JP2010026381A - Cooling device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device that reduces noise generated from the interior of the device, and also achieves low cost of the device, and to provide an image forming apparatus. <P>SOLUTION: The cooling device includes: a cooling fan 452 to cool a heating part by sending air; and louvers 453 and 454, which are arranged in an opening of a device case, and which are opened or closed by wind pressure developed by rotation of the cooling fan 452. A CPU 700 controls whether to close the louvers 453 and 454 by switching rotation direction of the cooling fan 452 for circulating air inside the device, or to open the louvers 453 and 454 for introducing air from the outside. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cooling device using a fan and a louver, and an image forming apparatus having the cooling device.

  In recent years, demands for reducing noise generated from the inside of an OA device or the like typified by an image forming apparatus are increasing year by year. As a measure for reducing noise, it is conceivable to close all the openings of the apparatus housing so that noise generated from the inside of the apparatus does not leak out of the apparatus.

  However, since heat generating parts such as a power supply circuit and a motor are built in the apparatus, heat is generated inside the apparatus when they operate. In order to cool this, it is necessary to take in the outside air and exhaust the heat inside the apparatus, so it is not possible to block all the openings of the apparatus housing.

Therefore, a louver that can be opened and closed at the opening for introducing and exhausting outside air is provided, and the opening and closing of the louver fins is adjusted according to the temperature inside the device, so that the opening is closed and noise reduction is achieved when it is not necessary. What has been proposed has been proposed (see, for example, Patent Document 1).
JP 7-168515 A

  However, the invention described in Patent Document 1 requires an actuator for opening and closing the louver, and also requires a control circuit and a drive source for controlling the actuator. Therefore, with the configuration of the invention described in Patent Document 1, the cost of the apparatus becomes high as a result.

  SUMMARY An advantage of some aspects of the invention is that it provides a cooling device and an image forming apparatus that can reduce noise generated from the inside of the apparatus and can reduce the cost of the apparatus.

  In order to achieve the above object, a cooling device according to the present invention is provided with a cooling fan that cools a heat generating part by sending wind and an opening of the apparatus housing, and is opened and closed by wind pressure generated by rotation of the cooling fan. And rotating the cooling fan in a first direction to close the louver and circulate the air internally, and rotate the cooling fan in a second direction opposite to the first direction. And a control means for controlling the rotation direction of the cooling fan so as to open the louver and introduce the outside air.

  An image forming apparatus according to the present invention includes an image forming unit that forms an image on a sheet, and the cooling device that cools heat generated in the apparatus.

  According to the present invention, it is possible to provide a cooling device and an image forming apparatus that can reduce noise generated from the inside of the apparatus and can reduce the cost of the apparatus.

  FIG. 1 is a cross-sectional view of the image forming apparatus 100.

  The image forming apparatus 100 includes a document reading device 400, a printer 401, and an ADF (Auto Document Feeder) 500. The ADF 500 feeds documents one by one onto the platen glass 402. The lamp 403 and the scanning mirror 405 move along the document on the platen glass 402. Then, the reflected light from the original is imaged by the image sensor unit 409 via the scanning mirrors 405 to 407 and the lens 408, whereby the image of the original is read.

  The exposure control unit 410 irradiates the photoconductor 411 with a light beam corresponding to the image data image-processed by the controller unit (CONT). The developing units 412 and 413 develop the electrostatic latent image formed on the photoconductor 411 with a light beam with a developer (toner) of a predetermined color.

  The sheets P stored in the sheet storage units 414 and 415 are separated one by one by the pickup rollers 421 and 431 and are fed to the registration rollers 425 by the paper supply rollers 422, 432 and 433. Then, the sheet P is sent to the transfer separation charger 416 by the registration roller 425 in synchronization with the leading edge of the image formed on the photoconductor 411.

  The transfer separation charger 416 transfers the toner image developed on the photoreceptor 411 to the sheet P, and then separates the sheet P from the photoreceptor 411. The fixing unit 417 fixes the toner image on the sheet P sent from the transfer separation charger 416 by the conveyance belt 423. The paper discharge roller 418 discharges the sheet P fixed by the fixing unit 417 onto the tray 420.

  Note that the image forming apparatus 100 includes a power supply unit 430 that supplies power to the entire apparatus. Hereinafter, the detailed configuration of the power supply unit 430 will be described.

