KR20120031360A - Backlight unit - Google Patents

Abstract

PURPOSE: A backlight unit is provided to partially block light using a polarization plate or a light shielding plate. CONSTITUTION: A reflecting plate includes a reflecting surface. An optical sheet is arranged on the reflecting surface. A light source is arranged on at least one space between the reflecting plate and the optical sheet. At least one polarizing plate(300) is arranged on the surface of the optical sheet facing the reflecting surface. An extension rate of an area adjacent to the light source is different from an extension rate of an area remote from the light source.

Description

Backlight unit

Embodiments relate to a backlight unit capable of providing uniform luminance.

In general, typical large display devices include liquid crystal displays (LCDs) and plasma display panels (PDPs).

Unlike the self-luminous PDP, an LCD requires a separate backlight unit due to the absence of its own light emitting device.

The backlight unit used in LCD is classified into an edge type backlight unit and a direct type backlight unit according to the position of the light source. In the edge type, the light source is disposed on the left and right sides or the top and bottom sides of the LCD panel and the light guide plate is used. Since the light is evenly distributed on the front surface, the light is uniform and the panel thickness can be made ultra thin.

The direct method is a technology that is usually used for displays of 20 inches or more. Since a plurality of light sources are disposed under the panel, it has an advantage of superior light efficiency compared to the edge method, and is mainly used for large displays requiring high brightness.

CCFL (Cold Cathode Fluorescent Lamp) was used as the light source of the existing edge type or direct type backlight unit.

However, since the CCFL-based backlight unit is always powered by the CCFL, a considerable amount of power is consumed, and the problems of environmental pollution due to the addition of about 70% color reproduction rate and mercury are pointed out as disadvantages.

As a substitute for solving the above problems, research on a backlight unit using an LED (Light Emitting Diode) has been actively conducted.

When the LED is used as a backlight unit, the LED array can be locally turned on and off, which can drastically reduce power consumption. For RGB LED, it exceeds 100% of the NTSC (National Television System Committee) color reproduction range specification. To provide consumers with more vivid picture quality.

In addition, the LED produced by the semiconductor process is characterized by harmless to the environment.

LCD products employing LEDs with the above advantages are being released one after another. However, since the driving mechanism is different from the existing CCFL light source, driving drivers and PCB substrates are expensive.

Therefore, the LED backlight unit is still applied only to expensive LCD products.

Embodiments provide a backlight unit capable of making luminance uniform by blocking some light by using a polarizing plate or a light shielding plate.

Embodiments include a reflecting plate including a reflecting surface, an optical sheet disposed on the reflecting plate, a light source disposed on at least one side of a space between the reflecting plate and the optical sheet, and a surface of the optical sheet facing the reflecting surface. At least one polarizing plate having a different elongation between a region adjacent to the light source and a region far from the light source may be included.

Here, the reflective surface of the reflector may be an inclined surface parallel to the horizontal plane or inclined at a predetermined angle with respect to the horizontal plane.

The reflective surface of the reflective plate may have a plurality of reflective patterns having a predetermined width.

Here, the reflective pattern may have a thickness different from a region adjacent to the light source and a region far from the light source, and as the reflective pattern increases from a light source, the width of the reflective pattern may increase and the distance between adjacent reflective patterns may decrease. have.

And, as the reflection pattern is further away from the light source, the width of the reflection pattern is constant and the spacing between adjacent reflection patterns is decreased, and as the reflection pattern is farther from the light source, the width of the reflection pattern is increased and The spacing between adjacent reflection patterns may be constant.

Subsequently, a light transmission supporter may be further disposed on the reflective surface of the reflector to support the optical sheet.

The polarizing plate has a higher elongation as it moves away from the light source, a first polarizing plate having an elongation direction in a first direction, and a second polarizing plate having a higher elongation as it moves away from the light source on a first polarizing plate, and a second polarizing plate in a second direction. It may include.

Further, the polarizing plate may include a first polarizing plate located in an area adjacent to the light source and having a first elongation, and a second polarizing plate located in an area far from the light source and having a second elongation.

Here, the first polarizing plate and the second polarizing plate may be arranged side by side on the plane.

Another embodiment includes a reflective plate including a reflective surface, an optical sheet disposed on the reflective plate, a light source disposed on at least one side of a space between the reflective plate and the optical sheet, and a surface of the optical sheet facing the reflective surface. The light blocking plate may include a light blocking plate having a different density of light shielding patterns between a region disposed adjacent to the light source and a region far from the light source.

Here, the light blocking plate may be an optical sheet having a metal light blocking pattern or a metal plate having a metal light blocking pattern.

As the light shielding pattern of the light shielding plate is further away from the light source, the width of the light shielding pattern is decreased and the distance between adjacent light shielding patterns is increased, or the light shielding pattern of the light shielding plate is farther from the light source, the width of the light shielding pattern is increased. The distance between the constant and adjacent light shielding patterns may be increased, or as the light shielding pattern of the light shielding plate is further from the light source, the width of the light shielding pattern may be increased and the distance between the adjacent light shielding patterns may be constant.

Embodiments use a polarizing plate having a different degree of stretching between a region adjacent to a light source and a region far from the light source, or a shielding plate having a different density of light shielding patterns between a region adjacent to the light source and a region far from the light source, thereby blocking a part of the light as a whole. It is possible to manufacture a backlight unit having a uniform brightness.

In addition, the embodiments are simple in the overall configuration, the manufacturing cost of the backlight unit is low, the overall weight is light, and can provide a uniform brightness, economic efficiency and reliability of the backlight unit can be improved.

