KR20200048446A - Display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device including a backlight unit, capable of improving light efficiency and luminance. The present invention provides the liquid crystal display device, wherein a composite optical sheet including a light collecting part in which an inverted prism hill which has a vertical angle of 66° (±2°) is arranged, a reflection polarization part, and a light diffusion adhesive is disposed on an outer side of a lower polarizing plate of a liquid crystal panel, an embossed pattern of a lenticular lens at a lower surface of the lenticular lens and an engraved pattern in which burrs are formed along an edge of the embossed pattern at an apex of the lenticular lens are provided on a lower portion of the composite optical sheet, a width-to-depth ratio of the engraved pattern satisfies 12% to 15%, and a height of the burr of the engraved pattern is 75% to 85% of a depth of the engraved pattern. Accordingly, a lightweight and thin backlight unit is provided, an assembly process is simplified, and productivity and competitiveness are improved. In addition, a light loss is minimized, visibility is improved, and moire and hot bands are prevented from being generated. Further, a higher luminance is implemented without reducing a half-power angle as compared with a typical liquid crystal display device.

Description

Liquid crystal display device

The present invention relates to a liquid crystal display device including a backlight unit capable of improving light efficiency and luminance.

2. Description of the Related Art Recently, with the development of information technology and mobile communication technology, a display device capable of visually displaying information has been developed, and the display device displays an image as a self-emissive display having large emission characteristics and other external factors. It is classified as a non-luminous display that can be used.

As a non-emissive display, which is a device that does not have a self-luminous element, a liquid crystal display (LCD) is exemplified.

Therefore, the LCD, which is a non-light emitting type display, requires a separate light source, and a backlight unit having a light source is provided on the rear surface to irradiate light toward the front of the LCD and thereby realize an identifiable image.

On the other hand, since the backlight unit stacks a plurality of optical sheets having different functions from a light source, it is necessary to pay close attention when the assembly process is cumbersome and work. Therefore, it causes problems of reduced productivity and competitiveness due to reduced workability and reduced product yield.

In addition, the overall thickness of the backlight unit is increased due to the number of sheets, the manufacturing cost is increased, and the luminance is also decreased due to the loss of light through the optical sheets. In addition, a problem that quality defects such as moiré occurs due to mutual interference between optical sheets is also caused.

The present invention is to solve the above problems, by providing a unitary optical sheet that is thinned by integrating a part of a plurality of films, the first object is to provide a lightweight and thin backlight unit, and also simplifies the assembly process. And the second objective of improving productivity and competitiveness.

In addition, a third object is to provide a backlight unit with improved quality by minimizing light loss and minimizing the occurrence of moiré.

In order to achieve the object as described above, the present invention is attached to the liquid crystal panel, the upper and lower polarizing plates located on both sides of the liquid crystal panel, and the lower polarizing plate, the light collecting portion, the reflective polarizing portion and the diffusion adhesive A composite optical sheet comprising a plurality of embossed patterns located below the composite optical sheet and projecting along the first direction across the incoming light surface from the incident light surface on the lower surface, and a plurality of embossed patterns along the longitudinal direction at the apex of the embossed pattern It includes a multi-pattern light guide plate including an engraved pattern spaced apart at regular intervals, an LED assembly arranged along the light incident surface, and a reflector positioned below the multi-pattern light guide plate, and burrs along an edge of the engraved pattern. It provides a liquid crystal display device protruding).

At this time, the intaglio pattern has a depth to depth ratio of 12 to 15%, and the height of the burr satisfies 75 to 85% of the depth of the intaglio pattern.

In addition, the intaglio pattern is positioned at a higher density per unit area as it is farther from the light incident surface, and the embossed pattern is arranged in a row with lenticular lenses protruding, and the intaglio pattern is formed in a concave circular or elliptical shape, and a cross section Has a hemisphere shape.

At this time, the light condensing unit includes a lens layer that is arranged to protrude in a row in a second direction perpendicular to the first direction, and the lens layer is made of an inverted prism having an apex angle of 66 ° (± 2 °). The light condensing unit includes a lens layer which is arranged to protrude in a row in a second direction perpendicular to the first direction, wherein the lens layer includes a first prism surface located in one direction in which the LED assembly is located, and the first And a second prism face forming an apex angle with the prism face and a third prism face extending from the second prism face to the opposite side of the first prism face.

In addition, the light converging portion includes a lens layer which is arranged to protrude in a row in a second direction perpendicular to the first direction, wherein the lens layer includes a first prism surface located in one direction in which the LED assembly is located, It includes a second prism surface convexly curved to move away from the first prism surface, and the light-diffusing adhesive comprises a light-diffusion bead.

As described above, according to the present invention, a composite optical system including a condensing unit in which an inverted prism acid having an apex angle of 66 ° (± 2 °) is arranged outside the lower polarizing plate of the liquid crystal panel, a reflective polarization unit, and a light diffusion adhesive Position the sheet, and place the embossed pattern of the lenticular lens on the lower surface under the composite optical sheet, and a plurality of engraved patterns with burrs formed along the edges at regular intervals from the vertices of the lenticular lens of the embossed pattern. At this time, the width to depth ratio of the intaglio pattern is set to satisfy 12 to 15%, and the height of the burr of the intaglio pattern is 75 to 85% of the depth of the intaglio pattern, thereby providing a lightweight and thin backlight unit. There is an effect that can be done, and also has the effect of simplifying the assembly process and improving productivity and competitiveness.

In addition, it has an effect of minimizing light loss, and has an effect of improving visibility, but also has an effect of preventing moiré and hot bands from occurring. It has the effect of being able to realize a higher luminance without doing so.

1 is a cross-sectional view schematically showing a liquid crystal display device according to an exemplary embodiment of the present invention.
Figure 2 is a cross-sectional view schematically showing a state in which the composite optical sheet according to an embodiment of the present invention is attached to the outer surface of the lower polarizing plate through a light diffusion adhesive.
3A to 3B are cross-sectional views schematically showing various structures of a lens layer of a composite optical sheet.
4A is a rear perspective view of a multi-pattern light guide plate according to an embodiment of the present invention.
Figure 4b is a cross-sectional view schematically showing the intaglio pattern.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

1 is a cross-sectional view schematically showing a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a schematic view showing a composite optical sheet according to an embodiment of the present invention attached to an outer surface of a lower polarizing plate through a light diffusion adhesive. It is a cross-sectional view.

