JP2021026070A - Display unit - Google Patents

Abstract

To provide a technology that can efficiently prevent an increase in temperature of a display panel even if a display device does not include a front plate.SOLUTION: A display unit of the present invention comprises: a display panel that displays an image in a display area; a frame that covers an outer peripheral part of the display area of the display panel; and a blower member. A channel is formed between the display panel and the frame. Air is introduced from the blower member to an introduction part of the channel. The introduced air is exhausted from an exhaust part of the channel toward the display area. The cross-section of the channel obtained by a surface perpendicular to a flow direction in which the air is caused to flow in the channel is larger at a part at a first distance from the introduction part along the flow direction than a part at a second distance farther than the first distance from the introduction part along the flow direction.SELECTED DRAWING: Figure 3

Description

The present invention relates to a display device, and more particularly to a technique for cooling (dissipating heat) the display panel.

In a conventional display device, when displaying with high brightness or the like, heat generation of the display panel, a drive circuit, or the like increases, and the temperature of the display panel increases. Since the temperature increase of the display panel causes a decrease in display performance, it is necessary to suppress it. Patent Document 1 discloses a technique in which a transparent plate is provided on the front side of a liquid crystal panel (the side having a display surface on which an image is displayed) and air is allowed to flow through a gap between the transparent plate and the liquid crystal panel.

Japanese Unexamined Patent Publication No. 2006-163217

However, in the technique disclosed in Patent Document 1, it is necessary to provide a transparent plate on the front side of the liquid crystal panel, and various image quality deteriorations (for example, an image displayed on the display surface of the liquid crystal panel is reflected on the transparent plate) due to the transparent plate. (Generation of double image) will occur.

An object of the present invention is to provide a technique capable of efficiently suppressing a temperature rise of a display panel even in a display device not provided with a front plate.

The display device of the present invention includes a display panel that displays an image in the display area, a frame that covers the outer peripheral portion of the display area of the display panel, and a blower member, and is between the display panel and the frame. A flow path is formed, air is introduced from the blower member into the introduction portion of the flow path, and the introduced air is discharged from the discharge portion of the flow path to the display region side in the flow path. The cross section of the flow path obtained by the plane perpendicular to the flow direction in which the air flows is such that the cross section of the flow path from the introduction portion along the flow direction is larger than the portion at the first distance along the flow direction from the introduction portion. It is characterized in that the portion at the second distance, which is farther than the first distance, is smaller.

According to the present invention, it is possible to efficiently suppress the temperature rise of the display panel even in the display device not provided with the front plate.

It is an external perspective view which shows the display device which concerns on Example 1. FIG. It is an exploded perspective view which shows the structure of the display module which concerns on Example 1. FIG. It is sectional drawing which shows the structure of the display device which concerns on Example 1. FIG. It is sectional drawing which shows the structure of the display device which concerns on Example 1. FIG. It is an external perspective view which shows the panel blower fan which concerns on Example 1. FIG. It is a three-view view which shows the air duct which concerns on Example 1. FIG. It is a developed view which shows the air duct which concerns on Example 1. FIG. It is a front view which shows the direction and size of the outlet which concerns on a modification. It is a rear view of the display device which concerns on a modification. It is sectional drawing in the vicinity of a specific area (the central part of a display area) which concerns on a modification. It is sectional drawing of the vicinity of the edge portion of the display area which concerns on a modification. It is a block diagram which shows the display device which concerns on Example 2. FIG. It is a flowchart which shows the processing flow of the display device which concerns on Example 2. It is a front view which shows the flow rate of the air to the liquid crystal panel which concerns on Example 2. FIG. It is a graph which shows the change of the air volume of the panel blower fan which concerns on Example 2. FIG. It is sectional drawing which shows the stagnation point which concerns on Example 2. FIG. It is a graph which shows the temperature rise at the flow velocity equilibrium point which concerns on Example 2. FIG. It is a schematic front view which shows the arrangement of the air guide pipe which concerns on Example 3. FIG. It is a front view which shows the flow rate of the air to the liquid crystal panel which concerns on Example 4. FIG. It is a graph which shows the change of the air volume of the panel blower fan which concerns on Example 4. FIG. It is a front view which shows the flow rate of the air to the liquid crystal panel which concerns on Example 5. It is a graph which shows the change of the air volume of the panel blower fan which concerns on Example 5. It is a front view which shows the direction and size of the air outlet which concerns on Example 6. It is sectional drawing which shows the structure of the display device which concerns on Example 7. FIG. It is sectional drawing which shows the air guide pipe which concerns on Example 8. FIG.

<Example 1>
Hereinafter, Example 1 of the present invention will be described. An example in which the present invention is applied to a liquid crystal display device will be described, but the display device to which the present invention can be applied is not limited to the liquid crystal display device. For example, the present invention may be applied to another transmissive display device such as a MEMS shutter type display device using a MEMS (Micro Electro Mechanical System) shutter instead of a liquid crystal element. The present invention may be applied to a self-luminous display device such as an organic EL display device or a plasma display device.

In the first embodiment, in the display device, the surface having the display surface including the display area on which the image is displayed is "front", the surface opposite to the front is "rear", and the other surface (the surface connecting the front and the back). Is defined as "side". Looking at the display device facing the front is defined as "front view", and looking at the display device facing the side is defined as "side view". Then, the side surface located on the upper side in the front view is defined as "upper surface" or "top surface", the side surface located on the right side is defined as "right surface", and the side surface located on the left side is defined as "left surface". , The side surface located on the lower side is defined as "bottom surface" or "bottom surface".

FIG. 1 is an external perspective view showing a display device 101 according to the first embodiment. FIG. 2 is an exploded perspective view showing the configuration of the display module 112 included in the display device 101. FIG. 3 is a view of the display device 101 viewed from the right side (right side), and is a cross-sectional view showing the configuration of the display device 101. FIG. 4 is a view of the display device 101 viewed from above (upper surface side), and is a cross-sectional view showing the configuration of the display device 101.

In the display device 101, the bezel 103 is arranged on the front side of the liquid crystal panel 102, and the backlight module 104 is arranged on the back side. The liquid crystal panel 102 has a display surface 113, and displays an image in the display area of the display surface 113. The backlight module 104 is a light emitting module that irradiates the back surface of the liquid crystal panel 102 with light. The liquid crystal panel 102 has light transmission and displays an image by transmitting the light emitted from the backlight module 104. The backlight module 104 is composed of a light source substrate 105, a drive substrate (not shown), a heat sink 106, a case 107, and the like.

A plurality of LEDs 108 are provided on the light source substrate 105. The light source provided on the light source substrate 105 is not limited to the LED (light emitting diode; Light Emitting Dimension), but CCFL (cold cathode fluorescent tube; Cold Cathode Fluores).
It may be cent Lamp) or the like. On the front side of the light source substrate 105, a reflection sheet 109 is arranged to efficiently reflect the light emitted from the light source substrate 105 and diffused to the liquid crystal panel 102. On the front side of the reflective sheet 109, optical sheets 110 for diffusing and condensing the light from the reflective sheet to reduce unevenness of light irradiating the liquid crystal panel 102 and improve the brightness of the light are provided. Be placed. On the front side of the optical sheets 110, a panel holder 111 that holds the optical sheets 110 and the like and supports the liquid crystal panel 102 from the back side is arranged.

The case 107 covers the light source substrate 105 from the back surface side, and the light source substrate 105 is fixed to the case 107. The heat sink 106 is fixed to the back surface side of the case 107 in a state of being thermally adhered to the case 107 with a heat conductive member (not shown) interposed therebetween. In the first embodiment, a plurality of heat sinks 106 are fixed to the back surface side of the case 107. The heat generated from the light source substrate 105 is released to the space on the back side of the heat sink 106 through the heat sink 106. The case 107 and the heat sink 106 may be integrally configured.

The display module 112 shown in FIG. 2 is composed of various members from the liquid crystal panel 102 shown in FIG. 2 to the backlight module 104, a drive board (not shown), a heat sink 106 shown in FIG. 3, and the like.

The bezel 103 is a front side housing (frame) that covers and protects the liquid crystal panel 102 and the display module 112, and has an opening 114 for making the image displayed in the display area of the display surface 113 of the liquid crystal panel 102 visible. Have. That is, the bezel 103 covers the outer peripheral portion of the display area.