1A and 1B are views for explaining the basic concept of the backlight unit according to the present embodiment.
2A-2C illustrate various types of light sources
3A and 3B illustrate a first embodiment showing the polarizer of FIG. 1.
4A to 4C illustrate a second embodiment showing the polarizer of FIG. 1.
5A to 5D are third embodiments showing the polarizer of FIG.
6 is a view illustrating a backlight unit according to another exemplary embodiment.
7A and 7B illustrate a first embodiment showing the polarizer of FIG. 6.
8A to 8C illustrate a second embodiment showing the polarizer of FIG. 6.
9A to 9D illustrate a third embodiment showing the polarizer of FIG. 6.
10 to 17 illustrate embodiments of a reflecting plate having a reflecting pattern.
18A to 18C illustrate a backlight unit including an optical sheet and a light transmitting supporter.
19 to 22 illustrate embodiments of the light transmitting supporter of FIG. 18A.
23A to 23C are exemplary embodiments illustrating a positional relationship between a reflector and a light source
24A to 24C show another embodiment showing a positional relationship between a reflector and a light source
25 shows a backlight unit including a parallel optical lens
26 is a view illustrating a backlight unit having a light blocking plate;
27 to 29 illustrate embodiments of a light blocking plate having a metal light blocking pattern.
30 is a view illustrating a backlight unit having a dimming structure
31 is a view showing a display module having a backlight unit according to the present embodiment.
32 and 33 show a display device according to the present embodiment.

Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings.

In the description of the embodiments, it is to be understood that each layer (film), region, pattern or structure is formed "on" or "under" a substrate, each layer The terms " on "and " under " encompass both being formed" directly "or" indirectly " In addition, the criteria for the top or bottom of each layer will be described with reference to the drawings.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size of each component does not necessarily reflect the actual size.

1A and 1B are diagrams for explaining a basic concept of a backlight unit according to the present embodiment. FIG. 1A is a backlight unit including a reflector having a flat reflective surface, and FIG. 1B is a reflector having an inclined reflective surface. It includes a backlight unit.

As shown in FIGS. 1A and 1B, the backlight unit may include a light source 100, a reflector 200, and a polarizer 300.

Here, the light source 100 is disposed on at least one side of the reflector 200 and serves to propagate light to the reflecting surface 210 of the reflector 200.

In addition, at least one light source 100 may be formed on the support layer 110.

The support layer 110 may be a substrate on which at least one light source 100 is mounted, and an adapter (not shown) for supplying power and an electrode pattern (not shown) for connecting the light source 100 may be formed. .

For example, a carbon nanotube electrode pattern (not shown) for connecting the light source 100 and an adapter (not shown) may be formed on an upper surface of the substrate.

The support layer 110 may be made of polyethylene terephthalate (PET), glass, polycarbonate (PC), silicon (Si), or the like, and may be a printed circuit board (PCB) substrate on which a plurality of light sources 100 are mounted. It may be formed in the form.

Meanwhile, the light source 100 may be a light emitting diode chip, and the light emitting diode chip may include a blue LED chip or an ultraviolet LED chip, or a red LED chip, a green LED chip, a blue LED chip, and yellow green. ) It may be configured in a package form combining at least one or more of the LED chip, the white LED chip.

The white LED may be implemented by combining yellow phosphor on a blue LED, or using red phosphor and green phosphor on a blue LED at the same time.

Here, the light source 100 may be classified into a horizontal type, a vertical type, and a hybrid type according to the structure.

Figure 2a is a view showing a light source of a horizontal structure, Figure 2b is a view showing a light source of a vertical structure, Figure 2c is a view showing a light source of a hybrid structure.

As shown in FIG. 2A, the light source 100 having a horizontal structure has a substrate 9 made of silicon or sapphire at the bottom thereof.

The n-type semiconductor layer 2 may be located on the substrate 9, and the n-type semiconductor layer 2 may be formed of, for example, n-GaN.

The active layer 3 may be positioned on the n-type semiconductor layer 2, and the active layer 3 may be formed of, for example, InGaN.

The p-type semiconductor layer 4 may be positioned on the active layer 3, and the p-type semiconductor layer 4 may be formed of, for example, p-GaN.

The p-type electrode 5 may be positioned on the p-type semiconductor layer 4, and the p-type electrode 5 may include at least one of chromium, nickel, and gold, for example.

In addition, the n-type electrode 6 may be positioned on the n-type semiconductor layer 2, and the n-type electrode 6 may include, for example, at least one of chromium, nickel, and gold.

Subsequently, as shown in FIG. 2B, the light source 100 having the vertical structure includes a p-type electrode 5 having a reflective surface 5a, a p-type semiconductor layer 4, an active layer 3, and an n-type semiconductor layer. (2) and the n-type electrode 6 may be formed in a stacked structure sequentially.

When the voltage is applied to the p-type electrode 5 and the n-type electrode 6, the light source 100 corresponds to the height difference (energy gap) of the conduction band and the home appliance band while the holes and the electrons are coupled in the active layer 3. Can be operated on the principle of emitting light energy.

Next, as shown in FIG. 2C, the n-type semiconductor layer 2, the active layer 3, and the p-type semiconductor layer 4 are formed on the substrate 9 in the hybrid light source 100.

The n-type electrode 6 is formed on the n-type semiconductor layer 2, and the p-type electrode 5 is formed between the substrate 9 and the n-type semiconductor layer 2 to form the n-type semiconductor layer 2. And the p-type semiconductor layer 4 via the active layer 3.

That is, the p-type electrode 5 is contacted with the p-type semiconductor layer 4 through holes formed to pass through the n-type semiconductor layer 2 and the active layer 3.

Then, the insulating film 7 is coated on the side of the hole so that the p-type electrode 5 is electrically insulated.

As such, the light source 202 of the present embodiment may use various types of light emitting devices.

On the other hand, the polarizing plate 300 is disposed to face the reflecting surface 210 of the reflecting plate 200, and is disposed away from the reflecting surface 210 of the reflecting plate 200 by a predetermined distance.

Here, the polarizing plate 300 does not have the same elongation for the entire area, but has an elongation that gradually increases as it moves away from the light source 100.

3A and 3B are first embodiments showing the polarizer of FIG. 1, FIG. 3A is a plan view of the polarizer, and FIG. 3B is a cross-sectional view of the polarizer.

As shown in FIGS. 3A and 3B, although the elongation 310 is low in the area adjacent to the light source among the entire areas of the polarizing plate 300, the elongation 310 is gradually increasing toward the area farther from the light source.