3A to 3B are cross-sectional views schematically showing various structures of the lens layer of the composite optical sheet.

As shown in FIG. 1, the liquid crystal display device 100 according to an exemplary embodiment of the present invention is largely composed of a liquid crystal panel 110 and a backlight unit 120.

Let's take a closer look at each of these.

First, the liquid crystal panel 110 is a part that plays a key role in the image expression of the liquid crystal display device 100, and is interposed between the first substrate 112 and the second substrate 114 bonded to each other. It includes a liquid crystal layer (not shown).

Although not shown in the drawing, a plurality of gate lines and data lines are intersected and pixels are defined on the inner surface of the first substrate 112 called a lower substrate or an array substrate, and a thin film transistor at each intersection. : TFT) is provided to be connected one-to-one with a transparent pixel electrode formed in each pixel.

In addition, as an inner surface of the second substrate 114 called an upper substrate or a color filter substrate, color filters of red (R), green (G), and blue (B) colors are examples of the pixels. A black matrix is provided to cover each gate line, data line, and thin film transistor.

In addition, a red (R), green (G), and blue (B) color filter and a transparent common electrode covering the black matrix are provided.

In addition, upper and lower alignment layers (not shown) for determining the initial molecular alignment direction of the liquid crystal are interposed at the boundary between the first and second substrates 112 and 114 and the liquid crystal layer (not shown), and the first and second substrates are interposed. A seal pattern (not shown) is formed along the edges of both substrates 112 and 114 to prevent leakage of the liquid crystal layers (not shown) filled between the layers 112 and 114.

In addition, upper and lower polarizing plates 115 and 116 that selectively transmit only specific light are attached to the outer surfaces of the first and second substrates 112 and 114, respectively.

A printed circuit board (not shown) is connected via a connecting member (not shown) such as a flexible circuit board or a tape carrier package (TCP) along one edge of the liquid crystal panel 110.

Accordingly, when the thin film transistor selected for each gate line is turned on by the on / off signal of the thin film transistor scanned and transferred to the gate line, the liquid crystal panel 110 displays an image signal of the data line to the corresponding pixel electrode. Is transferred, and the alignment direction of the liquid crystal molecules is changed by an electric field between the pixel electrode and the common electrode, thereby representing a difference in transmittance.

And in the liquid crystal display device 100 according to an embodiment of the present invention, the light from the rear surface of the liquid crystal panel 110 under the premise that the display surface of the liquid crystal panel 110 faces forward so that the difference in transmittance represented by the liquid crystal panel 110 is externally expressed. It is provided with a backlight unit 120 for supplying.

A high-brightness surface light source implemented from the backlight unit 120 is provided to the liquid crystal panel 110, so that the liquid crystal panel 110 displays an image.

The backlight unit 120 includes an LED assembly 129 arranged along one edge, a reflective plate 121, a multi-pattern light guide plate 220 mounted on the reflective plate 121, and a multi-pattern light guide plate 220 to an upper portion. It includes a composite optical sheet 210 located.

The LED assembly 129 is a light source of the backlight unit 120, and includes a plurality of LEDs 129a and a PCB 129b in which the plurality of LEDs 129a are spaced apart at regular intervals.

In this case, the plurality of LEDs 129a emit light having red (R), green (G), and blue (B) colors toward the light incident surface 221a of the multi-pattern light guide plate 220, respectively. By lighting the RGB LEDs 129a at a time, white light by color mixing can be realized.

In particular, in order to improve the luminous efficiency and brightness, recently, the blue LED 129a including a blue LED chip having excellent luminous efficiency and brightness is used, and as a phosphor, 'cerium doped yttrium aluminum garnet (YAG: Ce)', That is, a blue LED 129a made of a yellow phosphor is used.

The blue light emitted from the LED 129a passes through the phosphor and is mixed with the yellow light emitted by the phosphor, thereby realizing white light.

And, in addition to the LED assembly 129, a fluorescent lamp such as a cold cathode fluorescent lamp or an external electrode fluorescent lamp may be used.

The multi-pattern light guide plate 220 in which light emitted from the plurality of LEDs 129a is incident is multi-pattern light guide plate 220 while the light incident from the LED 129a proceeds in the multi-pattern light guide plate 220 by multiple total reflections. ) Spreads evenly over a wide area to provide a surface light source to the liquid crystal panel 110.

Thus, the multi-pattern light guide plate 220 is a plastic material such as polymethyl methacrylate (polymethylmethacrylate (PMMA)), which is one of the transparent materials that can transmit light, or polycarbonate (PC). It is manufactured in a flat type.

The multi-pattern light guide plate 220 is excellent in transparency, weather resistance, and colorability, thereby inducing light diffusion when light is transmitted.

In addition, the multi-pattern light guide plate 220 may include patterns 223 and 225 of a specific shape on the lower surface 221d to supply a uniform surface light source. Here, the patterns 223 and 225 are configured by mixing the embossed pattern 223 and the intaglio pattern 225 with each other in order to more efficiently guide the light incident into the multi-pattern light guide plate 220.

Here, as the light incident surface 221a of the multi-pattern light guide plate 220 is defined in the longitudinal direction of the multi-pattern light guide plate 220, that is, in the X-axis direction defined in the drawing, the light incident surface 221a of the multi-pattern light guide plate 220 The LED assembly 129, which is positioned forward toward the direction, is also arranged in the X-axis direction defined in the drawing.

At this time, the embossed pattern 223 is a drawing in the longitudinal direction from the light incident surface 221a to the light incident surface 221b of the multi-pattern light guide plate 220 so as to have a straightness toward the light incident surface 221b from the light incident surface 221a. A plurality of lenticular lenses of a shape in which mountains and valleys are repeated are arranged in a row by arranging adjacent in a band shape along the Y-axis direction defined by. We will look at this in more detail later.

In addition, the reflective plate 121 positioned below the multi-pattern light guide plate 220 is made of white, thereby reflecting light passing through the rear surface of the multi-pattern light guide plate 220 toward the liquid crystal panel 110 to improve the luminance of the light.