The rear cover 115 is a rear housing that covers the circuit board 116 that processes the image signal and sends the image signal to the display module 112, the power supply 117, and other members. The overall cooling fans 118 and 119 are attached to the front side of the rear cover 115 so as to face the ventilation holes 120 and 121 formed in the rear cover 115. The overall cooling fan 118 arranged on the lower surface side sucks (introduces) the air (outside air) outside the display device 101 into the inside of the display device 101 through the ventilation holes 120. The air sucked by the overall cooling fan 118 passes through the power supply 117, the circuit board 116, the heat sink 106, and the like, and is discharged to the outside of the display device 101 from the overall cooling fan 119 arranged on the upper surface side through the ventilation holes 121. To. As a result, convection of air on the back surface of the display module 112 occurs, and heat on the back surface side of the display module 112 is released to the outside of the display device 101.

The panel blower fans 122 to 125 are blower members that introduce and discharge air (outside air) for cooling the display surface 113 of the liquid crystal panel 102 from the outside of the display device 101. The images include a high-definition image with a resolution of 4K (the number of pixels in the horizontal direction (horizontal direction) is about 4000 pixels), an ultra-high-definition image with a resolution of 8K, and a dynamic range of HDR (luminance range with high maximum brightness). There are high-brightness images of. Then, in order to display these images, it is necessary to use a large number of light sources for the backlight module and the self-luminous display panel, and to increase the emission brightness of the light sources. Therefore, when displaying these images, the temperature of the display panel tends to rise due to the heat generated by the light source, causing display deterioration (display color shift, etc.) due to the temperature characteristics of the display panel, or deterioration of the display panel. Becomes faster. Therefore, in the first embodiment, the liquid crystal panel 102 is cooled by using the panel blower fans 122 to 125.

In the front view, the panel blower fan 122 is arranged in the upper right, the panel blower fan 123 is arranged in the upper left, the panel blower fan 124 is arranged in the lower right, and the panel blower fan 125 is arranged in the lower left. The air flow path by the panel blower fans 122 to 125 is different from the air flow path by the overall cooling fans 118 and 119. FIG. 5 is an external perspective view showing the panel blower fans 122 to 125 and the like.

The air ducts 126 to 129 are members for guiding the air supplied (introduced) from the panel blower fans 122 to 125 to the display surface 113 of the liquid crystal panel 102, and the panel blower fan 122 is provided by the pipe-shaped joint 130. Connected to ~ 125. The air ducts 126 and 127 connected to the panel blower fans 122 and 123 are built in on the upper surface side, and the air ducts 128 and 129 connected to the panel blower fans 124 and 125 are built in on the lower surface side, respectively. Will be done.

The plurality of outlets 131 are gaps on the front side between the liquid crystal panel 102 and the bezel 103. In the first embodiment, there are two outlets 131, one of the two outlets 131 is formed on the upper surface side, and the other of the two outlets 131 is formed on the lower surface side. The air discharged from the panel blower fans 122 to 125 is blown to the display surface 113 of the liquid crystal panel 102 from the plurality of outlets 131. Specifically, an outlet 132 for discharging the air introduced from the panel blower fans 122 to 125 through the joint 130 is formed on the front side of the air ducts 126 to 129. Each outlet 131 is formed in a direction in which air is blown out substantially parallel to the display surface 113. Here, the outlet 131 is located ahead of the outlet 132. As a result, the air discharged from the panel blower fans 124 and 125 on the lower surface side is discharged to the upper surface side from the air outlet 131 on the lower surface side through the air ducts 128 and 129 on the lower surface side, and reaches the display surface 113. It is sprayed (arrow A in FIG. 3). Similarly, the air discharged from the panel blower fans 122 and 123 on the upper surface side is discharged to the lower surface side from the air outlet 131 on the upper surface side through the air ducts 126 and 127 on the upper surface side, and reaches the display surface 113. It is sprayed (arrow B in FIG. 3). The outlet 132 is the outlet 131 without using the gap on the front side between the liquid crystal panel 102 and the bezel 103 as the outlet 131 (the outlet formed at a position or direction in which air can be blown onto the display surface 113). The air ducts 126 to 129 may be extended so as to serve as the above.

As described above, in the first embodiment, a plurality of panel blower fans are provided (panel blower fans 122 to 125), and a plurality of flow paths are formed between the liquid crystal panel 102 and the bezel 103. The air from each of the panel blower fans 122 to 125 is introduced into the introduction portion of the corresponding flow path (eg, the portion of the joint 130). Then, the introduced air is discharged from the discharge portion of the flow path (for example, the portion of the outlet 131 or the outlet 132) to the display surface 113 (display region) side. As a result, the display surface 113 can be cooled.

The panel blower fans 122 to 125 are built in the vicinity of the four ridges of the rear cover 115 extending rearward from the four corners of the bezel 103. With such an arrangement, the air flow path by the panel blower fans 122 to 125 and the air flow path by the overall cooling fans 118 and 119 can be prevented from interfering with each other, that is, can be separated.

Specifically, ventilation holes 137 and 138 are formed on the right side surface and the left side surface of the display device 101 (rear cover 115), respectively. The vent 137 is formed on the lower surface side, and the vent 138 is formed on the upper surface side. The panel blower fans 122 and 124 are arranged in a direction of sucking outside air from the right side of the display device 101 through the vents 138 and 137 (right side). Similarly, the panel blower fans 123 and 125 are arranged in a direction of sucking outside air from the left side of the display device 101 through the vents 138 and 137 (left side). The display device 101 is relatively thin in the front-rear direction (direction perpendicular to the display surface 113). Therefore, the vents 120 and 121 of the overall cooling fans 118 and 119 are formed on the back surface of the display device 101 (rear cover 115), and the overall cooling fans 118 and 119 are arranged in the vicinity of the vents 120 and 121. Since the panel blower fans 122 to 125 are provided so as to suck in the outside air from the side surface side of the display device 101, the fresh air is not affected by the intake air of the overall cooling fan 118 and the exhaust of the overall cooling fan 119. Can be inhaled. Further, assuming that the display device 101 is installed in close contact with a wall surface or the like, the width from the left side to the right side of the display device 101 is the largest at the positions of the panel blower fans 122 to 125 (vent holes 137, 138). It is set narrower than significantly. As a result, even when the display device 101 is brought into close contact with the wall surface or the like, a gap can be secured between the ventilation holes 137 and 138 and the wall surface and the like, and the ventilation holes 137 and 138 are not blocked by the wall surface and the like. The suction of fresh air can be guaranteed.

The panel blower fans 122 to 125 suck the outside air from the side surface side of the display device 101 and send it to the front side side of the display device 101. Therefore, the panel blower fans 122 to 125 are preferably sirocco fans. The arrangement of the panel blower fans 122 to 125 is not particularly limited. For example, the panel blower fans 122 to 125 may be arranged on the upper surface, the lower surface, the back surface, or the like of the display device 101. It is preferable to determine the arrangement of the panel blower fans 122 to 125 in consideration of the arrangement of the overall cooling fans 118 and 119. The types of panel blower fans 122 to 125 are not particularly limited. For example, when the panel blower fans 122 to 125 are arranged on the back surface, the panel blower fans 122 to 125 may be axial fans. preferable.

The air ducts 126 to 129 are connected to the panel blower fans 122 to 125 on a one-to-one basis. The air duct 126 is a member dedicated to the panel blower fan 122, the air duct 127 is a member dedicated to the panel blower fan 123, and the air duct 128 is a member dedicated to the panel blower fan 124. The pipe 129 is a member dedicated to the panel blower fan 125. Therefore, there is no loss (loss of airflow energy) due to the branching of air from one panel blower fan to a plurality of air guide pipes. Further, there is no airflow turbulence (airflow turbulence) due to the air from the plurality of panel blower fans merging in one air duct. Then, the load on each of the panel blower fans 122 to 125 can be reduced, the size of each of the panel blower fans 122 to 125 can be reduced, and the size of the display device 101 can be reduced.

