JP2019003014A - Display device - Google Patents

Abstract

To provide a display device capable of efficiently performing heat dissipation and cooling of a control circuit board for activating a display module.SOLUTION: A display device 1 includes: a display module 13; a fan 16; a power source 14 for supplying power to the display module 13 and the fan 16; a control circuit board 17 for controlling the display module and a first fan; a cover 15; and a partition plate 19 for dividing a space covered by back surfaces of the cover 15 and the display module 13 into a first heat source space 20 and a second heat source space 21. The cover 15 includes a first vent channel and a second vent channel for the first heat source space 20, and has a third opening connecting the second heat source space 21 and an outside of an exterior member. The control circuit board 17 operates the fan 16 in a high cooling mode by the number of revolutions higher than the predetermined number of revolutions, and operates the fan 16 in a manner of saving energy and in a cooling mode by the number of revolutions below the predetermined number of revolutions.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a display device including a fan that cools a display module that displays an image.

  In recent years, there is a display device capable of displaying an image in a dynamic range (HDR) including higher luminance than before. For example, when the display device uses a display module composed of a backlight and a liquid crystal panel, it is necessary to operate the backlight so that it emits light with higher brightness than before in order to increase the maximum brightness to be displayed. .

  As the backlight brightness increases, the amount of heat generated from the control board for driving the light source may increase. The control board is a printed board on which electronic components such as a transformer and a driver IC are mounted. Therefore, in the vicinity of the control board, there is a large distribution of air resistance due to unevenness caused by electronic components. Therefore, it may be difficult to improve the cooling performance of the control board.

  In Patent Document 1, in a forced air-cooled projector using a fan, a first flow path for sucking outside air from a suction port and discharging it from the discharge port to the outside of the housing, and a second flow path for circulation inside the housing are disclosed. It is disclosed that the efficiency is increased by switching with a wind direction adjusting plate.

JP 2009-122483 A

  However, the technique disclosed in Patent Document 1 requires a complicated mechanism because the flow path is switched by moving the airflow rectifying plate by an actuator.

  Therefore, an object of the present invention is to provide a display device capable of efficiently radiating and cooling a control board for operating a display module.

  In order to solve the above-described problems, a display device of the present invention includes a display module that displays an image on the front side, a fan that is provided on the back side of the display module and cools the display module, and the display A control board for driving the display module and the first fan, a back face on the display module side, the first fan, and the control board are provided on the back side of the module and the first fan. A space where the exterior member and the first fan are installed and covered with the exterior member and the back surface of the display module, the interior of the first space including the control board and the exterior member is the back surface of the display module A partition plate that is divided into a second space including the first space and the second opening that connects the first space and the outside of the exterior member. A third opening that connects the second space and the exterior of the exterior member; and the control board includes a first cooling mode in which a rotation speed of the first fan is higher than a predetermined level; The first fan is controlled in a second cooling mode in which the rotational speed of the first fan is a predetermined level or less.

  According to the present invention, the fan for cooling the display module can switch the flow rate of the air passing through the vicinity of the control board without requiring a complicated mechanism / control. Therefore, the control board for operating the display module can be efficiently radiated and cooled.

It is a disassembled perspective view which shows the structure of a display module. It is a 1st sectional view of an image display device. It is a 1st schematic diagram which shows the flow path of an image display apparatus. It is a 2nd sectional view of an image display device. It is a 2nd schematic diagram which shows the flow path of an image display apparatus. It is a 3rd sectional view of an image display device. It is a 3rd schematic diagram which shows the flow path of an image display apparatus. It is a 4th sectional view of an image display device. It is a 4th schematic diagram which shows the flow path of an image display apparatus. It is a 5th sectional view of an image display device. It is a 5th schematic diagram which shows the flow path of an image display apparatus.

[Example 1]
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is an exploded perspective view showing a configuration of a display module 13 in the display device 1 according to Embodiment 1 of the present invention. The display module 13 includes a liquid crystal panel 2 and a backlight 4 and is a liquid crystal display module that displays an image on the front side. The liquid crystal panel 2 is a display panel that modulates light emitted from the backlight 4 and displays an image on a screen.

  In the image display device 1, a bezel 3 is disposed on the front side of the liquid crystal panel 2, and a backlight 4 is disposed on the back side. The backlight 4 includes a case 8 to which a light source substrate 5, a driving substrate 6 (not shown in FIG. 1), and a heat sink 7 (not shown in FIG. 1) are attached.

