JP2008145795A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device of high brightness, high definition, and high reliability by introducing air sucked through an opening of a cover side face on the non-display surface side, to a space between a fixing substrate of flexible cable and display driving substrates by a cooling fan to promote cooling of a high-temperature part of a display panel and promoting cooling of a high-temperature part formed in an upper part of the display panel by cooling air sucked through an opening of a rear cover top face. <P>SOLUTION: In the image display device, an opening is provided in a side face part of a cover on the non-display surface side, and a fixing substrate 3 and display driving substrates 5a and 5b are installed so that a gap between the display driving substrates and a display panel 1 is larger than that between the fixing substrate and the display panel, and the fixing substrate and the display driving substrates are connected by a connector provided with a difference in height between the connection part for the fixing substrate and that of the display driving substrates so that the difference between installation positions of the fixing substrate and the display driving substrates is absorbed, and the display driving substrates are installed between the opening and a cooling fan 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image display device, and more particularly to a heat dissipation technique for a display panel or a display drive substrate of a flat-type image display device such as a plasma display or a liquid crystal display.

  Large flat image display devices such as plasma displays and liquid crystal displays are required to have high brightness and high definition of images. With this, heat generation of display panels and heat generation of display drive substrates are increasing. Cooling has become an issue.

  An image display device that solves problems associated with increased heat generation of the display panel and the display drive substrate is described in, for example, Japanese Patent Application Laid-Open No. 2005-235843 (hereinafter referred to as Patent Document 1). In the invention described in Patent Document 1, a cooling fan for exhaust is installed on the ceiling of the back cover, and cooling is performed by exhausting exhaust heat from the display panel and the display drive substrate.

Japanese Patent Laid-Open No. 2005-235843

  However, the invention described in Patent Document 1 does not take much consideration into the temperature distribution of the display panel. In particular, at the location where the display panel and the display drive substrate are opposed to each other, the flow passage cross-sectional area is small, so that the cooling air flow rate is reduced and the temperature tends to rise locally.

  The display drive board is connected to a fixed board installed at the same interval from the display panel via a connector, and further supplies a drive signal and power to the display panel via a flexible cable. The flexible cable is wider and covers most of the side of the display panel. Therefore, even if there is cooling air that tries to flow into the gap between the display panel and the display drive board from the side of the display panel, the majority is shielded by the flexible cable, fixed board, and display drive board, and it is difficult to promote ventilation cooling of the display panel. There is a problem.

  Furthermore, in the invention described in Patent Document 1, the cooling air sucked into the housing from the opening provided on the lower side of the housing is lifted by the action of buoyancy by natural convection and the cooling fan installed on the back cover ceiling surface. Therefore, a temperature distribution is formed in which the air temperature in the housing increases toward the upper side. Along with this, a temperature distribution is formed which is higher on the upper side and lower on the lower side of the display panel, and there may be a temperature difference of 10 ° C. or more between the upper and lower surfaces. In general, the life of the display panel depends on the highest temperature. Therefore, increasing the air flow of the cooling fan to lower the temperature at the top of the display panel will unnecessarily increase the temperature margin on the lower side of the display panel and reduce fan noise. There is a problem that increases.

  On the other hand, in image display devices, high brightness and high definition of images are progressing year by year, and accordingly heat generation of the display panel and heat generation of the display driving substrate tend to increase. Therefore, there is a need for a cooling structure for an image display device that effectively cools a display panel and a display drive substrate without increasing fan noise.

  In the present invention, the air sucked from the opening on the side surface of the non-display surface side cover is ventilated by a cooling fan through the gap between the fixed substrate of the flexible cable and the display driving substrate, and the cooling of the high temperature portion of the display panel is promoted, The purpose is to provide a high-brightness, high-definition and highly reliable image display device by promoting cooling of the high temperature part formed on the upper part of the display panel by the cooling air sucked from the opening of the back cover ceiling surface To do.

  In order to solve the above problems, an image display device of the present invention is provided on a display panel having an image display surface on the front surface side, and on a back surface side opposite to the image display surface of the display panel. Cable fixing the flexible cable in an image display device comprising: a display driving substrate for driving a display; and a flexible cable connected to the display panel and inputting a signal or power from the display driving substrate to the display panel. A distance between the display driving substrate and the display panel in a direction perpendicular to the image display surface of the display panel is greater than a distance between the cable fixing substrate and the display panel; The substrate and the display driving substrate are electrically connected by a connector.

