JP2012208521A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in maintainability and occurrence of useless space in a liquid crystal display device arranging a plurality of LED substrates mounted with LEDs at a back side of a liquid crystal panel, and also to prevent LED light leakage and leakage of unnecessary radiation from the LED substrates.SOLUTION: A liquid crystal display device comprises: a plurality of LED substrates 30 arranged at a back side of a liquid crystal panel 20; a plurality of connection members 60 between substrates which electrically connect adjacent LED substrates 30 at each back; a back light chassis 40 for supporting a plurality of the LED substrates 30 at the back and having apertures 40a formed at a portion corresponding to each mounted position of the plurality of the substrate connection members 60 between substrates; and a removable chassis tray 50 covering the back light chassis 40 at the back to shade light leaked from the apertures 40a.

Description

  The present invention relates to a liquid crystal display device in which a liquid crystal panel is illuminated from the back side by irradiation light of an LED.

In recent years, in a liquid crystal display device typified by a liquid crystal television receiver, there is an increasing demand for expanding the color reproduction range and improving the image quality. In order to meet this demand, recently, a liquid crystal display device including a liquid crystal panel illuminated by a backlight using an LED having high emission color purity as a light source is becoming widespread. A liquid crystal display device using an LED as a light source for backlight realizes a color reproduction range wider than that of the general sRGB standard, and can display an image of a brighter (higher saturation) color than the conventional one.
A liquid crystal display device using an LED as a light source for backlight is a backlight chassis that supports a liquid crystal panel, an LED mounting substrate (hereinafter referred to as an LED substrate), and the LED substrate on the back side from the front side to the back side. It has a laminated structure in which (LED substrate support members) are arranged to overlap.

On the other hand, liquid crystal display devices have been diversified in screen size (the size of a liquid crystal panel), and products having various screen sizes are provided on the market.
Therefore, in a liquid crystal display device using LEDs as a light source for backlight, the LED substrate opposed to the back side of the liquid crystal panel is a relatively small-sized substrate on which a small number of LEDs are mounted, and the number and arrangement of the LED substrates. Is appropriately changed according to the screen size. This is because in various liquid crystal display devices having various screen sizes, the LED substrate can be used in common, and effects such as shortening the design period and cost reduction can be obtained.
In Patent Document 1, a display panel unit is supported by a top bracket disposed above and a chassis plate disposed below, and the mounting positions of the top bracket and the chassis plate correspond to the size of the display panel. The configuration to be selected is shown.

By the way, when a plurality of LED substrates are arranged on the back side of the liquid crystal panel, a member (hereinafter referred to as an inter-substrate connecting member) for electrically connecting each LED substrate, for example, a connector for connecting to the LED substrate is provided. FPCs (Flexible Printed Circuits), harnesses, etc. must be provided.
In addition, due to the demand for thinning the device, the space between the liquid crystal panel and the LED substrate is very narrow, and a light guide plate for light diffusion is arranged in this narrow space. Therefore, the inter-substrate connecting member is mounted on the back side of the LED substrate, that is, on the side opposite to the side where the liquid crystal panel is located (front side).

