KR20120042682A - Frame member for liquid crystal display device - Google Patents

Abstract

PURPOSE: A frame member in a liquid crystal display device is provided to supply more light to a liquid crystal panel by reflecting light. CONSTITUTION: A frame member includes a light reflection surface with a 10% average reflection rate at a wavelength which is in the range of 400 to 800nm on a portion of a rear side or the entire rear side. When the frame member is mounted on an LCD(Liquid Crystal Display) device, the maximum point brightness of a display screen(10) is lower than the maximum point brightness of a distant location.

Description

Frame member in liquid crystal display device {FRAME MEMBER FOR LIQUID CRYSTAL DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame member used for fixing an optical sheet, a light guide plate, a chassis, or the like, which is used for improving the brightness, or for uniformizing the brightness, in an edge light type liquid crystal display device.

Generally, a liquid crystal display device is comprised by arrange | positioning the backlight unit which supplies light to the liquid crystal panel on the back side of a liquid crystal panel.

The backlight unit of the liquid crystal display device mainly has two methods, a direct type type system and an edge light type type. Among them, the direct type method is a method in which a plurality of light sources are arranged on a substrate and a diffuser plate is arranged at a position where a space is formed to some extent from the light source to uniform the luminance. After arranging a plurality of light sources along one side (side or bottom) at appropriate intervals on a straight line, incident light rays from the side of the light guide plate to uniform luminance, and then emitting light to the liquid crystal panel from the front surface of the light guide plate. That's the way.

The liquid crystal display device employing the edge light type method will be described in detail. For example, as shown in FIGS. 1 and 2, the liquid crystal panel 2 is disposed on the front side of the elongated surface 3a of the frame member 3. , The optical sheet 4, the light guide plate 6, and the reflecting plate 7 are sequentially arranged on the back side of the liquid crystal panel 2 with the elongated surface 3a of the frame member 3 interposed therebetween, A plurality of light sources 5 are disposed at appropriate intervals along the edges of the 6, and the top chassis 1 is disposed so as to cover these side portions from the front edge of the liquid crystal panel 2, and the reflection plate 7 It is common to arrange the bottom chassis 8 on the back side.

In the liquid crystal display device employing such an edge light type system, a part of the light emitted from the light source 5 is refracted by the light guide plate 6 to the front side, and is applied to the liquid crystal panel 2 through the optical sheet 4. The other part of the light which is supplied and emitted from the light source 5 is refracted by the light guide plate 6 to the rear side and reflected by the reflecting plate 7, and the liquid crystal panel () through the light guide plate 6 and the optical sheet 4. 2) is supplied. However, in the light emitted from the light source 5, since there is a lot of light emitted to the frame (frame) member 3 without going to the light guide plate 6, this may be a loss. Therefore, by providing light reflectivity to the back surface of the conventional frame (frame) member 3, the light emitted from the light source 5 to the frame (frame) member 3 is reflected and supplied to the liquid crystal panel 2 It is proposed (refer patent document 1-3).

Japanese Laid-Open Patent Publication 2005-327720 Japanese Unexamined Patent Publication No. 2007-108739 Japanese Unexamined Patent Publication No. 2008-091317

By the way, for example, patent document 1? As shown in Fig. 3, it was found that when high reflectivity is imparted to the frame member 3, the vicinity of the light source on the screen becomes excessively high, resulting in uneven luminance, which makes it difficult to see.

Therefore, the present invention intends to propose a new frame member which can supply more light from the light source to the liquid crystal panel and can suppress unevenness in luminance.

When the high reflectance is given to the frame member as in the prior art (for example, see Patent Documents 1 to 3), the inventors found that the vicinity of the light source on the screen is excessively high and causes high luminance unevenness. It was examined from various angles. As a result, for example, as shown in the "99% reflectance frame" shown in FIG. 7, the luminance on the center vertical line orthogonal to the longitudinal direction of the screen edge where the light source is arranged is measured on the display screen, and the light source vicinity of the center vertical line is measured. When the peak value of the luminance shown in the figure becomes higher than the peak value near the center portion of the center vertical line, the luminance in the vicinity of the light source is excessively increased, and it has been found to cause unevenness of the luminance in the entire screen. Thus, the present inventor further develops this knowledge and envisions the following invention.