  In recent years, the LED 9 is frequently used as the light source substrate 5 as the light source substrate, but the light source is not limited to this and may be a CCFL (Cold Cathode Fluorescent Lamp). A reflective sheet 10 for efficiently reflecting the light diffused from the light source substrate 5 to the liquid crystal panel 2 is disposed on the liquid crystal panel 2 side of the case 8. Further on the liquid crystal panel 2 side of the case 8 is disposed an optical sheet 11 for improving luminance by eliminating light unevenness by diffusing and condensing light. A panel holder 12 that holds the optical sheet 11 and supports the liquid crystal panel 2 from the back side is disposed on the liquid crystal panel 2 side of the optical sheet 11. The liquid crystal panel 2 is light transmissive, and thus emits light from the backlight 4 efficiently and transmits light through the liquid crystal panel 2 to display an image on the liquid crystal panel 2.

  On the back side of the case 8, a plurality of heat sinks 7 are fixed in a state of being in thermal contact with the case 8 with a heat conducting member (not shown) interposed therebetween. Released into the space on the back side. There is no problem even if the case 8 and the heat sink 7 are formed integrally.

  As described above, the display module 13 is configured by adding the drive substrate 6 and the heat sink 7 from the bezel 3 to the backlight 4 including the liquid crystal panel 2 shown in FIG. 1, and the display module 13 is the second heat source as referred to in the present invention. It is. Specific electronic devices as heating elements are the liquid crystal panel 2, the light source substrate 5 including the LEDs 9, and the drive substrate 6, but the display module 13 is generally a second heat source to be cooled and radiated.

  FIG. 2 is a cross-sectional view of the image display apparatus 1 according to Embodiment 1 of the present invention. It is assumed that the image display device 1 is installed so that the screen of the display module 13 is parallel to the vertical direction when in use. Therefore, the subsequent vertical position means the vertical direction during use.

  In this invention, a 1st heat source is the power supply 14 which supplies an electric current to the display module 13 which is a 2nd heat source, and operates the display module 13. As shown in FIG. The power supply 14 is installed on the power supply board 26. The power source 14 is provided on the back side of the display module 13 and a fan 16 described later.

  The cover 15 is an exterior member that houses the back surface of the display module 13, the power supply 14, the fan 16, and the control board 17. In addition, the cover 15 also accommodates an image processing board 18 that receives an image signal from an external device and transmits it to the display module 13 (not shown in FIG. 2).

  In the first embodiment, the power supply 14 is mounted with the power supply board 26 standing in a horizontally long manner so as not to impair the thinness of the image display device 1 in the side sectional view of FIG. The control board 17 and the image processing board 18 are attached to the other side of the paper surface of the power supply 14 in FIG. The control board 17 and the image processing board 18 are also a kind of heat source, and it can be said that the first heat source includes a plurality of power sources including the power source 14. First, the heat source to be cooled and radiated is the power source 14 and the display module 13. It is.

  The space covered by the cover 15 and the back surface of the display module 13 includes the second heat source space 21 including the back surface of the display module 13 and the power source 14 on the back side from the second heat source space 21 by the partition plate 19. And the first heat source space 20. The partition plate 19 is installed so as to be parallel to the screen of the display module 13 in the vertical direction. The arrangement direction of the partition plate 19 may not be arranged parallel to the display module 13, and may be arranged obliquely with respect to the back surface of the display module 13. Moreover, the partition plate 19 may be a metal plate molded so as to function as a chassis on which the power supply board 26 is disposed.

  A first vent 22 and a second vent 23 that connect the first heat source space 20 and the outside of the cover 15 are provided on the first heat source space 20 side of the cover 15, and on the second heat source space 21 side, A third air vent 24 that connects the second heat source space 21 and the outside of the cover 15 is provided.

  The first vent 22 is provided at the rearmost portion of the cover 15 below the power supply 14. The second vent 23 is provided in the first heat source space 20 at a diagonal position of the first vent 22, that is, above the power source 14 and in front of the cover 15. As shown in FIG. 2, the second vent 23 is provided in the vicinity of the partition plate 19.

  The third vent 24 is provided at the top of the cover 15. The first ventilation port 22 may be provided on the back surface instead of the bottom surface of the cover 15 shown in FIG. 2, and the third ventilation port 24 is provided on the top surface instead of the back surface of the cover 15 shown in FIG. It doesn't matter.

  The fan 16 is attached to the partition plate 19 and the stop / drive and the rotational speed are controlled by a signal sent from the control board 17. The fan 16 is provided to cool and dissipate the display module 13 first, and is disposed below the second heat source space 21 in the first embodiment. On the other hand, the fan 16 is provided so that its center position is equal to or above the power source 14 when viewed from the back side of the display module 13. Further, the fan 16 is disposed in the vicinity of the second vent 23. In FIG. 2, the fan 16 is disposed on the second heat source space 21 side, but may be disposed on the first heat application space 20 side.

  FIG. 3 is a cross-sectional view showing a flow path of the image display device 1 shown in FIG. As shown in FIG. 3A, in the first flow path A, the first vent 22 is used as the outside air inlet of the first heat source space 20, and the second vent 23 is used as the external outlet of the first heat source space 20. Formed. The first vent 22 and the second vent 23 increase the volume of the introduced air through the first heat source space 20. Accordingly, the suction amount F1in of the first vent 22 and the discharge amount F2out of the second vent 23 are each given an opening area so that a relationship of F2out> F1in is satisfied.