That is, the elongation 310 of the polarizing plate 300 gradually increases as the distance from the light source 100 increases.

As such, the reason for using the polarizing plate 300 having the elongation 310 that increases as the distance from the light source 100 increases is that the luminance of the light can be adjusted so that the light having uniform luminance is emitted from the backlight unit.

In general, since the backlight unit has a high luminance of light in an area adjacent to the light source and a low luminance of light in an area far from the light source, the backlight unit does not have a uniform luminance as a whole. When using a polarizing plate having a silver elongation, the area adjacent to the light source has a low elongation of the polarizing plate, thereby blocking a part of the light, thereby lowering the brightness of the light, and relatively far away from the light source, the light is almost blocked because of the high elongation of the polarizing plate. Therefore, the brightness of light can be maintained as it is.

Therefore, the elongation of the polarizing plate can be adjusted to uniformly adjust the luminance of the light emitted from the backlight unit as a whole.

4A to 4C are second embodiments illustrating the polarizing plate of FIG. 1, FIG. 4A is a plan view of the polarizing plate, and FIGS. 4B and 4C are cross-sectional views of the polarizing plate.

As shown in FIG. 4A, the polarizer 300 may be configured of the first polarizer 300a and the second polarizer 300b, and in some cases, two or more polarizers may be used.

In this case, the first polarizing plate 300a has a higher elongation 310a as the distance from the light source and the stretching direction is in the first direction, and the second polarizing plate 300b overlaps the first polarizing plate 300a and as the distance from the light source increases. Reference numeral 310b is high and the stretching direction is the second direction.

In addition, as shown in FIG. 4B, the first polarizing plate 300a and the second polarizing plate 300b may overlap each other by a predetermined distance d.

In addition, as illustrated in FIG. 4C, the first polarizing plate 300a and the second polarizing plate 300b may be stacked to overlap each other and overlap each other.

As described above, the luminance of the light can be uniformly adjusted by using a plurality of polarizing plates having different elongation directions and increasing elongation as the distance from the light source increases.

5A to 5D are third embodiments showing the polarizing plate of FIG. 1, and FIG. 5A is a plan view of the polarizing plate, and FIGS. 5B, 5C and 5D are cross-sectional views of the polarizing plate.

As illustrated in FIG. 5A, the polarizer 300 may have a form in which the first polarizer 300a and the second polarizer 300b are coupled to each other on the same plane or on different planes.

In some cases, it may be one polarizing plate having a plurality of regions having different elongations.

Here, the first polarizing plate 300a may be located in an area adjacent to the light source and have a first elongation 310a, and the second polarizing plate 300b may be located in a region far from the light source and may have a second elongation 310b.

In this case, the first polarizing plate 300a and the second polarizing plate 300b may be arranged side by side on a plane, as shown in FIG. 5B, or may be disposed on another plane and coupled to each other, as shown in FIGS. 5C and 5D.

That is, FIG. 5B illustrates a structure in which the first polarizing plate 300a having the first elongation 310a and the second polarizing plate 300b having the second elongation 310b are arranged side by side on the same plane.

5C illustrates a structure in which the first polarizing plate 300a having the first elongation 310a and the second polarizing plate 300b having the second elongation 310b are disposed on different planes, and the first polarizing plate 300a is provided. ) Is disposed lower than the second polarizing plate 300b.

5D illustrates a structure in which the first polarizing plate 300a having the first elongation 310a and the second polarizing plate 300b having the second elongation 310b are disposed on different planes, and the first polarizing plate 300a is illustrated in FIG. ) Is arranged higher than the second polarizing plate 300b.

On the other hand, as another embodiment, the light sources may be disposed on both sides of the polarizing plate 300, in this case, the shape of the elongation 310 of the polarizing plate 300 may vary.

6 is a diagram illustrating a backlight unit according to another embodiment, and shows a backlight unit having light sources at both sides.

As illustrated in FIG. 6, the backlight unit has a structure in which a reflector 200 and a polarizer 300 are disposed between the first light source 100a and the second light source 100b.

As illustrated in FIG. 6, in the structure in which the polarizing plate 300 is disposed between the first light source 100a and the second light source 100b, the elongation of the polarizing plate 300 may vary.

7A and 7B illustrate a polarizer of FIG. 6, in which FIG. 7A is a plan view of the polarizer and FIG. 7B is a cross-sectional view of the polarizer.

As shown in FIGS. 7A and 7B, although the elongation 310 is low in the area adjacent to the light source among the entire areas of the polarizing plate 300, the elongation 310 is gradually increasing toward the area farther from the light source.

That is, the elongation 310 of the polarizing plate 300 gradually increases as the distance from the light source 100 increases.

8A to 8C are second embodiments illustrating the polarizing plate of FIG. 6, and FIG. 8A is a plan view of the polarizing plate, and FIGS. 8B and 8C are cross-sectional views of the polarizing plate.

As shown in FIG. 8A, the polarizer 300 may be configured of the first polarizer 300a and the second polarizer 300b, and in some cases, two or more polarizers may be used.

In this case, the first polarizing plate 300a has a higher elongation 310a as the distance from the light source and the stretching direction is in the first direction, and the second polarizing plate 300b overlaps the first polarizing plate 300a and as the distance from the light source increases. Reference numeral 310b is high and the stretching direction is the second direction.

In addition, as illustrated in FIG. 8B, the first polarizing plate 300a and the second polarizing plate 300b may overlap each other by a predetermined distance d.

In addition, as illustrated in FIG. 8C, the first polarizing plate 300a and the second polarizing plate 300b may be stacked to overlap each other and overlap each other.

9A to 9D are third embodiments showing the polarizing plate of FIG. 6, and FIG. 9A is a plan view of the polarizing plate, and FIGS. 9B, 9C, and 9D are cross-sectional views of the polarizing plate.

As shown in FIG. 9A, the polarizer 300 may have a form in which the first polarizer 300a and the second polarizer 300b are coupled to each other on the same plane or on different planes.

