JP2011075598A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device in which a diffusion sheet can be aligned even if using a small number of components, and the diffusion sheet is prevented from being pinched. <P>SOLUTION: A diffusion plate 18 has a first protrusion 30 protruding while avoiding both ends of a first side 28 and a second protrusion 34 protruding while avoiding both ends of a second side 32. A frame has slits 42 where both ends in a lateral direction of a diffusion sheet 20 and both ends in a lateral direction of a rectangular region 26 of the diffusion plate 18 are inserted. A first support frame 44 has a first elastic body 46 at a side close to a back frame 36. The first protrusion 30 of the diffusion plate 18 is pinched and held while avoiding the diffusion sheet 20 between the first elastic body 46 and the back frame 36. A second support frame 48 has a second elastic body 50 at a side close to the back frame 36. The second protrusion 34 of the diffusion plate 18 is pinched and held while avoiding the diffusion sheet 20 between the second elastic body 50 and the back frame 36. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device.

  In a direct type backlight of a liquid crystal display device in which a light source is disposed overlapping the liquid crystal display panel, a diffusion plate or a diffusion sheet is disposed between the light source and the liquid crystal display panel. The diffuser plate achieves uniform brightness, and the diffuser sheet achieves high brightness. The diffusion plate is sandwiched and fixed by other members at the upper end and the lower end. On the other hand, since the diffusion sheet has a thin shape, wrinkles are generated when the diffusion sheet is inserted, and thus the diffusion sheet is not inserted. Therefore, as for positioning of the diffusion sheet, the right and left ends on the short side of the diffusion sheet are respectively provided with convex portions with holes formed therein, pins are provided on the frame holding the liquid crystal display panel, and the frames are formed in the holes of the convex portions. The diffusion sheet was positioned by inserting a pin (Patent Document 1).

JP 2006-351527 A

  The frame for positioning the diffusion sheet is divided so that the frame at the position overlapping the short side of the diffusion sheet has a two-layer structure. Specifically, pins are formed on the light source side (lower layer side) divided frame, and the upper ends of the protruding pins are placed on the liquid crystal display panel side (upper layer side) divided frame to mount the liquid crystal display panel. It was. Therefore, since the frame is composed of two members, the cost is high. However, if the frame is composed of one member, it is difficult to position the diffusion sheet with pins. If the diffusion sheet is not accurately positioned with respect to the diffusion plate, there is a problem that the diffusion sheet is displaced when the diffusion plate is sandwiched, and the diffusion sheet is wrinkled.

  An object of the present invention is to enable alignment of a diffusion sheet even with a small number of parts, and to prevent the diffusion sheet from being caught.

  (1) A liquid crystal display device according to the present invention includes a liquid crystal display panel, a fluorescent tube disposed on the back side opposite to the display surface of the liquid crystal display panel, and a space between the liquid crystal display panel and the fluorescent tube. A diffusion sheet and a diffusion plate arranged in a stack; a back frame that covers the back side of the fluorescent tube; and a frame-like frame disposed between the liquid crystal display panel and the back frame, The frame has a pair of side frames facing both ends in the lateral direction of the diffusion sheet and the diffusion plate, and a first end facing one end of the diffusion sheet and the longitudinal ends of the diffusion plate. 1 support frame, and a second support frame facing the second end that is the other of the longitudinal ends of the diffusion sheet and the diffusion plate, and the diffusion plate includes a rectangular region, The first of the rectangular regions; A first convex portion that protrudes from the first side on the end side while avoiding both end portions of the first side, and an end portion of the second side from the second side on the second end side of the rectangular region. And the diffusion sheet has a rectangular shape that fits within the rectangular area, and the frame has the lateral ends of the diffusion sheet. And a slit into which both lateral ends of the rectangular region of the diffusion plate are inserted, and the length of the slit is the vertical length of the both ends of the diffusion sheet and the vertical length of the both ends of the rectangular region The first support frame has a first elastic body on the back frame side, and is shorter than the length from the tip of the first projection to the tip of the second projection. And the diffusion case between the first elastic body and the back frame. And the second support frame has a second elastic body on the side of the back frame, and the second elastic body and the back surface are avoided. The second convex portion of the diffusion plate is sandwiched and held between the frame and the diffusion sheet, avoiding the diffusion sheet. According to the present invention, the diffusion sheet can be aligned by the slit, and the first and second protrusions are formed on the diffusion plate. Holding is possible.