  As shown in FIG. 3B, in the second flow path B, the second vent 23 is used as the outside air inlet of the second heat source space 21, and the third vent 24 is blown into the second heat source space by the air blown by the fan 16. It is formed to be 21 external outlets. As shown in FIG. 3C, the third flow path C uses the first ventilation port 22 as the outside air suction port of the first heat source space 20, and the third ventilation port 24 becomes the first heat source space by blowing air from the fan 16. 20 external outlets are formed.

The intake air from the first ventilation port 22 and the intake air from the second ventilation port 23 are added together and exhausted from the third ventilation port 24. As described above, when the air sucked from the outside passes through the first heat source space 20 and the second heat source space 21, the temperature rises and the volume increases. Therefore, the opening area of each vent is provided and the maximum flow rate of the fan 16 is set so that the maximum discharge amount F3out_max of the third vent 24 satisfies the following formula 1.
F3out_max> F1in_max + F2in_max (Formula 1)

  Here, the maximum suction amount F1in_max of the first ventilation port 22 indicates. The maximum suction amount F2in_max of the second vent 23 indicates.

  The schematic configuration of Embodiment 1 of the present invention has been described so far, but the gist of the present invention will be described here. The present invention is a technique for improving the exhaust flow velocity by switching the flow path. More specifically, by increasing the speed of the fan 16, the discharge flow path on the first heat source space 20 side is moved from the second vent 23 provided on the first heat source space 20 side to the second heat source space 21 side. Switch to the third vent 24 provided. Thereby, the exhaust flow velocity of the first heat source space 20 is improved.

  Here, increasing the speed of the fan 16 means that the fan 16 is controlled in a high-efficiency cooling mode in which the rotational speed of the fan 16 is higher than a predetermined rotational speed. The display device 1 disclosed in the first embodiment of the present invention includes a strong cooling mode in which the rotational speed of the fan 16 is higher than a predetermined rotational speed, an energy saving cooling mode in which the rotational speed of the fan 16 is equal to or lower than the predetermined rotational speed, Thus, the rotation of the fan 16 can be controlled. The flow of air in the space inside the cover 15 in each cooling mode will be described.

  Hereinafter, the control of the three flow paths and the fan 16 according to the first embodiment of the present invention will be described in detail. The image transmitted from the image processing board 18 to the display module 13 is not always an HDR image, but includes various images such as an image having a standard dynamic range, a so-called SDR (Standard Dynamic Range) image.

  When an image that does not require so much luminance is transmitted to the backlight 4 and the liquid crystal panel 2 displays the image, the heat generation of the display module 13 is relatively small and the heat generation of the power source 14 is also relatively small. In this state, the control board 17 operates the fan 16 in the energy saving cooling mode. Specifically, the control board 17 stops the fan 16.

  FIG. 3A shows the air flow in the space inside the cover 15 when the fan 16 is operated in the energy saving cooling mode. The first vent 22 takes in air as an outside air inlet, and the air cools and dissipates the power supply 14. Since the fan 16 is stopped, the blade 25 functions as a shielding member, and air does not flow into the second heat source space 21 but is discharged out of the cover 15 using the vent 23 as an external outlet. That is, when the display module 13 is in a low load state, the heat generated by the power source 14 is dissipated through the first flow path A by stopping the fan 16.

  When the control board 17 controls the display module 13 to display an image with a high dynamic range (HDR image), the display module 13 and the power source 14 generate a large amount of heat. In this state, the control board 17 operates the fan 16 in the strong cooling mode. Specifically, the control board 17 rotates the fan 16 at a high speed.

  3B and 3C show the air flow in the space inside the cover 15 when the fan 16 is operated in the strong cooling mode. In FIG. 3B, the fan 16 rotating at a high speed causes the second vent 23 to take in air as an outside air inlet, the air is sent to the second heat source space 21, cools and dissipates the display module 13, and The vent 24 is discharged outside the cover 15 as an external outlet.

  In FIG. 3C, the air taken in with the first ventilation port 22 as the outside air suction port is sent to the second heat source space 21 without being discharged from the second ventilation port 23 by the fan 16 rotating at high speed. The air vent 24 is discharged outside the cover 15 as an external discharge port. That is, when the display module 13 is in a high load state, the heat of the power source 14 is switched from the first flow path A to the third flow path C to dissipate heat by rotating the fan 16 at a high speed. When the fan 16 is controlled in the strong cooling mode by the above-described control, the air flowing in from the first vent 22 passes near the power source 14, and most of the air flows through the fan 16 through the third vent 24. As a result, the heat generated by the power source 14 is discharged. Further, when the fan 16 is controlled in the energy saving cooling mode, the air flowing in from the first vent 22 passes near the power source 14, and most of the air is discharged from the second vent 23. The heat generated in 14 is discharged to the outside.