The air ducts 126 to 129 are arranged point-symmetrically (vertically and horizontally symmetrically) with respect to the center of the display surface 113 (liquid crystal panel 102) so that air can be efficiently discharged to the entire display surface 113. The air ducts 126 and 127 are provided on the upper surface side, and in a front view, the air duct 126 is in charge of the right half (upper surface side) of the display surface 113, and the air duct 127 is the left half of the display surface 113. In charge of (upper surface side). Similarly, the air ducts 128 and 129 are provided on the lower surface side, and in the front view, the air duct 128 is in charge of the right half (lower surface side) of the display surface 113, and the air duct 129 is the display surface 113. In charge of the left half (bottom side) of. By doing so, the load on each of the panel blower fans 122 to 125 is reduced, and a desired air volume can be easily obtained.

Further, in the first embodiment, the size of the cross section of the flow path obtained by the plane perpendicular to the flow direction in which the air from the panel blower fan flows in the flow path (the front-rear direction in the first embodiment) is devised. Specifically, the cross section becomes smaller as the distance from the introduction portion of the flow path along the flow direction increases. As a result, the flow velocity of the air blown from the outlet 131 to the display surface 113 can be increased, and the display surface 113 (liquid crystal panel 102) can be efficiently cooled. It should be noted that a part of the flow path may have a small cross section in the flow direction, and the flow path may include a portion having a large cross section in the flow direction.

This will be described more specifically. Each of the baffle pipes 126 to 129 has a shape in which the width in the vertical direction (direction perpendicular to the front-rear direction) gradually decreases from the upstream where the joint 130 is connected to the downstream where the outlet 132 is located. The air ducts 126 to 129 are airtight, and the inside of the air ducts 126 to 129 is maintained at a positive pressure by the rotational drive of the panel blower fans 122 to 125. As a result, the flow velocity of the air blown out from the outlet 132 can be increased. As a result, the flow velocity of the air blown from the outlet 131 to the display surface 113 can be increased, and the display surface 113 can be efficiently cooled.

The manufacturing method, material, and the like of the air ducts 126 to 129 will be described. Since the only difference between the air guide tubes 126 to 129 is the difference in shape (orientation) so as to be point-symmetric with respect to the center of the display surface 113, only the air guide tube 126 will be described. FIG. 6 is a three-view view showing the air duct 126. FIG. 7 is a developed view showing the air duct 126.

The air duct 126 is manufactured by bending a flexible sheet-like member, and PE (polyethylene), PET (polyethylene terephthalate), or the like is suitable as the material thereof. The reasons for selecting these materials are that they are inexpensive, that they are easy to handle in assembly, and that they are lightweight. Further, by selecting these materials, it is possible to manufacture the airtight pipe 126 having excellent airtightness. The air duct 126 can be manufactured by die-casting metal or the like, but since the air duct 126 is arranged in the vicinity of the liquid crystal panel 102, there is a concern about the influence of radio noise such as EMI / EMC. From this point as well, it is desirable that the material of the air duct 126 is a material having an insulating property such as PE. The manufacturing method of the air duct 126 is not particularly limited. For example, the air duct 126 may be manufactured by using a blow molded product made of resin, or by processing a resin tube by extrusion processing. It may be manufactured.

As shown in FIG. 7, the air duct 126 punches out the original fabric made of PE or the like by a biku type or the like, folds it back at the position of the broken line 133, and heat-welds the peripheral portions (peripheral portions facing each other by folding back) to each other. Manufactured by The joint 130 is also made of PE or the like, and the joint 130 is fixed to the air duct 126 by heat welding with one end of the joint 130 sandwiched between the original fabrics. The other end of the joint 130 (the end portion on the side opposite to the side of the air duct 126) is attached to the panel blower fan 122.

Since the gusset 134 is provided in the air duct 126, when the air sent from the panel fan 122 is filled in the air duct 126, the air duct 126 has a three-dimensional shape. The air duct 126 comes into contact with the plurality of ribs 135 formed on the bezel 103 and the case 107 of the display module 112 in a state of being inflated under positive pressure, and the shape of the air duct 126 is maintained. The abutment portion 136 of each rib 135 is inclined, and the shape of the air duct 126 has a shape in which the cross section becomes smaller as described above.

The bezel 103 is an injection-molded product made of resin, and a plurality of ribs 135 are integrally formed inside the bezel 103. The bezel 103 may be an aluminum die-cast product, and even so, the rib 135 can be formed in the same manner.

As described above, the tips of the air ducts 126 to 129 may be extended so that the outlet 132 also serves as the outlet 131. In FIGS. 4 to 7, an elongated slit is shown as the outlet 132, but the outlet 132 may have a plurality of holes. In FIG. 1, a plurality of holes are shown as the outlet 131, but the outlet 131 may be an elongated slit. For example, the air outlet 131 may be four slits corresponding to each of the four air ducts 126 to 129, or may be one slit corresponding to all of the air ducts 126 to 129. That is, a plurality of holes arranged along the side of the liquid crystal panel 102 may be formed at the discharge portion of the air flow path by the panel blower fan as an outlet connecting the inside and the outside of the flow path, or the liquid crystal. Slits along the sides of the panel 102 may be formed.

As described above, according to the first embodiment, the cross section of the air passage by the panel blower fan becomes smaller from the upstream to the downstream in at least a part of the air flow path. As a result, the flow velocity of the air blown to the display surface can be increased, and the display surface (display panel) can be efficiently cooled (the temperature rise of the display surface (display panel) can be efficiently suppressed).

Further, since the panel blower fan sucks the outside air from the side surface side of the display device, fresh air can be blown to the display surface, and the cooling effect of the display surface can be further improved. Further, by connecting a plurality of air ducts to a plurality of panel blower fans on a one-to-one basis, air can be efficiently blown onto the display surface.

<Modification example>
Hereinafter, a modified example of the first embodiment of the present invention will be described. In the modified example, an example will be described in which the display surface (display panel) is cooled more efficiently by further devising the air volume, the wind direction, the shape, and the like with respect to the discharge portion of the air flow path by the panel blower fan. In the modified example, the discharge portion is formed so that the air volume in a specific area which is a part of the display area of the display surface (display panel) is larger than the air volume in the other part of the display area.

FIG. 8 is a front view showing the direction and size of the air outlet 410 (corresponding to the above-mentioned air outlet 131) for blowing the air from the panel blower fan onto the display surface 113 of the liquid crystal panel 102. In FIG. 8, a plurality of holes are formed as the outlet 410. In FIG. 8, the orientation and size of each outlet 410 (each hole) are devised so that air can be intensively blown to a specific area of the display surface 113.

Due to the configuration (structure) of the display device, the display surface 113 may have a portion where the temperature tends to rise more than other portions. For example, although it depends on the configuration and power consumption of the backlight module 104 and the liquid crystal panel 102, the temperature tends to rise in the central portion of the display area, which has a size of 50% of the entire display area. Therefore, in the modified example, it is assumed that the central portion of the display surface 113 (display area) is a specific area. The specific area is not limited to the central portion of the display surface 113, and may be an edge portion of the display surface 113 or the like. A specific area is a region where the temperature increases by a predetermined temperature (for example, 10 ° C.) or more by driving the display device 101, a region where the temperature difference from the surroundings becomes a predetermined temperature (for example, 5 ° C.) or more while driving the display device 101, and the like. May be.

By making the air blown intensively to a specific region where the temperature tends to rise, the temperature unevenness of the display surface 113 can be efficiently reduced, and the image quality unevenness of the image displayed on the display surface 113 can also be reduced.

The air outlet 410 will be specifically described. The shape of each of the plurality of outlets 410 (plurality of holes) can be various shapes such as a circular shape and a quadrangular shape, and is not particularly limited. When a member connected to the air ducts 126 to 129 is used as a member forming the plurality of air outlets 410 (plural holes), the members forming the plurality of air outlets 410 are referred to as air ducts 126 to 129. It is preferable to manufacture with the same material.

In the modified example, as shown in FIG. 8, the outlet 410 (hole) is made larger as it is closer to the specific region. By doing so, the air volume in the specific area (central portion of the display area) can be made larger than the air volume in the edge portion of the display area. Although it depends on the temperature difference between the central portion and the end portion, the air flow rate 411 at the outlet 410 of the central portion is preferably twice or more the air flow rate 412 at the outlet 410 of the end portion. In other words, the flow rate of air at the outlet 410 at the end is preferably less than half the flow rate of air at the outlet 410 at the center. The area of each outlet 410 (hole), the pitch of the plurality of outlets 410, etc. are not particularly limited, but the area of the outlet 410 ^{is preferably about 0 to 50 mm 2} , and the pitch of the plurality of outlets 410 is 3. It is preferably about 30 mm.