Here, in the liquid crystal display device 100 according to an embodiment of the present invention, the composite optical sheet 210 is positioned above the multi-pattern light guide plate 220, and the composite optical sheet 210 is a condenser 216 (see FIG. 2). And a reflective polarizer (215, see FIG. 2), and is attached to the outer surface of the lower polarizing plate 116 of the liquid crystal panel 110 through a light diffusion adhesive (211, see FIG. 2).

The composite optical sheet 210 includes only a light-diffusing adhesive (211, see FIG. 2), one condensing unit (216, see FIG. 2), and one reflective polarization unit (215, see FIG. 2). Along with 220, it is possible to provide a high-brightness and high-quality surface light source to the liquid crystal panel 110.

In particular, through the light-diffusing adhesive (211, see FIG. 2) to improve the high brightness and visibility, and also, it is possible to prevent the light efficiency from being lowered as several optical sheets are provided.

In addition, light weight and thinness of the liquid crystal display device 100 may be realized, and at the same time, the process of modularizing the liquid crystal display device 100 may be simplified to reduce assembly time and reduce material cost, thereby improving process efficiency. We will look at this in more detail later.

Although the liquid crystal panel 110 and the backlight unit 120 are not illustrated, they are integrally modularized through a case top, a guide panel, and a cover bottom.

Here, referring to FIG. 2, the structure of the composite optical sheet 210 will be described in more detail.

As shown in FIG. 2, the composite optical sheet 210 is largely composed of a light converging portion 216 and a reflective polarizing portion 215. The light converging portion 216 includes a support layer 217 and a lower portion of the support layer 217. And a lens layer 218 for condensing light from the surface.

Here, the support layer 217 of the light converging portion 216 is a polycarbonate-based, polysulfone-based, polyacrylate-based, polystyrene-based, which can transmit light, It is composed of polyvinyl chloride series, poly vinyl alcohol series, poly norbornene series, and polyester series.

In addition, the lens layer 218 formed on the lower surface of the support layer 217 and, more precisely, the lower surface facing the multi-pattern light guide plate 220 is made of a transparent acrylic-based resin. Accordingly, a plurality of inverted prismatic acids 219a and 219b in which mountains and valleys are repeated by being arranged adjacent to each other in a band shape are arranged to protrude from the supporting layers 211a and 211b.

Here, the inverted prismatic acids 219a and 219b of the lens layer 218, which are arranged in a row along the longitudinal direction of the composite light collecting sheet 210, are arranged to be arranged in a row in the X-axis direction defined in the drawing, It is preferable that the embossed pattern 223 of the lenticular lens formed on the lower surface 221d of the multi-pattern light guide plate 220 be perpendicular to each other.

Through this, the subject moire generated between the inverted prism acids 219a and 219b of the lens layer 218 of the composite light collecting sheet 210 and the embossed pattern 223 formed on the lower surface 221d of the multi-pattern light guide plate 220 ( It is possible to improve luminance while preventing moire) from occurring.

That is, when the embossed pattern 223 of the lenticular lens formed on the lower surface 221d of the multi-pattern light guide plate 220 is arranged to protrude in the Y-axis direction defined in the drawing, the lens layer of the composite light collecting sheet 210 ( The inverted prismatic mountains 219a and 219b of 218 are arranged in a row in the X-axis direction perpendicular to the Y-axis direction defined in the drawing, so that the lenticular formed on the lower surface 221d of the multi-pattern light guide plate 220 It is to make the embossed pattern 223 of the lens and the longitudinal direction perpendicular to each other.

By the lens layer 218, the composite light collecting sheet 210 condenses light into the liquid crystal panel 110 positioned on the composite light collecting sheet 210, thereby having a luminance increase effect.

Here, the inverted prismatic acids 219a and 219b of the lens layer 218 may be formed of first and second prism surfaces 219a and 219b forming the apex angle α, and the first and second prism surfaces 219a , 219b) are symmetrical to each other based on a direction perpendicular to the support layer 217, and the size of the apex angle α may be 66 ° (± 2 °).

At this time, the cross sections of the inverted prismatic mountains 219a and 219b become an isosceles triangle. In the above range, the front contrast ratio of the liquid crystal display device 100 may be condensed to increase the front contrast ratio.

In addition, the lens layer 218 may be formed of an inverted prism having a cross-section of multiple cross-sections as shown in FIGS. 3A to 3B, in addition to the inverted prism mountains 219a and 219b, that is, the inverted prism as shown in FIG. 3A. The first and second prism faces 219a and 219b forming the apex angle α and the third prism face 219c may be further included to have a double angle.

Here, when the first prism face 219a is formed to be positioned in one direction in which the LED assembly 129 as the light source is located, the third prism face 219c is first prism face 219a from the second prism face 219b. ).

Also, as illustrated in FIG. 3B, the second prism surface 219b may be formed to be curved, that is, the second prism surface 219b has a convex curved surface away from the first prism surface 219a. Is formed. As a result, the light reflected from the second prism surface 219b is provided almost vertically toward the liquid crystal panel 110.

In addition, the second prism surface 219b may be formed of a combination of a plurality of planes contacting the curved surface, instead of being formed as a curved surface, and may have a polygonal shape as a whole.

At this time, the support layer 217 of the light collecting portion 216 is characterized by having an adhesive property.

Therefore, the light collecting portion 216 and the reflective polarizing portion 215 positioned above the light collecting portion 216 are integrally bonded to each other through the adhesive properties of the support layer 217.

As described above, the reflective polarization unit 215 forming a state of bonding with the light collecting unit 216 is a layer that transmits specific polarized light and reflects other specific polarized light, and the transmittance is 40 to 60 across the entire visible wavelength range of 380 nm to 780 nm. %. The reflective polarization unit 215 reflects and recycles light of polarization to be absorbed without passing through the polarizing plates 115 and 116 of the liquid crystal display device 100, thereby improving light efficiency.

The reflective polarization unit 215 is formed of a multi-layer type in which the high-refractive layer and the low-refractive layer are stretched and alternately stacked, or a polymer dispersion type having a plurality of second polymers having different refractive indices in the first polymer layer, or the second. It may be made of a polymer type having fibers instead of a polymer, or a wire grid type having a plurality of fine nano patterns.

