KR102053438B1 - BackLight Unit and Liquid Crystal Display device Comprising The Same - Google Patents

Abstract

According to an embodiment of the present invention, a backlight unit includes a light source that provides light, a light incident part that guides light incident from the light source, a light incident part including a first lower pattern, a reflecting part including a second lower pattern, and the And a light guide plate positioned between the light incident part and the reflecting part and including a mixing part including the first and second lower patterns.

Description

Backlight unit and manufacturing method thereof, and liquid crystal display including the same {BackLight Unit and Liquid Crystal Display device Comprising The Same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit and a liquid crystal display device. In particular, a backlight unit capable of controlling light output by a light guide plate, improving a light collecting effect, and improving a hot spot and a bright line of a light incident portion of the light guide plate, and a manufacturing method thereof It relates to a liquid crystal display device comprising.

Liquid crystal display devices (LCDs) are widely used due to advantages such as low power driving, thin structure, and excellent image quality. Such a liquid crystal display device uses a liquid crystal panel composed of two substrates facing each other and a liquid crystal interposed therebetween. In addition, the liquid crystal panel displays an image by changing the liquid crystal array by an electric field generated with the liquid crystal interposed therebetween.

Such a liquid crystal panel is a non-light emitting display panel and requires a light supply device such as a back light unit (BLU) to display an image. Generally, a liquid crystal display device includes a liquid crystal panel and a back light unit (BLU). ) Are configured together. Such a backlight unit is classified into an edge type backlight unit (Edge type BLU) and a direct type backlight unit (Bottom Type BLU) according to the position of the light source. In addition, the backlight unit BLU includes a light guide plate and various kinds of optical sheets so as to efficiently transmit and use the light supplied to the light source to the liquid crystal panel.

Recently, due to the trend of thinner liquid crystal display devices, product development is being made so that the optical sheet and the light guide plate may be made as thin and small as possible. Therefore, the edge type backlight unit is used more than the direct type backlight unit and forms a pattern on the upper and lower surfaces of the light guide plate to compensate for the reduced optical sheet.

In the conventional backlight unit, the light guide plate and the reverse prism sheet to which the pattern is applied are disposed on the light guide plate to achieve a light collecting effect. However, this structure has a problem in that hot spots and bright lines are generated in the light incident portion of the light guide plate on which the light source is located.

The present invention provides a backlight unit capable of controlling light output by a light guide plate, improving a light collecting effect, and improving a hot spot and a bright line of a light incident part of the light guide plate, and a manufacturing method thereof, and a liquid crystal display device including the same.

In order to achieve the above object, the backlight unit according to an embodiment of the present invention guides a light source for providing light, and the light incident from the light source, the light incident part including a first lower pattern, the second lower pattern And a light guide plate including a reflection unit including a reflection unit, and a mixing unit positioned between the light incident unit and the reflection unit and including the first and second lower patterns.

The light incidence part may be an area of up to 10% of the length of the light guide plate from an incident surface of the light guide plate through which light is incident from the light source.

The first lower pattern is characterized in that the intaglio hemispherical.

The reflector may be a region other than an area of up to 30% of the length of the light guide plate from the incident surface.

The second lower pattern is characterized in that the intaglio or embossed.

The second lower pattern may be formed in a prism shape by an inclined surface and a sub inclined surface.

The inclined plane angle formed by the inclined plane and the bottom surface of the light guide plate may be smaller than the inclined sub inclined plane angle formed by the bottom plane and the sub inclined plane.

The inclined surface may be located closer to the incident surface of the light guide plate than the sub inclined surface.

The mixing unit is characterized in that the first lower pattern and the second lower pattern is arranged regularly or irregularly.

In addition, the liquid crystal display according to the exemplary embodiment of the present invention may include a light source for providing light, a light incident part that guides light incident from the light source, a light incident part including a first lower pattern, a reflective part including a second lower pattern, And a light guide plate disposed between the light incident part and the reflective part and including a mixing part including the first and second lower patterns, an optical sheet positioned on the light guide plate, and positioned on the optical sheet to implement an image. It characterized in that it comprises a; liquid crystal panel.