That is, this invention is a member attached to the edge light type | mold liquid crystal display device, Comprising: The part provided with the part in which the side wall part was extended in the inside, In addition, in part or the whole surface of the back surface, wavelength 400? It is a frame member provided with the light reflection surface whose average reflectance in 800 nm is 10% or more, The center vertical line orthogonal to the longitudinal direction of the screen edge part in which a light source is arrange | positioned in a display screen when the said frame member is attached to a liquid crystal display device. The frame characterized in that the maximum viscosities measured from the light source side end of the image to a position separated by 5% of the length of the center vertical line are lower than the maximum viscosities at a position separated from the length of 5%. It is to suggest absence.

As a preferable example of such a frame member, this invention is a member attached to the edge-lit type | mold liquid crystal display device, Comprising: The part provided with the part in which the side wall part was extended in the inside, and also in a part or whole surface of the back surface is carried out. , Wavelength 400? The average reflectance at 800 nm is 10? The frame member 3 provided with the light reflection surface which is 80% is proposed.

However, the frame member of the present invention is not limited to such a frame member 3. For example, an area portion of 50% of the rear surface of the frame member has a wavelength of 400? It is a light reflection surface whose average reflectance in 800 nm is 100%, and the remaining 50% area part is wavelength 400? Even in the case where the average reflectance at 800 nm is 0% or the like, it can be considered that the conditions of the frame member of the present invention are satisfied.

When the frame member of the present invention is mounted to form a liquid crystal display device, the light from the light source toward the frame member can be reflected to supply more light from the light source to the liquid crystal panel, and further, the luminance unevenness can be suppressed. The screen can be brightened with good balance.

1 is an exploded perspective view for explaining an example of the configuration of a liquid crystal display device.
2 is a cross-sectional view for explaining an example of the configuration of a liquid crystal display device, especially a backlight.
3 is a diagram illustrating the configuration when the display screen of the liquid crystal display device is viewed from the front (or upper surface) in the case where the liquid crystal display device is configured using the frame members of Examples and Comparative Examples.
FIG. 4 is a front view (or top view) showing a display screen of the liquid crystal display device in the case where the liquid crystal display device is configured by using the frame members of Examples and Comparative Examples. FIG. In addition, it is L1 = 213mm, L2 = 233mm, L3 = 375mm, L4 = 397mm in FIG.
FIG. 5 is a cross-sectional view showing respective dimensions in the case where a liquid crystal display device is constructed using the frame members of Examples and Comparative Examples. FIG. In addition, it is L5 = 4.0mm, L6 = 9.5mm, L7 = 7.0mm in FIG.
6 is a diagram illustrating an example of luminance distribution on a display screen when a liquid crystal display device is configured using the frame member of the present invention.
7 is a graph showing the relationship between the distance from the lower side of the display screen and the luminance in the case where the liquid crystal display device is configured using the frame of the example and the comparative example.
FIG. 8 is a view showing measurement points of luminance on a screen in Examples and Comparative Examples. FIG.

Hereinafter, the frame member 3 (it calls "this frame member 3") as an example of embodiment of this invention is demonstrated. However, the scope of the present invention is not limited to the embodiment described below.

<Bone frame member 3>

The frame member 3 is an optical sheet 4, a light guide plate 6, or a chassis 1, which is used for the improvement of brightness, the uniformity of brightness, etc. in a liquid crystal display device employing an edge light type system. 8) It is a member for fixing etc., and when it is attached to the liquid crystal display device employing an edge light type system, it is a frame member provided with the part (ejection surface 3a) which a part of side wall part extends inward.

In addition, with the edge light type | mold system, many light sources 5 are arrange | positioned at intervals suitably on a straight line along the left-right one side edge part or the up-down one side edge part of the light-guide plate 6, and a light ray is emitted from the side surface of the light-guide plate 6. It is the meaning of the method of making incident.

The frame member 3 has a side wall portion that has a frame shape similar to a rectangular edge, and has a portion in which the side wall portion is extended inwardly, for example, in an edge light type system as shown in FIGS. When attached to the liquid crystal display device, in the display screen 10, from the light source side end part on the center vertical line Z orthogonal to the longitudinal direction of the screen edge part (for example, screen lower side) in which the light source 5 is arrange | positioned , The maximum viscosities Tp measured in the region (also referred to as "region P") to a position separated by 5% of the length of the central vertical line Z, the total length L is the length of the 5%. It is characterized in that it becomes lower than the maximum viscosities Tq measured in the area | region (also called "region Q") of a further distant position.