In some cases, it may be one polarizing plate having a plurality of regions having different elongations.

Here, the first polarizing plate 300a may be located in an area adjacent to the light source and have a first elongation 310a, and the second polarizing plate 300b may be located in a region far from the light source and may have a second elongation 310b.

In this case, the first polarizing plate 300a and the second polarizing plate 300b may be arranged side by side on a plane, as illustrated in FIG. 9B, or may be disposed on another plane and coupled to each other, as shown in FIGS. 9C and 9D.

That is, FIG. 9B illustrates a structure in which the first polarizing plate 300a having the first elongation 310a and the second polarizing plate 300b having the second elongation 310b are arranged side by side on the same plane.

9C illustrates a structure in which the first polarizing plate 300a having the first elongation 310a and the second polarizing plate 300b having the second elongation 310b are arranged on different planes, and the first polarizing plate 300a is provided. ) Is disposed lower than the second polarizing plate 300b.

Next, FIG. 9D illustrates a structure in which the first polarizing plate 300a having the first elongation 310a and the second polarizing plate 300b having the second elongation 310b are disposed on different planes, and the first polarizing plate 300a. ) Is arranged higher than the second polarizing plate 300b.

Meanwhile, the reflective plate 200 may include a flat reflective surface 210, as shown in FIG. 1A, or may include a reflective surface 210 having a predetermined slope, as illustrated in FIG. 1B.

That is, the reflective surface 210 of the reflective plate 200 may have an inclined surface that is parallel to the horizontal plane or inclined at a predetermined angle with respect to the horizontal plane.

The reflecting surface 210 of the reflector 200 serves to reflect light incident from the light source 100 to the upper display panel.

In this case, as shown in FIG. 1B, the reflecting plate 200 including the reflecting surface 210 having a predetermined inclination may be inclined at an angle of about 0 to 85 degrees with respect to the optical axis from which the reflecting surface 210 is incident from the light source 100. Is preferred.

In addition, the reflective plate 200 may be formed of a conductive material having a high reflectance of light, and in some cases, may be formed of a non-conductive material.

In addition, in order to increase the light reflection efficiency of the reflective plate 200, a reflective layer may be further formed on the reflective surface 210 of the reflective plate 200.

In this case, the reflective layer may be a reflective coating film manufactured in the form of a film, or may be a reflective coating material layer on which a reflective material is deposited.

The reflective layer may include at least one of a metal or a metal oxide, for example, a metal or metal oxide having a high reflectance such as aluminum (Al), silver (Ag), gold (Ag), or titanium dioxide (TiO ₂ ). It may be configured to include.

In this case, the reflective layer may be formed by depositing or coating a metal or metal oxide on the reflective surface 210 of the reflective plate 200, or may be formed by printing a metal ink.

Here, as a deposition method, a vacuum deposition method such as a thermal evaporation method, an evaporation method or a sputtering method may be used, and as a coating or printing method, a printing method, a gravure coating method, or a silk screen method may be used.

In addition, the reflective layer may be manufactured in the form of a film or sheet, and may be formed by adhering on the reflective surface 210 of the reflective plate 200.

In some cases, the reflective layer may have a reflective pattern on the surface thereof, or may form a reflective pattern on the reflective surface 210 itself of the reflective plate 200.

10 to 17 illustrate embodiments of a reflective plate having a reflective pattern.

10 illustrates a structure in which a plurality of reflective patterns 230 having a predetermined width are formed on the reflective surface 210 of the reflective plate 200.

As shown in FIG. 10, the reason for forming the reflective pattern 230 on the reflector 200 is that not only the reflection of the light but also the diffusion effect of uniformly spreading the light may be provided.

Here, the reflective pattern 230 may have the same shape as the reflective surface 210 of the reflective plate 200 or may be different from each other.

For example, when the reflecting surface 210 of the reflecting plate 200 has a concave-convex shape of a planar structure, the shape of the reflecting pattern 230 formed on the reflecting surface 210 may also be manufactured to have a concave-convex shape of a planar structure.

In some cases, the reflective pattern 230 may be mixed with the pattern shape of the planar structure and the pattern shape of the curved structure.

In addition, the reflective pattern 230 may have mixed patterns of various sizes.

For example, the reflective pattern 230 may increase in size as it moves away from the light source.

FIG. 11 is a view illustrating a reflecting plate having a reflecting pattern having a different size, and as shown in FIG. 11, the size of the reflecting pattern 230 formed in the reflecting plate 200 increases gradually as the distance from the light source 100 increases. Formed structure.

As such, the reason for manufacturing is that the angle of the incident light may change as the distance from the light source 100 changes, and the brightness of the light may also decrease.

Therefore, when the size of the reflective pattern 230 increases as the distance from the light source 100 increases, the light reflectance of a region far from the light source 100 is higher, thereby increasing the brightness of the light.

As described above, the reflective pattern 230 may be manufactured in various sizes in the corresponding area according to the overall luminance distribution of the backlight.

FIG. 12 is a view illustrating a reflector having a reflective pattern having a different thickness, and as shown in FIG. 12, the thickness of the reflective pattern 230 formed on the reflector 200 gradually increases as the distance from the light source 100 increases. Structure.

That is, the thickness d1 of the reflective pattern 230 of the region adjacent to the light source 100 is thinner than the thickness d2 of the reflective pattern 230 of the region far from the light source 100.

In this case, the surface of the reflective pattern 230 may have an inclined surface that is inclined at an angle with respect to the horizontal surface.

FIG. 13 is a view illustrating a reflective plate having a multilayer reflective pattern. As illustrated in FIG. 13, a first reflective pattern layer 230a is formed in a region adjacent to the light source 100, and is slightly separated from the light source 100. The second reflective pattern layer 230b is formed on the first reflective pattern layer 230a in the region, and the third reflective pattern layer 230c is disposed on the second reflective pattern layer 230b in the region far from the light source 100. Can be formed.