In addition, the method of manufacturing a backlight unit according to an exemplary embodiment of the present invention includes preparing a base of a light guide plate having a light incident part, a mixing part, and a reflecting part, and forming a second lower pattern on the mixing part and the reflecting part of the lower surface of the base. And forming a first lower pattern on the light incident part and the mixing part of the lower surface of the base.

The forming of the first lower pattern may include forming a first lower pattern by directly irradiating a laser on a lower surface of the base.

The forming of the second lower pattern may include: a lower cutting step of cutting a lower surface of the base to form an inclined surface and a sub slope, and a flat portion forming a flat portion by recutting the base on which the inclined surface and the sub inclined surface are formed Characterized in that it comprises a step.

The backlight unit according to the present invention forms a plurality of first lower patterns and a second lower pattern on a light guide plate including a light incident part, a mixing part, and a reflecting part, thereby preventing hot spots occurring in an area adjacent to the light source and generating bright lines. There is an advantage that can be prevented.

1 is an exploded perspective view showing a liquid crystal display device according to an embodiment of the present invention.
2 is a perspective view showing a front surface of a light guide plate according to an embodiment of the present invention.
3 is a perspective view illustrating a rear surface of the light guide plate of FIG. 2.
4 is a cross-sectional view illustrating a cross section of the light guide plate of FIG. 2.
5 illustrates a first lower pattern of the light guide plate;
6 is a photograph showing a first lower pattern of the light guide plate;
7 and 8 are a perspective view and a cross-sectional view showing the second lower patterns of the light guide plate.
9 is a photograph showing a second lower pattern of the light guide plate;
FIG. 10 is a photo illustrating a first lower pattern and a second lower pattern formed on the light guide plate; FIG.
11 is a cross-sectional view for explaining a path of light caused by a lower pattern in the light guide plate;
12 is a flowchart illustrating a method of manufacturing a light guide plate according to the present invention.
13 illustrates a method of forming an upper pattern on a light guide plate;
14 is a photograph showing a second lower pattern.
15 to 17 illustrate a method of manufacturing a second lower pattern on a light guide plate;
18 is a view illustrating a method of manufacturing a first lower pattern on a light guide plate;
19 is a photograph showing a first lower pattern.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like numbers refer to like elements throughout. In the following description, when it is determined that the detailed description of known contents or configurations related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the liquid crystal display device 100 according to an exemplary embodiment of the present invention includes a liquid crystal panel 110, a backlight unit 130, a support main 140, a bottom cover 150, and a top cover 160. It is configured to include.

The liquid crystal panel 110 is mounted on the panel support of the support main 140 to adjust the transmittance of light supplied from the backlight unit 130 to implement an image. The liquid crystal panel 110 includes a first substrate 111 and a second substrate 112 bonded to each other with a liquid crystal layer interposed therebetween. Although not shown in the drawing, a plurality of pixels may be defined in the first substrate 111 called a TFT array substrate by crossing a plurality of scan lines and data lines in a matrix shape. Each pixel may include a thin film transistor (TFT) capable of turning on / off a signal, and a pixel electrode connected to the thin film transistor may be positioned.

The second substrate 112, also called a color filter substrate, includes color filters of red (R), green (G), and blue (B) corresponding to a plurality of pixels, and surround them with scan lines, data lines, and thin films, respectively. A black matrix may be provided to cover non-display elements such as transistors. In addition, a transparent common electrode may be provided to cover them. In the present embodiment, the pixel electrode is provided on the first substrate and the common electrode is provided on the second substrate as an example. However, the present invention is not limited thereto and both the pixel electrode and the common electrode may be provided on the first substrate.

In addition, the printed circuit board 116 is connected to at least one side of the liquid crystal panel 110 through a connecting member 114 such as a flexible circuit board or a tape carrier package (TCP) to support the main unit in the modularization process. It may be in close contact with the side of the side 140 or the bottom of the bottom cover 150.

In the liquid crystal panel 110 having the above structure, when the thin film transistor selected for each scan line is turned on by the on / off signal of the gate driving circuit transmitted from the scan line, the data voltage of the data driver circuit is transferred through the data line. The liquid crystal molecules may be transferred to the corresponding pixel electrode, and thus the alignment direction of the liquid crystal molecules may be changed by an electric field between the pixel electrode and the common electrode, thereby indicating a difference in transmittance.