A part or the whole surface of the back surface 3A of the frame member 3 has a wavelength of 400? In the case where a light reflecting surface having an average reflectance at 800 nm of 10% or more is used, the peak Tp as shown in Figs. 6 and 7 appears when luminance is measured in the area P on the center vertical line Z on the display screen. . If this peak is high above the maximum value Tq of the luminance measured in the region Q, the luminance near the light source is excessively increased, causing unevenness in the entire screen, so that the present frame member 3 has a region ( It is important that the luminance peak Tp in P) can be made lower than the luminance maximum value Tq measured in the region Q.

From such a viewpoint, more preferably, the ratio of the luminance peak Tp in the region P to the luminance maximum value Tq measured in the region Q is 1.0 or less, and in particular, 0.9? It is more preferable that it is 1.0.

This frame member 3 is viewed from the viewing side (outside of the liquid crystal panel 2), and a part or the entire surface of the back surface 3A has a wavelength of 400? It is important that the average reflectance at 800 nm is a light reflection surface of 10% or more. If the average reflectance is 10% or more, the brightness of the screen can be effectively increased.

In addition, considering the improvement of the brightness of the screen and the suppression of the unevenness of the brightness, a part or the entire surface of the back surface 3A has a wavelength of 400? The average reflectance at 800 nm is 10? It is preferable that it is a light reflection surface which is 80%, Especially, it is more preferable that it is 75% or less, and especially 60% or less.

However, the area portion of 50% of the back surface 3A of the present frame member 3 has a wavelength of 400? The average reflectance in 800 nm is made into 100% of the light reflection surface, and the remaining 50% area part has wavelength 400? The average reflectance at 800 nm may be made 0%.

The shape of the present frame member 3 is particularly limited as long as it has a side wall portion that is shaped like a rectangular edge when viewed from the top, that is, a side wall portion that shows a frame shape, and a part of the side wall portion is extended to the inside. It is not. As an example, when seen from a cross section, as shown, for example in FIG. 2, the shape which shows the substantially L-shape which has the elongate surface part 3a and the drooping edge part 3b is mentioned.

For example, as shown in FIG. 2, when it is provided with the shape which shows the substantially L shape which has the elongate surface part 3a and the drooping edge part 3b, the length of the elongated surface part 3a and the drooping edge part 3b is shown. The entire back surface may be the above-mentioned light reflection surface, and a part of the back surface of the elongated surface portion 3a and the drooping edge portion 3b, preferably the entire back surface of the elongated surface portion 3a, may be the light reflective surface. The light reflection surface may be part of the back surface of the elongated surface portion 3a. For example, in the back surface 3A of the present frame member 3, the light reflection surface may be a portion disposed in the space surrounding the light source 5, that is, a portion in contact with the light source 5 through the space.

The frame member 3 is not particularly limited in its material, but may be formed of a resin or a metal.

Moreover, although this kind of frame member is often colored in black, this frame member 3 may be colored in black, may be colored in a different color, and as mentioned above, back surface 3A A part or whole surface of) may be the said light reflection surface.

The present frame member 3 may be manufactured by bonding a light reflection sheet to the rear surface of the frame member 3 after manufacturing the ordinary frame member, and after manufacturing the ordinary frame member, as if shaping a fine shape on the rear surface of the frame member 3. You may process and make a light reflection surface. Moreover, you may form a light reflection surface by metal vapor deposition on the back surface of a frame member.

As a method of manufacturing a normal frame member, the injection molding of the pellet of a resin composition may be carried out to a mold cavity, for example. At this time, more specifically, it is preferable to form a frame-shaped frame (hereinafter also referred to as an FPD fixing frame) having at least one protrusion, hole, or groove for snap fit.

For example, a pellet composed of a resin composition in which the combustion rank in a 1.5 mm thick test piece in the vertical combustion test of UL Standard 94 is V-0, and in which a compound in which chlorine and bromine atoms are chemically bonded is not blended is prepared. The pellet may be injected into the mold cavity to produce the FPD fixing mold from the mold cavity.