Here, the thicknesses and materials of the first, second, and third reflective pattern layers 230a, 230b, and 230c may be the same or different from each other.

FIG. 14 is a view illustrating a reflecting plate having reflective patterns having different thicknesses, as shown in FIG. 14, having a first thickness in an area adjacent to the light source 100, and a second thickness in an area slightly away from the light source 100. And a reflection pattern 230 having a third thickness may be formed in a region far from the light source 100.

Here, the reflective pattern 230 has a structure in which the second thickness d1 is thicker than the first thickness and the third thickness d2 is thicker than the second thickness d1.

15 is a view illustrating reflective patterns having different widths and intervals.

As shown in FIG. 15, as the reflection pattern 230 becomes farther from the light source 100, the width W of the reflection pattern 230 may increase and the distance D between adjacent reflection patterns 230 may decrease. have.

In the embodiment of FIG. 15, since the width increases as the distance from the light source 100 increases, and the interval between adjacent reflection patterns 230 is narrowed, the reflectance of a region far from the light source 100 is increased, so that the brightness of light is improved. An area farther away from 100 may solve the existing problem of decreasing luminance.

16 is a view showing reflective patterns having a constant width and different intervals.

As shown in FIG. 16, as the reflection pattern 230 is farther from the light source 100, the width W of the reflection pattern 230 may be constant, and the distance D between adjacent reflection patterns may decrease.

In the embodiment of FIG. 16, as the distance between the adjacent reflection patterns 230 decreases as the distance from the light source 100 increases, the density of the reflection pattern 230 increases, so that the reflectance of a region far from the light source 100 is high. The brightness can be improved.

FIG. 17 is a view showing reflective patterns having constant intervals and different widths.

As shown in FIG. 17, as the reflection pattern 230 is farther from the light source 100, the width W of the reflection pattern 230 increases, and the distance D between adjacent reflection patterns may be constant.

In the embodiment of FIG. 17, the width of the reflective pattern 230 increases as the distance from the light source 100 increases, so that the luminance of the light may be improved due to high reflectance of a region far from the light source 100.

Meanwhile, the backlight unit of the present embodiment may further include an optical sheet 400 and a light transmitting supporter 500.

18A, 18B, and 18C show a backlight unit including an optical sheet and a light transmitting supporter. FIG. 18A is a cross-sectional view, FIG. 18B is a perspective view of FIG. 18A, and FIG. 18C is another embodiment of FIG. 18A.

As shown in FIGS. 18A and 18B, the backlight unit may include a reflector 200, an optical sheet 400, a light source 100, and a polarizer 300.

Here, the reflecting plate 200 includes a reflecting surface 210, and the optical sheet 400 is disposed above the reflecting plate 200.

In this case, the optical sheet 400 may include a fluorescent sheet made of a fluorescent material.

In addition, the space between the reflecting plate and the optical sheet may be filled with any one of vacuum, air, and a polymer material.

In addition, the light source 100 may be supported by the circuit board 110 and disposed on at least one side of the space between the reflecting plate 200 and the optical sheet 400.

In this case, the light source 100 and the circuit board 110 may be disposed in contact with at least one side of the reflector 200, or may be disposed at a predetermined distance from the reflector 200.

As such, the distance between the reflector 200 and the light source 100 may vary according to the light directing angle of the light source 100 and the arrangement space of the backlight component.

Subsequently, the polarizing plate 300 may be disposed on the surface of the optical sheet 400 facing the reflective surface 210, and may have a high elongation toward the light source 100.

Here, the polarizing plate 300 may be one single polarizing plate or a composite polarizing plate formed by overlapping a plurality of polarizing plates having different elongation or stretching directions.

In addition, the light transmitting supporter 500 may be disposed in a space between the reflecting plate 200 and the optical sheet 400 to support the optical sheet 400.

Here, at least one light transmitting supporter 500 may be disposed in a stripe form along the column direction of the reflector 200.

In the light transmitting supporter 500 illustrated in FIG. 18B, the width W1 of the region adjacent to the light source 100 is substantially the same as the width W2 of the region far from the light source.

In some cases, the upper area of the light transmission supporter 500 may be formed to become smaller as it moves away from the light source 100.

The light transmitting supporter 500 may transmit the light emitted from the light source 100 and support the optical sheet 400.

The light transmitting supporter 500 may be made of a light transmitting material, for example, silicone or acrylic resin.

However, the light transmitting supporter 500 is not limited to the above materials and may be made of various materials.

In addition, the light transmission supporter 500 may be formed of a material having a refractive index of about 1.4 to 1.6 so that the light emitted from the light source 100 can be uniformly diffused.

For example, the light transmitting supporter 500 may include polyethylene terephthalate (PET), polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyepoxy (PE), silicone, acrylic, and the like. It may be formed of any one material selected from the group consisting of.

In addition, the light transmission supporter 500 may include a polymer material to firmly support the optical sheet 400.

For example, the light transmitting supporter 500 may include unsaturated polyester, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, Hydroxy ethyl methacrylate, hydroxy propyl methacrylate, hydroxy ethyl acrylate, acryl amide, metyrol acrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, normal butyl acrylate, 2 -Acryl-based, urethane-based, epoxy-based, melamine-based, and the like, such as ethyl hexyl acrylate polymer or copolymer or terpolymer.

The light transmitting supporter 500 may be formed by applying a liquid or gel-like resin and curing the resin.

FIG. 18C is a view illustrating a light transmitting supporter having a two-layer structure, in which the light transmitting supporter 500 is in contact with the first layer 500a adjacent to the reflecting plate 200 and on the first layer 500a and the polarizing plate 300. It may be composed of a second layer (500b) adjacent to.

Here, the materials of the first layer 500a and the second layer 500b may be different from each other.

For example, the first layer 500a may include a polymer material to firmly support the optical sheet 400, and the second layer 500b may be damaged in contact with the polarizer 300 or the optical sheet 400. It may also include an elastic material so as not to.

19 to 22 illustrate embodiments of the light transmitting supporter of FIG. 18A.