The support main 140 wraps the edges of the light guide plate 200, the optical sheet 139, and the reflective sheet 128, and the bottom cover 150 covers the light guide plate 200, the optical sheet 139, and the reflective sheet 128. And a role of supporting the liquid crystal panel 110. Here, the role of the support main 140 may be replaced or omitted by a structure added to the top cover 160 and the bottom cover 150.

On the other hand, the liquid crystal display device 100 of the present invention may be provided with a backlight unit 130 that can provide light to the liquid crystal panel 110 from the back of the liquid crystal panel 110. The backlight unit 130 may include a light source 120, a white or silver reflective sheet 128, a light guide plate 200 positioned on the reflective sheet 128, and a plurality of optical sheets interposed on the light guide plate 200. 139).

The light source 120 is mounted on a light source circuit board and driven by a power source to generate light. The light source 120 may be formed of any one of a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), and an external electrode fluorescent lamp (EEFL). The light emitted from the light source 120 is incident into the light guide plate 200 and is supplied to the liquid crystal panel 110 by the light guide plate 200, the optical sheet 139, and the reflective sheet 128. The light source 120 is formed to face at least one surface of the light guide plate 200. In the present embodiment, when explaining the LED as an example of the light source 120, the LED assembly is located on one side of the light guide plate 200, the plurality of LED light source 121 and the LED light source 121 is mounted at a predetermined interval spaced It is configured to include a support 123 that can support the substrate 122 and the bottom cover 150.

Meanwhile, in the present invention, it is advantageous that the backlight unit 130 is configured in an edge type. The light guide plate of the present invention induces total reflection of the light emitted from the light source 120 not only by the upper pattern and the light collecting sheet but also by the lower pattern, thereby improving luminance and preventing hot spots or bright lines.

The optical sheet 139 collects or diffuses light emitted through the light guide plate 200 to be transmitted to the liquid crystal panel 110. To this end, the optical sheet 139 is configured to include at least one diffusion sheet or light collecting sheet. The diffusion sheet prevents the light emitted through the light guide plate 200 from being concentrated in some areas and distributes the light to be transmitted to the liquid crystal panel 110 in an even distribution. The light collecting sheet collects light emitted from the light guide plate 200 and allows light to be vertically transmitted to the liquid crystal panel 110. In particular, the light collecting sheet of the present invention may be composed of a reverse prism sheet having a sheet pattern formed on a surface facing the light guide plate 200.

The reflective sheet 128 is disposed below or on the side of the light guide plate 200 and reflects light emitted to the exit surface or the bottom of the light guide plate 200 into the light guide plate 200. The reflective sheet 128 may be formed at different positions depending on the arrangement of the light sources 120. For example, as shown in FIG. 1, the edge type backlight unit may be disposed on a lower surface of the light guide plate 200, that is, a surface facing the liquid crystal panel 110 with the light guide plate 200 therebetween. In addition, the direct type backlight unit may be configured on the side surface of the light guide plate 200 or may be omitted as necessary. The direct backlight unit may be modified by various acceptances such as the arrangement of the light source 120 without being limited to those described.

The light guide plate 200 serves to provide a primary surface light source to the liquid crystal panel 110 by spreading the light incident from the light source 120 into a wide area of the light guide plate 200 while traveling in the light guide plate 200 by a plurality of total reflections. can do. The light guide plate 200 may include a pattern of a specific shape on the rear surface to supply a uniform surface light source.

The liquid crystal panel 110 and the backlight unit 130 may be modularized through the top cover 160, the support main 140, and the bottom cover 150. The top cover 160 may have a rectangular frame shape covering the top and side surfaces of the liquid crystal panel 110. The top cover 160 may open an entire surface of the top cover 160 to display an image implemented in the liquid crystal panel 110. The bottom cover 150 combines the liquid crystal panel 110 and the backlight unit 130 to serve as a basis for the liquid crystal display, and may have a rectangular plate shape.

The configuration of the light guide plate described above will be described in more detail with reference to the following drawings.

