, and the circuit board is disposed with respect to the surrounding member so that the heat sink faces the air discharge port, and the cooling fan is provided on the circuit board. the opposite end to the air outlet in a direction perpendicular to the mounting surface is the central processing unit is mounted is, from the end of the air outlet side in the vertical direction of the hard disk drive Also, the hard disk drive device is disposed between the air inlet and the air outlet in a direction along the mounting surface of the circuit board in a position away from the air outlet in the vertical direction , The hard disk drive device is cooled by the cooling fan by the air flowing in from the air inlet, and the air outlet The heat sink is characterized in that it is cooled by al discharged air.

In the present invention, air is introduced from the air inlet into the enclosure member that surrounds the hard disk drive device by the cooling fan, thereby cooling the hard disk drive device . The air that has cooled the hard disk drive device is discharged from the discharge port and is used to cool the central processing unit . At this time, the central processing unit has a heat generation amount larger than that of the hard disk drive device . Thus, the airflow by the cooling fan of the hard disk drive apparatus, even if the temperature increases by absorbing heat by the cooling of the hard disk drive, yet, can be cooled central processing unit efficiently.

Further, since the hard disk drive device is surrounded by the surrounding member, the air flowing in from the air inlet by the cooling fan is effectively used for cooling the hard disk drive device .

Therefore, according to the present invention, both the hard disk drive device and the central processing unit can be efficiently cooled by the cooling fan , and the device in a direction intersecting the mounting surface on which the central processing unit of the circuit board is mounted. Can be miniaturized .

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment of the present invention. It is sectional drawing which shows the structure of the electrical equipment unit of embodiment of this invention. It is a top view of the plate-shaped member of embodiment of this invention. It is a front view of the electrical equipment unit of the embodiment of the present invention. 4A shows a state where the door is removed, and FIG. 4B shows a state where the door is attached. It is a perspective view of the electrical equipment unit of the embodiment of the present invention. It is a figure which shows the state of the airflow in the case of cooling of the electrical equipment unit of embodiment of this invention. It is sectional drawing which shows the structure of the electrical equipment unit which concerns on the comparative example of this invention. It is a top view of the cover member concerning the comparative example of the present invention. It is a figure which shows the state of the airflow in the case of cooling of the electrical equipment unit which concerns on the comparative example of this invention. It is sectional drawing which shows the structure of the electrical equipment unit of other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiment is an example of the best embodiment of the present invention, and the present invention is not limited only to the following embodiment.

<First Embodiment>
(Overall configuration of image forming apparatus)
FIG. 1 is a schematic diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. An image forming apparatus A shown in FIG. 1 is an electrophotographic full color laser printer.

  The image forming apparatus A is configured to form toner images of four different colors according to image forming portions Py, Pm, Pc, and Pb through charging, exposure, development, and transfer processes. When a print command signal output from an external device such as a host computer is input, the image forming units Py, Pm, Pc, and Pb are sequentially operated.

  In the image forming units Py, Pm, Pc, and Pb, the photosensitive drum 1 that carries the toner image is rotated at a process speed of a predetermined peripheral speed. Further, the intermediate transfer belt 7 stretched around the driving roller 6a, the driven roller 6b, and the tension roller 6c is rotated at a peripheral speed corresponding to the rotational peripheral speed of the photosensitive drum 1 by the driving roller 6a. Note that the surface of the intermediate transfer belt 7 is in contact with the photosensitive drums 1 of the image forming portions Py, Pm, Pc, and Pb.

  In the image forming unit Py, the outer peripheral surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by the charger 2. Next, the exposure device 3 scans and exposes the surface of the photosensitive drum 1 with laser light generated based on image information from the external device. As a result, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum 1. The latent image is developed by the developing device 4 using a yellow developer, and a yellow toner image is formed on the surface of the photosensitive drum 1. In the same charging, exposure, and development processes, magenta, cyan, and black toner images are formed in the image forming unit Pm, the image forming unit Pc, and the image forming unit Pb.

  The toner images of the respective colors formed on the surface of the photosensitive drum 1 in the image forming units Py, Pm, Pc, and Pb are transferred to the intermediate transfer belt by the primary transfer roller 8 that is disposed to face the photosensitive drum 1 with the intermediate transfer belt 7 interposed therebetween. 7 are successively transferred onto the outer peripheral surface of the sheet. As a result, a full-color toner image is formed on the surface of the intermediate transfer belt 7. The transfer residual toner remaining on the surface of the photosensitive drum 1 after the toner image transfer is removed by the drum cleaner 5 and used for the next image formation.