  Here, when the fan 16 is operated in the strong cooling mode, the flow rate of the air flowing into the first heat source space 20 from the second vent 23 is larger than that in the energy saving cooling mode. Further, the flow rate of the air flowing into the first heat source space 20 from the first ventilation port 22 is larger when the fan 16 is operated in the strong cooling mode than when the fan 16 is operated in the energy saving cooling mode. The flow rate of air discharged from the third vent 24 in the strong cooling mode is larger than the flow rate of air discharged from the second vent 23 and the third vent 24 in the energy saving cooling mode. Therefore, the flow rate and flow velocity of the air flowing in the vicinity of the power supply 14 are larger (faster) in the strong cooling mode than in the energy saving cooling mode. Thereby, the exhaust flow velocity of the first heat source space 20 is improved. Therefore, the cooling efficiency of the power source 14 is increased. And the heat | fever of the display module 13 is discharge | released by the 2nd flow path B by rotating the fan 16 at high speed.

  That is, the control board 17 operates the fan 16 in the strong cooling mode when the display module 13 is controlled in the high luminance display mode so that an image is displayed with high luminance. If not, the control board 17 operates the fan 16 in the energy saving cooling mode. Specifically, the case where an image is displayed with high luminance is a case where an image is displayed with an upper limit value of display luminance higher than 100 nits.

  For example, it is assumed that the control board 17 can control the display control mode of the display module 13 in either an HDR display mode for displaying an HDR image or an SDR display mode for displaying an SDR image. When the display module 13 is controlled in the HDR display mode, the control board 17 operates the fan 16 in the strong cooling mode. When the display module 13 is controlled in the SDR display mode, the control board 17 operates the fan 16 in the energy saving cooling mode.

  The relationship between the display control mode of the display module 13 and the cooling mode is not limited to the above. A plurality of high brightness display modes may be set. For example, when an image is displayed with an upper limit value of display brightness higher than 1000 nit, the fan 16 is operated in the strong cooling mode. Even if the fan 16 is operated at a rotational speed between the strong cooling mode rotational speed and the energy saving cooling mode rotational speed when an image is displayed with a luminance higher than 100 nit and lower than 1000 nit as an upper limit value of the display luminance. Good.

  When an image having a medium luminance required for the backlight 4 is transmitted from the image processing board 18 to the display module 13 and the liquid crystal panel 2 displays the image, the second vent 23 is connected to the first heat source space 20. And the function of the outside air inlet of the second heat source space 21. In other words, when the fan 16 is driven in an intermediate state from the stopped state to the high speed rotation, the second vent 23 functions as an external exhaust port of the first heat source space 20 and an outside air intake port of the second heat source space 21. Have both.

  If the fan 16 is at a very low speed, both discharge and suction are performed at the second vent 23, and the air in the first heat source space 20 is discharged from the second vent 23 and partly the second heat source. It is sent to the space 21. If the fan 16 has a relatively high speed, the air is hardly discharged from the second vent 23 and suction is mainly performed, and most of the air in the first heat source space 20 is sent to the second heat source space 21.

  In the first embodiment of the present invention, the display module 13, the power source 14, the first heat source space 20, and the second heat source space 21 do not necessarily require a temperature sensor as temperature detecting means. This is because the first heat source is the power source 14 and the second heat source is in the relationship of the display module 13 that receives current supply from the power source 14 and operates. When the display module 13 becomes high temperature, the power source 14 inevitably becomes high temperature. Therefore, depending on what kind of image is transmitted from the image processing board 18 to the display module 13, how much current the power supply 14 supplies to the display module 13 and how much the display module 13 and the power supply 14 rise in temperature. , Make a database in advance. Based on the data, the control board 17 determines the stop / drive of the fan 16 and the rotational speed.

  A suction fan as a ventilation means may be attached inside the first ventilation port 22. However, a fan cannot be attached inside the second vent 23. This is because switching between inhalation and exhaustion, and coexistence of inhalation and exhaustion are difficult to achieve, or rather inefficient.

  As described above, according to the structure of the first embodiment of the present invention, when an image requesting high brightness is transmitted to the backlight 4, the fan 16 on the backlight 4 side is operated in the strong cooling mode. To control. Thereby, the discharge flow path on the power supply 14 side can be switched from the second vent 23 to the third vent 24, and the exhaust flow velocity on the power supply 14 side can be improved. Therefore, it is possible to switch the flow path and outlet without requiring complicated mechanisms and controls, and it is possible to efficiently dissipate and cool the power supply 14 without the need for additional fans to improve the exhaust flow rate. become.