2 is a perspective view illustrating a front surface of a light guide plate according to an embodiment of the present invention, FIG. 3 is a perspective view illustrating a rear surface of the light guide plate of FIG. 2, FIG. 4 is a cross-sectional view illustrating a cross section of the light guide plate of FIG. 2, and FIG. 5 is FIG. 6 is a diagram illustrating a first lower pattern of the light guide plate, and FIG. 6 is a photograph illustrating the first lower pattern.

2 to 4, in the light guide plate 200 of the present invention, upper and lower patterns 210 and lower patterns 220 are formed on upper and lower surfaces, respectively. The upper pattern 210 is formed on the upper surface of the light guide plate 200. The upper pattern 210 is formed in a prism pattern. The prism pattern has a triangular cross section and is linearly formed along the longitudinal direction of the prism pattern, and thus may be formed in a triangular prism bar shape in appearance, but is not limited thereto. The upper pattern 210 serves to cause the light incident on the light guide plate 200 to be reflected several times in the light guide plate 200 so as to be distributed in an even distribution, and to collect light in the direction of the liquid crystal panel through reflection. Play a role.

Meanwhile, as shown in FIGS. 3 and 4, lower patterns 220 are formed on the lower surface of the light guide plate 200. The lower patterns 220 are intaglio and embossed on the bottom surface of the light guide plate 200. In more detail, the lower surface of the light guide plate 200 may be largely divided into three regions: the light incident portion A, the mixing portion B, and the reflecting portion C. The light incident part A is a portion where the light emitted from the light source 120 is incident on the light guide plate 200, and is a region having the highest luminance. The mixing part B may be disposed adjacent to the light incident part A and may be an area in which light incident through the light incident part A is totally reflected and spreads out. In addition, the reflector C occupies most of the area of the light guide plate 200, and may be an area in which the totally reflected light in the light guide plate 200 is focused and emitted to the upper surface of the light guide plate 200.

In detail, referring to FIG. 5, a plurality of first lower patterns 230 are formed in the light incident portion A of the light guide plate 200. The plurality of first lower patterns 230 may have a shape of an intaglio hemispherical surface. Depending on the size and the density of the hemispherical surface of the first lower pattern 230, the degree of diffusion, the degree of refraction, the light condensing property, etc. may vary. The pitch P between the first lower patterns 230 may be at regular intervals or at irregular intervals. In addition, the diameter L or the length D of the first lower pattern 230 may also be constant or irregular. In addition, the distribution of the first lower pattern 230 in the total area of the light incident portion A may be formed to have 50 to 90% or more, but is not limited thereto. In addition, the first lower patterns 230 may be formed to have the same depth without having a difference in depth from each other, or may have different depths.

When the first lower pattern 230 is formed to have a negative hemispherical surface, some of the light incident through the incident surface 205 of the light guide plate 200 may be uniformly refracted at all azimuth angles in the hemisphere. have. Therefore, some light reaching the hemispherical surface of the first lower pattern 230 may be uniformly diffused upward and focused.

The light incident portion A of the light guide plate 200 may be an area within 10% of the length of the light guide plate 200 from the incident surface 205 of the light guide plate 200. The light incident part A is an area closest to the light source 120 and becomes an area having the highest luminance of the light emitted from the light source 120. Accordingly, there is a problem that a hot spot of too high luminance is generated in the light incident part A of the light guide plate 200. Therefore, in the present invention, a plurality of first lower patterns 230 are formed in an area within 10% of the length of the light guide plate 200 from the incident surface 205 of the light guide plate 200, thereby generating hot spots generated in the light guide plate 200. There is an advantage that can be removed.

Meanwhile, a plurality of first lower patterns 230 and second lower patterns 240 are mixed in the mixing part B of the light guide plate 200. Since the first lower pattern 230 has been described above, the second lower pattern 240 will be described below. 7 and 8 are perspective and cross-sectional views illustrating second lower patterns of the light guide plate, and FIG. 9 is a photograph showing a second lower pattern formed on the light guide plate.