  FIG. 2 is a top view of the power supply unit 430.

  A power supply board 451 in the power supply unit 430 converts an alternating current input from a power cord (not shown) into a direct current, and supplies power to each part in the image forming apparatus 100. The cooling fan 452 can rotate in the forward and reverse directions, and cools the power supply board 451 to suppress heat generation. The temperature sensor 456 is temperature detection means for detecting the temperature near the power supply board 451.

  In addition, a first louver 453 and a second louver 454 that are provided in the opening of the casing of the power supply unit 430 and have fins that can be opened and closed by being rotated by wind pressure generated by the cooling fan 452 are provided. Furthermore, the power supply unit 430 includes a switching member 455 for switching the direction of airflow generated by the rotation of the cooling fan 452.

  The first louver 453 is opened by its own weight when the cooling fan 452 is stopped. Further, when wind is blown from the cooling fan 452, the opening of the first louver 453 is closed by the wind pressure.

  When the cooling fan 452 is stopped, the second louver 454 is applied with a force in a direction in which the opening is closed by a spring (not shown). Further, when wind is blown from the cooling fan 452, the second louver 454 is opened by the wind pressure.

  In the state where the cooling fan 452 is stopped, the switching member 455 is applied with a force in a direction in which the opening is closed by a spring (not shown). Further, when the wind is blown from the cooling fan 452, the switching member 455 moves so as to open by the wind pressure and form an air path.

  FIG. 3 is a control block diagram including the cooling fan 452 and the temperature sensor 456.

  The CPU 700 is a control circuit that controls the image forming apparatus 100. The CPU 700 is connected to a RAM 711 that provides a work area, a ROM 712 that stores a control program for the entire image forming apparatus 100, and an operation unit 710 that receives an operation input from a user.

  The fan drive circuit 610 drives the fan motor 450 and rotates the cooling fan 452 in accordance with a command from the CPU 700. The CPU 700 receives an input from the temperature sensor 456, monitors the temperature near the power supply board 451, and controls the rotation of the cooling fan 452 in the forward direction, the rotation in the reverse direction, and the stop of the cooling fan 452.

  FIG. 4 is a diagram illustrating an air flow generated in the power supply unit 430 during the forward rotation operation of the cooling fan 452.

  The arrows in the figure represent the wind flow generated by the rotation of the cooling fan 452. When the cooling fan 452 is rotated in the forward direction, the first louver 453 is pushed by the wind and the opening is closed. The wind that has lost its destination pushes the switching member 455, and the wind circulates inside the power supply unit 430.

  When the image forming apparatus 100 is in a standby state or the like, the temperature detected by the temperature sensor 456 is low because less power is consumed and the power supply board 451 generates less heat. In such a case, since strong cooling power by introducing outside air is not necessary, the cooling fan 452 is driven forward to close all the openings so that noise generated from inside the apparatus does not leak outside the apparatus. Yes.

  FIG. 5 is a diagram showing airflow generated in the power supply unit 430 during the reverse rotation operation of the cooling fan 452.

  The arrows in the figure represent the wind flow generated by the rotation of the cooling fan 452. When the cooling fan 452 is rotated in the reverse direction, a negative pressure is generated in the space between the cooling fan 452 and the first louver 453, and the first louver 453 is opened. As a result, outside air is introduced from the first louver 453, the second louver 454 is pushed by the wind pressure generated in the power supply unit 430, and exhaust is performed.

  When the heat generation amount of the power supply substrate 451 increases due to the continuous operation of the image forming apparatus 100 or the like, the first louver 453 and the second louver 454 are opened to introduce outside air, thereby effectively cooling the power supply unit 430. It becomes possible.

  The switching member 455 is movable between the position shown in FIG. 4 and the position shown in FIG. That is, the switching member 455 can be moved to a position where an air path is formed so as to promote the internal circulation of air and a position where an air path is formed so as to encourage the introduction of outside air by the wind pressure generated by the rotation of the cooling fan 452. It is configured.

  FIG. 6 is a diagram illustrating the relationship between the detection result of the temperature sensor 456 and the operating state of the cooling fan 452.