When the reflective polarization unit 215 is illustrated and described as an example of a multi-layer type, the reflective polarization unit 215 includes a plurality of alternately stacked first refractive layers and second refractive layers, wherein the first The refractive layer may be a PEN layer, and the second refractive layer may be a COPEN layer.

The number of stacks of the first refractive layer and the second refractive layer in the reflective polarization unit 215 may be tens to hundreds of layers, or more.

At this time, the first refractive layer and the second refractive layer may have different refractive indices in the direction of the reflection axis, and may have the same refractive index in the direction of the polarization axis (transmission axis) perpendicular to the reflection axis, and the first and second refractive layers Since the layers have substantially the same refractive index in the polarization axis direction, linearly polarized light that vibrates in the polarization axis direction passes through the reflective polarization unit.

On the other hand, since the refractive index directions of the first refractive layer and the second refractive layer are different from each other, light oscillating in the direction can be reflected at the interface between the first refractive layer and the second refractive layer.

Here, the reflection efficiency at the interface between the first refractive layer and the second refractive layer is correlated with the corresponding wavelength and the thickness of the first refractive layer and the second refractive layer. As the wavelength increases, the thickness of each layer showing the maximum reflection efficiency increases. . Therefore, in order to have excellent reflection efficiency in the entire wavelength range of visible light, it is preferable that the reflective polarization unit 215 includes a first refractive layer and a second refractive layer having various thicknesses.

For example, the reflective polarization unit 215 may include a first refractive layer and a second refractive layer of the first thickness having the maximum reflection efficiency at the blue wavelength, or a larger than the first thickness having the maximum reflection efficiency at the green wavelength. It may include a first refractive layer and a second refractive layer of a second thickness having a second thickness having a maximum reflection efficiency at the red wavelength and the first refractive layer and the second refractive layer of 2 thickness.

Through the reflective polarization unit 215, light efficiency is further improved.

In addition, a light diffusion adhesive 211 is positioned above the reflective polarization unit 215, and the composite optical sheet 210 is outside the lower polarizing plate 116 of the liquid crystal panel 110 through the light diffusion adhesive 211. As it is attached, it is possible to implement a lighter and thinner liquid crystal display device 100 through this, and also to further simplify the modularization process, further improving the efficiency of the process.

Here, the light-diffusing adhesive 211 includes a light-diffusing bead 213, through which the composite optical sheet 210 according to an embodiment of the present invention can improve visibility even though it does not have a separate diffusion. Higher brightness can also be implemented.

That is, the light-diffusing adhesive 211 is positioned above the reflective polarization part 215 to attach and fix the composite optical sheet 210 to the outside of the lower polarizing plate 116.

The light-diffusing adhesive 211 includes a light-diffusing bead 213 included in the base polymer 211a, and the base polymer 211a contains a (meth) acrylic polymer (A). The (meth) acrylic polymer (A) is, as a monomer unit, an alkyl (meth) acrylate (a1) constituting the main skeleton of the (meth) acrylic polymer (A) and an aromatic ring-containing (meth) acrylic monomer (a2). It contains.

As the aromatic ring-containing (meth) acrylic monomer (a2), for example, benzyl (meth) acrylate may be used. Since the aromatic ring-containing (meth) acrylic monomer has positive intrinsic birefringence, it can be used in combination with an alkyl (meth) acrylate and (meth) acrylate monomer having negative intrinsic birefringence.

In this case, when a predetermined amount of the aromatic ring-containing (meth) acrylic monomer is used together with the carboxyl group-containing monomer (a3) and the hydroxyl group-containing monomer (a4), an adhesive having a desired refractive index can be obtained.

The base polymer 221 has a refractive index of 1.47 or more, and more preferably a refractive index of 1.49.

The light-diffusing beads 213 contained in the base polymer 211a are made of polymer fine particles. Examples of the material of the polymer fine particles include silicone resins, methacrylic resins, polystyrene resins, polyurethane resins, and melamine resins. Can be.

Since these resins have excellent dispersibility with respect to the base polymer 211a and an appropriate refractive index difference with the base polymer 211a, it is possible to implement a light diffusion adhesive 211 having excellent diffusion performance.

That is, the light diffusion beads 213 are preferably lower than the refractive index of the base polymer 211a, and the light diffusion beads 213 have a refractive index of 1.30 to 1.70, more preferably 1.45.

Here, it is preferable that the absolute value of the refractive index difference between the light-diffusing bead 213 and the base polymer 211a is more than 0 and preferably 0.2 or less. desirable.

The light diffusion beads 213 have a particle diameter of 4 to 7 μm, an average particle diameter of 6 μm on average, and preferably have a content of 2.6 to 3.5% in the base polymer 211 a. Through this, excellent light diffusion A light-diffusing adhesive 211 having performance can be obtained.

That is, the composite optical sheet 210 according to an embodiment of the present invention is largely composed of only the light converging portion 216, the reflective polarizing portion 215, and the light diffusion adhesive 211, as such, the condensing portion 216 With the reflective polarization part 215 and the light diffusion adhesive 211, the high-brightness and high-quality surface light source together with the multi-pattern light guide plate 220 positioned below the composite light diffusion sheet 210, the liquid crystal panel 110 Will be provided.

At this time, the liquid crystal display device 100 according to an embodiment of the present invention improves visibility through a light-diffusing adhesive 211, and also prevents light efficiency from deteriorating as multiple optical sheets are provided. .

In addition, light weight and thinness of the liquid crystal display device 100 may be realized, and at the same time, the process of modularizing the liquid crystal display device 100 may be simplified to reduce assembly time and reduce material cost, thereby improving process efficiency.

4A is a rear perspective view of a multi-pattern light guide plate according to an embodiment of the present invention, and FIG. 4B is a cross-sectional view schematically showing an intaglio pattern.