7 to 9, the plurality of second lower patterns 240 are asymmetrically formed. In particular, one or more inclined surfaces 247a for reflecting light are formed. In addition, another sub-inclined surface 247b may be formed to face the inclined surface 247a, and the inclined surface 247a and the sub-inclined surface 247b constituting the band are not formed in parallel. The sub sloped surface 247b may be formed at a right angle with respect to the base side, but is not limited thereto. The lower pattern 240 may be formed in a shape similar to a prism, and the inclined surface 247a and the sub inclined surface 247b are asymmetrically formed for total reflection.

The second lower patterns 240 may be engraved or embossed on the bottom surface of the light guide plate 200. Here, referring to FIG. 7A, when the second lower pattern 240 is intaglio, the inclined surface 246a is formed to face the incident surface 205 to which light is incident. In addition, as shown in FIG. 7B, when the second lower pattern 240 is embossed, the sub sloped surface 246b is formed to face the incident surface 205. Through this, light incident through the incident surface 205 and traveling through the light guide plate 200 is totally reflected on the inclined surface 246a and is emitted to the light guide plate 200.

Meanwhile, referring to FIG. 8, the second lower pattern 240 of the present invention serves to emit light traveling through the light guide plate 200 through the front of the light guide plate. Specifically, when the light emitted through the front surface of the light guide plate 200 maintains a constant exit angle with respect to the front surface of the light guide plate 200, the light collecting efficiency is increased, so that the brightness increase effect can be expected.

To this end, the second lower pattern 240 of the light guide plate 200 has an inclined plane angle θ1 formed by the inclined surface 246a and the lower surface 206 of the light guide plate 200, and the sub inclined surface 246b and the lower surface of the light guide plate 200. It is formed smaller than the sub-inclined plane angle θ2 formed by 206 (θ1 <θ2). More specifically, the inclined plane angle θ1 may be an angle within a range of 5 to 10 degrees to favor the total reflection effect and the emission angle to be emitted at a specific angle of 10 to 30 degrees. In addition, the angle θ3 between the inclined surface 246a and the sub-inclined surface 246b may be an angle of 50 degrees or more and 170 degrees or less. The inclined plane angle θ1, the sub-inclined plane angle θ2, and the inclined angle θ3 may be formed outside the above-described angle ranges, but in this case, the total reflection effect is lowered and the brightness enhancement effect is lowered, thereby lowering the second lower pattern 240. It becomes difficult to expect the effect improvement by this. In addition, as described above, the inclined surface 246a of the lower pattern 240 is disposed in a shape for reflecting light incident through the incident surface 205 of the light guide plate 200.

3 and 4, the first lower pattern 230 and the second lower pattern 240 are mixed in the mixing portion B of the light guide plate 200. The mixing part B serves to prevent a bright line from occurring due to a difference in luminance of light at the boundary between the light incident part A and the reflecting part C of the light guide plate 200. Therefore, in the mixing unit B, the first lower pattern 230 diffuses light uniformly and the second lower pattern 240 reflects light uniformly to improve brightness to generate bright lines. To prevent them.

In the mixing part B, the first lower pattern 230 and the second lower pattern 240 may be regularly arranged alternately with each other, as shown in FIG. 3, but is not limited thereto. Any arrangement is acceptable as long as the luminance uniformity can be achieved. In addition, the area occupied by the first lower pattern 230 and the second lower pattern 240 in the mixing part B is preferably 50:50. However, the first lower pattern 230 and the second lower pattern 240 may have a uniform brightness while achieving a luminance uniformity. The area occupied by the lower pattern 230 may be larger than the area occupied by the second lower pattern 240, or the area occupied by the second lower pattern 240 may be larger than the area occupied by the first lower pattern 230. .

In addition, the first lower pattern 230 and the second lower pattern 240 of the mixing part B may overlap each other. 10 is a photo illustrating a first lower pattern and a second lower pattern formed on the light guide plate. Referring to FIG. 10, the first lower pattern 230 may be disposed to be spaced apart from the second lower pattern 240 while overlapping the second lower pattern 240. That is, the first lower pattern 230 may be further formed on the second lower pattern 240. However, the present invention is not limited thereto, and the first lower pattern 230 and the second lower pattern 240 may have any structure as long as luminance uniformity can be achieved in the mixing unit B.