The number (density) of the outlets 410 may be reduced as the distance from the specific region increases, and the outlets 410 may not be formed in a portion close to a portion (end portion) where the temperature does not easily rise. The size of each air outlet 410 may be the same, and the flow rate, flow velocity, etc. of the air blown to the display surface 113 may be changed by devising the shape, size, and the like of the air ducts 126 to 129. May be good. The flow rate, flow velocity, and the like of the air blown to the display surface 113 may be changed by making the tip of each outlet 410 thinner.

Further, in the modified example, as shown in FIG. 8, each direction of the plurality of outlets 410 (axial direction of the outlet 410 (hole)) is set as a direction toward the specific region. As a result, it is possible to concentrate the air on a specific area.

It is preferable that both the condition of the size of the outlet 410 (closer to the specific region) and the condition of the orientation of the outlet 410 (toward the specific region) are satisfied, but one of the size and orientation of the outlet 410 It may be possible to satisfy only the condition of.

FIG. 9 is a rear view of the display device 101. FIG. 10 is a view of the display device 101 viewed from the right side (right side), and is a cross-sectional view of the vicinity of a specific area (central portion of the display area). FIG. 11 is a view of the display device 101 viewed from the right side (right side), and is a cross-sectional view of the vicinity of the end portion of the display area.

In FIGS. 9 to 11, the outlet 410 is composed of a partition plate 420 and spacers 421 and 422. According to such a configuration, a relatively large air outlet 410 can be formed, and the display surface 113 can be cooled more efficiently.

Since a plurality of outlets 410 are formed between the liquid crystal panel 102 and the bezel 103, a plurality of partition plates 420 are formed. Each of the plurality of partition plates 420 is erected vertically on the liquid crystal panel 102 (display surface 113), and the gap between the liquid crystal panel 102 and the bezel 103 is divided into a plurality of horizontal portions by the plurality of partition plates 420. Be done. The partition plate 420 may be integrally formed on the bezel 103 by aluminum die casting or resin molding, and thus an increase in manufacturing cost can be suppressed. The thickness of the partition plate 420 is about 0.5 to 5.0 mm. The plurality of partition plates 420 are in contact with the air ducts 126 to 129 and are close to the liquid crystal panel 102 so that the air from the air ducts 126 to 129 is divided and blown onto the liquid crystal panel 102. The inclination of each partition plate 420 so that the outlet 410 faces a specific area (the central portion of the display area) and the angle of the partition plate 420 (the plate surface of the partition plate 420) with respect to the horizontal direction increases as the air outlet 410 faces the specific area. Has been adjusted. As a result, it is possible to concentrate the air on a specific area.

Further, a plurality of spacers 421 and 422 are attached to the back surface side of the bezel 103 so as to be arranged between the plurality of partition plates 420. The spacer 421 is provided near a specific area (central portion of the display area), and the spacer 422 is provided at a portion far from the specific area. The spacer 421 is thicker than the spacer 422. As a result, the air volume in the specific area (central portion of the display area) can be made larger than the air volume in the edge portion of the display area.

The height of the spacers 421 and 422 (thickness in the front-rear direction (direction perpendicular to the display surface 113)) is 1 to 10 mm, and the material of the spacers 421 and 422 is a flexible material such as a cushion or rubber. If the clearance between the spacers 421 and 422 and the liquid crystal panel 102 is large, the flow velocity of the air blown to the liquid crystal panel 102 decreases, and the cooling efficiency of the liquid crystal panel 102 decreases. Therefore, it is preferable to set the heights of the spacers 421 and 422 based on the flow rate and the flow velocity of the air to be blown to the liquid crystal panel 102. Specifically, it is preferable to set the height of the spacers 421 and 422 so that the clearance between the spacers 421 and 422 and the liquid crystal panel 102 is about 0 to 20 mm. Further, the clearance C1 between the spacer 421 and the liquid crystal panel 102 near the specific region is set to be the clearance C1 between the spacer 422 and the liquid crystal panel 102 far from the specific region so that the air volume in the specific region is larger than the air volume in the other region. It is preferably twice or more.

It should be noted that, instead of using a plurality of spacers corresponding to a plurality of portions, such as spacers 421 and 422, one spacer whose height decreases as it approaches a specific region may be used.

Although it depends on the amount of heat generated by the display device 101, the environment around the display device 101, and the like, in an experiment using the display device 101 having a display area size of 30 inches, air was blown onto the display panel at a flow velocity of 1 m / s. The temperature of the liquid crystal panel 102 dropped by 10 ° C. Further, the flow velocity of the air discharged from the outlet 410 attenuated as the distance from the outlet 410 increased, and at a position 150 mm away from the outlet 410, the flow velocity decreased to about half of the flow velocity in the vicinity of the outlet 410. Then, the amount of temperature decrease of the liquid crystal panel 102 was also reduced by the decrease of the flow velocity, and the amount of temperature reduction was almost halved by the half of the flow velocity. Therefore, it is necessary to set the shape of the outlet 410, the air flow velocity by the panel blower fans 122 to 125, the air flow rate by the panel blower fans 122 to 125, and the like.

As described above, according to the modified example of the first embodiment, the air volume in the specific area where the discharge portion of the air flow path by the panel blower fan is a part of the display area of the display surface (display panel) is determined. It is formed so that the air volume is larger than that in other parts of the display area. As a result, temperature unevenness on the display surface can be efficiently reduced.

<Example 2>
Hereinafter, Example 2 of the present invention will be described. In the following, a configuration different from that of the first embodiment will be described in detail, and a description of the same configuration as that of the first embodiment will be omitted as much as possible. In the first embodiment, in order to efficiently lower the temperature of the display surface 113, an example of blowing air onto the display surface 113 from a plurality of locations around the display surface 113 has been described. However, in the case of such a configuration, although the temperature of the display surface 113 can be lowered, a stagnation point where air from a plurality of places collide with each other may occur. Since the temperature of the stagnation point is less likely to drop than that of the surrounding area, the stagnation point may cause temperature unevenness on the display surface 113. Therefore, in the second embodiment, an example will be described in which the air blown to the display surface 113 is controlled to reduce / eliminate the temperature unevenness caused by the stagnation point.

FIG. 12 is a block diagram showing a display device 101 according to the second embodiment.

The display device 101 can be driven by supplying electric power from an external commercial power source 551 to a power source 117 which is a power supply board. The power supply 117 supplies electric power to the backlight module 104, the control unit 501, and the like, and makes each unit driveable.

The image signal from the outside is input to the control unit 501 via a signal input unit 502 such as an interface. The image signal is transmitted to the backlight control unit 511, the image control unit 521, and the like via the control unit 501. Image processing is performed in the image control unit 521, and the image after the image processing is displayed on the liquid crystal panel 102.

The control unit 501 controls each unit of the display device 101. For example, the control unit 501 receives a command from the operation unit 503 such as a button, and executes each process according to the received command. Further, the control unit 501 performs various image processing (for example, color correction) and various temperature controls based on the temperature information from the outside air temperature detection unit 504, the backlight temperature detection unit 512, and the like.

Specifically, the control unit 501 uses the overall cooling fans 118 and 119 as the outside air temperature detection unit 5.
It is driven based on the temperature information from 04, the backlight temperature detection unit 512, etc. (temperature control in the housing of the display device 101). In the control of the overall cooling fans 118 and 119, the voltage for driving the overall cooling fans 118 and 119 is calculated from the outside air temperature and the backlight temperature based on the overall cooling fan drive table 543 recorded in the recording unit 541. It is determined. The overall cooling fan drive table 543 is, for example, a table showing the correspondence between temperature and voltage. A function may be used instead of the overall cooling fan drive table 543.