  (2) In the liquid crystal display device described in (1), the diffusing plate has the center of the diffusion plate more than the center in the vertical direction of the region surrounded by the pair of side frames, the first support frame, and the second support frame. The center of the rectangular region in the vertical direction may be located below.

  (3) In the liquid crystal display device described in (1) or (2), the first support frame is spaced apart from the back frame by an interval exceeding the total thickness of the diffusion sheet and the diffusion plate from the back frame. Opposing first flanges, wherein the first flange has a first width in the longitudinal direction, and the second support frame exceeds the total thickness of the diffusion sheet and the diffusion plate from the back frame. A second flange facing the back frame at an interval, the second flange having a second width in the longitudinal direction, the second width being greater than the first width, The vertical width of the second end portion of the diffusion sheet facing the second support frame is larger than the vertical width of the first end portion of the diffusion sheet facing the first support frame. Ikoto may be characterized.

  (4) In the liquid crystal display device described in (1), the first convex portion of the diffusion plate is formed at a central portion of the first side of the rectangular region, and the second convex portion of the diffusion plate. May be formed so as to avoid the central portion of the second side of the rectangular region.

1 is a perspective view showing a liquid crystal display device according to an embodiment of the present invention. It is an enlarged view of the II-II line cross section of the liquid crystal display device shown in FIG. It is a top view of a diffusion plate. It is a top view of a diffusion sheet. It is a top view of the diffusion sheet and diffusion plate which were piled up. It is a top view which shows the structure which removed the front frame and the liquid crystal display panel from the liquid crystal display device shown in FIG. It is the VII-VII sectional view taken on the line of the structure shown in FIG. FIG. 7 is a sectional view taken along line VIII-VIII of the structure shown in FIG. 6. It is the IX-IX sectional view taken on the line of the structure shown in FIG. It is XX sectional drawing of the structure shown in FIG. It is a top view which shows the structure which removed the 1st support frame and the 2nd support frame from the structure shown in FIG. FIG. 12 is an enlarged view of a region indicated by XII in FIG. 11. FIG. 13 is an enlarged view of a region indicated by XIII in FIG. 11.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is an enlarged view of a section taken along line II-II of the liquid crystal display device shown in FIG.

  The liquid crystal display device includes a liquid crystal display panel 10. The driving method of the liquid crystal display panel 10 may be any method such as an IPS (In Plane Switching) method, a TN (Twisted Nematic) method, or a VA (Vertical Alignment) method, and electrodes and wirings corresponding to the method are formed. The

  The liquid crystal display panel 10 is placed vertically when the liquid crystal display device is properly installed. That is, the display surface 12 of the liquid crystal display panel 10 faces in the horizontal direction (for example, the horizontal direction). The display surface 12 of the liquid crystal display panel 10 is rectangular, a pair of parallel sides (short sides in FIG. 1) are arranged in the vertical direction (for example, the height direction), and another pair of parallel sides (long in FIG. 1). Side) is arranged in the horizontal direction (for example, the horizontal direction).

  In the following description, “front” or “front surface” is a direction in which the display surface 12 of the vertically disposed liquid crystal display panel 10 faces or a surface in the direction. The “rear surface” is a surface opposite to the display surface 12. The “vertical direction” or “vertical length” is the height direction of the vertically disposed liquid crystal display panel 10 or the length in that direction. The “lateral direction” is a direction in which a side (long side) in contact with a side (short side) arranged in the “vertical direction” of the vertically arranged liquid crystal display panel 10 is arranged. Further, “upper side” and “lower side” mean “upper side” and “lower side” when the liquid crystal display device is appropriately arranged.