The mixing part B may be an area within a range of 10% to 30% of the length of the light guide plate 200 from the incident surface 205 of the light guide plate 200. The mixing part B is formed in a range capable of reducing a difference in luminance of light at the boundary between the light incident part A and the reflecting part C of the light guide plate 200, and thus, the first lower pattern 230 and the second lower pattern ( 240) uniformly mixed to prevent the generation of bright lines.

The plurality of second lower patterns 240 described above are formed in the reflective part C of the light guide plate 200. The reflective part C of the light guide plate 200 may be a remaining area except for an area up to 30% of the length of the light guide plate 200 from the incident surface 205 of the light guide plate 200. The reflector C reflects the light in the light guide plate 200 to the upper surface of the light guide plate 200. The reflection part C reflects the total light of the light incident into the light guide plate 200 due to the plurality of second lower patterns 240. By improving the effect, the light utilization efficiency is increased and the brightness is improved.

11 is a cross-sectional view for describing a path of light by a lower pattern in the light guide plate. Referring to FIG. 11, when light is incident from the light source 120 through the incident surface 205 of the light guide plate 200, the light reaches the light incident part A of the light guide plate 200. Light incident on the light incident portion A is diffused by the plurality of first lower patterns 230 formed on the light incident portion A. FIG. And, the light reaching the mixing portion B is partially spread by the plurality of first lower patterns 230 formed in the mixing portion B, and partially by the plurality of second lower patterns 240. Reflected upwards. Meanwhile, the light reaching the reflector C is reflected upward by the plurality of second lower patterns 240 formed in the reflector C, and part of the light is emitted to the outside through the upper surface of the light guide plate 200. .

As described above, the light guide plate of the present invention includes a light incidence part, a mixing part, and a reflecting part, and forms a plurality of first lower patterns 230 and second lower patterns 240 to prevent hot spots generated in an area adjacent to the light source. There is an advantage that can prevent and prevent the occurrence of bright lines due to the difference in brightness.

12 is a flowchart illustrating a method of manufacturing a light guide plate according to the present invention, FIG. 13 is a view illustrating a method of forming an upper pattern on a light guide plate, FIG. 14 is a photograph showing a second lower pattern, and FIGS. 15 to 17 FIG. 18 is a view illustrating a method of manufacturing a second lower pattern on a light guide plate, FIG. 18 is a view illustrating a method of manufacturing a first lower pattern on a light guide plate, and FIG. 19 is a photograph illustrating the first lower pattern.

12 to 14, the method of manufacturing a backlight unit according to the present invention includes a base preparation step S10, an upper pattern forming step S20, and a lower pattern forming step S30.

Base preparation step (S10) is a step of preparing a base that is the base material of the light guide plate. The upper pattern forming step S20 is a step of forming the upper pattern 210 on the base prepared in the base preparation step S10 as shown in FIG. 13. In the upper pattern forming step S20, the upper pattern is formed by cutting the surface of the base 250 by the cutting tip 260 to form a groove.

In the lower pattern forming step S30, the first lower pattern 230 and the second lower pattern 240 are formed on the bottom surface of the base 250. First, the manufacturing method varies depending on whether the second lower pattern 240 is intaglio or embossed. In detail, when the second lower pattern of the intaglio is formed, the second lower pattern may be formed by processing a predetermined position by a punching method using a cutting tip. That is, only the second lower pattern forming position may be partially drilled to form a negative second lower pattern as shown in FIG. 14 on the lower surface of the light guide plate.

On the other hand, referring to Figures 15 to 17, in order to form the embossed second lower pattern 240 may be configured to include a lower cutting step and a flat portion forming step. In the lower cutting step, as shown in FIG. 15, a groove is formed on the lower surface of the light guide plate 200 by using the cutting tip 260, and a line pattern 247 is formed in which the inclined surface 246a and the sub inclined surface 246b are connected in one direction. It's a step.

The flat portion forming step is a step of separating the line pattern 247 to form a pattern formed of the line pattern 247 as each of the separated second lower patterns 240, as shown in FIG. Specifically, in the flat portion forming step, the flat portion 248 is formed by cutting the lower surface of the light guide plate 200 on which the line pattern 247 is formed by the cutting tip 260 in a direction crossing or parallel to the line pattern 247. do. Through this, the flat portion 248 is formed according to the direction in which the cutting tip 260 is moved, and the pattern formed in the form of the line pattern 247 by the flat portion 248 is separated into each of the second lower patterns 240. Will be.