Further, the control unit 501 individually controls the panel blower fans 122 to 125. In the second embodiment, the control unit 501 individually drives the panel blower fans 122 to 125 according to the panel blower fan drive function 542 recorded in the recording unit 541, and discharges from the panel blower fans 122 to 125. Controls the flow rate and flow velocity of the air to be produced. Specifically, the control unit 501 is discharged from the panel blower fans 122 to 125 by using the panel blower fan drive function 542 each time a clock is generated from the timekeeping unit 505 built in the control unit 501. Determine the flow rate of air. The flow velocity of the air discharged from the panel blower fans 122 to 125 may be determined instead of the flow rate of the air discharged from the panel blower fans 122 to 125, or the voltage for driving the panel blower fans 122 to 125. May be determined. The panel blower fan drive function 542 is, for example, a function indicating the correspondence between the number of clocks and the flow rate. A table may be used instead of the panel blower fan drive function 542. In the second embodiment, the panel blower fans 122 to 125 are individually controlled so that the time change of the air volume becomes non-uniform among the panel blower fans 122 to 125. As a result, the stagnation point is moved, and temperature unevenness caused by the stagnation point can be reduced or eliminated.

FIG. 13 is a flowchart showing a processing flow of the display device 101. When the display device 101 is activated, the processing flow of FIG. 13 starts. In step S1, the control unit 501 acquires the panel blower fan drive function 542 from the recording unit 541. In step S2, the control unit 501 transmits a drive signal to the panel blower fans 122 to 125. In step S3, the panel blower fans 122 to 125 are driven in response to the drive signal from the control unit 501. In step S4, the control unit 501 determines whether or not an error (fan error) has occurred in the panel blowing fans 122 to 125. The fan error is a failure of the panel blower fans 122 to 125, a foreign matter mixed in the panel blower fans 122 to 125, and the like, and the panel blower fans 122 to 125 stop due to the fan error. If no fan error has occurred, the process is returned to step S3, and if a fan error occurs, the process proceeds to step S5. In step S5, the control unit 501 displays an error (display for notifying the user of a fan error) on the display surface 113. In step S6, the control unit 501 turns off the power of the display device 101.

In the second embodiment, the control unit 501 periodically controls each of the panel blower fans 122 to 125 by periodically controlling the respective drive voltages of the panel blower fans 122 to 125. As a result, the flow rate of air at the four outlets 131 corresponding to the four panel blower fans 122 to 125 changes periodically. Since the air guide pipes 126 to 129 are connected to the panel blower fans 122 to 125 on a one-to-one basis, the four panel blower fans 122 to 125 are individually controlled so that the four air outlets 131 can be used. The air flow rate is also controlled individually. In the second embodiment, the other fan of the panel blower fans 122 to 125 is controlled in conjunction with the control of any fan of the panel blower fans 122 to 125. Therefore, in conjunction with the control of the air flow rate at the outlet 131 corresponding to any fan among the panel blower fans 122 to 125, it corresponds to the other fan among the panel blower fans 122 to 125. The flow rate of air at the outlet 131 is controlled.

14 (A) to 14 (D) are front views showing the flow rate of air to the liquid crystal panel 102. FIG. 15 is a graph showing the time change of the flow rate (air volume) of the air discharged from the panel blower fans 122 to 125. The flow rate of the air discharged by the panel blower fans 122 to 125 corresponds to the drive voltage of the panel blower fans 122 to 125. 14 (A) corresponds to the timing t1 of FIG. 15, FIG. 14 (B) corresponds to the timing t2 of FIG. 15, FIG. 14 (C) corresponds to the timing t3 of FIG. 15, and FIG. 14 (D). Corresponds to the timing t4 of FIG. The time change in FIG. 15 is defined by the panel blower fan drive function 542.

In FIGS. 14 (A) to 14 (D), the arrow F1 indicates the flow rate of the air discharged from the panel blower fan 122, specifically, the flow rate of the air discharged from the outlet 131 corresponding to the panel blower fan 122. Is shown. The arrow F2 indicates the flow rate of the air discharged from the panel blower fan 123, specifically, the flow rate of the air discharged from the outlet 131 corresponding to the panel blower fan 123. The arrow F3 indicates the flow rate of the air discharged from the panel blower fan 124, specifically, the flow rate of the air discharged from the outlet 131 corresponding to the panel blower fan 124. The arrow F4 indicates the flow rate of the air discharged from the panel blower fan 125, specifically, the flow rate of the air discharged from the outlet 131 corresponding to the panel blower fan 125. Each of the arrows F1 to F4 is shown larger as the corresponding flow rate increases. In FIGS. 14 (A) to 14 (D), the point C is the flow velocity equilibrium point on the display surface 113 when the panel blower fans 122 to 125 are driven at the same flow rate, and in the second embodiment, the display surface 113. It is the center of (liquid crystal panel 102).

In the state of FIG. 14A, the flow rate F1 of the air discharged by the panel blower fan 122 becomes the minimum, and the flow rate F3 of the air discharged by the panel blower fan 124 becomes the maximum. Transition from the state of FIG. 14A to the state of FIG. 14B, the flow rate F2 of the air discharged by the panel blower fan 123 is the minimum, and the flow rate F4 of the air discharged by the panel blower fan 125 is the maximum. Become. Transition from the state of FIG. 14B to the state of FIG. 14C, the flow rate F3 of the air discharged by the panel blower fan 124 is the minimum, and the flow rate F1 of the air discharged by the panel blower fan 122 is the maximum. Become. Then, the state of FIG. 14 (C) is changed to the state of FIG. 14 (D), the flow rate F4 of the air discharged by the panel blower fan 125 becomes the minimum, and the flow rate F4 of the air discharged by the panel blower fan 125 becomes the minimum. It becomes the maximum.

According to the time change of FIG. 15, the state change shown in FIGS. 14 (A) to 14 (D) is periodically repeated. The vertical axis of FIG. 15 shows the flow rates F1 to F4 of the air discharged from the panel blower fans 122 to 125, and the horizontal axis of FIG. 15 shows the time. The time change of the flow rates F1 to F4 is represented by a sine wave, and if the period is time P, the phases of the four sine waves corresponding to the four panel blower fans 122 to 125 are shifted by time P / 4. There is. The time change of the flow rate is not limited to that represented by a sine wave, and may be represented by, for example, a rectangular wave.

FIG. 16 is a view showing the stagnation point D, and is a cross-sectional view of the display device 101 viewed from the right side (right side). The point where the air blown out in the opposite directions collides with each other is the stagnation point D, and the air flow rate is not sufficiently obtained at the stagnation point D, and the temperature of the liquid crystal panel 102 tends to rise. FIG. 16 shows a state in which the flow rates F1 and the flow rate F3 are equal to each other, and if such a state continues, the temperature at the stagnation point D rises. Therefore, in the second embodiment, the stagnation point D is moved by setting the time change of the flow rate F1 to be different from the time change of the flow rate F3. Thereby, the temperature unevenness caused by the stagnation point D can be reduced / eliminated.

FIG. 17 is a graph showing the temperature rise at the flow velocity equilibrium point (center of the display surface 113) C on the display surface 113 when the panel blower fans 122 to 125 are driven at the same flow rate. The drive cycle P of the panel blower fans 122 to 125 is the time from when the power of the display device 101 is turned on or when the supply of the image signal is started until the temperature at the flow velocity equilibrium point C described above reaches 90% of the steady temperature Ts. It is set shorter than T. Alternatively, a time of several sec to several min is set as the drive cycle P. When the drive cycle P is longer than the time T, temperature unevenness in which the temperature at the stagnation point D is higher than the temperature at other positions is likely to appear remarkably. In order to reduce / eliminate the temperature unevenness, it is preferable to set the drive cycle P shorter than the time T.

In the second embodiment, an example in which four panel blower fans 122 to 125 are used has been described, but the number of panel blower fans is not particularly limited. When n panel blower fans are used, for example, the n panel blower fans may be periodically driven in a phase shifted by time P / n.