JP 2007-334244 A

However, when the LED substrate is connected by the inter-substrate connecting member mounted on the back side, the inter-substrate connecting member portion protrudes to the back side of the LED substrate. For this reason, the LED board is disposed on the support surface of the backlight chassis at a distance corresponding to the protruding height of the inter-board connection member, and is wasted on the front side of the backlight chassis (the support surface side of the LED board). There is a problem that a large space is generated and it is difficult to meet the demand for thinning the liquid crystal display device. Further, in this case, when the backlight is maintained, the inter-substrate connecting member cannot be attached / detached unless the LED substrates are removed from the backlight chassis, resulting in poor maintenance.
This problem can be solved by providing an opening in a portion corresponding to the mounting position of the inter-substrate connecting member of the backlight chassis and projecting the inter-substrate connecting member from this opening. In this case, the backlight chassis can be arranged close to the LED board, no useless space is generated on the front side of the backlight chassis, and the inter-board connecting member can be detached from the back side of the backlight chassis through the opening. And maintainability is improved.
However, if an opening is provided in the backlight chassis, there is a problem in that light emitted from the LEDs in the backlight chassis leaks to the back side through the gaps between the LED boards and the openings in the backlight chassis. Further, since the leaked light leaks to the outside of the apparatus through the heat radiating hole of the back side cabinet (exterior), there is a problem that the quality of the product is lowered. In addition, the state where the light emission of the LED leaks to the outside of the device is a state in which floating substances such as dust and lime (lime) are likely to enter the backlight chassis from the outside of the device. It also leads to a decline in the lighting performance of the LCD panel.
Further, there is a problem that unnecessary radiation generated from the LED substrate that is subjected to PWM control at a high frequency leaks to the outside from the opening of the backlight chassis and may become noise of other devices.
The present invention has been made in view of the above circumstances, and an object thereof is to arrange a plurality of LED substrates on which LEDs are mounted side by side on the back side of a liquid crystal panel, and connect adjacent LED substrates to each other. In a liquid crystal display device connected by members, it is possible to prevent deterioration of maintainability and generation of useless space, and also prevent leakage of LED light and unnecessary radiation from the LED substrate.

  The liquid crystal display device according to the present invention is a liquid crystal display device in which a liquid crystal panel is illuminated from the back side thereof by irradiation light of the LED, each of which is mounted with a plurality of LEDs arranged side by side on the back side of the liquid crystal panel. LED substrates, a plurality of inter-substrate connection members that are mounted on the back surfaces of the LED substrates and electrically connected to adjacent LED substrates, and a member that supports the plurality of LED substrates from the back surface side, An LED board support member having an opening provided in a portion corresponding to the mounting position of each of the plurality of inter-board connection members, and the LED board support member is mounted so as to cover the back side, and leaks light from the openings. And a light shielding member that shields light.

In the present invention, since the light shielding member is mounted so as to cover the back side of the LED substrate support member provided with an opening at a position corresponding to the inter-substrate connection member, the LED light in the LED substrate support member It is possible to prevent leakage from the gap and the opening provided in the LED substrate support member to the back side. The light shielding member also serves to prevent leakage of unnecessary radiation from the LED substrate. The LED substrate support member is a member corresponding to the backlight chassis.
Moreover, by removing the light shielding member, the inter-board connecting member mounted on the back surface of each LED substrate can be seen from the opening of the LED substrate supporting member, and the connection state, the presence or absence of damage, etc. can be confirmed. There is no need to remove each LED substrate from the main body, so that the maintainability is not deteriorated.
In addition, the inter-substrate connecting members of the adjacent LED substrates can be protruded to the back side through the openings provided in the LED substrate supporting member, and the LED substrate can be disposed close to the LED substrate supporting member, which is useless. It can eliminate the space and meet the demand for thinner equipment.

Further, in the liquid crystal display device according to the present invention, the LED board support member has a circuit board attachment portion on a surface opposite to the surface supporting the LED substrate, and the light shielding member is provided on the attachment portion. An opening provided at a corresponding position and a removable cover member that closes the opening are provided.
The back surface of the LED substrate support member (the surface opposite to the support surface of the LED substrate) can be effectively used as a mounting space for circuit boards such as LED control boards, LED power supply boards, and panel control boards. Will increase.
The circuit board attached to the back surface of the LED board support member can be inspected without removing the light shielding member through the opening provided to correspond to the attachment portion. Further, the opening of the light shielding member can be blocked by a detachable cover member, thereby preventing leakage of light, unwanted radiation, etc. to the outside.
Further, in the liquid crystal display device according to the present invention, the light shielding member is arranged at an interval that regulates a range in which the inter-substrate connecting member can protrude from the opening of the LED substrate supporting member with respect to the LED substrate supporting member. It is characterized by being.
It is possible to prevent the inter-substrate connecting member from being lifted off from the LED substrate, or coming out of the LED substrate by the restriction of the light shielding member, and it is difficult for the inter-substrate connecting member to contact the LED substrate.

