JP2009026611A - Backlight device and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backlight device capable of attaining miniaturization and space saving by shortening the length of a support member and a pressing member in their thickness direction of an optical member by providing a movement stopper in the optical member, and a display device equipped with it. <P>SOLUTION: This backlight device 2 is equipped with a cold cathode ray tube 8 disposed on the back side of a liquid crystal panel 1, an optical member 3 composed of laminated optical sheets 31-34 and a diffusion sheet 35 and disposed between the cold cathode ray tube 8 and the liquid crystal panel 1, an optical member receiving part 61 to support the peripheral part of the optical member 3 from the cold cathode ray tube 8 side, and an optical member pressing part 7 which presses the peripheral part of the optical member 3 to sandwich the optical member 3 together with the optical member receiving part 61, and the display device is equipped with this backlight device. The optical member 3 has a movement stopper 311 formed by almost perpendicularly bending the peripheral part of the optical sheet 31 toward the cold cathode ray tube 8, and the movement stopper 311 faces the restricting part 62 perpendicular to the optical member receiving part 61. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a backlight device that is built in a display device such as a liquid crystal display device and includes a backlight and an optical member, and a display device including the backlight device.

  A display device having a flat display panel has been popularized by replacing the use of a CRT display because of its thinness and low power consumption. In addition, with the trend of increasing the size of display devices, attempts to differentiate the products by making them thinner have become active.

A backlight device (a so-called direct type backlight device) in which a backlight is disposed on the back side of a display panel displays an optical member by holding an optical member in which an optical sheet is laminated between the backlight and the display panel. We are trying to improve the quality. As a structure for holding an optical member, Patent Document 1 discloses a technique for supporting an optical member while using a guide member to guide a housing position of the optical member. Patent Document 2 discloses a technique in which an optical member having a peripheral portion bent toward a backlight is pressed and supported by a fixture inside the peripheral portion.
JP 2006-216540 A JP 2007-114590 A

However, in the technique disclosed in Patent Document 1, a separate member serving as a guide member is required, and when the backlight device is assembled, the optical sheet constituting the optical member does not get over the guide member. It is necessary to make the wall portion of the guide member higher than the total thickness of the optical member, and there is a limit to reducing the thickness.
Further, in the technique disclosed in Patent Document 2, although the optical member is bent, it is possible to suppress the separation and movement of the optical sheet constituting the optical member at the time of assembly, but the shape that straddles the peripheral portion of the bent optical member. Since a fixing tool is required and a mounting space for the fixing tool becomes large, it is an obstacle to thinning and space saving of the backlight device.

  On the other hand, since the number of optical sheets constituting the optical member may be changed at the time of assembly according to the light collecting characteristics required for the backlight device, the guide members and fixtures shared mechanically or these The member corresponding to is required to have a structure capable of absorbing the difference in the number of laminated optical sheets. Therefore, as shown in FIG. 5, an apparatus has been devised in which the optical member 3 is attached to the optical member receiving portion 61 of the backlight chassis 6 by pressing it with the optical member presser 7a.

  The limiting portion 62 of the backlight chassis 6 is bent substantially perpendicularly at the outer edge of the optical member receiving portion 61 and faces the end of the optical member 3 so as to move in the direction along the surface of the optical member 3. It is a limitation. The length of the limiting portion 62 in the direction along the end portion exceeds the thickness of the optical member 3 regardless of the number of optical sheets stacked. When the backlight device is assembled, the optical member 3 is attached to the backlight chassis 6. When placing, the optical sheet which comprises the optical member 3 is made not to get over the restriction | limiting part 62. FIG. The optical member presser 7 a includes a presser plate portion 71 that faces the optical member 3, a rising plate portion 72 that rises from one end of the presser plate portion 71 in the thickness direction of the optical member 3, and the surface of the optical member 3. The connecting plate portion 73 extends in the direction along the limit portion 62 and the falling plate portion 74 falls over the restricting portion 62, and the upper surface of the connecting plate portion 73 holds the liquid crystal panel 1. And contact with each other through the buffer member 15.

  In the apparatus shown in FIG. 5 described above, the height of the rising plate portion 72 is such that the lower surface of the coupling plate portion 73 does not contact the upper end of the limiting portion 62 regardless of the number of stacked optical sheets constituting the optical member 3. Therefore, it is necessary to secure a value for this purpose, and the gap generated between the presser plate 71 and the holding member 14 prevents the display device from being thinned.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide each optical sheet by having a detent for preventing relative movement of each of the optical sheets laminated with optical members. Can be prevented from independently moving along the surface direction, and the length of the support member and the pressing member in the thickness direction of the optical member can be reduced to reduce the thickness and save space. It is to provide a display device.

  A backlight device and a display device according to the present invention include a backlight disposed on the back side of a display panel, and an optical member that is disposed between the backlight and the display panel, and includes a laminated optical sheet. In a backlight device comprising: a support body that supports the peripheral edge portion of the optical member from the backlight side; and a pressing body that presses the peripheral edge portion of the optical member to sandwich the optical member together with the support body. The optical member has a movement stop for preventing relative movement of each of the optical sheets.