  As shown in FIG. 2, the liquid crystal display panel 10 is prevented from dropping by a part of the front frame 14 facing the peripheral portion on the display surface 12 side. As shown in FIG. 2, the front frame 14 is configured by assembling bars with an L-shaped cross section into a rectangular shape. The front frame 14 is made of metal.

  A fluorescent tube 16 (for example, a cold cathode tube) is disposed on the back side of the liquid crystal display panel 10 opposite to the display surface 12. The fluorescent tube 16 is filled with gas (for example, an inert gas such as neon-argon (Ne-Ar) gas) and mercury.

  A diffusion plate 18 and a diffusion sheet 20 are disposed between the liquid crystal display panel 10 and the fluorescent tube 16. In the present embodiment, a plurality of diffusion sheets 20 are stacked. Each of the diffusing sheet 20 and the diffusing plate 18 includes a first end 22 at one of the longitudinal ends (for example, on the upper side).

  FIG. 3 is a plan view of the diffusion plate 18. The diffusing plate 18 includes a rectangular region 26, and includes a first convex portion 30 that protrudes from the first side 28 on the first end 22 side of the rectangular region 26 to avoid both ends of the first side 28. The first protrusion 30 of the diffusion plate 18 is formed at the center of the first side 28 of the rectangular region 26. Each of the diffusion sheet 20 and the diffusion plate 18 includes a second end 24 on the other (for example, the lower side) of both ends in the vertical direction. The diffusion plate 18 has a second convex portion 34 that protrudes from the second side 32 on the second end 24 side of the rectangular region 26 to avoid both end portions of the second side 32. The second convex portion 34 of the diffusion plate 18 is formed so as to avoid the central portion of the second side 32 of the rectangular region 26.

  FIG. 4 is a plan view of the diffusion sheet 20. The diffusion sheet 20 is disposed between the liquid crystal display panel 10 and the diffusion plate 18 so as to overlap the diffusion plate 18. FIG. 5 is a plan view of the diffusion sheet 20 and the diffusion plate 18 that are overlaid. The diffusion sheet 20 has a rectangular shape that fits within the rectangular area 26 of the diffusion plate 18. In the diffusion plate 18, the first protrusion 30 and the second protrusion 34 protrude from the diffusion sheet 20.

  The liquid crystal display device has a frame. The frame includes a metal back frame 36, as shown in FIG. The back frame 36 covers the back side of the fluorescent tube 16. The back frame 36 has portions facing the peripheral portions of the diffusion sheet 20 and the diffusion plate 18 on the back side. A reflective sheet 38 is disposed between the fluorescent tube 16 and the back frame 36. The light emitted from the fluorescent tube 16 is reflected by the reflection sheet 38, passes through the diffusion plate 18 and the diffusion sheet 20, and is used as a uniform surface light source.

  FIG. 6 is a plan view showing a structure in which the front frame 14 and the liquid crystal display panel 10 are removed from the liquid crystal display device shown in FIG. 7 is a cross-sectional view taken along the line VII-VII of the structure shown in FIG. 8 is a cross-sectional view taken along line VIII-VIII of the structure shown in FIG. 9 is a cross-sectional view taken along the line IX-IX of the structure shown in FIG. 10 is a cross-sectional view of the structure shown in FIG.

  The frame is a resin frame-like body disposed between the back frame 36 and the liquid crystal display panel 10 and includes a pair of side frames 40 as shown in FIG. As shown in FIGS. 7 and 8, the pair of side frames 40 is disposed at the end of the back frame 36, and the liquid crystal display panel 10 is placed on the side opposite to the side facing the back frame 36. The side frame 40 has a slit 42 into which the lateral end of the diffusion sheet 20 (see FIG. 4) and the lateral end of the rectangular region 26 (see FIG. 3) of the diffusion plate 18 are inserted.