As shown in Figure 4a, the multi-pattern light guide plate 220 according to an embodiment of the present invention, the LED assembly (129 in FIG. 1) corresponding to the light incident surface 221a and the opposite side of the light incident surface (221b) and Connecting the light incident surface 221a and the light incident surface 221b, the upper surface 221c through which light is emitted, the lower surface 221d facing the reflector (121 in FIG. 1), and both sides facing each other (221e, 221f) Is made of

In addition, the lower surface 221d of the multi-pattern light guide plate 220 is provided with an embossed pattern 223 for condensing light. The embossed pattern 223 is provided with a light entering surface from the light incident surface 221a of the multi-pattern light guide plate 200 ( To have a straightness toward 221b), the mountains and valleys are repeated by arranging adjacently in a band shape along the Y-axis direction defined in the drawing in the longitudinal direction from the light incident surface 221a of the multi-pattern light guide plate 200 to the light incident surface 221b. A plurality of lenticular lenses in the form are arranged in a row, respectively.

The embossed pattern 223 of the lenticular lens is formed in the direction perpendicular to the longitudinal direction (Y-axis direction) of the embossed pattern 223, and by setting the output distribution angle of the multi-pattern light guide plate 220 in the Z-axis direction defined in the drawing. , To improve the luminance.

At this time, it is preferable that the height of the embossed pattern 223 is lower than the width of the embossed pattern 134, so that the ratio of the height of the embossed pattern 223 to the width of the embossed pattern 223 is formed to be 20% or more. It is desirable to do.

Through this, the light incident into the multi-pattern light guide plate 220 through the light-receiving surface 221a of the multi-pattern light guide plate 220 is lower than the general light guide plate in which the total reflection condition is broken to emit light. It is possible to reduce the amount of loss through the outside through 221b, thereby increasing the amount of emitted light emitted through the upper surface 221c of the multi-pattern light guide plate 220.

On the other hand, if the height of the embossed pattern 223 has a value higher than the width, the effect of increasing the amount of emitted light becomes insufficient, and the meaning of forming the embossed pattern 223 is lost.

Here, when the ratio of the height to width of the embossed pattern 223 is 10%, the difference in the amount of light near the light incident surface 221a and near the light incident surface 221b is severe, and the amount of emitted light decreases, indicating that the straightness is low. Can be. In addition, when the height of the embossed pattern 223 is 20 to 50% of the width, it can be seen that the straightness is improved due to a small difference in the amount of light near the light incident surface 221a and near the light incident surface 221b.

That is, it can be seen that the higher the ratio of the height to width of the embossed pattern 223 is, the larger the straightness effect is, and when the ratio becomes 40% or more, the straightness effect is similar with little change.

Since the embossed pattern 223 protrudes toward the reflector (121 in FIG. 1), that is, toward the opposite direction of the front surface of the multi-pattern light guide plate 220, it is possible to prevent the embossed pattern 223 from being viewed. The shape of the embossed pattern 223 and the overlap of the pixels of the liquid crystal panel (110 of FIG. 1) can prevent moiré.

On the other hand, if the embossed pattern 223 is formed to protrude toward the liquid crystal panel (110 of FIG. 1), a moire phenomenon may occur due to the shape of the embossed pattern 223 and the pixel overlap of the liquid crystal panel (110 of FIG. 1). Alternatively, the embossed pattern 223 may be recognized.

The moire phenomenon and visibility of the pattern are factors that deteriorate the image quality of the liquid crystal display (100 in FIG. 1).

At the apex of the lenticular lens of the embossed pattern 223, a plurality of embossed patterns 225 in which a part of the embossed pattern 223 is concave along the longitudinal direction of the embossed pattern 223 is spaced apart at regular intervals to form a plurality of overlaps. It is made of a concave circular, elliptical shape, and the cross section is made of a hemispherical shape.

The intaglio pattern 225 serves to further improve the light collecting performance of the multi-pattern light guide plate 220.

Here, the liquid crystal display according to an embodiment of the present invention (100 in FIG. 1) is characterized in that it forms a burr (227) along the edge of the intaglio pattern 225 of the multi-pattern light guide plate 220, The burr 227 has a rough surface, and serves to diffuse light more. Therefore, the multi-pattern light guide plate 220 has a light diffusion performance by the burr 227 provided in the engraved pattern 225, and visibility is also improved.

Meanwhile, as shown in FIG. 4B, the intaglio pattern 225 formed by overlapping the embossed pattern 223 is preferably such that the ratio of the depth (H) to the width (D) satisfies 12 to 15%, and the cathode pattern ( When the ratio of the width (D) to the depth (H) of 225) is 12% or less, or 15% or more, the luminance may be lower than that of a general liquid crystal display device, or the half height angle may be implemented.

Table 1 below shows the experimental results of measuring luminance and half-value according to the width (D) and depth (H) ratio of the intaglio pattern 225.

Sample A
(Width (D) 45um / Depth (H) 7um) Sample B
(Width (D) 45um / Depth (H) 6um) Sample C
(Width (D) 45um / Depth (H) 5um) Sample D
(Width (D) 45um / Depth (H) 4um) Sample E
(Width (D) 45um / Depth (H) 3um) Sample F
(Width (D) 45um / Depth (H) 2um) Viewing angle

반치각 V 31.5˚

Half angle V 31.5˚

Half angle V 29˚

Half angle V 26.5˚

Half- value angle V 24.5˚

Half angle V 23˚

Half angle V 21.5˚ Condensing intensity (brightness) 99% 110% 121% 137% 154% 180%

In (Table 1) above, Sample A represents the viewing angle and light intensity (luminance) when the width (D) of the intaglio pattern 225 is 45 um and the depth (H) is 7 um, and Sample B is the intaglio pattern ( When the width (D) of 225) is 45um, the depth (H) represents the viewing angle and condensation (luminance) when it is 6um, and Sample C is the depth when the width (D) of the intaglio pattern 225 is 45um ( H) represents the viewing angle and light intensity (luminance) when 5um, Sample D is when the width (D) of the intaglio pattern 225 is 45um, and the depth (H) is 4um when the viewing angle and light concentration ( Luminance), Sample E represents the viewing angle and light intensity (luminance) when the width (D) of the intaglio pattern 225 is 45 μm, and the depth (H) is 3 μm, and Sample F is the intaglio pattern 225. When the width (D) is 45um, the depth (H) represents the viewing angle and the light convergence (luminance) when it is 2um. At this time, in the multi-pattern light guide plate 220 according to the embodiment of the present invention, the intaglio pattern 225 is formed to have a width (D) of 45 um, and at this time, when the depth (H) is formed to have 7 um, burrs ( 227) is formed to have a height (h) of 5.6um, and when the depth (H) is formed to have 6um, the burr (227) is formed to have a height (h) of 4.8um.