19 is a view illustrating a light transmitting supporter having a different width of an upper surface according to a length direction. As shown in FIG. 19, the width of an upper surface of the light transmitting supporter may gradually decrease as it moves away from the light source 100. have.

That is, in the light transmitting supporter 500, the upper surface width W2 of the region far from the light source 100 is smaller than the upper surface width W1 of the region adjacent to the light source 100.

As such, the reason for manufacturing is because the luminance of the region adjacent to the light source 100 can be reduced and the luminance of the region far from the light source 100 can be increased.

That is, since the area of the light transmitting supporter 500 is wide in the region adjacent to the light source 100, the light diffusion and brightness can be blocked. In the area far from the light source 100, the area of the light transmitting supporter 500 is increased. Since it is narrow, there is an effect of improving or maintaining light diffusion and brightness, so that a backlight having a uniform luminance as a whole can be obtained.

20 to 22 are views illustrating a light transmitting supporter separated into a plurality of individual units.

20 illustrates a structure in which individual units of the light transmitting supporter 500 are arranged side by side along the column direction of the reflector 200.

As shown in FIG. 20, the reason for separating the light transmitting supporter 500 into a plurality of individual units is that the luminance of the light may be improved as compared with the backlight using the light transmitting supporter 500 having a stripe shape.

21 is a structure in which individual units of the light transmitting supporter 500 are alternately arranged along the column direction of the reflector 200.

Subsequently, FIG. 22 is a structure in which the number of individual units of the light transmitting supporter 500 gradually decreases along the column direction of the reflector 200.

In the structure of FIG. 22, in the region adjacent to the light source 100, the number of individual units of the light transmitting supporter 500 may be increased to block the diffusion and the brightness of the light. In the region far from the light source 100, the light transmitting supporter may be used. Since the number of individual units of 500 is reduced, there is an effect of improving or maintaining the light diffusion and brightness, so that a backlight having a uniform luminance as a whole can be obtained.

On the other hand, the present embodiment can further reduce the light directing angle of the light source to additionally attach the reflector to the light source, so that the light output almost horizontally.

The reflector may be formed in a structure surrounding the entire surface of the light source except for the direction in which the light of the light source is emitted.

Therefore, the light emitted from the light source may travel directly toward the reflecting surface of the reflecting plate or indirectly toward the reflecting surface of the reflecting plate after being reflected by the reflecting mirror.

In this case, since the light emitted from the light source has a small directivity angle due to the reflector, most of the light travels horizontally toward the reflecting surface of the reflecting plate, and the light reflected from the reflecting surface of the reflecting plate is uniformly transmitted to the display panel. Can be.

23A to 23C illustrate an example of a positional relationship between a reflector and a light source, and FIGS. 24A to 24C illustrate another example of a positional relationship between a reflector and a light source.

23A to 23C illustrate a structure in which the reflector 240 is disposed to face the light exit surface of the light source 100, and FIGS. 24A to 24C illustrate regions in which the reflector 240 is opposite to the light exit surface of the light source 100. It is a structure that is placed on.

FIG. 23A illustrates a structure in which the light exit surface of the vertical light source 100 faces the reflector 240, and the reflector 240 is elliptical in an open direction in a direction opposite to the light exit surface of the light source 100. Has

23B is a structure in which the light exit surface of the vertical light source 100 faces the reflector 240, and the reflector 240 is opened in a direction opposite to the light exit surface of the light source 100. Hemispherical

Next, FIG. 23C illustrates a structure in which the light exit surface of the horizontal light source 100 faces the reflector 240, and the reflector 240 is opened in a direction opposite to the light exit surface of the light source 100. Hemispherical

In addition, FIG. 24A illustrates a structure in which the light exit surface of the vertical light source 100 does not face the reflector 240, and the reflector 240 is an elliptical shape that is open in the same direction as the light exit surface of the light source 100. Has a phase.

Next, FIG. 24B illustrates a structure in which the light exit surface of the vertical light source 100 does not face the reflector 240, and the reflector 240 is open in the same direction as the light exit surface of the light source 100. It has a shape.

Next, FIG. 24C illustrates a structure in which the light exit surface of the horizontal light source 100 does not face the reflector 240, and the reflector 240 is open in the same direction as the light exit surface of the light source 100. It has a shape.

In addition, the structure of the reflector 240 may be manufactured in a polygonal shape having at least one bent surface.

In addition, in the present embodiment, the reflector 240 is used to make the light of the light source 100 parallel, but instead of the reflector 240, a lens or the like may be used in front of the light exit surface of the light source 100. It is also possible to use a structure of a specific shape in which the light exit surface of 100 is open.

25 is a view illustrating a backlight unit including a parallel optical lens, and as shown in FIG. 25, the parallel optical lens 600 is disposed in front of the light exit surface of the light source 100 and is emitted from the light source 100. It can serve to convert the light into parallel light.

As described above, the present embodiment makes it possible to reduce the light directing angle of the light source by making the light emitted from the light source proceed in parallel by using a reflector or a parallel optical lens. effective.

In the present exemplary embodiment, the light shielding plate may be disposed on the surface of the optical sheet facing the reflective surface for uniformity of overall luminance.

26 is a view illustrating a backlight unit having a light blocking plate.

As illustrated in FIG. 26, the backlight unit may include a reflective plate 200, a light source 100, and a light blocking plate 350.

In some cases, an optical sheet may be further formed on the light blocking plate 350.

Here, the optical sheet may include a fluorescent sheet made of a fluorescent material.

The reflecting plate 200 may include a reflecting surface 210, and the light source 100 may be supported by the circuit board 110 and disposed on at least one side of a space between the reflecting plate 200 and the optical sheet 400. .

In this case, the light source 100 and the circuit board 110 may be disposed in contact with at least one side of the reflector 200, or may be disposed at a predetermined distance from the reflector 200.

As such, the distance between the reflector 200 and the light source 100 may vary according to the light directing angle of the light source 100 and the arrangement space of the backlight component.