  The frame includes a first support frame 44 as shown in FIG. The first support frame 44 is a frame located on the upper side when used as a liquid crystal display device. As shown in FIG. 9, the first support frame 44 has a hole for screwing to the back frame 36. In addition, the first flange 52 facing the back frame 36 is provided at an interval exceeding the total thickness of the diffusion sheet 20 and the diffusion plate 18 from the back frame 36. The first support frame 44 has a first elastic body 46 on the back frame 36 side of the first flange 52. Between the first elastic body 46 and the back frame 36, the first protrusion 30 (see FIG. 3) of the diffusion plate 18 is sandwiched and held avoiding the diffusion sheet 20. The diffuser plate 18 is configured such that portions other than the first protrusions 30 are not sandwiched between the first elastic body 46 and the back frame 36.

  The frame includes a second support frame 48 as shown in FIG. The second support frame 48 is a frame positioned on the lower side when used as a liquid crystal display device. As shown in FIG. 10, the second support frame 48 has a second flange 54 that faces the back frame 36 with a space exceeding the total thickness of the diffusion sheet 20 and the diffusion plate 18 from the back frame 36. The second support frame 48 has a second elastic body 50 on the rear frame 36 side of the second flange 54. Between the second elastic body 50 and the back frame 36, the second protrusion 34 (see FIG. 3) of the diffusion plate 18 is sandwiched and held avoiding the diffusion sheet 20. The diffuser plate 18 is configured such that portions other than the second convex portions 34 are not sandwiched between the second elastic body 50 and the back frame 36.

The first flange 52 of the first support frame 44, as shown in FIG. 9, has a first width W ₁ in the vertical direction. The second flange 54 of the second support frame 48, as shown in FIG. 10, has a longitudinal direction of the second width W _2. The second width _{W 2} is greater than the first width _{W 1.}

Further, the second support frame 48 (second flange 54) is larger than the vertical width W ₁₁ (see FIG. 9) of the first end 22 of the diffusion sheet 20 facing the first support frame 44 (first flange 52). The vertical width W ₂₂ (see FIG. 10) of the second end portion 24 of the diffusion sheet 20 that is opposed to the upper part) is large. Similarly, the second support frame 48 on the second convex portion 34 side of the diffusion plate 18 is larger than the vertical width of the portion of the diffusion plate 18 facing the first support frame 44 on the first convex portion 30 side. The vertical width of the facing part is large.

Due to the difference in the vertical width as described above, as shown in FIG. 6, the vertical center C ₁ of the region surrounded by the pair of side frames 40, the first support frame 44 and the second support frame 48, longitudinal center C ₂ of the rectangular region 26 of the diffusion plate 18 is positioned below.

This is because the liquid crystal display panel 10 is connected to a plurality of flexible printed circuit boards (FPCs) on which drain drivers are formed. In general, however, the FPCs need to be arranged on the side frames 40. This is because the size of the width in the direction needs to match the size of the FPC and cannot be increased. Therefore, in this embodiment, by increasing the second flange 54 of the support frame 48 side, shifting the center C ₂ of the diffuser plate 18 downward, and to increase the stability for fixing the diffusion plate 18 .

  FIG. 11 is a plan view showing a structure in which the first support frame 44 and the second support frame 48 are removed from the structure shown in FIG. FIG. 12 is an enlarged view of a region indicated by XII in FIG. FIG. 13 is an enlarged view of a region indicated by XIII in FIG.

The length L ₁ of the slit 42 of the side frame 40, a diffusion sheet 20 (or a rectangular region 26 of the diffusion plate 18) than the longitudinal length L ₂ of the end of the, small but is longer. The length L ₁ of the slit 42 is shorter than the length L ₃ from the tip of the first convex portion 30 to the tip of the second convex portion 34 of the diffusion plate 18. Further, as shown in FIG. 13, L ₁ and L ₂ are aligned on the lower side. That is, the lower side of the rectangular region 26 of the diffusion sheet 20 and the diffusion plate 18 is positioned on the lower surface of the slit 42.

  As a result, the rectangular region 26 of the diffusion plate 18 and the diffusion sheet 20 are inserted into the slit 42 in the slit 42, so that these positioning can be performed simultaneously.