  According to the present invention, the cooling air flowing in from the opening on the side surface of the housing due to the suction action of the cooling fan causes the display panel and the display drive from the gap generated by the difference in installation position between the cable fixing board and the display drive board. It is possible to reduce a local temperature rise formed in this portion by being ventilated between the substrate and the substrate. Therefore, since the cooling effect can be enhanced without increasing the cooling air volume and fan noise, it is possible to provide an image display device with high brightness, high definition and high reliability.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIGS. 1-6 is explanatory drawing of the 1st Example of this invention. FIG. 1 is a perspective transparent external view of a main part non-display surface side of an image display device as a first embodiment of the present invention. FIG. 2 is a perspective view of the display surface side of the image display device as the first embodiment of the present invention. FIG. 3 is a side perspective perspective external view of the main part of the image display apparatus as the first embodiment of the present invention. FIG. 4 is an enlarged view of a main part when the AA cross section of FIG. 1 is viewed from above. FIG. 5 is an enlarged view of a main part corresponding to the AA cross section of FIG. 1 in the conventional structure. FIG. 6 is an enlarged view of the main part of the AA cross section of FIG.

In FIG. 1, 1 is a display panel, 2 is a flexible cable, 3 is a fixed board, 4 is a connector, 5 is a display drive board, 6 is a power supply board, 7 is a control unit, 8 is a cooling fan, and 9 is a display screen side. Cover, 10 is a non-display surface side cover, 11 is a fixture, 12 is a non-display surface side cover opening, 12a is a left side opening, 12b is a right side opening, 12c is a lower opening, and 12d is Rear side opening, 12e is an upper opening, 13 is a gap between the fixed substrate 3 and the display driving substrate 5,
Reference numeral 15 denotes a component on the display driving substrate 5. In the following, the same function is marked with a different alphabet on the same number, and the description is omitted.

  In the image display device, a surface on which an image is displayed on the display panel 1 in FIG. 1 corresponds to a display surface (front side), and a surface on which a display driving substrate on the back side of the display panel 1 is installed is a non-display surface (back surface). Hereinafter, for convenience of explanation, the horizontal direction is defined as the direction when the image display apparatus is viewed from the display surface side.

A flexible cable 2 is provided at an end of the display panel 1 to supply an image signal and driving power. The flexible cable 2 is often provided on the left and right end surfaces (side surfaces) and the upper and lower end surfaces (upper surface and lower surface) of the display panel 1. In FIG. 1, the flexible cable 2a is provided on the left end surface, the flexible cable 2b is provided on the right end surface, and the flexible cable is provided on the lower end surface. The case where the cable 2c is provided is shown, and the flexible cable 2 is folded in a U shape, and the end is fixed by a fixed substrate 3 installed on the non-display surface side of the display panel 1. By fixing to the fixed substrate 3, the tensile force and shearing force acting on the connecting portion between the flexible cable 2 and the display panel 1 from the outside are alleviated and the disconnection is prevented. The fixed substrate 3 is provided for each group of flexible cables 2. In FIG. 1, the fixed substrate 3a is provided for the flexible cable 2a, the fixed substrate 3b is provided for the flexible cable 2b, and the fixed substrate 3c is provided for the flexible cable 2c. Show the case. In order to distribute and send pixel signals to all the vertical and horizontal pixels of the display panel 1, the flexible cable 2 is installed so as to cover most of the side surface and the lower surface of the display panel 1. A display drive substrate 5 is connected to the fixed substrate 3 via a connector 4. The display drive board 5 is generally provided for each flexible cable 2, and FIG. 1 shows the case where the display drive board 5a is provided for the fixed board 3a and the display drive board 5b is provided for the fixed board 3b. . In addition, a power supply board 6, a control unit 7 having an input / output terminal, a control circuit, and the like, a cooling fan 8, and the like are housed in the casing. FIG. 1 shows a case where two cooling fans, a left cooling fan 8a and a right cooling fan 8b, are mounted. The display panel 1 and each device are surrounded by a display surface side cover 9 and a non-display surface side cover 10 as a case from the outside, and a fixture 11 is mounted to constitute the case. The non-display surface side cover 10 is provided with a plurality of openings 12. In FIG. 1, a left side opening 12a, a right side opening 12b, a lower side opening 12c, a back side opening 12d, and an upper opening 12e are provided. It shows the state that is being done. Although the detailed shape of the opening is not shown, it is assumed to be composed of a perforated plate, a slit, a mesh or the like. Here, with respect to the lower opening 12c, the back opening 12d, and the upper opening 12e, some of these openings may not be provided. The cooling fans 8a and 8b have openings 12a and 12a, respectively.
The display drive substrates 5a and 5b are arranged between the cooling fan 12a and the cooling fans 8a and 8b.