  In the present invention, when the optical member has a movement stop, relative movement of each optical sheet constituting the optical member in the direction along the surface is restricted.

  In the backlight device and the display device according to the present invention, the detent is formed by bending the entire circumference or a part of the peripheral edge of the optical sheet closest to the pressing body substantially vertically to the support side. It is characterized by.

  In the present invention, the detent is formed by bending the entire circumference or part of the peripheral edge of the optical sheet closest to the pressing body substantially vertically toward the support. This effectively restricts relative movement of each optical sheet constituting the optical member in the direction along the surface.

  In the backlight device and the display device according to the present invention, the support has a restricting portion that opposes the movement stop of the optical member and restricts movement of the optical member in a direction along the surface of the optical member. The length of the portion in the optical member thickness direction does not exceed the total thickness of the optical member.

  In the present invention, the support has a limiting portion that faces the movement stop of the optical member, and the length of the limiting portion in the optical member thickness direction does not exceed the total thickness of the optical member. Thereby, since the edge part of the said limitation part does not contact | abut to a press body, while contributing to thickness reduction, the movement to the direction along the surface of an optical member is restrict | limited via a detent.

  In the backlight device and the display device according to the present invention, the pressing body includes a flat pressing portion that presses the optical member and an engaging portion that engages with the limiting portion.

  In the present invention, the flat pressing portion of the pressing body presses the optical member, and the engaging portion engages with the limiting portion of the support. Thereby, since it does not have a part which protrudes in the direction perpendicular | vertical to the surface of an optical member, while contributing to thickness reduction, the relative positional relationship of a press body and a support body is decided.

  According to the present invention, since the optical member has a movement stop, relative movement in the direction along the surface of each optical sheet constituting the optical member is limited. Thereby, it can prevent that each optical sheet moves independently along a surface direction. Therefore, the support member and the pressing member can be made thin and space-saving by reducing the length in the optical member thickness direction.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
(Embodiment)
FIG. 1 is a front view showing an appearance of a display device according to the present invention, FIG. 2 is a schematic side sectional view showing an internal configuration of the display device, and FIG. 3 is a schematic cross section showing a mounting state of an optical member. FIG. In the figure, reference numeral 1 denotes a liquid crystal panel. A liquid crystal panel 1 and a backlight device 2 according to the present invention provided on the back side thereof are arranged in a space formed by a front cabinet 4 and a back cabinet 5. The front cabinet 4 is a molded product having a side wall having an appropriate length, and is provided with a display opening 4a on the front side so that an image of the liquid crystal panel 1 can be seen through the opening 4a. .

In the liquid crystal panel 1, the front and back peripheral portions are sandwiched by two sandwiching members 13 and 14, and one sandwiching member 14 is supported by a support plate 16 fixed to the back cabinet 5.
The backlight device 2 is fixed to a support frame (not shown) and a support plate 16 having dimensions that match the outer dimensions of the liquid crystal panel 1. Two columns are fixed to the lower part of the support frame, and a stand 20 is attached to the lower part of the column.

  The backlight device 2 has a substantially rectangular parallelepiped backlight chassis (box) 6 whose front surface is opened as a base, and a reflective film 12 on which aluminum is deposited is formed on the inner wall of the backlight chassis 6. As a light source of the backlight device 2, a plurality of straight tubular cold cathode fluorescent lamps (CCFLs) 8 are juxtaposed in a horizontal state, and are uniformly close to natural light through an optical member 3 provided in an opening of the backlight chassis 6. White light is incident on the liquid crystal panel 1.

  An optical member receiving portion 61 for supporting the peripheral edge portion of the optical member 3 from the back surface is provided on the opening side outer edge portion of the peripheral wall of the backlight chassis 6. Further, a restricting portion 62 for restricting movement in the direction along the surface of the optical member 3 is formed on the outer edge portion of the optical member receiving portion 61 so as to be substantially perpendicular to the optical member receiving portion 61. The forward extension length of the restricting portion 62 is shorter than the total thickness of the optical member 3. As a result, the end portion of the limiting portion 62 does not come into contact with the optical member presser 7 described below.

  An optical member presser 7 for holding the optical member 3 so as to face the optical member receiving portion 61 is disposed on the peripheral portion of the optical member 3. In the optical member presser 7, a flat presser plate portion 71 that presses the optical member 3 is pressed from the holding member 14 via the buffer member 15. The optical member retainer 7 has an engaging portion 74 that bends substantially perpendicularly from the peripheral portion toward the back surface. The engaging portion engages with the restricting portion 62, whereby the backlight chassis 6 of the optical member retainer 7. The position relative to is determined.