As described above, the stagnation point D is the point where the air blown out in the opposite directions collides with each other. Therefore, the control unit 501 controls the air flow rate at the other of the two air outlets 131 in conjunction with the control of the air flow rate at one of the two opposing air outlets 131. Specifically, the control unit 501 controls the panel blower fan 124 arranged in the lower right in the front view in conjunction with the control of the panel blower fan 122 arranged in the upper right in the front view. To do. The control unit 501 reduces the flow rate of the air discharged by the panel blower fan 124 in accordance with the increase in the flow rate of the air discharged by the panel blower fan 122. By doing so, the stagnation point caused by the collision of the air from the panel blower fan 122 and the air from the panel blower fan 124 can be moved downward. Further, the control unit 501 increases the flow rate of the air discharged by the panel blower fan 124 in accordance with the decrease in the flow rate of the air discharged by the panel blower fan 122. By doing so, the stagnation point caused by the collision of the air from the panel blower fan 122 and the air from the panel blower fan 124 can be moved upward. Similarly, the control unit 501 controls the panel blower fan 125 arranged in the lower left in the front view in conjunction with the control of the panel blower fan 123 arranged in the upper left in the front view.

The panel blower fans 122 and 123 arranged on the upper surface side may be interlocked and controlled, or the panel blower fans 124 and 125 arranged on the lower surface side may be interlocked and controlled. Interlocking control of the panel blower fans 122, 125 arranged point-symmetrically with respect to the center of the display surface 113, that is, diagonally located, or diagonally located panel blower fans 123, 124 may be performed. You may perform interlocking control of.

As described above, according to the second embodiment, the plurality of panel blower fans are individually controlled so that the time change of the air volume becomes non-uniform among the plurality of panel blower fans. As a result, the stagnation point is moved, and temperature unevenness caused by the stagnation point can be reduced or eliminated.

<Example 3>
Hereinafter, Example 3 of the present invention will be described. In the following, configurations different from those of Examples 1 and 2 will be described in detail, and description of the same configurations as those of Examples 1 and 2 will be omitted as much as possible. In the first and second embodiments, the air flow paths (air ducts) from the panel blower fan are provided at four locations including the upper two locations and the lower side of the four sides of the display panel, respectively. Been formed. Specifically, the air ducts 126 and 127 are located at two of the four sides of the liquid crystal panel 102 (four sides of the display surface 113; four sides formed by the opening 114 of the bezel 103) on the upper side (front view). It was provided in two places on the left and right in the state). Then, the air ducts 128 and 129 are provided at two places on the lower side (two places on the left and right in the front view) of the four sides of the liquid crystal panel 102, respectively. In the third embodiment, various arrangements of air flow paths (air ducts) from the panel blower fan will be described. Although an example in which the display panel is a quadrangular panel will be described, the shape of the display panel does not have to be quadrangular.

18 (A) to 18 (D) are schematic front views showing the arrangement of air flow paths (air ducts) from the panel blower fan.

In FIG. 18A, a baffle tube 139 is provided on the upper side of the liquid crystal panel 102 (opening 114), and in FIG. 18B, a baffle tube 140 is provided on the lower side of the liquid crystal panel 102 (opening 114). Has been done. Two panel sending fans are connected to both ends of the air duct 139 (right end and left end in front view; two places indicated by arrows), and the air from the two panel blowing fans is taken from the air duct 139. Is discharged from the upper side to the lower side of the liquid crystal panel 102. Similarly, two panel sending fans are connected to both ends of the air duct 140 (right end and left end in front view; two places indicated by arrows), and the air from the two panel blowing fans is guided. It passes through the air duct 140 and is discharged from the lower side to the upper side of the liquid crystal panel 102.

Depending on the arrangement of the power supply 117 and the like, the region of the liquid crystal panel 102 near the upper side or the lower side of the liquid crystal panel 102 may become hot. According to the arrangement of the air ducts 139 and 140, it is possible to preferably suppress the temperature of the region near the upper side or the lower side of the liquid crystal panel 102 from becoming high. Combining the configurations of FIGS. 18 (A) and 18 (B), as shown in FIG. 18 (C), the air duct 139 and the air duct 140 are provided on the upper side and the lower side (two facing sides) of the liquid crystal panel 102. Each may be provided.

In FIG. 18D, the air duct 139 of FIG. 18A is divided into air ducts 141 and 142 arranged side by side in a front view. In FIG. 18E, the air duct 140 shown in FIG. 18B is divided into air ducts 143 and 144 arranged side by side in a front view. Then, in FIG. 18 (F), the air ducts 141 to 144 are arranged by combining the configurations of FIGS. 18 (D) and 18 (E). In FIGS. 18 (D) to 18 (F), one panel blower fan is connected to each end (point indicated by an arrow) of the air ducts 141 to 144. That is, each of the air ducts 141 to 144 is connected to the panel blower fan on a one-to-one basis. The arrangement of the air ducts 141 to 144 in FIG. 18F is nothing but the arrangement of Examples 1 and 2.

In FIG. 18 (G), four air ducts 139, 140, 145, and 146 are provided on the four sides of the liquid crystal panel 102 (opening 114), respectively. The air introduced into the air duct 139 is discharged from the upper side to the lower side of the liquid crystal panel 102, and the air introduced into the air duct 140 is discharged from the lower side to the upper side of the liquid crystal panel 102. Then, the air introduced into the air duct 145 is discharged from the left side to the right side of the liquid crystal panel 102, and the air introduced into the air duct 146 is discharged from the right side to the left side of the liquid crystal panel 102. According to such a configuration, it is possible to more reliably blow air to the central portion (central region) of the display surface 113 that becomes hot, or to blow air to the display surface 113 entirely.

As shown by the arrows, four panel blower fans are connected to the four air ducts 139, 140, 145, and 146. Each panel blower fan is connected to one end of each of two adjacent air ducts. Specifically, the panel blower fan 147a is connected to one end of the air duct 139 (the left end in the front view) and one end of the air duct 145 (the upper end in the front view). The panel blower fan 147b is connected to one end of the air duct 139 (the right end in the front view) and one end of the air duct 146 (the upper end in the front view). The panel blower fan 147c is connected to one end of the air duct 140 (the right end in the front view) and one end of the air duct 146 (the lower end in the front view). Then, the panel blower fan 147d is connected to one end of the air duct 140 (the left end in the front view) and one end of the air duct 145 (the lower end in the front view). Therefore, the air from one panel blower fan branches into two air ducts, and the air from the two panel blower fans joins in one air duct.

It should be noted that four panel blower fans may be connected to the four air guide tubes 139, 140, 145, 146 on a one-to-one basis. For example, the panel blower fan 147a is only at the left end of the air duct 139, the panel blower fan 147b is only at the upper end of the air duct 146, the panel blower fan 147c is only at the right end of the air duct 140, and the panel blower fan 147d is. It may be connected only to the lower end of the air duct 145.

FIG. 18H is applied to show an example in which the display surface 113 is vertically long. In FIG. 18H, two air ducts 152 and 153 are provided on the two long sides of the display surface 113 (liquid crystal panel 102), specifically, the left side and the right side. As shown by the arrows, two panel feeding fans are connected to both ends of the air duct 152 (upper end and lower end in the front view), and both ends of the air duct 153 (upper end and lower end in the front view). Two panel sending fans are connected to each. The air introduced into the air duct 152 is discharged from the left side to the right side of the liquid crystal panel 102, and the air introduced into the air duct 153 is discharged from the right side to the left side of the liquid crystal panel 102. The distance from the left side to the right side or the center of the liquid crystal panel 102 is shorter than the distance from the upper side to the lower side or the center of the liquid crystal panel 102. Therefore, according to the configuration of FIG. 18H, the liquid crystal panel 102 can be cooled more efficiently than when the air ducts are provided on the short sides (upper side and lower side) of the liquid crystal panel 102. The display device 101 having a vertically long display surface 113 is often installed outdoors, and the present invention can be applied to both indoor devices and outdoor devices.

As described above, the air flow path (air duct) from the panel blower fan can be arranged in various ways. The correspondence between the flow path (blower pipe) and the panel blower fan is not particularly limited, and the flow path and the panel blower fan may correspond one-to-one or one-to-many. It may be a many-to-one correspondence.

<Example 4>
Hereinafter, Example 4 of the present invention will be described. In the following, configurations different from those of Examples 1 to 3 will be described in detail, and description of the same configurations as those of Examples 1 to 3 will be omitted as much as possible. In the second embodiment, the control of the panel blower fan was made different from the control of all the other panel blower fans for each of the panel blower fans 122 to 125. In the fourth embodiment, an example will be described in which the panel blower fans 122 and 123 arranged on the upper surface side are collectively controlled (similarly), and the panel blower fans 124 and 125 arranged on the lower surface side are collectively controlled. ..