  On the other hand, the recording material P is conveyed from the feeding cassette 10 by the delivery roller 11 to the registration roller 13 through the conveyance path 12a. Next, the recording material P is conveyed by the registration roller 13 to the secondary transfer nip Tn between the intermediate transfer belt 7 and the secondary transfer roller 14. The recording material P is nipped and conveyed by the secondary transfer nip Tn, and the toner image on the surface of the intermediate transfer belt 7 is transferred to the recording material P by the secondary transfer roller 14. The transfer residual toner remaining on the surface of the intermediate transfer belt 7 after the toner image transfer is removed by the belt cleaner 9 and used for the next image formation.

  The recording material P carrying an unfixed toner image is introduced into the nip portion of the fixing device 15 with the image carrying surface facing upward. The recording material P is nipped and conveyed at the nip portion of the fixing device 15, whereby the toner image is heated and fixed on the recording material P.

  Then, the recording material P fixed by the fixing device 15 is discharged through a discharge roller 17 onto a discharge tray 18 provided on the side surface of the image forming apparatus A.

  Further, heat from the fixing device 15 is discharged to the outside of the image forming apparatus A by the fan 130.

  Furthermore, an electrical unit 100 provided with electronic devices such as a CPU and a memory is mounted on the upper part of the image forming apparatus A.

(Configuration of electrical unit)
FIG. 2 is a cross-sectional view showing the configuration of the electrical unit 100.

  As shown in the figure, the electrical unit 100 has a hard disk drive storage unit B for storing the hard disk drive 20 (first component) and a board storage unit C for storing the electrical board 24 (circuit board). Yes.

  On the electrical board 24, an electronic device such as a CPU 50 (second component, central processing unit) for executing a part of the image forming process and a memory is mounted. A CPU 50 is a microprocessor that controls the entire control of the image forming apparatus, and is a main body of the system controller. The memory temporarily stores programs and data when the CPU 50 performs control.

  The hard disk drive 20 is a large-sized storage device for storing electronic data, and mainly stores an image processing program, digital image data, and the like. In order to prevent data loss due to hard disk damage or the like, the same data is stored in the two hard disk drives 20, and even if some problem occurs on the one hand, mirroring processing is executed to compensate for it on the other hand. .

  As shown in FIG. 2, in the substrate storage unit C, the electrical board 24 is supported by the frame sheet metal 26. A heat sink 25 for radiating heat from the CPU 50 is provided above the CPU 50 disposed on the electrical board 24. The upper part of the frame metal plate 26 is covered with a plate-like member 23.

  On the other hand, in the hard disk drive storage unit B, the hard disk drive 20 is stored in the cover member 21 provided on the plate-like member 23. The hard disk drive 20 is supported by a support member 51 provided on the upper surface of the plate-like member 23, and the hard disk drive 20 is located above the electrical board 24.

  In the hard disk drive storage B, a cooling fan 22 is provided on the plate-like member 23. The cooling fan 22 is disposed beside the hard disk drive 20 and in the immediate vicinity of the upper surface of the heat sink 25. With this arrangement, the cooling fan 22 generates an air flow from the hard disk drive 20 side toward the heat sink 25 on the electrical board 24. That is, the hard disk drive 20 is provided on the upstream side of the airflow generated by the cooling fan 22, and the electrical board 24 is provided on the downstream side. The hard disk drive 20 and the electrical board 24 are electrically connected by a connection cable and a connector (not shown).

  In the present embodiment, the maximum temperature due to heat generation of the hard disk drive 20 is 70 ° C., and the maximum temperature due to heat generation of the CPU 50 disposed on the electrical board 24 and provided with the heat sink 25 is 90 ° C. That is, the amount of heat generated by the hard disk drive 20 is set to be smaller than the amount of heat generated by the electronic device on the electrical board 24. That is, since the heat generation amount of the hard disk drive 20 is smaller than the heat generation amount of the electronic device on the electrical board 24, the electronic device on the electrical board 24 can be sufficiently obtained even after the airflow generated by the cooling fan 22 passes through the hard disk drive 20. Is at a temperature that can be cooled.

  When the heat generation amount of the hard disk drive 20 is larger than the heat generation amount of the electronic device on the electrical board 24, the positions of the electrical board 24 and the hard disk drive 20 are switched. That is, the electric circuit board 24 is configured to be positioned upstream of the airflow in the cooling fan 22 and the hard disk drive 20 is positioned downstream.

  Further, the hard disk drive 20, the connection cable (not shown), and the cooling fan 22 are surrounded by a cover member 21 and a plate-like member 23. The cover member 21 and the plate-like member 23 are made of metal. Thereby, radiation noise from the hard disk drive 20 and the connection cable (not shown) can be shielded.