In addition, when the depth H of the intaglio pattern 225 is formed to have 5 um, the burr 227 is formed to have a height h of 4.0 um, and when the depth H is formed to have 4 um. The burr 227 is formed to have a height h of 3.2 um, and when the depth H is formed to have 3 um, the burr 227 is formed to have a height h of 2.4 um. , When the depth (H) is formed to have 2um, the burr (227) is formed to have a height (h) of 1.6um.

In (Table 1) above, the half-power angle is the azimuth angle at which light of an intensity corresponding to half of the maximum value of light intensity is emitted, and the narrower the half-angle is, the worse the viewing angle characteristic difference is. it means.

Looking at this (Table 1), Sample A has a half-value angle similar to a general liquid crystal display (half-angle V31 °), but it can be seen that the luminance is lowered, whereas Sample B implements a half-value angle similarly. As it can be seen that the luminance was further increased.

In addition, it can be seen that in Sample C, Sample D, Sample E, and Sample F, the luminance increases but the half angle decreases as compared to a general liquid crystal display device.

Here, Sample B, which has good characteristics in both half-angle and luminance, has a width (D) of the intaglio pattern 225 of 45 µm and a depth (H) of 6 µm, compared to the width (D) of depth (H). The ratio is 13.3%, Sample A has a width (D) to depth (H) ratio of 15.6%, Sample C has a width (D) to depth (H) ratio of 11.1%, and the intaglio pattern 225 has a width (D) ratio. It can be seen that the depth (H) ratio satisfying 12 to 15% is effective in increasing luminance and half-value.

That is, it can be seen that it is desirable to make the depth (H) ratio of the cathode pattern 225 to the width (D) satisfy 12 to 15%.

On the other hand, in the description so far, the intaglio pattern 225 has been described as an example in which it is desirable to have a depth (H) ratio compared to a width (D) of 12 to 15%, which satisfies a half angle of 28 to 32 °. As an optimal design element for designing, when the half-value angle is to be designed to be 28 degrees or less, the ratio of the depth (H) to the width (D) of the intaglio pattern 225 may be designed to have 8 to 12%.

When the ratio of the depth (H) to the width (D) of the intaglio pattern 225 is 8% or less, it is difficult to form the intaglio pattern 225 having the burr 227 at the apex of the embossed pattern 223, 12% When designed as above, the half angle can be narrowly implemented. Here, the intaglio pattern 225 is preferably formed such that the density per unit area increases as the distance away from the LED assembly (129 in FIG. 1) as the light source, that is, the intaglio pattern 225 is the input of the multi-pattern light guide plate 220. It is formed so that the density per unit area becomes high as it goes from the light surface 221a toward the carrying light surface 221b. Through this, the spacing between the intaglio patterns 225 adjacent to the light incident surface 221b of the multi-pattern light guide plate 220 is narrower than the spacing between the intaglio patterns 225 adjacent to the light incident surface 221a of the multi-pattern light guide plate 220. Lose.

As described above, the light traveling along the longitudinal direction of the embossed pattern 223 is formed by forming the density of the intaglio pattern 225 at a higher density per unit area from the light incident surface 221a to the light incident surface 221b, thereby allowing the multi-pattern light guide plate 220 ) Can be prevented from being emitted to a surface other than the upper surface 221c (for example, the light entering surface 221b or the side surfaces 221e, 221f), and light loss can be prevented.

Here, the height h of the burr 227 is preferably formed to have 75 to 85% of the depth of the intaglio pattern 225, which will be described in more detail with reference to (Table 2) below. .

Below (Table 2) is a multi-pattern light guide plate 220 including a composite optical sheet 210 and an engraved pattern 225 according to an embodiment of the present invention, the burr 227 of the engraved pattern 225 It is the result of the experiment that measured the viewing angle and luminance according to the presence and absence (h) of.

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Viewing angle

반치각 V31˚

Half angle V31˚

Half angle V23˚

Half angle V24˚

Half angle V29˚

Half angle V38˚ Condensing intensity (brightness) 100% 130% 125% 110% 92%

Prior to the description, Sample 1 is a configuration of a general liquid crystal display device, and the composite optical sheet is composed of a structure including a double light collecting part, a diffusion part, and a light diffusion adhesive, and Sample 2 is a composite according to an embodiment of the present invention. In a multi-pattern light guide plate including an optical sheet and an intaglio pattern, it shows a case where no burr is provided in the intaglio pattern. And, Sample 3 shows the case where the burr height of the intaglio pattern is 20% compared to the depth of the cathode pattern, and Sample 4 shows the case where the burr height of the intaglio pattern is 80% compared to the depth of the cathode pattern. Sample 5 shows the case where the burr height of the intaglio pattern is 160% of the depth of the cathode pattern.

Looking at (Table 2), in the case of Sample 2 in which no burr 227 is formed in the cathode pattern 225, the luminance is higher than that of Sample 1, which is a general liquid crystal display device, but the half-value angle is narrow. You can confirm that.

In addition, Sample3, which is a case where the burr 227 of the cathode pattern 225 is formed to have a height (h) of 20% compared to the depth H of the cathode pattern 25, also has a higher luminance than Sample 1 However, it can be seen that the half-value angle is narrow, and the burr 227 of the cathode pattern 225 is formed to have a height (h) of 160% compared to the depth (H) of the cathode pattern 225. In the case of Sample 5, the half-value angle appears similar to Sample 1, but it can be confirmed that the luminance is lowered.

On the other hand, when the sample 4, which is the case where the burr 227 of the negative electrode pattern 225 is formed to have a height (h) of 80% compared to the depth (H) of the negative electrode pattern 225, is confirmed, the luminance is Sample It can be seen that it rises compared to 1, and it can be seen that the half-value angle appears similarly.

Here, the burr 227 serves to diffuse the light incident into the multi-pattern light guide plate 220 in the process of exiting to the upper surface 221c of the multi-pattern light guide plate 220, so that the burr If the (227) is not provided or is formed to have a height (h) of 75% or less compared to the depth (H) of the intaglio pattern 225, the light diffusion performance is lowered, so that the half angle is narrowed.