  According to this embodiment, the diffusion sheet 20 can be aligned by the slit 42 of the side frame 40. Moreover, since the 1st convex part 30 and the 2nd convex part 34 are formed in the diffusion plate 18, the sandwiching of the diffusion sheet 20 is prevented and the diffusion plate 18 can be held.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the configuration described in the embodiment can be replaced with substantially the same configuration, a configuration that exhibits the same operational effects, or a configuration that can achieve the same purpose.

  DESCRIPTION OF SYMBOLS 10 Liquid crystal display panel, 12 Display surface, 14 Front frame, 16 Fluorescent tube, 18 Diffusion plate, 20 Diffusion sheet, 22 1st edge part, 24 2nd edge part, 26 Rectangular area | region, 28 1st edge, 30 1st convexity Part, 32 second side, 34 second convex part, 36 back frame, 38 reflective film, 40 side frame, 42 slit, 44 first support frame, 46 first elastic body, 48 second support frame, 50 second elasticity Body, 52 first flange, 54 second flange.

Claims (4)

A liquid crystal display panel;
A fluorescent tube disposed on the back side opposite to the display surface of the liquid crystal display panel;
A diffusion sheet and a diffusion plate disposed between the liquid crystal display panel and the fluorescent tube;
A back frame covering the back side of the fluorescent tube;
A frame-like frame disposed between the liquid crystal display panel and the back frame;
Have
The frame opposes a pair of side frames facing both end portions in the lateral direction of the diffusion sheet and the diffusion plate and a first end portion which is one of both end portions in the vertical direction of the diffusion sheet and the diffusion plate. A first support frame, and a second support frame facing a second end which is the other of the longitudinal ends of the diffusion sheet and the diffusion plate,
The diffusion plate includes a rectangular region, a first convex portion that protrudes from the first side of the rectangular region on the first end side to avoid both ends of the first region, and the second end of the rectangular region. A second convex part that protrudes from the second side on the part side to avoid both ends of the second side,
The diffusion sheet has a rectangular shape that fits within the rectangular area,
The frame has slits into which both end portions in the lateral direction of the diffusion sheet and both end portions in the lateral direction of the rectangular region of the diffusion plate are inserted,
The length of the slit is longer than both of the longitudinal length of the both end portions of the diffusion sheet and the longitudinal length of the both end portions of the rectangular region, from the tip of the first convex portion to the tip of the second convex portion. It is shorter than the length of
The first support frame has a first elastic body on the back frame side,
Between the first elastic body and the back frame, avoiding the diffusion sheet, the first convex portion of the diffusion plate is sandwiched and held,
The second support frame has a second elastic body on the back frame side,
The liquid crystal display device, wherein the second convex portion of the diffusion plate is sandwiched and held between the second elastic body and the back frame, avoiding the diffusion sheet. The liquid crystal display device according to claim 1,
The vertical center of the rectangular region of the diffuser plate is positioned below the vertical center of the region surrounded by the pair of side frames, the first support frame, and the second support frame. A characteristic liquid crystal display device. The liquid crystal display device according to claim 1 or 2,
The first support frame has a first flange facing the back frame at an interval exceeding the total thickness of the diffusion sheet and the diffusion plate from the back frame, and the first flange is arranged in the longitudinal direction. Having a first width;
The second support frame has a second flange facing the back frame at a distance exceeding the total thickness of the diffusion sheet and the diffusion plate from the back frame, and the second flange is the vertical flange. Having a second width in the direction;
The second width is greater than the first width;
The vertical width of the second end portion of the diffusion sheet facing the second support frame is greater than the vertical width of the first end portion of the diffusion sheet facing the first support frame. A large liquid crystal display device. The liquid crystal display device according to claim 1,
The first convex portion of the diffusion plate is formed at a central portion of the first side of the rectangular region,
The liquid crystal display device, wherein the second convex portion of the diffusion plate is formed so as to avoid a central portion of the second side of the rectangular region.

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