  The optical member 3 is formed by laminating prism sheets 31 to 33, a diffusion sheet 34, and a diffusion plate 35 in order from the front, and the number of the laminated sheets depends on the front luminance required for the image displayed on the display device. Increased or decreased during assembly. The prism sheet 31 has a detent 311 that is formed by bending the peripheral edge portion substantially perpendicularly toward the back surface of the display device. The tip of the detent 311 reaches the end of the diffusion plate 35. Thereby, the prism sheets 31 to 33, the diffusion sheet 34, and the diffusion plate 35 are restricted from moving in the direction along the surface so as to face the movement stop 311 and the restriction portion 62.

In the present embodiment, a plurality of clip members 11 in which a pair of clips 9 that hold the cold cathode tubes 8 and a single protrusion 10 sandwiched between them are integrally formed with the backlight chassis 6. It is fixed evenly over the entire bottom surface. The protrusion 10 supports the optical member 3 from the back surface to prevent bending.
Instead of the cold cathode tube 8, a white LED and / or a multi-color LED may be used.

FIG. 4 is a development view schematically showing the prism sheet 31 and the detent 311. In the prism sheet 31, the aspect ratio of the rectangular sheet surface excluding the detent 311 is 16: 9, and bent portions to be the detents 311 are added to two sides of the outer periphery of the sheet surface. When the detent 311 is formed, a perforation is made at the boundary between each bent portion and the outer periphery of the sheet surface, and it is bent so as to be perpendicular to the sheet surface.
The detent 311 may be provided over the entire circumference of the seat surface as indicated by a broken line in the figure.

  As described above, in the display device according to the present embodiment, since the optical member has a movement stop, the prism sheet, the diffusion sheet, and the diffusion plate are restricted in relative movement in the direction along the surface. Is done. Thereby, it can prevent that each sheet | seat and a diffusion plate move independently along a surface direction. For this reason, the optical member receiving portion and the optical member presser can be reduced in length in the optical member thickness direction to achieve a reduction in thickness and space.

Further, the detent is formed by bending the peripheral edge of the foremost prism sheet substantially vertically toward the backlight chassis. This effectively restricts the prism sheet, the diffusion sheet, and the diffusion plate from relatively moving in the direction along the surface.
That is, the purpose of effectively restricting the relative movement of each sheet and the diffusion plate in the direction along the surface can be achieved.

Furthermore, the optical member receiving portion of the backlight chassis has a limiting portion that faces the movement stop of the optical member, and the length of the limiting portion in the optical member thickness direction does not exceed the total thickness of the optical member. . Thereby, since the edge part of the said restriction | limiting part does not contact | abut to an optical member presser, while contributing to thickness reduction, the movement to the direction along the surface of an optical member is restrict | limited via a detent.
That is, it is possible to achieve the purpose of reducing the thickness and restricting movement in the direction along the surface of the optical member.

Further, the pressing plate portion of the optical member press presses the optical member, and the engaging portion engages with the limiting portion of the optical member receiving portion of the backlight chassis. Thereby, since it does not have the part which protrudes in the direction perpendicular | vertical to the surface of an optical member, while contributing to thickness reduction, the relative positional relationship of an optical member holder and a backlight chassis is decided.
That is, it is possible to achieve the purpose of reducing the thickness and determining the relative positional relationship between the optical member presser and the backlight chassis.

It is a front view which shows the external appearance of the display apparatus which concerns on this invention. It is a typical sectional side view which shows the internal structure of a display apparatus. It is typical sectional drawing which shows the attachment state of an optical member. It is an expanded view which shows a prism sheet and a movement stop typically. It is typical sectional drawing which shows the attachment state of the conventional optical member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Backlight apparatus 3 Optical member 31, 32, 33 Prism sheet (optical sheet)
311 Movement stop 34 Diffusion sheet (optical sheet)
35 Diffuser 6 Backlight chassis 61 Optical member receiving part 7, 7a Optical member holder 71 Presser board part 8 Cold cathode tube

Claims (5)

A backlight disposed on the back side of the display panel, and an optical member that is laminated, and an optical member to be disposed between the backlight and the display panel, and a peripheral portion of the optical member on the backlight side In a backlight device comprising: a support that supports the optical member; and a pressing body that presses a peripheral edge of the optical member in order to sandwich the optical member together with the support.
The backlight device according to claim 1, wherein the optical member has a movement stop for preventing relative movement of each of the optical sheets.   2. The backlight according to claim 1, wherein the detent is formed by bending the entire circumference or a part of the peripheral edge of the optical sheet closest to the pressing body substantially vertically toward the support. apparatus.   The support body has a limiting portion that faces the movement stop of the optical member and limits movement in a direction along the surface of the optical member, and the length of the limiting portion in the optical member thickness direction is The backlight device according to claim 2, wherein the total thickness of the optical member is not exceeded.   The backlight device according to claim 3, wherein the pressing body includes a flat pressing portion that presses the optical member, and an engaging portion that engages with the limiting portion.   A display device comprising: a display panel; and the backlight device according to any one of claims 1 to 4 disposed on a back side of the display panel.

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