In addition, when the height h of the burr 227 compared to the depth H of the intaglio pattern 225 is formed too high, the light diffusion performance by the burr 227 becomes too large. , The luminance is lowered.

Therefore, forming the height (h) of the burr 227 of the cathode pattern 225 to 75 to 85% of the depth H of the cathode pattern 225 has a half-value angle similar to that of a general liquid crystal display device. The brightness can be increased while being able to have it.

That is, the liquid crystal display device according to an embodiment of the present invention (100 in FIG. 1), the embossed pattern 223 of the lenticular lens on the lower surface 221d of the multi-pattern light guide plate 220, and the lenticular lens of the embossed pattern 223 The intaglio pattern 225 in which burrs 227 are formed along the edge of the vertex is positioned, and the depth (H) ratio compared to the width (D) of the intaglio pattern 225 satisfies 12 to 15%. The height h of the burr 227 of the intaglio pattern 225 is 75 to 85% of the depth H of the intaglio pattern 225, and the lower surface of the multi-pattern light guide plate 220. The embossed pattern 223 of the lenticular lens at 221d and the engraved pattern 225 where the burr 227 is formed along the edge at the vertex of the lenticular lens of the embossed pattern 223 are positioned, and the multi-pattern An inverted prism mountain (219a, 219b in FIG. 2) having an apex angle (α in FIG. 2) of 66 ° (± 2 °) toward the upper portion of the light guide plate 220 and a longitudinal direction of the embossed pattern 223 of the multi-pattern light guide plate 220 This orthogonal house The composite optical sheet (210 of FIG. 2) including the light portion (216 of FIG. 2), the reflective polarization portion (215 of FIG. 2) and the light diffusion adhesive (211 of FIG. 2) is positioned.

Through this, the liquid crystal display according to the embodiment of the present invention (100 in FIG. 1) can further improve visibility, but also prevent generation of a hot band. In addition, compared to a general liquid crystal display device, it is possible to realize higher luminance without reducing the half-value angle.

In addition, the liquid crystal display device according to an embodiment of the present invention (100 in FIG. 1) is located only a composite optical sheet (210 in FIG. 2) including a light diffusion adhesive (211 in FIG. 2) on top of the multi-pattern light guide plate 220. By doing so, it is possible to improve high brightness and visibility through a light-diffusing adhesive (211 in FIG. 2), and also prevent light efficiency from deteriorating as multiple optical sheets are provided.

In addition, light weight and thinness of the liquid crystal display device (100 of FIG. 1) can be realized, and at the same time, the process of modularizing the liquid crystal display device (100 of FIG. 1) is simplified, reducing assembly time and reducing material cost, thereby improving the efficiency of the process. It can also be improved.

The following (Table 3) is an experimental result showing the optimal design results according to the configuration of the composite pattern light guide plate 220 of the liquid crystal display device (100 of FIG. 1) according to an embodiment of the present invention compared to a conventional general liquid crystal display device.

Sample 1 Sample 4 Sample 6 Sample 7 Sample 8 Concentration
(Luminance) 100% 110% 107% 94% 143% Viewing angle

반치각 V31˚

Half angle V31˚

Half angle V29˚

Half angle V31˚

Half angle V29˚

Half angle V18˚ FOS Visibility OK Hot band OK Visibility OK
Hot band OK Visibility NG
Hot band OK Visibility OK
Hot band OK Visibility NG
Hot Band NG

Prior to the description, Sample 1 is a general liquid crystal display device composed of a composite optical sheet comprising a double light-collecting part, a diffusion part, and a light-diffusing adhesive. Sample 4 is a multi-pattern according to an embodiment of the present invention. The light guide plate and the multi-pattern light guide plate have a configuration in which a composite optical sheet provided with a light collecting agent, a light diffusing adhesive, and a reflective polarizing portion having an apex angle of 66 degrees (± 2 degrees) at the top of the inverted prism acid is located. Sample 6 consists of a composite optical sheet equipped with one light-collecting part, light-diffusing adhesive, and reflective polarizing part, and an embossed pattern and an intaglio pattern formed on the upper surface of the light guide plate.

And in Sample 7, a composite optical sheet equipped with one light-collecting part, light-diffusing adhesive, and reflective polarizing part, and an embossed pattern and an intaglio pattern are formed on the lower surface of the light guide plate, and the apex angle of the inverted prism acid of the light-collecting part is formed at 70˚. In the configuration, Sample 8 shows a structure in which the embossed pattern and the intaglio pattern are formed on the lower surface of the light guide plate, and the composite optical sheet positioned above the light guide plate includes only one light collecting part and reflective polarizing part.

Here, the visibility indicates that the embossed pattern 223 and the engraved pattern 225 are visually recognized. When the embossed pattern 223 is visually observed, the moiré phenomenon is caused by overlapping the pixels of the liquid crystal panel (110 of FIG. 1). When the intaglio pattern 225 is viewed, the area where the intaglio pattern 225 is formed is displayed as a black dot, so that the visibility is poor means that the image quality of the liquid crystal display (100 in FIG. 1) is not good.

In addition, the hot band is a boundary between the light and dark at the edge of the liquid crystal display (100 of FIG. 1), and the surface light source implemented from the backlight unit (120 of FIG. 1) is evenly distributed to the front of the liquid crystal panel (110 of FIG. 1). It is generated because it is not incident. This bad hot band also means that the picture quality of the liquid crystal display (100 in FIG. 1) is not good.

Looking at (Table 3) above, Sample 6 has a similar half-value and a higher luminance than Sample 1, which is a general liquid crystal display device, but it can be seen that the visibility due to the pattern is poor.

In addition, although Sample 7 has a similar half-angle to Sample 1, it can be seen that the visibility by the pattern is also good, but it can be confirmed that the luminance is low.

On the other hand, Sample 4 is good in both visibility and hot band by the pattern, and the luminance also increases more than Sample 1, and it can be seen that the half-angle is also formed similarly.