[Example 2]
FIG. 4 is a cross-sectional view of the image display device 1 according to Embodiment 2 of the present invention. FIG. 5 is a cross-sectional view showing a flow path of the image display device 1 shown in FIG. In FIG. 4 and FIG. 5, description of parts common to the first embodiment is omitted.

  The power supply 14 is disposed in the lower part of the first heat source space 20 with a power supply board 26 attached in parallel to the display module 13 and the partition plate 19 in the side sectional view of FIG. This is because the fan 16 is attached at a position that is substantially in the center of the partition plate 19 and that faces the center of the display module 13. And the 2nd ventilation hole 23 is provided in the position higher than the Embodiment 1 of this invention in the vicinity according to the fan 16. As shown in FIG.

  The reason why the fan 16 is arranged in this way is that many liquid crystal panels 2 tend to have a high temperature at the center when viewed from the front. As a blowing fan that blows air in a direction substantially perpendicular to the display module 13 at a position facing the central portion of the display module 13 in order to cool and dissipate heat mainly in the central portion of the display module 13. It depends on the provision. Therefore, the power supply 14 and the second vent 23 follow the fan 16 and are arranged as described above.

  The second ventilation port 23 is provided to be inclined with respect to the cover 15 in order to place importance on taking outside air into the display module 13 as compared with the first embodiment of the present invention. The third vent 24 is provided on the top and bottom surfaces of the cover 15 because the fan 16 is a blowing fan.

  By disposing the power supply 14, the fan 16, and the second vent hole 23 as described above, the liquid crystal panel 2 in which the heat generation distribution is biased toward the center, the display module on which the liquid crystal panel 2 is mounted, and the power supply 14 are efficiently radiated and cooled. Is possible.

[Example 3]
FIG. 6 is a cross-sectional view of the image display device 1 according to Embodiment 3 of the present invention. FIG. 7 is a cross-sectional view showing a flow path of the image display device 1 shown in FIG. In FIG. 6 and FIG. 7, the description of the parts common to the first and second embodiments is omitted.

  The advantage of using the LED 9 as the light source of the backlight 4 instead of the CCFL is that the light quantity of the light source can be individually adjusted. High image quality and power saving are realized by a method called local dimming, in which the LED 9 is divided into a plurality of regions and the LEDs 9 are driven at a luminance required by the image for each region. Each of the backlights 4 of the present invention is a direct type backlight using an LED 9 as a light source, and it is easy to adopt a local dimming method. With these technologies, an image display device 1 equipped with a 4K or 8K high-definition liquid crystal panel 2 and a backlight 4 capable of high brightness HDR is provided.

  In the third embodiment of the present invention, the arrangement of the fans 16 corresponding to the display modules 13 controlled for each area will be described. In addition, the fan 16 of Embodiment 1 and Embodiment 2 is called the 1st fan 16 in Embodiment 3. FIG.

  As shown in FIG. 6, the first fan 16 is composed of a plurality, and is arranged substantially in parallel with the display module 13, substantially in the same plane, and substantially vertically and horizontally. Each of the first fans 16 has a control area in which the temperature of the display module 13 can be controlled. Further, the backlight 4 can control the irradiation luminance for each of a plurality of display areas obtained by dividing the screen. As shown in FIG. 6, the first fans 16 are provided so that the control areas of the first fans 16 correspond to two or more display areas, respectively. In addition, you may provide as many as the number of display areas using a small fan so that the control area of each 1st fan 16 may correspond to a display area. The first fan 16 is provided as a blowing fan as in the second embodiment, and this is because a plurality of fans are arranged on the back surface of the display module 13. Although not shown in FIG. 6, the first fans 16 are arranged in a plurality of rows in the vertical direction on the paper surface and in the horizontal direction when viewed from the front of the image display device 1. The number is not limited.

  The first fan 16 forming the second flow path B and the third flow path C has a height equal to or higher than that of the power source 14 as the first heat source, and is attached and used in the vicinity of the second vent 24. The That is, the first fan 16 that forms the second flow path B and the third flow path C is at least one or more first fans 16 located at the top of the plurality of first fans 16.

  The power source 14 has a higher output and a larger size in order to cope with higher brightness than in the first and second embodiments, and the volume of the first heat source space 20 that includes the power source 14 is also increased. As a further corresponding means, in the third embodiment, a second fan 27 for sucking outside air is attached as a ventilation means in the lower part of the first heat source space 20 and inside the first ventilation port 22.

  The first heat source space 20 is provided with a second partition plate 30 that divides the first heat source space 20 into a power source space 28 and an intake space 29 that takes air into the second heat source space 21. The power supply space 28 and the intake space 29 are subspaces obtained by dividing the first heat source space 20. The second partition plate 30 is provided so that the second ventilation port 23 is located on the intake space 29 side, and the second partition plate 30 has a first flow path at a position facing the uppermost first fan 16. A relay opening 31 that forms A and the third flow path C is provided.