In the above configuration, when the cooling fans 8a and 8b in FIG. 1 are operated so that a flow is generated from the inside of the housing to the outside of the housing, cooling air flows into the housing from the opening 12. When the flow path structure around the display drive substrate 5 is seen in FIG. 3 and FIG. 4 which is a cross section along AA in FIG. 1, the flow entering from the left side opening 12a is shielded by the U-shaped flexible cable 2a. It flows to the back side of the flexible cable 2a and the fixed substrate 3a, and is hardly ventilated between the display panel 1 and the fixed substrate 3a. Here, as shown in FIGS. 3 and 4, the distance between the display drive substrate 5a and the display panel 1 is made larger than the distance between the fixed substrate 3a and the display panel 1, and the fixed substrate 3a is an image display device. The fixed substrate 3a and the display drive substrate 5a are arranged so that the outer side in the left-right direction (the side closer to the housing side opening 12a) and the display drive substrate 5a is the inner side in the left-right direction of the image display device (side closer to the cooling fan 8a). Then, the fixed substrate 3a and the display drive substrate 5a are connected by the connector 4 provided with a difference in the height of the connection portion between the fixed substrate 3a and the display drive substrate 5a so as to absorb the difference in installation position. Ventilation by suction of a fan is induced between the display panel 1 and the display drive substrate 5a from the gap 13a between the fixed substrate 3a and the display drive substrate 5a. Where the display panel 1 and the display drive substrate 5a face each other, the temperature tends to rise locally, but in the present invention, the relatively low temperature cooling air introduced from the outside of the housing is directly applied. Since it can supply to a temperature rise part, the effect which can implement | achieve the temperature reduction of the high temperature part of the display panel 1 is acquired.

  For comparison, the positional relationship between the display driving substrate 5 and the fixed substrate 3 in the conventional structure is shown in FIG. In the conventional structure, the distance between the display drive substrate 5 and the display panel 1 is substantially the same as the distance between the fixed substrate 3 and the display panel 1, and the substrates are connected by a connector 4 having no step. However, in this conventional structure, the gap 13a between the fixed substrate 3 and the display driving substrate 5 is small, and the opening direction of the gap 13a is perpendicular to the direction of flow, so that the gap 13a enters from the left side opening 12a. The cooling air passes through the back side of the display drive substrate 5 while being shielded by the U-shaped flexible cable 2 a, and hardly flows between the display panel 1 and the display drive substrate 5. Therefore, in the conventional structure, the cooling effect of the location where the display panel 1 and the display drive substrate 5 face each other is small.

  In addition, if the distance between the fixed substrate 3 and the display drive substrate 5 and the display panel 1 is made approximately the same, a cooling effect can be obtained by increasing the cross-sectional area of the flow path, but there is no change in the width and structure of the gap 13a. The cooling air is shielded by the flexible cable 2 a, and most of the cooling air having a low temperature flowing from the side opening 12 cannot be directly supplied between the display panel 1 and the display driving substrate 5.

  In the first embodiment of the present invention shown in FIG. 4, the distance between the display drive substrate 5 and the back cover 10 is smaller than that in the conventional structure shown in FIG. The cooling of the display panel 1 and the cooling of the display panel 1 are accelerated, and the temperature of the component 15a on the substrate is lowered, and in particular, protrusion to the back side becomes a problem. Even when the height of many heat sinks is reduced, the guaranteed temperature of parts can be satisfied. Therefore, even when the distance between the display drive substrate 5 and the back cover 10 is reduced, the distance between the backmost part of the component 15a on the substrate and the back cover can be kept constant, and the housing can be thinned in the front-rear direction. It is not a hindrance.

  Although the structure of the left side surface portion has been described here, the same effect can be obtained with the same configuration for the flexible cable 2b, the fixed substrate 3b, the display drive substrate 5b, and the fan 8b on the right side surface portion.