19 (A) and 19 (B) are front views showing the flow rate of air to the liquid crystal panel 102. FIG. 20 is a graph showing the time change of the flow rate (air volume) of the air discharged from the panel blower fans 122 to 125. FIG. 19A corresponds to the timing t1 of FIG. 20, and FIG. 19B corresponds to the timing t2 of FIG. In FIGS. 19A and 19B, the arrow F21 indicates the flow rate of the air discharged by the panel blower fan 122, and the arrow F22 indicates the flow rate of the air discharged by the panel blower fan 123. The arrow F23 indicates the flow rate of the air discharged by the panel blower fan 124, and the arrow F24 indicates the flow rate of the air discharged by the panel blower fan 125.

In the state of FIG. 19A, the air flow rates F21 and F22 discharged by the panel blower fans 122 and 123 are minimized, and the air flow rates F23 and F24 discharged by the panel blower fans 124 and 125 are maximized. Then, the state of FIG. 19 (A) is changed to the state of FIG. 19 (B), the flow rates F21 and F22 of the air discharged by the panel blower fans 122 and 123 become maximum, and the panel blower fans 124 and 125 are discharged. The air flow rates F23 and F24 are minimized.

According to the time change of FIG. 20, the state change shown in FIGS. 19 (A) and 19 (B) is periodically repeated. By periodically repeating the state changes shown in FIGS. 19A and 19B, the stagnation point D can be moved up and down on the display surface 113, and the temperature unevenness caused by the stagnation point can be reduced and eliminated. Can be done. The vertical axis of FIG. 20 shows the flow rates F21 to F24 of the air discharged from the panel blower fans 122 to 125, and the horizontal axis of FIG. 20 shows the time. The time change of the flow rates F21 to F24 is represented by a sine wave, and if the period is time P, the panel blower fan 122,
The phase of the sine wave corresponding to 123 is shifted by time P / 2 with respect to the phase of the sine wave corresponding to the panel blower fans 124 and 125.

As described above, according to the fourth embodiment, there are a plurality of corresponding panel blower fans for each of the plurality of sides of the display panel (the plurality of sides of the display surface; the plurality of sides formed by the opening of the bezel). It is controlled collectively (as well). Then, the control of the corresponding plurality of panel blower fans is different among the plurality of sides of the display panel. As a result, the stagnation point is moved, and temperature unevenness caused by the stagnation point can be reduced or eliminated.

The number of sides to which the panel blower fan is associated (sides to which the air duct is provided) is not limited to two. When air ducts are provided on each of the n sides, for example, the n panel blower fans corresponding to the n sides are periodically driven in phases shifted by time P / n. Just do it. Then, a plurality of panel blower fans corresponding to the same side may be periodically driven with the same sine wave (same phase and same period).

Further, the control of the fourth embodiment can be applied to the configuration of FIG. 18 (C), the configuration of FIG. 18 (G), the configuration of FIG. 18 (H), and the like.

<Example 5>
Hereinafter, Example 5 of the present invention will be described. In the following, configurations different from those of Examples 1 to 4 will be described in detail, and description of the same configurations as those of Examples 1 to 4 will be omitted as much as possible. In Examples 1, 2 and 4, four panel blower fans 122 to 125 were provided at four locations, upper right, upper left, lower right, and lower left, respectively, in a front view. In the fifth embodiment, an example will be described in which two panel blower fans 124 and 125 are provided at two locations, a lower right and a lower left, in a front view state without providing the panel blower fans 122 and 123, respectively. That is, an example in which the display device 101 has the configuration shown in FIG. 18 (E) will be described.

21 (A) and 21 (B) are front views showing the flow rate of air to the liquid crystal panel 102. FIG. 22 is a graph showing the time change of the flow rate (air volume) of the air discharged by the panel blower fans 124 and 125. 21 (A) corresponds to the timing t1 of FIG. 22, and FIG. 21 (B) corresponds to the timing t2 of FIG. 22. In FIGS. 21 (A) and 21 (B), the arrow F33 indicates the flow rate of the air discharged by the panel blower fan 124, and the arrow F34 indicates the flow rate of the air discharged by the panel blower fan 125.

In the state of FIG. 21A, the flow rate F33 of the air discharged by the panel blower fan 124 becomes the minimum, and the flow rate F34 of the air discharged by the panel blower fan 125 becomes the maximum. Then, the state of FIG. 21 (A) is changed to the state of FIG. 21 (B), the flow rate F33 of the air discharged by the panel blower fan 124 becomes maximum, and the flow rate F34 of the air discharged by the panel blower fan 125 becomes maximum. It becomes the minimum.

According to the time change of FIG. 22, the state change shown in FIGS. 21 (A) and 21 (B) is periodically repeated. By periodically repeating the state changes shown in FIGS. 21 (A) and 21 (B), the stagnation point D can be moved on the display surface 113, and the temperature unevenness caused by the stagnation point can be reduced or eliminated. be able to. The vertical axis of FIG. 22 shows the flow rates F33 and F34 of the air discharged by the panel blower fans 124 and 125, and the horizontal axis of FIG. 22 shows the time. The time change of the flow rates F33 and F34 is represented by a sine wave, and when the period is time P, the phase of the sine wave corresponding to the panel blower fan 124 is relative to the phase of the sine wave corresponding to the panel blower fan 125. The time is off by P / 2.

As described above, according to the fifth embodiment, the control of the panel blower fan is different among the plurality of panel blower fans corresponding to one side of the display panel. As a result, the stagnation point is moved, and temperature unevenness caused by the stagnation point can be reduced or eliminated. The control of the fifth embodiment can also be applied to the configuration of FIG. 18D.

<Example 6>
Hereinafter, Example 6 of the present invention will be described. In the following, configurations different from those of Examples 1 to 5 will be described in detail, and description of the same configurations as those of Examples 1 to 5 will be omitted as much as possible. In the sixth embodiment, a configuration capable of cooling the liquid crystal panel 102 more efficiently will be described.

FIG. 23 is a front view showing the direction and size of the air outlet 425 (corresponding to the air outlet 131 of the first embodiment) for blowing the air from the panel blower fan onto the display surface 113 of the liquid crystal panel 102. Each of the air ducts 148 to 151 is continuous so as to extend not only to one side (upper side or lower side in the longitudinal direction) of the liquid crystal panel 102 but also to other adjacent sides (left side or right side in the lateral direction). It is formed in an L-shape. That is, the air ducts 148 to 151 are provided on all four sides of the liquid crystal panel 102 (four sides of the display surface 113; four sides formed by the opening 114 of the bezel 103). Since the four panel blower fans 122 to 125 are connected to the four air ducts 148 to 151 on a one-to-one basis, the air from the plurality of panel blower fans is connected to each of the four air ducts 148 to 151. No merging occurs. As a result, the loss (loss of airflow energy) can be reduced as compared with the configuration shown in FIG. 18 (G) (two panel blower fans are connected to both ends of each air duct), and the liquid crystal panel 102. Can be cooled more efficiently.

The plurality of outlets 425 are a plurality of holes arranged along the sides of the liquid crystal panel 102. On each side of the liquid crystal panel 102, the size of the outlet 425 (hole) is smaller as it is closer to the edge of the side and larger as it is closer to the center of the side. Therefore, the air flow rate 421,427 at the air outlet 425 near the edge of the side is smaller than the air flow rate 411,426 at the air outlet 425 near the center of the side.

Also in the sixth embodiment, the four panel blower fans 122 to 125 are periodically driven in a phase shifted by time P / 4 (time P is a cycle). In the periodic drive of the sixth embodiment, for example, interlocking control of the diagonally located panel blower fans 122 and 125 and interlocking control of the diagonally located panel blower fans 123 and 124 are realized. Panel blower fans 122 to 125 are controlled.

As described above, according to the sixth embodiment, air ducts (air flow paths from the panel blower fan) are formed on all sides of the display panel, and the display surface is seen from all sides of the display panel. Air is blown to. As a result, the display panel can be cooled more efficiently. The configuration of the sixth embodiment can be suitably applied when the region having a high temperature is large or when there are a plurality of regions having a high temperature.