  When the temperature detected by the temperature sensor 456 is lower than a predetermined temperature (less than T1), the cooling fan 452 is stopped. Further, when the temperature detected by the temperature sensor 456 is equal to or higher than a predetermined temperature (T1 or higher), the cooling fan 452 is driven to rotate forward and the air is circulated in the power supply unit 430 (state shown in FIG. 4). Furthermore, when the temperature detected by the temperature sensor 456 is equal to or higher than a predetermined temperature (T2 or higher), the cooling fan 452 is rotated in the reverse direction to actively introduce outside air to cool the heat generating portion (see FIG. 5). Status).

  FIG. 7 is a flowchart regarding temperature adjustment of the power supply unit 430.

  A control program for executing this flowchart is stored in the ROM 712, and is executed by the CPU 700 after the image forming apparatus 100 is powered on.

  The CPU 700 confirms the temperature detected by the temperature sensor 456 (S701). Next, the CPU 700 determines whether or not the temperature detected by the temperature sensor 456 is lower than T1 (S702). When the detected temperature is lower than T1, the CPU 700 stops the rotation of the cooling fan 452 (S703).

  When the detected temperature is equal to or higher than T1, the CPU 700 determines whether the detected temperature detected by the temperature sensor 456 is equal to or higher than T1 and lower than T2 (S704). When the detected temperature is equal to or higher than T1 and lower than T2, the cooling fan 452 is driven to rotate in the forward direction to perform internal circulation of air in the power supply unit 430 (S705). As a result, noise generated from the inside of the apparatus can be reduced.

  When the detected temperature is equal to or higher than T2, the CPU 700 drives the cooling fan 452 in the reverse direction to open the first louver 453 and the second louver 454 and introduce outside air (S706). Thereby, effective cooling in the power supply unit 430 becomes possible.

  As described above, in this embodiment, a louver that opens and closes due to the wind pressure generated by the rotation of the cooling fan is provided in the opening for introducing and exhausting outside air, and the rotation direction of the cooling fan is switched depending on the temperature inside the apparatus. The louver is opened and closed.

  With this configuration, the temperature inside the device can be accurately adjusted without providing a control circuit for opening and closing the louver and a drive source such as an actuator. Further, by closing the louver when it is not necessary, it is possible to suppress noise generated from the inside of the apparatus from leaking to the outside of the apparatus.

1 is a cross-sectional view of an image forming apparatus. It is a top view of a power supply unit. It is a control block diagram including a cooling fan and a temperature sensor. It is a figure which shows the air flow which generate | occur | produces in a power supply unit at the time of forward rotation operation | movement of a cooling fan. It is a figure which shows the airflow which generate | occur | produces in a power supply unit at the time of reverse rotation operation | movement of a cooling fan. It is a figure which shows the relationship between the detection result of a temperature sensor, and the operation state of a cooling fan. It is a flowchart regarding temperature control of a power supply unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 401 Printer 430 Power supply unit 450 Fan motor 451 Power supply board 452 Cooling fan 453 1st louver 454 2nd louver 455 Switching member 456 Temperature sensor 610 Fan drive circuit 700 CPU

Claims (5)

A cooling fan that cools the heat generating part by sending wind;
A louver provided at an opening of the apparatus housing and opened and closed by wind pressure generated by rotation of the cooling fan;
The louver is closed by rotating the cooling fan in a first direction to perform internal circulation of air, and the louver is rotated by rotating the cooling fan in a second direction opposite to the first direction. Control means for controlling the direction of rotation of the cooling fan so as to open and introduce outside air;
A cooling device comprising: Having temperature detection means for detecting the temperature inside the device,
The cooling device according to claim 1, wherein the control unit controls a rotation direction of the cooling fan based on a temperature detected by the temperature detection unit.   The control means stops the cooling fan when the detected temperature is lower than the first temperature, and stops the cooling fan when the detected temperature is equal to or higher than the first temperature and lower than the second temperature. 3. The cooling device according to claim 2, wherein when the detected temperature is equal to or higher than the second temperature, the cooling fan is rotated in the second direction.   A switching member movable between a position where an air path is formed so as to promote internal circulation of air and a position where an air path is formed so as to encourage introduction of outside air by wind pressure generated by rotation of the cooling fan; The cooling device according to claim 1. Image forming means for forming an image on a sheet;
The cooling device according to any one of claims 1 to 4, for cooling heat generated inside the device;
An image forming apparatus comprising:

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