In addition, the liquid crystal display device according to the present invention includes a sheet-like heat transfer member sandwiched between the LED substrate support member and the light shielding member.
The heat generation of the LED substrate due to the light emission of the LED is transmitted from the LED substrate support member to the light shielding member via the heat transfer member, and can be effectively radiated from the light shielding member to the outside air. It is possible to prevent the space between them from being overheated.
Furthermore, the liquid crystal display device according to the present invention is characterized in that the LED substrate support member and the light shielding member are metal members.
The metal LED substrate support member and the light shielding member can promote the heat radiation of the LED substrate to the outside, and can more reliably prevent unnecessary radiation from leaking to the outside.

  According to the present invention, in a liquid crystal display device in which a plurality of LED substrates mounted with LEDs are arranged side by side on the back side of the liquid crystal panel, it is possible to prevent deterioration of maintainability and generation of useless space, Leakage of unwanted radiation from the substrate to the outside can be prevented.

It is an exploded view of the liquid crystal display device concerning an embodiment. It is an exploded view of the front panel unit in a liquid crystal display device. It is a top view of the backlight chassis which supports an LED board. It is sectional drawing of the principal part of a front panel unit. It is an enlarged view of the opening part provided in the backlight chassis.

Embodiments of the present invention will be described below with reference to the accompanying drawings for understanding of the present invention. In addition, the following embodiment is an example which actualized this invention, Comprising: It is not the thing of the character which limits the technical scope of this invention.
FIG. 1 is an exploded view of the liquid crystal display device according to the embodiment. FIG. 2 is an exploded view of the front panel unit in the liquid crystal display device. FIG. 3 is a plan view of a backlight chassis that supports the LED substrate. FIG. 3A is a view from the front side, and FIG. 3B is a view from the back side. FIG. 4 is a cross-sectional view of a main part of the front panel unit. FIG. 5 is an enlarged view of an opening provided in the backlight chassis.

The liquid crystal display device X according to the embodiment is a liquid crystal display device in which a liquid crystal panel is illuminated from the back side by irradiation light of an LED.
First, a schematic configuration of the liquid crystal display device X will be described with reference to FIGS.
As shown in FIG. 1, the liquid crystal display device X includes a front panel unit 2 in which a liquid crystal panel 20 is incorporated, and a back panel unit 1 that is mounted so as to cover the back side thereof and forms an exterior. . In the following description, the side on which the liquid crystal panel 20 is located is referred to as the front side, and the side on which the back panel unit 1 is located is referred to as the back side.
As shown in FIG. 2, the front panel unit 2 is a unit in which the front panel frame 10, the liquid crystal panel 20, the LED substrate 30, the backlight chassis 40 and the chassis tray 50 are assembled together.
The liquid crystal panel 20 includes a glass panel, a light diffusion plate, an optical sheet, and the like in which liquid crystal is incorporated, and is attached to the inside of the front panel frame 10.
The LED substrate 30 is supported on the front side of the backlight chassis 40. In FIG. 2, the LED substrate 30 is hidden on the front side of the backlight chassis 40.

As shown in FIG. 3A, the LED substrate 30 is a relatively small substrate on which a plurality of LEDs 31 that are light sources for a backlight are mounted. In the liquid crystal display device X, the plurality of LED substrates 30 are supported on the front surface of the backlight chassis 40 in a state of being arranged side by side on the back side of the liquid crystal panel 20.
The number and arrangement of the LED substrates 30 are determined according to the screen size of the liquid crystal display device X (the size of the liquid crystal panel 20). In the liquid crystal display device X, a common LED substrate 30 is used regardless of the screen size.
As shown in FIG. 3B, adjacent LED substrates 30 are connected by an inter-substrate connection member 60. The inter-substrate connecting member 60 is detachably attached to the back surface of each LED substrate 30. As shown in FIG. 3B, a plurality of inter-substrate connection members 60 are provided, and each of them electrically connects two LED substrates 30 adjacent to each other on the left and right.