  A fourth vent 32 is provided on the intake space 29 side of the cover 15, and a fifth vent 33 is provided on the second heat source space 21 side of the cover 15. As shown in FIG. 7B, the fourth flow path D uses the fourth vent 32 as the outside air inlet of the second heat source space 21, and the fifth fan D is blown by the first fan 16 positioned other than the uppermost part. The vent 33 is formed to be an external outlet of the second heat source space 21. That is, when the first fan 16 located outside the uppermost part is rotating, the air outside the cover 15 flowing in from the fourth vent 32 passes through the first fan 16 located outside the uppermost part. It is discharged from the fifth vent 33.

  A plurality of first temperature sensors 34 that detect the temperature of the display module 13 are mounted on the light source substrate 5 at positions facing the centers of the plurality of first fans 16 on the second heat source space 21 side. The first temperature sensor 34 is mounted directly behind the LED 9, and the detection value of the first temperature sensor 34 is a value that approximately corresponds to the temperature of the LED 9 that is a light source in the display module 13. In addition, a second temperature sensor 35 that detects the temperature of the outside air sucked from the fourth vent 32 is attached to the first partition plate 19 inside the fourth vent 32. The detection value of the second temperature sensor 35 is a value corresponding to the temperature of the outside air (outside air temperature) sucked from the fourth vent 32. The first temperature sensor 34 and the second temperature sensor 35 are thermistors, thermocouples, etc., but are not limited to these.

  Hereinafter, the control of the first fan 16 and the second fan 27 will be described in detail. The control board 17 determines the luminance level of the image signal in the display area corresponding to each control area. The brightness level of the image signal in the display area corresponding to each control area is set as the brightness level of each control area. The control board 17 controls the stop, drive, and rotation speed of the corresponding first fan 16 based on the luminance level of each control area.

  As an example, some threshold values are stored in the control board 17 in advance. When a video signal having a low luminance level equal to or lower than the first threshold value is transmitted, the control board 17 sets the first threshold value corresponding to the control area. The fan 16 is stopped. When a video signal having a high luminance level equal to or higher than the second threshold is transmitted, the control board 17 drives the first fan 16 corresponding to the control area at the set maximum number of rotations. The control board 17 stores various brightness levels and the corresponding rotation speeds of the first fan 16 as a table, and drives the first fan 16 at an optimum rotation speed based on the determined brightness levels.

  Not only the first fan 16 corresponding to the control area but also the surrounding first fans 16 are controlled in cooperation. In particular, the uppermost first fan 16 increases the temperature of the power supply 14 depending on not only the brightness level of the opposing control area but also the brightness level of the other control area, so that the thermal load of all the control areas is comprehensively determined. And controlled.

  The second fan 27 is always driven to sufficiently ventilate the large-capacity first heat source space even when the first fan 16 stops or rotates at a low speed and because the first flow path A is long.

  The image display apparatus 1 of Embodiment 1 and Embodiment 2 did not have a temperature sensor. However, in the third embodiment, a more precise temperature control is performed in the image display device 1 that is equipped with the 4K or 8K high-definition liquid crystal panel 2 and the backlight 4 that enables high brightness HDR and adopts the local dimming method. Desired. Above all, such an image display device 1 needs to withstand professional use at broadcast stations and video production sites. The control board 17 controls the stop, drive, and rotation speed of all the first fans 16 based on the outside air temperature acquired from the second temperature sensor 35 and the approximate temperature of the light source acquired from the first temperature sensor 34. The rotational speed of the second fan 27 is controlled.

  Finally, the relationship between the four flow paths according to the third embodiment of the present invention will be described. The first flow path A and the third flow path C function in the same manner as in the first and second embodiments. When the first fan 16, in particular, the first fan 16 located at the uppermost part is driven, the heat dissipation / cooling of the first heat source space 20 is switched from the first flow path A to the third flow path C as the rotational speed increases. .

  In a state where the first fan 16 other than the uppermost portion is driven and the uppermost first fan 16 is stopped, the air passing through the opening 31 from the first heat source space 20 is not in the second ventilation port 23 or other than the uppermost portion. The air is discharged from the fifth vent through the first fan 16. If it is determined from the outside air temperature and the image signal transmitted to the control area and the approximate temperature of the LED 9 that it is necessary to suppress the temperature rise of the power supply 14, the control board 17 appropriately sets the uppermost first fan 16. Drive at an appropriate speed.

  As described above, by disposing the plurality of first fans 16 and newly providing the fourth vent 32 and the fifth vent 33 to form the fourth flow path D, the liquid crystal panel 2 and the LED 9 are efficiently radiated for each region.・ Can be cooled. Then, the second fan 27 is provided, and the first temperature sensor 34 and the second temperature sensor 35 are provided. Based on the detected values, the high-output / large-sized power supply 14 can be efficiently radiated and cooled. become.