<Example 7>
Hereinafter, Example 7 of the present invention will be described. In the following, the configurations different from those of Examples 1 to 6 will be described in detail, and the description of the same configurations as those of Examples 1 to 6 will be omitted as much as possible. In the modified example of Example 1, the outlet 410 (hole) was formed by the partition plate 420 and the spacers 421 and 422. In the seventh embodiment, an example in which the air outlet (hole) is formed by the display panel, the bezel, and the partition plate will be described.

FIG. 24 is a view of the display device 101 viewed from above (upper surface side), and is a cross-sectional view showing the configuration of the display device 101. As shown in FIG. 24, in the seventh embodiment, the liquid crystal is displayed from the peripheral portion 455 of the bezel 103 (the portion far from the central portion of the display area) to the central portion 454 of the bezel 103 (the portion close to the central portion of the display area). The clearance between the panel 102 and the bezel 103 has been increased. Then, the central portion 454 is provided with a partition plate 461 having a height (thickness in the front-rear direction (direction perpendicular to the display surface 113)) larger than that of the partition plate 462 of the peripheral portion 455. Specifically, a plurality of partition plates are provided between the liquid crystal panel 102 and the bezel 103 so that the height of the partition plate becomes larger as it is closer to the central portion 454, and the liquid crystal panel 102, the bezel 103, and the plurality of partition plates are used. Multiple outlets were formed. As a result, the size of the outlet (hole) can be changed according to the position without using the spacers 421 and 422 in the modified example of the first embodiment. That is, a plurality of air outlets can be formed so that the same effect as that of the first embodiment can be obtained with fewer parts (members) than the modified example of the first embodiment.

The bezel 103 may or may not have a curved shape so that a change in clearance with the liquid crystal panel 102 can be realized. It is preferable that the clearance between the liquid crystal panel 102 and the bezel 103 gradually increases from the peripheral portion 455 to the central portion 454, but it is not necessary. The first air outlet (hole) and the second air outlet (hole) whose distance to the specific area (central portion of the display area) is shorter than the first air outlet and larger than the first air outlet. It only needs to be formed.

Further, the slit which is the gap between the liquid crystal panel 102 and the bezel 103 may be used as the air outlet without forming the partition plate. In this case, for example, the width of the slit (clearance between the liquid crystal panel 102 and the bezel 103; the width in the front-rear direction (the direction perpendicular to the display surface 113)) may be increased as it is closer to the specific area (central portion of the display area). .. In other words, the width of the slit may be gradually increased from the peripheral portion 455 to the central portion 454. There may be a portion where the width of the slit gradually decreases from the peripheral portion 455 to the central portion 454.

As described above, according to the seventh embodiment, the display surface (display panel) can be efficiently cooled with a simpler configuration as compared with the comparative example of the first embodiment.

<Example 8>
Hereinafter, Example 8 of the present invention will be described. In the following, the configurations different from those of Examples 1 to 7 will be described in detail, and the description of the same configurations as those of Examples 1 to 6 will be omitted as much as possible. In the first embodiment, each of the air ducts 126 to 129 was composed of only a flexible sheet-like member. In the eighth embodiment, an example in which a part of the air duct is composed of another member originally provided in the display device 101 will be described.

FIG. 25 is a view of the display device 101 viewed from the right side (right side), and is a cross-sectional view showing the air duct 328 according to the eighth embodiment. The air duct 328 includes a frame member 301 which is an internal housing and an internal structure, a bezel 103 which is a front side housing, a display module 112 which is also an internal structure, and a flexible seat member (sheet-like). Member) It is composed of 302a and 302b. The air duct 328 corresponds to the air duct 128 of the first embodiment. The three air ducts corresponding to the air ducts 126, 127, and 129 of the first embodiment are also formed in the same manner as the air duct 328.

The seat member 302a connects the display module 312 and the frame member 301, and the seat member 302b connects the bezel 103 and the frame member 301. It is difficult to form an airtight duct having excellent airtightness only by combining the frame member 301, the bezel 103, and the display module 112. By using the seat members 302a and 302b, the gap between the frame member 301, the bezel 103, and the display module 112 can be closed, and the airtight pipe 328 having excellent airtightness can be formed. Further, by utilizing the existing housing, structure, etc., it is possible to suppress the increase in material cost and form the air duct 328.

The sheet members 302a and 302b are joined to other members (frame member 301, bezel 103, display module 112, etc.) with double-sided tape, an adhesive, or the like. The materials of the sheet members 302a and 302b are, for example, PET (polyethylene terephthalate), PE (polyethylene), PA (polyamide) and the like, and the thickness of the sheet members 302a and 302b is, for example, about 0.1 to 1 mm. Since such sheet members 302a and 302b have flexibility, they can be closely joined to other members, and the airtightness of the air guide pipe 328 can be improved.

The air duct 328 is connected to the panel blower fan 124 by a known method.

As described above, according to the eighth embodiment, a part of the air duct is composed of other members originally provided in the display device 101. As a result, the air duct can be formed while suppressing the increase in material cost.

It should be noted that Examples 1 to 8 (including the above-mentioned modified examples) are merely examples, and configurations obtained by appropriately modifying or changing the configurations of Examples 1 to 8 within the scope of the gist of the present invention. Is also included in the present invention. The present invention also includes configurations obtained by appropriately combining the configurations of Examples 1 to 8.

101: Display device 102: Liquid crystal panel 103: Bezel 122 to 125: Panel blower fan 126 to 129: Air duct 131: Air outlet

Claims (16)

A display panel that displays an image in the display area,
A frame that covers the outer peripheral portion of the display area of the display panel,
Blower and
With
A flow path is formed between the display panel and the frame.
Air is introduced from the blower member into the introduction portion of the flow path,
The introduced air is discharged from the discharge portion of the flow path to the display area side.
The cross section of the flow path obtained by the plane perpendicular to the flow direction in which the air flows in the flow path is the flow direction from the introduction portion rather than the portion at the first distance along the flow direction from the introduction portion. A display device characterized in that a portion at a second distance farther than the first distance is smaller along the above. The display device according to claim 1, wherein the cross section of the flow path becomes smaller as the distance from the introduction portion is increased along the flow direction. The display device according to claim 1 or 2, wherein the blower member sends outside air from the side surface side of the display device to the introduction portion of the flow path inside the display device. The discharge portion is characterized in that the air volume in a specific region which is a part of the display region is formed to be larger than the air volume in the other portion of the display region. The display device according to any one item. The display device according to claim 4, wherein the specific area is an area of a central portion of the display area. A plurality of holes arranged along the sides of the display panel are formed in the discharge portion, each of which connects the inside and the outside of the flow path.
4. Claim 4 is characterized in that at least one of a condition that each direction of the plurality of holes is a direction toward the specific region and a condition that the hole is larger as it is closer to the specific region is satisfied. Or the display device according to 5. A slit along the side of the display panel is formed in the discharge portion to connect the inside and the outside of the flow path.
The display device according to claim 4 or 5, wherein the width of the slit is larger as it is closer to the specific region. The display device according to any one of claims 1 to 7, wherein a plurality of the flow paths are formed between the display panel and the frame. The display device according to claim 8, wherein the plurality of flow paths are formed at least on two opposite sides of the plurality of sides of the display panel. The display device according to claim 8 or 9, wherein the plurality of flow paths are formed on all sides of the display panel. The display device according to any one of claims 8 to 10, wherein the plurality of flow paths are formed at a plurality of points symmetrical with respect to the center of the display panel. The display device according to any one of claims 8 to 11, further comprising a plurality of the blower members. The display device according to claim 12, wherein the plurality of blower members and the plurality of flow paths have a one-to-one correspondence. The display device according to claim 12 or 13, further comprising a control means for individually controlling the plurality of blower members so that the time variation of the air volume becomes non-uniform among the plurality of blower members. .. The control means is characterized in that the blower member corresponding to the other flow paths of the plurality of flow paths is controlled in conjunction with the control of the blower member corresponding to any one of the plurality of flow paths. The display device according to claim 14. Further having a light emitting module that irradiates light on the back surface of the display panel,
The display device according to any one of claims 1 to 15, wherein the display panel displays the image by transmitting light emitted from the light emitting module.

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