  The cover member 21 and the plate-like member 23 constitute an enclosing member that encloses the hard disk drive 20.

  FIG. 3 is a plan view of the plate-like member 23. FIG. 3A shows a state where the cooling fan 22 is attached, and FIG. 3B shows a state where the cooling fan 22 is not attached.

  As shown in these drawings, the cooling fan 22 is fixed with a screw substantially above a ventilation opening 29 (air discharge port) provided in the plate-like member 23. As a method for fixing the cooling fan 22, in addition to screws, fasteners (fasteners, fasteners, caulking), for example, stepped conical pins made of metal or plastic, and metal rivets can be used. Further, bonding using an adhesive or spot welding can also be used.

  FIG. 4 is a front view of the electrical unit 100. FIG. 4A shows a state where the door 27 is removed, and FIG. 4B shows a state where the door 27 is attached.

  In the present embodiment, a removable system is adopted so that the hard disk drive 20 can be attached and detached. When installing or removing the hard disk drive 20, the door 27 is removed as shown in FIG. 4A, and when the installation of the hard disk drive 20 is completed, the door 27 is closed as shown in FIG. 4B. .

  FIG. 5 is a perspective view of the electrical unit 100.

  As shown in the figure, an opening 30 (air inlet) is provided on the surface of the cover member 21 away from the cooling fan 22. The opening 30 is a set of a plurality of small openings. By closing the door 27, the inflow of air by the cooling fan 22 is only from the opening 30.

(Cooling operation of electrical unit)
FIG. 6 is a diagram illustrating a state of airflow when the electrical unit 100 is cooled.

  As shown in the figure, when the cooling fan 22 rotates, outside air flows from the opening 30 of the cover member 21 into the cover member 21 (inside the enclosure member) from the direction indicated by the arrow D. The outside air flows along the hard disk drive 20 and cools the hard disk drive 20, and then is exhausted in the direction of arrow E by the cooling fan 22.

  The hard disk drive 20 is disposed in a substantially sealed space except for the opening 30 by the cover member 21 and the plate-like member 23. For this reason, the airflow from the opening 30 effectively flows to the hard disk drive 20, and the air warmed by the heat generated by the hard disk drive 20 can be effectively discharged. Therefore, the hard disk drive 20 can be effectively cooled. Then, the exhaust flow from the hard disk drive 20 side directly hits the heat sink 25 on the electrical board 24 from the direction of the arrow F, and the electronic devices such as the CPU 50 can be intensively cooled.

  As described above, the heat generation amount of the hard disk drive 20 is set smaller than the heat generation amount of the CPU 50 of the electrical board 24. For this reason, even if the heat is exhausted after the hard disk drive 20 is cooled, the CPU 50 can be effectively cooled via the heat sink 25.

< Comparative example >
Next, a comparative example of the present invention will be described. This comparative example differs in the configuration of the electrical unit in the first embodiment. For this reason, only a different part from 1st Embodiment of an electrical equipment unit is demonstrated. In addition, the same code | symbol is attached | subjected to the part which is the same as or similar to 1st Embodiment, and the overlapping description is abbreviate | omitted.

FIG. 7 is a cross-sectional view showing the configuration of the electrical unit 100a of this comparative example .

As shown in the figure, in this comparative example , a cooling fan 22 is fixed by a plate-like member 23a immediately below the hard disk drive 20 stored in the cover member 21a and above the heat sink 25.

  FIG. 8 is a top view of the cover member 21a.

  As shown in the figure, an opening 30 is provided on the upper surface of the cover member 21a. An opening 30 is provided in the upper part of the hard disk drive 20, and a cooling fan 22 is provided in the lower part of the hard disk drive 20. The hard disk drive 20 is disposed between the opening 30 and the cooling fan 22.

  FIG. 9 is a diagram illustrating a state of an air flow when the electrical unit 100a is cooled.

  As shown in the figure, outside air that flows in the direction indicated by the arrow G from the opening 30 provided on the upper surface of the cover member 21a flows through the hard disk drive 20 and is sucked into the cooling fan 22 from the direction indicated by the arrow H. The air is exhausted in the direction of arrow I and supplied to the electrical board 24 side.