At this time, the injection filling is not only ordinary injection molding but also injection compression molding, injection press molding, gas assist injection molding, foam molding (including a method of injecting supercritical fluid), insert molding, in-mold coating molding, Heat insulation mold molding, rapid heating cooling mold molding, dichroic molding, sandwich molding, and ultrafast injection molding. Molding can be selected from both cold runner and hot runner methods.

In the case of manufacturing the present frame member 3 by attaching the light reflection sheet to the back surface of the frame member, the light reflection sheet mixes an organic or inorganic filler with the base resin of the resin sheet, or uses a base resin and an incompatible resin. It may mix | blend and make light scattering reflection generate | occur | produce using the refractive index difference of a base resin and these combinations. Moreover, by extending | stretching a resin sheet, a space | gap may be formed in a sheet | seat, and light-scattering reflection may be made using the refractive index difference of the space | gap and a base resin. Moreover, you may combine these.

As said base resin, For example, cellulose-based resins, such as cellulose acetate and acetate, polyester-based resins, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polylactic acid (PLA), and polyethylene ( Polyolefin resins such as PE), polypropylene (PP), cycloolefin-based (COC, COP) resins, acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate (PC) resins, and polytetrafluoro Fluorine resins, such as a low ethylene (PTFE), etc. are mentioned. However, it is not limited to these.

As an inorganic filler mix | blended with a base resin, for example, calcium carbonate, magnesium carbonate, barium carbonate, magnesium sulfate, barium sulfate, calcium sulfate, zinc oxide, magnesium oxide, calcium oxide, titanium oxide, alumina, aluminum hydroxide, hydroxy At least 1 sort (s) chosen from apatite, silica, mica, talc, kaolin, clay, glass powder, asbestos powder, zeolite, clay silicate and the like can be mentioned. However, it is not limited to these.

As an organic filler which can be mix | blended with a base resin, cellulose-based powders, such as a tree powder and pulp powder, thermocrosslinkable resin powders, such as polymer beads and a polymer hollow particle, are mentioned, for example. However, it is not limited to these.

Moreover, as incompatible thermoplastic resin (henceforth incompatible resin) which can be mix | blended with a base resin, it is polyester resin, polycarbonate resin, polystyrene resin, acrylic resin, polyphenylene ether resin, poly Sulfone resins, polyolefin resins, and the like. However, it is not limited to these.

In the case where light scattering reflection is caused by using the refractive index difference of the base resin and the above compound, the refractive index difference of the base resin and the compound is preferably 0.05 or more, more preferably 0.1 or more, particularly 0.2 or more.

When mix | blending an inorganic filler with a big difference in refractive index with a base resin, it is more preferable at the point which can control broad reflectance comparatively easily by adjusting filler addition amount and a sample thickness suitably.

<Liquid crystal display device>

The frame member 3 is mounted to a liquid crystal display device employing an edge light type system as shown in Figs. 1 and 2, for example, so that the light directed from the light source 5 to the frame member 3 is transferred to the frame member. The screen can be brightened with a good balance in that it can reflect on the back surface 3A of (3), can supply more light to the liquid crystal panel 2, and can suppress the nonuniformity of brightness | luminance.

The specific structure of the liquid crystal display device which mounts this frame member 3 is not specifically limited. As a preferable example, as shown to FIG. 1-FIG. 2, what arrange | positions a backlight unit in the back side of the liquid crystal panel 2 is mentioned.

As a structural example of a backlight unit, for example, as shown in FIGS. 1-2, the optical sheet 4, the light guide plate 6, and the reflecting plate 7 are arrange | positioned one by one, and along one edge of the light guide plate 6 along. A plurality of light sources 5 are arranged at appropriate intervals, and the top chassis 1 is disposed so as to cover these side portions from the front edge of the liquid crystal panel 2, and the bottom chassis 8 is provided on the back side of the reflecting plate 7. And the elongated surface 3a of the present frame member 3 are inserted between the liquid crystal panel 2 and the optical sheet 4 to fix both of them. However, it is not limited to such a structure.

However, in the form of providing a sheet-shaped reflector, which is bent in a co-shape and provided on the upper surface of the light guide plate, light from the light source is guided to the light guide plate by the reflector, and light leaked to the frame member is suppressed. It is not suitable for the liquid crystal display device provided with the reflector bent in the same co-shape.