Subsequently, the light blocking plate 350 may be disposed to be spaced apart from the light source 100 so as to face the reflective surface 210, and may have a light blocking pattern 351 that decreases in density as it moves away from the light source 100.

Here, the light blocking plate 350 may be an optical sheet having the metal light blocking pattern 351 or a metal plate having the metal light blocking pattern 351.

In this case, the light blocking plate 350 may be made of at least one of TiO 2, CaCO 3, and ZnO.

The metal blocking pattern 351 of the light blocking plate 350 may be manufactured in various forms according to the distance from the light source 100.

27 to 29 illustrate examples of light blocking plates having metal light shielding patterns.

27 is a view illustrating a metal light shielding pattern having a different width and a gap, and as the light shielding pattern 351 of the light shielding plate 350 moves away from the light source 100, the width W of the metal light shielding pattern 351 decreases. The spacing D between the adjacent metal light blocking patterns 351 may have an increasing structure.

In addition, FIG. 28 is a view showing a metal light shielding pattern having a constant width and different intervals. As the light shielding pattern 351 of the light shielding plate 350 moves away from the light source 100, the width of the metal light shielding pattern 351 is increased. W may be constant, and the distance D between adjacent metal light blocking patterns 351 may have an increasing structure.

Next, FIG. 29 is a view showing a metal light shielding pattern having a constant interval and a different width. As the light shielding pattern 351 of the light shielding plate 350 is farther from the light source 100, the width of the metal light shielding pattern 351 is increased. W decreases, and the spacing D between adjacent metal light blocking patterns 351 may have a constant structure.

30 is a diagram illustrating a backlight unit having a dimming structure.

The backlight unit of FIG. 30 may include a light source 100, a reflector 200, a polarizer 300, and an optical sheet 400.

Here, the light source 100, the reflecting plate 200, and the polarizing plate 300 may be disposed at a predetermined angle with respect to the optical sheet 400 arranged horizontally as a module.

That is, the unit module including the light source 100, the reflecting plate 200, and the polarizing plate 300 is inclined at a predetermined angle with respect to the surface of the optical sheet 400. Can overlap.

In other words, one unit module may have a first end and a second end facing the first end, and the first end may have a structure in which the light source 100 is disposed. The ends are disposed to span over the first ends of neighboring unit modules.

As such, the reason for the arrangement is that the region where the light source 100 is located is covered by the neighboring unit module, so that the light spot phenomenon can be removed.

That is, in the backlight unit, when the light source 100 is disposed near the optical sheet 400, a light spot phenomenon occurs in an area where the light source 100 is located due to the strong light intensity of the light source 100, thereby adversely affecting image quality. However, as in the present embodiment, the unit module is disposed inclined from the optical sheet 400, and the first end of the unit module in which the light source is located is located far from the optical sheet 400, and at the same time, the light source is positioned The light spot phenomenon of the light source 100 may be eliminated by overlapping the second end of the neighboring unit module on the first end of the unit module.

31 is a view showing a display module having a backlight unit according to the present embodiment.

As shown in FIG. 31, the display module 20 may include a display panel 800 and a backlight unit 700.

The display panel 800 includes a color filter substrate 810 and a thin film transistor (TFT) substrate 820 bonded to face each other to maintain a uniform cell gap, and between the two substrates 810 and 820. A liquid crystal layer (not shown) may be interposed.

The color filter substrate 810 includes a plurality of pixels including red (R), green (G), and blue (B) sub-pixels, and generates light corresponding to the color of red, green, or blue when light is applied. You can.

The pixels may be composed of red, green, and blue subpixels, but the red, green, blue, and white (W) subpixels constitute one pixel, but are not necessarily limited thereto.

The TFT substrate 820 may switch a pixel electrode (not shown) as a device in which switching elements are formed.

For example, the common electrode (not shown) and the pixel electrode may change the arrangement of molecules of the liquid crystal layer according to a predetermined voltage applied from the outside.

The liquid crystal layer is composed of a plurality of liquid crystal molecules, and the liquid crystal molecules change their arrangement corresponding to the voltage difference generated between the pixel electrode and the common electrode.

As a result, the light provided from the backlight unit 700 may be incident on the color filter substrate 810 corresponding to the change in the molecular arrangement of the liquid crystal layer.

In addition, an upper polarizer 830 and a lower polarizer 840 may be disposed on upper and lower sides of the display panel 800, and more specifically, an upper polarizer 830 is disposed on an upper surface of the color filter substrate 810. The lower polarizer 840 may be disposed on the bottom surface of the TFT substrate 820.

Although not shown, a gate and a data driver for generating a driving signal for driving the panel 800 may be provided at the side of the display panel 800.

As illustrated in FIG. 31, the display module may be configured by closely placing the backlight unit 700 on the display panel 800.

For example, the backlight unit 700 may be adhered to and fixed to the lower side of the display panel 800, more specifically, the lower polarizer 840, and for this purpose, between the lower polarizer 840 and the backlight unit 700. An adhesive layer (not shown) may be formed on the substrate.

As described above, by forming the backlight unit 700 in close contact with the display panel 800, the overall thickness of the display device may be reduced to improve appearance, and additional structures for fixing the backlight unit 700 may be removed. Thus, the structure and manufacturing process of the display device can be simplified.

In addition, by removing the space between the backlight unit 700 and the display panel 800, it is possible to prevent the malfunction of the display device or the deterioration of the display image quality due to the infiltration of foreign matter into the space.

The backlight unit 700 according to the present exemplary embodiment may be configured in a form in which a plurality of functional layers are stacked, and at least one of the plurality of functional layers may include a plurality of light sources (not shown).

In addition, in order for the backlight unit 700 to be closely fixed to the lower surface of the display panel 800, the plurality of functional layers constituting the backlight unit 700, more specifically, the backlight unit 700, are each flexible. ) Can be made of a material.

The display panel 800 according to the present exemplary embodiment may be divided into a plurality of regions, and the light emitted from the region of the backlight unit 700 corresponding to the gray peak value or the color coordinate signal of each of the divided regions may be divided. The brightness, that is, the brightness of the corresponding light source may be adjusted to adjust the brightness of the display panel 800.