In other words, the opening 30 and the ventilation opening 29 are provided on opposite surfaces, respectively, and the hard disk drive 20 and the cooling fan 22 are disposed between the opening 30 and the ventilation opening 29 and the cover member 21a and the plate shape. With the member 23, the hard disk drive 20 is disposed in a substantially sealed space except for the opening 30. For this reason, the airflow from the opening 30 effectively flows to the hard disk drive 20, and the air warmed by the heat generated by the hard disk drive 20 can be effectively discharged. Therefore, the hard disk drive 20 can be effectively cooled. Then, the exhaust flow from the hard disk drive 20 side directly hits the heat sink 25 on the electrical board 24 from the direction of the arrow I, and the electronic devices such as the CPU 50 can be intensively cooled.

  As described in the first embodiment, the heat generation amount of the hard disk drive 20 is set smaller than the heat generation amount of the CPU 50 of the electrical board 24. For this reason, even if the heat is exhausted after the hard disk drive 20 is cooled, the CPU 50 can be effectively cooled via the heat sink 25.

Second Embodiment
Next, another embodiment of the present invention will be described. This embodiment differs from the first embodiment in the configuration of the electrical unit. For this reason, only a different part from 1st Embodiment of an electrical equipment unit is demonstrated. In addition, the same code | symbol is attached | subjected to the part which is the same as or similar to 1st Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 10 is a cross-sectional view showing the configuration of the electrical unit 100b of the present embodiment.

  As shown in the figure, the plate-like member 23 is provided with a diversion member 28 (diversion means) toward the electrical board 24 side. The flow dividing member 28 has a flat plate shape and is attached to the plate member 23 so as to have a predetermined angle.

  The heat sink 25 is cooled by the air flow exhausted from the hard disk drive 20 side in the direction of arrow J, and a part of the exhaust flow is shunted in the directions of arrow K and arrow L by the diverting member 28 and other than the CPU 50 of the electrical board 24. Guide to the area (area other than the central processing unit). For this reason, the electrical component substrate 24 can be cooled in a wide range.

DESCRIPTION OF SYMBOLS 20 ... Hard disk drive 21, 21a ... Cover member 22 ... Cooling fan 23, 23a ... Plate-like member 24 ... Electric component board 25 ... Heat sink 26 ... Frame member 27 ... Door 28 ... Flow dividing means 29 ... Ventilation opening 30 ... Ventilation opening 100 , 100a, 100b ... Electrical unit A ... Image forming apparatus

Claims (6)

An image forming apparatus for forming an image,
A hard disk drive that generates heat and stores data in accordance with the operation of the image forming apparatus;
An enclosing member surrounding the hard disk drive device and having an air inlet and an air outlet;
A central processing unit that is provided outside the surrounding member and controls the image forming apparatus, wherein a heat generation amount when the heat is generated with the operation of the image forming apparatus is larger than a heat generation amount of the hard disk drive device A central processing unit;
A heat sink for heat dissipation of the central processing unit;
A circuit board provided on the outside of the surrounding member and on which the central processing unit is mounted;
A cooling fan that is attached to the air outlet on the inside of the surrounding member and generates an air flow for cooling the hard disk drive device and the heat sink,
The circuit board is disposed with respect to the surrounding member such that the heat sink faces the air outlet;
Said cooling fan, the opposite end to the air outlet in a direction perpendicular to the mounting surface of the central processing unit is mounted in the circuit board, the vertical direction of the hard disk drive Than the end on the air outlet side in the vertical direction, is arranged at a position away from the air outlet in the vertical direction ,
The hard disk drive device is disposed between the air inlet and the air outlet in a direction along the mounting surface of the circuit board;
The image forming apparatus, wherein the hard disk drive device is cooled by the cooling fan by the air flowing in from the air inlet, and the heat sink is cooled by the air discharged from the air outlet. Storing the same data as the hard disk drive device at the same time, and having another hard disk drive device arranged in parallel with the hard disk drive device in a direction along the mounting surface of the circuit board,
The image forming apparatus according to claim 1, wherein the cooling fan allows air to flow in from the air inlet along the hard disk drive device and the other hard disk drive device.   2. A flow dividing unit that diverts air discharged from the air discharge port by the cooling fan and guides the air to a region other than a region where the central processing unit is mounted on the circuit board. Or the image forming apparatus according to 2;   The image forming apparatus according to claim 1, wherein the surrounding member is made of metal. A first storage unit for storing the hard disk drive device;
Storing the circuit board, and further comprising a second storage unit provided below the first storage unit,
The surrounding member constitutes the first storage portion,
The image forming apparatus according to claim 1, wherein the first storage unit and the second storage unit communicate with each other through the air discharge port. The hard disk drive device can be attached to and detached from the first storage unit,
The first storage unit has a door for attaching and detaching the hard disk drive device, and the inflow of air by the cooling fan when the door is closed is only the air inlet. The image forming apparatus according to claim 5.

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