<Explanation of term>

Generally, a "sheet" is thin in the definition in JIS, and generally refers to a product whose thickness is small and flat compared to the length and width. In general, the "film" is very thin compared to the length and width, It is a thin flat product whose maximum thickness is arbitrarily defined, and means what is normally supplied in the form of a roll (Japanese Industrial Standard JIS K6900). For example, when it talks about thickness, in a narrow sense, what is 100 micrometers or more is called a sheet, and what is less than 100 micrometers may be called a film. However, since the boundary between a sheet and a film is not certain and it is not necessary to distinguish both in the dialect in this invention, in this invention, even if it is called "film", it shall contain "sheet", and "sheet" Even if it is called, it shall contain a "film."

In the present invention, "X? Y "(X, Y is any number), unless otherwise stated, means" more than X "and" preferably greater than X "and" preferably less than Y ". It shall be included.

In addition, in this invention, when expressing as "X or more" (X is arbitrary number), unless it mentions specially, it contains the meaning "preferably larger than X", and "Y or less" (Y is arbitrary In this case, the term "preferably less than Y" shall be included unless otherwise specified.

(Example)

Although an Example is shown to the following and this invention is demonstrated to it further more concretely, this invention is not limited to these.

[Measurement and Evaluation Method]

First, the measuring method of each physical property value performed about the sample obtained by the Example and the comparative example is demonstrated.

(Light transmittance)

An integrating sphere was attached to a spectrophotometer ("U-4000", manufactured by Hitachi, Ltd.), and the transmittance with respect to light of 550 nm was measured. In addition, the photometer was set so that the reflectance of an alumina white plate might be 100% before a measurement.

(reflectivity)

An integrating sphere is attached to the spectrophotometer (U-4000, manufactured by Hitachi, Ltd.), and has a wavelength of 400? The reflectance for the 800 nm light was measured. And wavelength 400? The average reflectance with respect to the light of 800 nm is shown in Table 1. In addition, the photometer was set so that the reflectance of an alumina white plate might be 100% before a measurement.

(Luminance)

Luminance was measured using a luminance nonuniformity meter (manufactured by CA-2000 Konica Minolta Sensing Co., Ltd.) with a standard lens, 1 m between measurement distances, 16 integration times, and 490 * 490 pixel count, and averaged 9 points. The luminance and the overall surface average luminance were calculated. Nine-point average brightness | luminance is the average of the brightness | luminance of nine points shown in FIG. 8, and whole surface average brightness is the average of the brightness | luminance of the whole light emitting surface.

In all the measurement of an Example and a comparative example, the liquid crystal display device (17-inch liquid crystal television) which consists of a structure shown in FIGS. 4-5 was used, and the liquid crystal was removed and used. About members other than a frame member (brightness improvement sheet, prism sheet, diffusion sheet, light guide plate, and reflection sheet), the thing of the initial state of the said display was used as it is.

4 is a schematic diagram seen from the front of the liquid crystal television, and FIG. 5 is a schematic diagram when the frame 3 of the present invention is attached to the backlight unit of the television.

In addition, in the display screen 10 shown in FIG. 3, brightness is measured on the screen edge part in which the light source 5 was arrange | positioned, ie, on the center vertical line Z orthogonal to the longitudinal direction of the screen lower side, and from the screen lower side. The relationship between the distance and the brightness | luminance is shown in FIG. And on the center vertical line Z, the maximum viscosity luminance Tp measured in the area | region (also called "region P") to the position separated by the length of 5% of the total length L, and said 5 The maximum viscosity Tq measured in the area | region (also called "region (Q)") of the position separated from the length for% minutes was calculated | required.

<Example 1>

When the "frame member of 32% reflectance" was used, the nine-point average luminance of the display was improved to "5147.0", and the luminance nonuniformity was not diffused. Moreover, it was confirmed that the largest viscosities Tq measured in the area Q are larger than the maximum viscosities Tp measured in the area P. FIG. Moreover, the luminance nonuniformity in the vicinity of the light source also did not diffuse.

At this time, as shown in Fig. 2, the “frame member having a reflectance of 32%” has a frame-shaped side wall portion (submerged edge portion 3b) and an elongated surface portion 3a, as shown in Fig. 2, and has an elongated surface portion 3a. ), The sheet having a reflectance of 32% is affixed to the initial frame member.