[Example 4]
FIG. 8 is a cross-sectional view of the image display device 1 according to Embodiment 4 of the present invention. FIG. 9 is a cross-sectional view showing a flow path of the image display device 1 shown in FIG.

  The power source 14 of the fourth embodiment is not only increased in output and increased in size, but also provided in a plurality in order to cope with further increase in brightness as compared with the previous embodiment 3. Further, the control of the display module 13 and the power supply 14 is advanced, the image signal is increased in capacity, and the heat generation of the control board 17 and the image processing board 18 is also increased. Therefore, the fourth embodiment is characterized in that these are collectively accommodated in the first heat source space 20 and the folded first flow path A for performing common heat radiation and cooling is formed.

  The power supply space 28 is provided with a third partition plate 38 that divides the power supply space 28 into a space 36 and a space 37. The third partition plate 38 is provided with a second relay opening 39 that forms the first flow path A at the lowermost portion, and the cover 15 has an upstream space 36 and the cover 15 on the back side of the second relay opening 39. A sixth vent 40 is provided to connect the outside of the air.

  Since the first flow path A is longer than that of the third embodiment and is folded back, the second fan 27 is necessary and always driven.

Since the temperature of the first flow path A increases as it goes downstream, in order to sufficiently dissipate and cool the power source 14, outside air is replenished through the sixth vent 40.
In a state where the uppermost first fan 16 is stopped, a part of the air taken in by the second fan 27 is discharged to the outside from the sixth vent 40.
When the uppermost first fan 16 is driven, the air taken in by the second fan 27 is pulled from the opening 31 to the intake space 29 and also takes outside air from the sixth vent 40.

  As described above, the third partition plate 38, the second opening 39, and the sixth ventilation port 40 are provided for the first heat source space 20 having a large capacity for accommodating the high-power, large-sized, and multiple power sources 14. The folded first flow path A is formed. Thereby, the power supply 14 can be efficiently radiated and cooled using the speed increase of the first fan.

[Implementation system 5]
FIG. 10 is a cross-sectional view of the image display device 1 according to the fifth embodiment of the present invention. FIG. 11 is a cross-sectional view showing a flow path of the image display device 1 shown in FIG.

  In the fifth embodiment, among the heat sources in the first heat generation space 20 described in the fourth embodiment, heat sources that are relatively small in relation to the heat generation of the display module 13, that is, the control substrate 17 and the image processing substrate 18 are passed through the first flow path. Heat is dissipated and cooled using a flow path different from A.

  The power source space 28 is provided with a fourth partition plate 43 that divides the power source space 28 into small spaces of a space 41 and a space 42. The fourth partition plate 43 is provided with a third relay opening 44 in the lowermost portion and in the vicinity of the first vent 22. Further, the first vent is provided on the bottom surface of the power supply space 28. The second fan 27 is attached to the inside of the first vent 22 so as to straddle the third relay opening 44. The second fan 27 is arranged close to the space 41 side so that the amount of air sent out to the space 41 increases. The cover 15 is provided with a seventh vent 45 at the uppermost portion on the space 42 side. The fifth flow path E is formed so that the first ventilation port 22 serves as an external suction port for the space 42 and the seventh ventilation port 45 serves as an external discharge port for the space 42 by blowing air from the second fan 27.

  When the first fan is driven, only the air in the space 41 is drawn into the intake space 29 from the first opening 31 and discharged from the third vent 23.

  By arranging the fourth partition plate 43, the third opening 44, the second fan 27, and the seventh vent as described above, the power source 14 to be first cooled and radiated from the first heat source space 20 can be more efficiently used. It can dissipate and cool.

DESCRIPTION OF SYMBOLS 1 Image display apparatus 13 Display module 14 Power supply 15 Cover 16 Fan 17 Control board 19 Partition plate 20 1st heat-source space 21 2nd heat-source space 22 1st ventilation port 23 2nd ventilation port 24 3rd ventilation port

Claims (20)