And, looking at Sample 8, even if both the embossed pattern 223 and the intaglio pattern 225 are provided on the lower surface 221d of the light guide plate, the composite optical sheet (210 in FIG. 2) positioned above the light guide plate provides the light diffusion adhesive. If not included, the luminance is increased compared to Sample 1, which is a general liquid crystal display device, but it can be seen that both the visibility and the hot band due to the pattern are bad, and the half-angle is also poor.

That is, the liquid crystal display device according to an embodiment of the present invention (100 in FIG. 1), the embossed pattern 223 of the lenticular lens on the lower surface 221d of the multi-pattern light guide plate 220, and the lenticular lens of the embossed pattern 223 The intaglio pattern 225 where the burr 227 is formed along the edge of the vertex is positioned, and the apex angle (α in FIG. 2) is 66 ° (± 2 °) above the multi-pattern light guide plate 220. The inverted prism mountains (219a, 219b in FIG. 2) are arranged so that the longitudinal direction is perpendicular to the embossed pattern 223 of the multi-pattern light guide plate 220 (216 in FIG. 2), and the reflective polarization unit (FIG. 2) 215) And by placing the composite optical sheet (210 of FIG. 2) including the light diffusion adhesive (211 of FIG. 2), while improving visibility, it is also possible to prevent moiré and hot bands from occurring. In addition, compared to a general liquid crystal display device, it is possible to realize higher luminance without reducing the half-value angle.

As described above, the liquid crystal display according to the embodiment of the present invention (100 in FIG. 1) has an apex angle (α in FIG. 2) to the outside of the lower polarizing plate (116 in FIG. 2) of the liquid crystal panel (110 in FIG. 1). A condensing unit (216 in FIG. 2) in which an inverted prism acid (219a, 219b in FIG. 2) arranged at 66 ° (± 2 °) is arranged, a reflective polarization unit (215 in FIG. 2), and a light diffusion adhesive (in FIG. 2) A composite optical sheet (210 of FIG. 2) including 211) is positioned, and an embossed pattern 223 of the lenticular lens and an embossed pattern 223 on the lower surface 221d below the composite optical sheet (210 of FIG. 2) ) The intaglio pattern 225 in which burrs 227 are formed along the edge of the lenticular lens of the lenticular lens is positioned, and at this time, the ratio of the depth (H) to the width (D) of the intaglio pattern 225 is 12 to 15% satisfactory, and the height h of the burr 227 of the intaglio pattern 225 is 75 to 85% compared to the depth H of the intaglio pattern 225, thereby making the backlight light and thin. Units, and Simplification of the process and the granules productivity and competitiveness is also improved.

In addition, while minimizing light loss and improving visibility, it is also possible to prevent moiré and hot bands from occurring, and also, to achieve a higher luminance without reducing the half angle compared to a general liquid crystal display device.

On the other hand, in the above description, although the embossed pattern 223 formed on the lower surface 221d of the multi-pattern light guide plate 220 is described and illustrated as a lenticular lens, the embossed pattern 223 has a cross section in addition to the lenticular lens. Prisms, polygonal prisms, micro lens patterns, embossed patterns, or a combination of these may also be used.

In addition, although the heights of the embossed patterns 223 are all the same in the drawings, the heights of the embossed patterns may be configured differently.

In addition, in the drawing, each embossed pattern 223 is spaced apart at regular intervals, so that the lower surface 221d of the multi-pattern light guide plate 220 is partially exposed between the embossed patterns 223, but each embossed pattern 223 It may be formed in close contact.

In addition, the description so far has shown and described that the intaglio pattern 225 is located at the apex of the lenticular lens of the embossed pattern 223, but the ratio of the depth (H) to the width (D) of the intaglio pattern 225 is clear. If it can be implemented, it may be located in addition to the vertex of the lenticular lens of the embossed pattern 223. The present invention is not limited to the above-described embodiments, and can be implemented by variously changing within the limits without departing from the gist of the present invention.

220: multi-pattern light guide plate
221a: light entering surface, 221b: carrying light surface, 221c: upper surface, 221d: lower surface, 221e, 221f: side
223: embossed pattern
225: engraved pattern
227: burr

Claims (9)

A liquid crystal panel;
Upper and lower polarizing plates positioned on both sides of the liquid crystal panel;
A composite optical sheet attached to the lower polarizing plate and comprising a light collecting portion, a reflective polarizing portion, and a diffusion adhesive;
An embossed pattern positioned below the composite optical sheet and projecting along the first direction across the incoming light surface from the light incident surface on the lower surface, and a plurality of intaglio patterns positioned at regular intervals along the longitudinal direction at the apex of the embossed pattern A multi-pattern light guide plate including a pattern;
An LED assembly arranged along the light incident surface;
Reflector located below the multi-pattern light guide plate
It includes,
A liquid crystal display device with a burr protruding along the edge of the intaglio pattern.
According to claim 1,
The engraved pattern is a liquid crystal display device that satisfies the width to depth ratio of 12 to 15%.
According to claim 1,
The height of the burr is a liquid crystal display device that satisfies 75 to 85% of the depth of the engraving pattern.
According to claim 1,
The intaglio pattern is positioned at a high density per unit area as it moves away from the light incident surface.
According to claim 1,
In the embossed pattern, lenticular lenses are arranged in a row to protrude from each other,
The intaglio pattern is formed in a concave circular, elliptical shape, and the cross section is a hemispherical liquid crystal display device.
According to claim 1,
The condensing unit includes a lens layer which is arranged to protrude in a row in a second direction perpendicular to the first direction,
The lens layer is a liquid crystal display device made of an inverted prism having a vertical angle of 66 ° (± 2 °).
According to claim 1,
The condensing unit includes a lens layer which is arranged to protrude in a row in a second direction perpendicular to the first direction,
The lens layer extends from the first prism face located in one direction where the LED assembly is located, to the second prism face forming an apex angle with the first prism face, and from the second prism face to the opposite side of the first prism face. Display device comprising a third prism face.
According to claim 1,
The condensing unit includes a lens layer which is arranged to protrude in a row in a second direction perpendicular to the first direction,
The lens layer includes a first prism surface positioned in one direction in which the LED assembly is located, and a second prism surface convexly curved to be distant from the first prism surface.
According to claim 1,
The light diffusion adhesive is a liquid crystal display device comprising a light diffusion beads.

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