The sheet having a reflectance of 32% was mixed with COP (Xeonoa, RCY15; manufactured by Xeon Japan) and PP (Novatec EA9; manufactured by Nippon Polypro Co., Ltd.) at a ratio of 75:25, and heated to 200 ° C. It supplies to an extruder, it knead | mixes at 200 degreeC using this extruder, and then extruded the molten resin composition into the sheet form from the T die, and is 165 micrometers in thickness.

<Example 2>

When the "frame member with a reflectance of 57%" was used, the nine-point average luminance of the display was improved to "5268.9", and the luminance nonuniformity was not diffused. Moreover, it was confirmed that the maximum viscosity Tq measured in the area Q is larger than the maximum viscosity Tp measured in the area P. FIG. Moreover, the luminance nonuniformity in the vicinity of the light source also did not diffuse.

At this time, as shown in Fig. 2, the “frame member having a reflectance of 57%” has a frame-shaped side wall portion (submerged edge portion 3b) and an elongated surface portion 3a, as shown in Fig. 2, and has an elongated surface portion 3a. The sheet | seat of reflectance 57% is affixed on the whole back surface.

The "sheet of reflectance 57%" was mixed with PC (H4000; manufactured by Mitsubishi Engineer Plastics) pellets and titanium oxide (Chronos 2230; manufactured by Chronos) at a ratio of 99.5: 0.5, and then extruded to an extruder heated at 200 ° C. It supplies, it knead | mixes at 200 degreeC using this extruder, and then melt | dissolved the resin composition of a molten state in the form of a sheet | seat in T die | dye, and thickness is 400 micrometers.

<Example 3>

When the "frame member with a reflectance of 68%" was used, the nine-point average luminance of the display was improved to "5318.2", and the luminance nonuniformity was not diffused. Moreover, it was confirmed that the maximum viscosity Tq measured in the area Q is larger than the maximum viscosity Tp measured in the area P. FIG. Moreover, the luminance nonuniformity in the vicinity of the light source also did not diffuse.

At this time, as shown in Fig. 2, the “frame member having a reflectance of 68%” has a frame-shaped side wall portion (submerged edge portion 3b) and an elongated surface portion 3a, as shown in Fig. 2, and has an elongated surface portion 3a. The sheet | seat of reflectance 68% is affixed on the whole back surface of

The sheet of 68% reflectance is made of PLA (NW3001D: manufactured by Nature Works, 98.5% of L body content, 1.5% of D body content) and barium sulfate (B-55: manufactured by Sakai Chemical Co., Ltd.) at 75:25. After mixing at a ratio, it is supplied to the extruder heated at 200 degreeC, it knead | mixed at 200 degreeC using this extruder, and then the resin composition of the molten state was extruded from the T die into the sheet form, and is 400 micrometers in thickness. .

<Example 4>

When the "frame member with 76% reflectance" was used, the nine-point average luminance of the display was improved to "5372.0", and the luminance nonuniformity was not diffused. Moreover, it was confirmed that the maximum viscosity Tq measured in the area Q is larger than the maximum viscosity Tp measured in the area P. FIG. Moreover, the luminance nonuniformity in the vicinity of the light source also did not diffuse.

As shown in FIG. 2, the "frame member of 76% reflectivity" has a frame-shaped side wall portion (submerged edge portion 3b) and an elongated surface portion 3a, such as a rectangular edge, and has a back surface of the elongated surface portion 3a. The sheet | seat of reflectance 68% is affixed on the whole.

The sheet of 76% reflectance was mixed with PC (H4000; manufactured by Mitsubishi Engineering Plastics) pellets and titanium oxide (Chronos 2230; manufactured by Chronos) at a ratio of 98.5: 1.5, and then extruded to an extruder heated at 200 ° C. It supplies, it knead | mixes at 200 degreeC using this extruder, and then melt | dissolved the resin composition of a molten state in the form of a sheet | seat in T die | dye, and thickness is 400 micrometers.

<Comparative Example 1>

When the "frame member of 6% reflectance" was used, the nine-point average luminance of the display was "5014.9". The peak of the luminance in the area P was not measured.