  The connector 4 has a structure in which the display driving board 5 is moved in the left-right direction and connected to the fixed board 3 side. However, the structure is not limited to this structure. For example, as shown in FIG. The display drive substrate 5 may be moved in the direction and connected to the fixed substrate 3 side.

  7 and 8 are explanatory views of the second embodiment of the present invention. In FIG. 7, 14 is a windshield, and in FIG. 8, 16 is a heat sink.

  In the second embodiment of the present invention, as shown in FIG. 7, there is a shielding between the non-display surface side cover 10 and the display driving substrate 5 and between the side surface opening 13a and the cooling fan 8a. The structure is provided with a wind plate 14. Since the amount of air that has passed through the back side of the display drive substrate 5 by the wind shielding plate 14 can be concentrated and supplied between the display panel 1 and the display drive substrate 5, the display panel 1 is cooled. Especially can be promoted.

  In the second embodiment of the present invention, a heat sink is used as the wind shield 14 as shown in FIG. In many cases, a heat sink 16 is installed to promote cooling of the components 15 on the display drive substrate 5. However, by installing the heat sink 16 as the wind shield 14 on the fixed substrate 3 side on the display drive substrate 5. Further, ventilation between the display panel 1 and the drive display substrate 5 can be promoted without providing additional components, and cooling of the components 15 can be facilitated because the cooling air collides with the heat sink 16.

  The third embodiment of the present invention will be described with reference to FIG.

  In FIG. 1, reference numeral 17 denotes a cooling fan exhaust surface. The exhaust surface of the left cooling fan 8a is 17a, and the exhaust surface of the right cooling fan 8b is 17b. Further, the total opening area of the cooling fan exhaust surface 17 is represented as Afan.

In FIG. 1, the non-display surface side cover 10 is provided with a plurality of openings 12. In FIG. 1, a left side opening 12a, a right side opening 12b, a lower side opening 12c, a back side opening 12d, and an upper part are provided. The state in which the opening part 12e is provided is shown. Although the detailed shape of the opening is not shown, it is assumed to be composed of a perforated plate, a slit, a mesh or the like. Here, regarding the left side opening 12a, the right side opening 12b, the lower side opening 12c, and the back side opening 12d, some of these openings may not be provided. Here, the total opening area of the upper opening 12e
Let it be expressed as Ainlet.

  In the third embodiment of the present invention, the cooling fans 8a and 8b are installed on the back side of the non-display surface side cover 10 as a structure that acts as an exhaust fan that vents outward from the inside of the housing, and the upper opening 12e. It is set as the structure installed in the ceiling surface of the non-display surface side cover 10. Further, the total opening area Ainlet of the upper opening 12e is larger than the total opening area Afan of the cooling fan exhaust surface 17. Further, the display drive substrate 5 has a structure positioned between the cooling fan 8 and the upper opening 12e on a plane parallel to the display panel 1.

  According to the above configuration, the cooling air flowing into the housing from the upper opening 12e is directly supplied to the upper part of the display panel 1 whose temperature has been increased due to the upward flow due to natural convection, thereby cooling the display panel. After that, the air is sucked into the cooling fan 8 and exhausted outside the housing, so that the temperature of the upper part of the display panel 1 can be greatly reduced. On the upper side when viewed from the cooling fan, the upward flow due to natural convection and the downward flow due to fan suction face each other, but the total opening area Ainlet of the upper opening 12e is larger than the total opening area Afan of the cooling fan exhaust surface 17. If it is large, it has been confirmed with actual equipment that the downward flow by the fan is overwhelmingly dominant. Further, since a part of the cooling air flowing in from the upper opening 12e passes through the upper part of the display drive substrate 5 where the temperature is likely to rise and is sucked by the cooling fan 8, an effect of promoting the cooling of the display drive substrate 5 is obtained. It is done. On the other hand, since the intake from the upper side when viewed from the cooling fan is increased, the intake from the lower side is reduced accordingly, but the lower side of the display panel 1 is often lower in temperature by 10 ° C. or more than the upper side. The impact is minor.