A display module that displays an image on the front side;
A fan provided on the back side of the display module for cooling the display module;
A power source provided on the back side of the display module and the first fan for supplying power to the display module;
A control board for controlling the display module and the first fan;
An exterior member for housing the back surface of the display module, the first fan, and the control board;
A partition in which the first fan is installed and the space covered by the exterior member and the back surface of the display module is divided into a first space including the control board and a second space including the back surface of the display module. The board,
With
The exterior member is
A first opening and a second opening connecting the first space and the exterior of the exterior member;
A third opening that connects the second space and the exterior of the exterior member;
The control board is
When cooling the control board in the first cooling mode, the first fan is operated at a rotational speed higher than a predetermined rotational speed,
When the control board is cooled in the second cooling mode, the first fan is operated at a rotational speed equal to or lower than a predetermined rotational speed.   2. The display device according to claim 1, wherein a flow rate of air flowing into the first space from the second opening is larger in the first cooling mode than in the second cooling mode.   The display according to claim 1 or 2, wherein a flow rate of air flowing into the first space from the first opening is larger in the first cooling mode than in the second cooling mode. apparatus.   The flow rate of air discharged from the third opening in the first cooling mode is larger than the flow rate of air discharged from the second opening and the third opening in the second cooling mode. The display device according to any one of claims 1 to 3. The display device, when used, is installed so that the screen of the display module is parallel to the vertical direction,
5. The display device according to claim 1, wherein the second opening is provided above the power supply in the first space. 6. The display device, when used, is installed so that the screen of the display module is parallel to the vertical direction,
The partition plate is provided to be parallel to the back surface of the display module,
The first fan is provided so that a center of rotation of the first fan is the same as or higher than the power source when viewed from the back side of the display module. The display device according to claim 5.   The suction amount of the first opening is smaller than the discharge amount of the second opening, and the sum of the maximum suction amount of the first opening and the maximum suction amount of the second opening is the maximum discharge amount of the third opening. The flow rate of the first fan is set so that the opening area of the first opening, the second opening, and the third opening and the flow rate of the first fan are set so as to be smaller than each other. The display device according to claim 1. The display module includes a backlight having a light source substrate on which a plurality of LEDs are mounted, and a liquid crystal panel that is positioned on the front side of the backlight and displays an image by modulating light emitted from the backlight. A liquid crystal display module having
The display device according to claim 1, wherein the display device is a display device. A second partition plate that divides the first space into a first sub space including the control board and a second sub space for taking in air to flow into the second space on the back side of the first partition plate. In addition,
A first relay opening that connects the first subspace and the second subspace is provided at a position facing the first fan of the second partition plate,
The first opening is provided in the first subspace,
The second opening is provided in the second subspace,
The display device according to claim 1, wherein the display device is a display device. A second fan different from the first fan provided at a position not facing the first relay opening of the first partition plate;
The exterior member is
A fourth opening connecting the second subspace and the exterior of the exterior member;
A fifth opening connecting the second space and the exterior of the exterior member,
When the second fan is rotating, air outside the exterior member that has flowed in from the fourth opening is exhausted from the fifth opening through the second fan. Item 10. The display device according to Item 9. A first temperature sensor for detecting the temperature of the display module;
A second temperature sensor for detecting a temperature of outside air sucked from the fourth opening;
The display device according to claim 10, wherein the control board controls rotation speeds of the first fan and the second fan based on detection values of the first temperature sensor and the second temperature sensor. . A third partition plate that divides the first subspace into a first small space and a second small space;
A second relay opening is provided at a lower portion of the third partition plate;
The said exterior member has the 6th opening which connects the said 1st small space and the exterior of the said exterior member in the back side from the said 2nd relay opening, The any one of Claim 10 thru | or 11 characterized by the above-mentioned. The image display device according to item 1. The first opening is provided on a bottom surface of the first subspace,
The display device according to claim 12, wherein a part of the air flowing into the first subspace from the first opening is exhausted from the sixth opening. A third fan for sucking outside air is attached to the inside of the first opening.
The display device according to claim 1, wherein the display device is a display device. A plurality of first fans respectively corresponding to a plurality of display areas obtained by dividing the screen of the display module;
The said control board controls the rotation speed of each 1st fan according to the luminance level of the image displayed on each display area, The any one of Claims 1 thru | or 14 characterized by the above-mentioned. Display device. The control board is
Controlling the first fan corresponding to a display area having a luminance level equal to or lower than a predetermined threshold to operate at a rotational speed equal to or lower than the predetermined rotational speed;
16. The control unit according to claim 15, wherein the first fan corresponding to a display area having a luminance level equal to or higher than the predetermined threshold is controlled to operate at a rotational speed higher than the predetermined rotational speed. Display device. The control board is
The first fan is operated in the first cooling mode when the display module is in a high brightness display mode in which the image is displayed at a brightness higher than a predetermined brightness. The display device according to any one of claims 1 to 16, wherein the first fan is operated in two cooling modes.   The display device according to claim 17, wherein the high luminance display mode is an HDR display mode for displaying an image with a high dynamic range.   The display device according to any one of claims 1 to 18, wherein the control board does not rotate the first fan in the second cooling mode. When the first fan is controlled in the first cooling mode, the air flowing in from the first opening passes in the vicinity of the control board, and most of the air passes through the first fan to the third. By discharging from the opening, the heat generated in the control board is discharged to the outside of the exterior member,
When the first fan is controlled in the second cooling mode, the air flowing in from the first opening passes through the vicinity of the control board, and most of the air is discharged from the second opening. The display device according to any one of claims 1 to 19, wherein the heat generated in the control board is discharged to the outside of the exterior member.

Images