To this end, the backlight unit 700 may be operated by being divided into a plurality of divided driving regions corresponding to each of the divided regions of the display panel 800.

32 and 33 show a display device according to the present embodiment.

Referring to FIG. 32, the display apparatus 1 includes a display module 20, a front cover 30 surrounding the display module 20, a back cover 35, and a driver 55 provided in the back cover 35. And a driving unit cover 40 surrounding the driving unit 55.

The front cover 30 may include a front panel (not shown) of a transparent material that transmits light, and the front panel protects the display module 20 at regular intervals, and the light emitted from the display module 20. The light is transmitted through the display module 20 so that the image displayed on the display module 20 can be seen from the outside.

In addition, the front cover 30 may be made of a flat plate without the window 30a.

In this case, the front cover 30 is made of a transparent material that transmits light, for example, injection molded plastic.

In this way, when the front cover 30 is formed of a flat plate, the frame can be removed from the front cover 30.

The back cover 35 may be combined with the front cover 30 to protect the display module 20.

The driving unit 55 may be disposed on one surface of the back cover 35.

The driving unit 55 may include a driving control unit 55a, a main board 55b, and a power supply unit 55c.

The driving controller 55a may be a timing controller. The driving controller 55a may be a driver for controlling operation timing of each driver IC of the display module 20. The main board 55b may include a V sink, an H sink, and an R, G, The driving unit transmits a B resolution signal, and the power supply unit 55c is a driving unit that applies power to the display module 20.

The driving unit 55 may be provided in the back cover 35 and may be wrapped by the driving unit cover 40.

A plurality of holes may be provided in the back cover 35 to connect the display module 20 and the driving unit 55, and a stand 60 supporting the display device 1 may be provided.

On the other hand, as shown in FIG. 33, the driving control unit 55a of the driving unit 55 may be provided in the back cover 35, and the main board 55b and the power board 55c may be provided in the stand 60. have.

In addition, the driving unit cover 40 may wrap only the driving unit 55 provided in the back cover 35.

In the present embodiment, the main board 55b and the power board 55c are separately configured, but may be formed as one integrated board, but is not limited thereto.

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in each embodiment may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

In addition, the above description has been made with reference to the embodiment, which is merely an example, and is not intended to limit the present invention. Those skilled in the art to which the present invention pertains will be illustrated as above without departing from the essential characteristics of the present embodiment. It will be appreciated that various modifications and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

Claims (20)

A reflection plate including a reflection surface;
An optical sheet disposed on the reflective plate;
A light source disposed on at least one side of a space between the reflective plate and the optical sheet; And,
And at least one polarizer disposed on a surface of the optical sheet facing the reflective surface, the at least one polarizing plate having a different elongation between a region adjacent to the light source and a region far from the light source. The backlight unit of claim 1, wherein the reflecting surface of the reflecting plate is an inclined surface parallel to the horizontal plane or inclined at an angle with respect to the horizontal plane. The backlight unit of claim 1, wherein a reflection surface of the reflection plate is formed with a plurality of reflection patterns having a predetermined width. The backlight unit of claim 3, wherein the reflective pattern has a thickness different from a region adjacent to the light source and a region far from the light source. 4. The backlight unit of claim 3, wherein the reflection pattern increases in distance from the light source, and the width of the reflection pattern increases and the distance between the adjacent reflection patterns decreases. The backlight unit of claim 3, wherein the distance between the reflective patterns is constant and the spacing between the adjacent reflective patterns decreases as the reflective pattern becomes farther from the light source. 4. The backlight unit of claim 3, wherein the reflection pattern increases in distance from the light source, and the width of the reflection pattern increases and the distance between the adjacent reflection patterns is constant. The backlight unit of claim 3, wherein the reflective pattern is at least one of aluminum (Al), silver (Ag), gold (Au), or titanium dioxide (TiO ₂ ). The backlight unit of claim 1, wherein any one of a reflective coating film and a reflective coating material layer having a predetermined reflective pattern is attached on the reflective surface of the reflective plate. The backlight unit of claim 1, further comprising a light transmission supporter disposed in a space between the reflective plate and the optical sheet to support the optical sheet. The backlight unit of claim 10, wherein at least one light transmitting supporter is disposed in a stripe shape along a column direction of the reflecting plate. The backlight unit of claim 10, wherein an area of the light transmitting supporter becomes smaller as it moves away from the light source. The backlight unit of claim 1, wherein the optical sheet comprises a fluorescent sheet made of a fluorescent material. The backlight unit of claim 1, wherein the space between the reflecting plate and the optical sheet is filled with any one of vacuum, air, and a polymer material. The backlight unit of claim 1, further comprising a lens disposed in front of the light exit surface of the light source, the lens converting light emitted from the light source into parallel light. The method of claim 1, wherein the polarizing plate,
A first polarizing plate having an elongation higher as the distance from the light source increases and a drawing direction is a first direction;
And a second polarizing plate overlapping the first polarizing plate and having a higher elongation as the distance from the light source increases, and a stretching direction is a second direction. A reflection plate including a reflection surface;
An optical sheet disposed on the reflective plate;
A light source disposed on at least one side of a space between the reflective plate and the optical sheet; And,
And a light blocking plate disposed on a surface of the optical sheet facing the reflective surface, the light blocking plate having a different density of light blocking patterns between a region adjacent to the light source and a region far from the light source. The backlight unit of claim 17, wherein the light shielding pattern of the light shielding plate is farther from the light source, and the width of the light shielding pattern decreases and the distance between the adjacent light shielding patterns increases. The backlight unit of claim 17, wherein the light shielding pattern of the light shielding plate is farther from the light source, the width of the light shielding pattern is constant, and the distance between the adjacent light shielding patterns increases. The backlight unit of claim 17, wherein the light shielding pattern of the light shielding plate is farther from the light source, the width of the light shielding pattern decreases and the distance between the adjacent light shielding patterns is constant.

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