In particular, as illustrated in FIG. 17, a tilting process in which the second lower pattern 240 is formed at a predetermined angle at an angle with respect to the longitudinal axis Hx or the horizontal axis Vx of the light guide plate 200 is included. Here, FIG. 17 shows an example in which the tilting is performed in the longitudinal axis Hx direction by the cutting tip 260 on the longitudinal axis Hx. However, the present invention is not limited thereto, and the same method also applies to the horizontal axis Vx direction. As a result, it is possible to tilt the second lower pattern 240.

Meanwhile, referring to FIGS. 18 and 19, in the lower pattern forming step S30, after the second lower pattern 240 is formed, the step of forming the first lower pattern 230 is performed. The first lower pattern 230 is formed by using the laser device 270 having the scan head 280 in negative hemispherical patterns. That is, the first lower pattern 230 may be formed by directly irradiating a laser emitted from the laser device 270 through the scan head 280 to the lower surface of the light guide plate 200. Therefore, as shown in FIG. 19, the first lower patterns 230 may be formed by laser irradiation.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention. Therefore, the present invention should not be limited to the details described in the detailed description but should be defined by the claims.

100 liquid crystal display device 110 liquid crystal panel
120: light source 128: reflection sheet
130: backlight unit 139: optical sheet
140: support main 150: bottom cover
160: top cover 200: light guide plate

Claims (13)

A light source for providing light; And
The light incident part guides the light incident from the light source, and includes a light incident part including a first lower pattern, a reflector including a second lower pattern, and positioned between the light incident part and the reflecting part. It includes; a light guide plate including a mixing unit including a;
The mixing unit is a backlight unit, characterized in that the first lower pattern and the second lower patterns are arranged regularly or irregularly.
According to claim 1,
And the light incidence part is an area of up to 10% of the length of the light guide plate from an incident surface of the light guide plate through which light is incident from the light source.
The method of claim 2,
The first lower pattern is a backlight unit, characterized in that the intaglio hemispherical.
The method of claim 2,
The reflector is a backlight unit, characterized in that the remaining area except the area up to 30% of the light guide plate length from the incident surface.
The method of claim 4, wherein
The second lower pattern is a backlight unit, characterized in that the intaglio or embossed.
The method of claim 5,
The second lower pattern is a backlight unit, characterized in that formed in the prism shape by the inclined surface and the sub-inclined surface.
The method of claim 6,
And an inclined plane angle formed by the inclined plane and a bottom surface of the light guide plate is smaller than an inclined sub inclined plane angle formed by the bottom surface and the sub inclined plane.
The method of claim 6,
The inclined surface is a backlight unit, characterized in that located closer to the incident surface of the light guide plate than the sub-inclined surface.
delete A light source for providing light;
The light incident part guides the light incident from the light source, and includes a light incident part including a first lower pattern, a reflector including a second lower pattern, and positioned between the light incident part and the reflecting part. A light guide plate including a mixing unit including a;
An optical sheet positioned on the light guide plate; And
Located on the optical sheet, the liquid crystal panel for implementing an image; includes;
And wherein the mixing unit arranges the first lower pattern and the second lower pattern regularly or irregularly.
A base preparation step of a light guide plate partitioned by a light incident part, a mixing part, and a reflecting part;
Forming a second lower pattern on the mixing part and the reflecting part of the lower surface of the base; And
Forming a first lower pattern on the light incident part and the mixing part of the lower surface of the base,
The mixing unit manufacturing method of the backlight unit, characterized in that the first lower pattern and the second lower patterns are arranged regularly or irregularly.
The method of claim 11, wherein
Forming the first lower pattern,
The method of manufacturing a backlight unit, characterized in that to form a first lower pattern by directly irradiating a laser on the lower surface of the base.
The method of claim 11, wherein
Forming the second lower pattern,
A lower cutting step of cutting a lower surface of the base to form an inclined surface and a sub inclined surface; And
And a flat portion forming step of re-cutting the base on which the inclined surface and the sub inclined surface are formed to form a flat portion.

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