As shown in FIG. 3, the backlight chassis 40 (an example of an LED board support member) is a metal member that supports the back side of the plurality of LED boards 30 arranged as described above. The chassis 40 is provided with openings 40 a at portions corresponding to the mounting positions of the plurality of inter-substrate connection members 60 that connect the adjacent LED substrates 30.
As shown in FIG. 5, the inter-substrate connection member 60 includes, for example, two connectors 61 for connection to the LED substrate 30 and a conductive portion 62 that electrically connects the two connectors 61. Yes. The conductive portion 62 is configured by, for example, FPC (Flexible Printed Circuits).
As shown in FIG. 5, the conducting portion 62 of the inter-substrate connection member 60 corresponds to the mounting state of the inter-substrate connection member 60 in which the connector 61 is connected to the LED substrate 30 supported by the backlight chassis 40 at both ends, as shown in FIG. 5. It protrudes to the back side of the backlight chassis 40 through an opening 40a provided in the portion.
Note that the connector 61 of the inter-board connection member 60 is connected to each LED board 30 by being inserted into a receiving connector 32 (see FIG. 4) provided on the back surface thereof.

The chassis tray 50 (an example of a light shielding member) is a metal plate-like member that is mounted so as to cover the back surface of the backlight chassis 40 (the surface opposite to the support surface of the LED substrate 30). The chassis tray 50 is a member that blocks light leaking from the opening 40a provided in the backlight chassis 40, and is detachably attached to the backlight chassis 40 with screws or the like.
As shown in FIG. 2, a power source that rectifies by inputting AC power from an external power source (commercial power source) to the rear surface of the chassis tray 50 (a surface opposite to the surface facing the backlight chassis 40). An input board 51, a power supply board 52 that performs voltage transformation and power supply according to the application, and a signal interface board 53 that exchanges control signals and AV signals with external devices are attached.
Further, a metal heat sink 56 for efficiently radiating the heat is attached to the attachment portion of the signal interface board 53 on the rear surface of the chassis tray 50. The heat sink 56 also functions as a shield member that blocks unnecessary radiation from the signal interface board 53.

Further, on the back surface of the backlight chassis 40 (surface opposite to the support surface of the LED board 30), for example, an LED control board 41 that outputs a PWM signal (signal for controlling blinking of the LED 31) to the LED board 30, Circuit boards such as an LED power supply board 42 that supplies power to the LED board 30 and a panel control board 43 that controls the liquid crystal panel 20 are attached.
Further, a metal heat sink 44 for efficiently radiating the heat is attached to the panel control board 43 on the back surface of the backlight chassis 40. The heat sink 44 also functions as a shield member that blocks unnecessary radiation from the panel control board 43.
Furthermore, the chassis tray 50 is provided with openings 50a and 50b at positions corresponding to the mounting portions of the LED control board 41 and the LED power supply board 42 on the back surface of the backlight chassis 40, and the openings 50a and 50b are respectively provided with openings 50a and 50b. Removable metal cover members 54 and 55 are provided to close each of them. The cover members 54 and 55 are attached to the chassis tray 50 by screws or the like, and block light leakage from the backlight chassis 40 side, block unnecessary radiation, and prevent leakage to the outside. Also functions as a shield member.

Next, the internal structure of the front panel unit 2 will be described with reference to the cross-sectional view shown in FIG. In addition, the lower side and upper side of FIG. 4 are the front side and the back side in the liquid crystal display device X, respectively. As shown in FIG. 4, the LED substrate 30 is supported on the front surface of the backlight chassis 40, and the chassis tray 50 faces the back surface of the backlight chassis 40 with a predetermined interval.
As shown in FIG. 4, a receiving connector 32 to which the connector 61 of the inter-substrate connecting member 60 is connected is provided on the back surface of the LED substrate 30. The inter-substrate connecting member 60 can be connected to the LED substrate 30 from the back side of the backlight chassis 40 using the opening 40 a provided in the backlight chassis 40.
As shown in FIG. 4A, the opening 40 a provided in the backlight chassis 40 is covered by a chassis tray 50 facing the back side of the backlight chassis 40, and the LED 31 mounted on the LED substrate 30. Can be prevented from leaking to the back side of the backlight chassis 40 through the gaps between the LED substrates 30 and the openings 40a.
Further, the backlight chassis 40 tends to be insufficient in strength and rigidity due to the provision of many openings 40a. The chassis tray 50 attached to the back surface of the backlight chassis 40 functions to support the backlight chassis 40 from the back surface side and compensate for lack of strength and rigidity. As a result, the backlight chassis 40 has sufficient strength and rigidity as a member for supporting a number of LED boards 30 and circuit boards such as the LED control board 41, the LED power supply board 42, and the panel control board 43.
When the chassis tray 50 is removed, the inter-board connection member 60 that connects the adjacent LED boards 30, 30 protrudes through the corresponding opening 40 a provided in the backlight chassis 40 on the back side. Therefore, the operation (detachment) of the inter-substrate connecting member 60 can be performed from the back side of the backlight chassis 40 using the respective openings 40a, the LED substrate 30 is not required to be removed, and the maintainability is deteriorated. Not invited.