The luminance unevenness in the vicinity of the light source was not confirmed, but the luminance of the entire screen was low and the screen was dark.

The above-mentioned "frame member of 6% reflectance" is an initial frame member used for a liquid crystal television (TH-L17F1 Panasonic Corporation) (as shown in FIG. 2, a frame-like side wall portion (submerged edge 3b)). ) And the frame member having the elongated surface portion 3a) are used as it is.

<Comparative Example 2>

When the "frame member with 99.5% reflectivity" was used, the nine-point average brightness of the display was improved to "5584.3", but a significant brightness unevenness occurred. In addition, it was confirmed that the maximum viscosity Tq measured in the region Q is smaller than the maximum viscosity Tp measured in the region P. FIG.

As shown in Fig. 2, the “frame member having a reflectance of 99.5%” has a frame-shaped side wall portion (submerged edge portion 3b) and an elongated surface portion 3a, such as a rectangular edge, and has a back surface of the elongated surface portion 3a. The sheet | seat of reflectance 99.5% is affixed on the whole.

The "sheet of 99.5% reflectance" is a pellet of a lactic acid polymer (NW3001D: manufactured by Nature Works, L body content 98.5%, D body content 1.5%) having a weight average molecular weight of 200,000, and rutile titanium oxide by a chlorine process (Ti-PureR-105: manufactured by DuPont) and a polypropylene pellet (Novatec PPFY-4: manufactured by Nippon Polypro Co., Ltd .: MFR = 5 g / 10 min) were mixed at a mass ratio of 33:50:17. To form a mixture. To 100 parts by mass of this mixture, 2.5 parts by mass of a hydrolysis inhibitor (bis (dipropylphenyl) carbodiimide), and a styrene-ethylene-butylene-styrene block copolymer (butadiene component-introduced type) as a SEBS compound Dynaron 8630P: 3.5 parts by mass of butadiene / styrene / ethylene / butylene = 1/14/30/55 wt% (manufactured by JSR Co., Ltd.) was added and mixed, followed by pelletization using a twin screw extruder, so-called master batch. , The master batch and the lactic acid polymer were mixed at a mass ratio of 60:40 to prepare a resin composition, and the obtained resin composition was supplied to an extruder heated at 200 ° C, and 200 was extruded using this extruder. After kneading at 占 폚, the molten resin composition was extruded from the T die into a sheet form, and the film obtained by cooling and solidifying was 2.8 times roll-stretched with MD at 68 占 폚, and then 3 times with TD at 68 占 폚.Emitter carried by stretching a biaxially stretched, and a reflection film having a thickness of 150 ㎛ obtained by further heat treatment at 140 ℃.

As a result, a wavelength of 400? By forming a light reflecting surface having an average reflectance at 800 nm of 10% or more, the brightness of the screen can be preferably increased, and at that time, the maximum measured in the region Q is greater than the maximum viscosities Tp measured in the region P. It was found that by increasing the brightness Tq, luminance unevenness, in particular, luminance unevenness near the light source can be suppressed.

1: top chassis
2: liquid crystal panel
3: frame member (molded frame)
3a: long surface
3b: drooping edge
4: optical sheet
5: lamp (light source)
6: light guide plate
7: reflector
8: bottom chassis
Z: Center vertical line
L: total distance in longitudinal direction
P: 3? 5% away
10: display screen

Claims (4)

A member mounted on an edge light type liquid crystal display device,
A portion of the side wall portion is provided with a portion extending inwardly, and a portion of the rear surface or the entire surface has a wavelength of 400? It is a frame member provided with the light reflection surface whose average reflectance in 800 nm is 10% or more,
When the frame member is mounted on the liquid crystal display device, the display screen is separated from the light source side end portion on the center vertical line orthogonal to the longitudinal direction of the screen edge portion where the light source is arranged, by a length equal to 5% of the entire length of the center vertical line. The maximum viscosities measured to the position become lower than the maximum viscosities at the position apart from the said 5% length. A member mounted on an edge light type liquid crystal display device,
A portion of the side wall portion is provided with a portion extending inwardly, and the wavelength 400? The average reflectance at 800 nm is 10? The frame member provided with the light reflection surface which is 80%. The backlight unit provided with the frame member of Claim 1 or 2. A liquid crystal display device comprising the backlight unit according to claim 3.

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