  As shown in Patent Document 1, a method of directly mounting the cooling fan 8 on the ceiling surface of the non-display surface side cover 10 has already been proposed. When the opening 12e is provided, the upper opening 12e and the cooling fan 8 are close to each other. Therefore, the cooling fan 8 sucks the cooling air sucked from the upper opening 12e before the temperature rises sufficiently, and the outside of the casing. As a result, the temperature of the display panel 1 cannot be sufficiently reduced. Further, since the temperature of the cooling air sucked from the lower opening 12c gradually increases in the process of rising due to natural convection and fan suction, it is not possible to effectively promote the cooling of the high temperature portion at the upper part of the display panel 1.

  On the other hand, in the present embodiment, it is possible to reduce the maximum temperature of the display panel 1 by directly cooling the upper part of the display panel 1 that is likely to reach the highest temperature, and the upper and lower temperature distribution of the display panel 1. Since the temperature is uniformed and the thermal stress inside the display panel 1 is reduced, it is possible to provide a reliable image display device in terms of temperature and strength.

1 is a perspective view of an essential part non-display surface side perspective view of an image display device as a first embodiment of the present invention. 1 is a perspective view of a display surface side of an image display device as a first embodiment of the present invention. 1 is a side perspective perspective external view of an essential part of an image display device as a first embodiment of the present invention. The principal part enlarged view which looked at the AA cross section of FIG. 1 from the upper side. The principal part enlarged view equivalent to the AA cross section of FIG. 1 in a conventional structure. The principal part enlarged view which looked at the AA cross section of FIG. 1 which changed the connector structure from the upper side. Explanatory drawing of the 2nd Example of this invention. Explanatory drawing of the 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display panel 2 Flexible cable 3 Fixed board 4 Connector 5 Display drive board 6 Power supply board 7 Control unit 8 Cooling fan 9 Display surface side cover 10 Non-display surface side cover 11 Fixture 12 Non-display surface side cover opening 12a Left side surface Opening 12b Right side opening 12c Lower side opening 12d Rear side opening 12e Upper opening 13 Gap 14 between fixed substrate 3 and display drive substrate 5 Wind shield 15 Component 16 on display drive substrate 5 Heat sink 17 Cooling fan Exhaust surface

Claims (7)

A display panel having an image display surface on the front side;
A display driving substrate that is provided on the back side opposite to the image display surface of the display panel and drives the display panel;
In an image display device comprising a flexible cable connected to the display panel and inputting a signal or power from the display driving substrate to the display panel,
A cable fixing substrate for fixing the flexible cable;
The distance between the display drive substrate and the display panel in a direction perpendicular to the image display surface of the display panel is greater than the distance between the cable fixing substrate and the display panel,
The image display device, wherein the cable fixing substrate and the display driving substrate are electrically connected by a connector. In claim 1,
The width of the connector is smaller than the width of the flexible cable. In claim 1,
Covering the back side of the display panel, and having a housing that encloses the display driving substrate and the cable fixing substrate,
The housing has a fan for blowing air from the inside to the outside,
An image display device comprising: an opening provided on a side of the housing where the flexible cable is disposed. In claim 3,
The image display device, wherein the display drive substrate is between the fan and the opening on a plane parallel to the display panel. In claim 4,
An image display device comprising a wind shielding plate or a heat sink between the housing and the display driving substrate. A display panel having an image display surface on the front side;
A display driving substrate that is provided on the back side opposite to the image display surface of the display panel and drives the display panel;
In an image display device comprising a flexible cable connected to the display panel and inputting a signal or power from the display driving substrate to the display panel,
A cable fixing substrate for fixing the flexible cable;
The distance between the display drive substrate and the display panel in a direction perpendicular to the image display surface of the display panel is greater than the distance between the cable fixing substrate and the display panel,
The cable fixing board and the display driving board are electrically connected by a connector,
Covering the back side of the display panel, and having a housing that encloses the display driving substrate and the cable fixing substrate,
The housing has a fan for blowing air from the inside to the outside,
An image display device comprising: an opening provided on a side of the housing where the flexible cable is disposed. A flat display panel, a display surface side cover installed on the display surface side of the display panel, one or more non-display surface side covers installed on the non-display surface side, a display drive substrate, In an image display device including a cooling fan that exhausts air from inside the non-display surface side cover,
The cooling fan is installed on the back surface of the non-display surface side cover, and a plurality of openings having a total opening area larger than the cooling fan exhaust area are provided on the ceiling surface of the non-display surface side cover, Is located between the cooling fan and the opening on a plane parallel to the display panel.

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