Further, as shown in FIG. 4, the inter-board connection member 60 protrudes to the back side of the backlight chassis 40 through the respective openings 40a, so that the backlight chassis 40 and the LED board 30 can be disposed close to each other. And no useless space is created on the front side of the backlight chassis 40.
In addition, since the chassis tray 50 is provided with openings 50a and 50b that allow the LED control board 41 and the LED power supply board 42 to pass to the back side, the chassis tray 50 and the backlight chassis 40 can be disposed close to each other. There is no wasted space on the front side of the tray 50.

The chassis tray 50 is located near the inter-board connecting member 60 that protrudes toward the back side of the backlight chassis 40 through the opening 40a, and is disposed at an interval that regulates the range in which the inter-substrate connecting member 60 can be protruded. .
As a result, as shown in FIG. 4B, when the inter-board connecting member 60 starts to float from the LED board 30, it contacts the front surface of the chassis tray 50 at the initial stage, and the inter-board connecting member 60 It is prevented that it floats off further or becomes detached. As a result, contact failure of the inter-substrate connection member 60 with respect to the LED substrate 30 can be prevented.

As shown in FIG. 4, a sheet-like heat transfer member 70 is interposed between the backlight chassis 40 and the chassis tray 50 so as to be sandwiched between the two.
Thereby, the heat generated in the LED substrate 30 due to the light emission of the LED 31 is favorably transmitted to the chassis tray 50 through the backlight chassis 40 and the heat transfer member 70 and is easily radiated through the chassis tray 50. It is possible to prevent the space between the chassis tray 50 from being overheated.

X liquid crystal display device 1 rear panel unit 2 front panel unit 10 front panel frame 20 liquid crystal panel 30 LED substrate 31 LED
40 Backlight chassis (LED support member)
40a Opening 41 LED control board 42 LED power supply board 43 Panel control board 44 Heat sink 50 Chassis tray (light shielding member)
51 Power Input Board 52 Power Supply Board 53 Signal Interface Board 54, 55 Cover Member 56 Heat Sink 50a, 50b Opening 60 Inter-board Connection Member 61 Connector 62 Conducting Part 70 Heat Transfer Member

Claims (5)

A liquid crystal display device in which a liquid crystal panel is illuminated from the back side thereof by irradiation light of the LED, each of the LEDs being mounted, and a plurality of LED substrates arranged side by side on the back side of the liquid crystal panel;
A plurality of inter-substrate connection members mounted on the back surfaces of the plurality of LED substrates and electrically connected to adjacent LED substrates;
An LED substrate support member that supports the plurality of LED substrates from the back side, and an opening is provided in a portion corresponding to the mounting position of each of the plurality of inter-substrate connection members;
A liquid crystal display device comprising: a light shielding member which is attached to the LED substrate support member so as to cover a back side and shields light leaking from the opening. The LED board support member has a circuit board mounting portion on a surface opposite to a surface supporting the LED board,
The liquid crystal display device according to claim 1, wherein the light shielding member includes an opening provided at a position corresponding to the attachment portion, and a detachable cover member that closes the opening.   The said light shielding member is arrange | positioned at the space | interval which regulates the range which the said board | substrate connection member can project from the opening of this LED board support member with respect to the said LED board support member. Liquid crystal display device.   The liquid crystal display device according to any one of claims 1 to 3, further comprising a sheet-like heat transfer member sandwiched between the LED substrate support member and the light shielding member.   The liquid crystal display device according to claim 1, wherein the LED substrate support member and the light shielding member are metal members.

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