KR100660047B1 - Light guide panel for tft-lcd back light unit, tft-lcd back light unit and tft-lcd device thereby - Google Patents

Abstract

A light guide plate for a back light unit of an LCD(Liquid Crystal Display), a back light unit of an LCD including the light guide plate, and an LCD are provided to increase the number of lamps in order to obtain high luminance by using a subsidiary light guide. A light guide plate(30) for a back light unit of an LCD includes a main light guide(300) and a subsidiary light guide(330). The main light guide converts light inputted through the side thereof into uniform plane light and projects the plane light through the top face thereof. The subsidiary light guide is located at the side of the main light guide through which light is inputted and includes a first face adjacent to the side of the main light guide, a second face that is parallel with the first face and higher than the first face, and connecting faces connecting the first face and the second face. The second face is located in proximity to a light source(305) to receive light emitted from the light source.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a light guide plate for a liquid crystal display backlight unit, and a liquid crystal display (LCD) backlight unit and a liquid crystal display including the same,

1 is a sectional view showing an edge type backlight unit.

2 is a sectional view showing a direct-type backlight unit.

3 is a perspective view illustrating a liquid crystal display backlight unit according to an embodiment of the present invention.

FIG. 4 is a view separately showing the auxiliary light guide in FIG. 3 to further explain the auxiliary light guide.

5A to 5B show various embodiments of the auxiliary light emitting portion.

6 is a view for explaining the progress of light in a backlight unit of a liquid crystal display device according to an embodiment of the present invention.

7 and 8 are views showing a liquid crystal display backlight unit according to another embodiment of the present invention.

FIG. 9 is a perspective view illustrating an LCD TV to which a light guide plate for a liquid crystal display backlight unit according to an embodiment of the present invention shown in FIG. 3 is applied.

Description of the Related Art

300: main beam section 305: light source section

310: lamp 320: lamp housing

330: auxiliary light guide 331: first side

332: second surface 333,334: connecting surfaces

h ₁ : height of first surface h ₂ : height of second surface

h ₃ : height of the light source portion w: width of the second surface

900: liquid crystal panel part 910: LDI part

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a light guide plate for a liquid crystal display backlight unit and a liquid crystal display backlight unit including the light guide plate. More particularly, the present invention relates to an edge type liquid crystal display backlight unit, And more particularly, to a light guide plate for a liquid crystal display device backlight unit and an LCD backlight unit using the same, which can increase the brightness by increasing the number of lamps in the light source unit by providing a light portion.

BACKGROUND ART A liquid crystal display device is not a self-luminous device such as a plasma display panel (PDP) or an organic light emitting diode (OLED), but rather a liquid crystal display Refers to a device that controls the opening / closing of a passage through which light travels, thereby displaying the light passing through it.

Since the liquid crystal display device is not a self-luminous device, the liquid crystal display device requires a device called a backlight unit on the rear side thereof. The backlight unit of such a liquid crystal display device can be divided into an edge mode and a direct down mode. The double edge mode is mainly used for a computer monitor for a notebook or a desktop, and the direct mode is mainly used for a large area such as an LCD TV.

1 is a sectional view showing an edge type backlight unit.

1, the edge type backlight unit 10 is installed to face the panel unit 130 and includes a light guide plate 100 that receives light generated from the lamp 110 and converts the light into a plane light, And a lamp housing 120 surrounding the lamp 110 to direct the light generated from the lamp 110 toward the light guide plate 100. The lamp 110 is disposed on the side surface of the light guide plate 100, And a light source unit 105 constituted by the light source unit.

A light diffusion sheet, a prism sheet, or other protective film or the like for allowing the surface light generated by the light guide plate 100 to have a more uniform surface light may be provided between the light guide plate 100 and the panel 130, 100). ≪ / RTI >

Since the edge type backlight unit 10 has the light source unit 105 on the side surface of the light guide plate 100, the number of the lamps 110 constituting the light source unit 105 is limited by the thickness of the light guide plate 100 Considering that the thickness of the light guide plate 100 is generally about 12 mm, considering that the lamps 110 having a thickness of about 3 mm can not be installed at a maximum of three or more, There is a problem in that a desired brightness can not be obtained when the edge type backlight unit is applied to a large liquid crystal display device of 32 inches or more.

2 is a sectional view showing a direct-type backlight unit.

The reason why the backlight unit 20 shown in FIG. 2 is called the direct type is that the fluorescent lamp is not located on the side of the backlight unit 20 but the fluorescent lamp is disposed at a position perpendicular to the panel 230 on which the actual image information is displayed 200) is located.

The direct-type backlight unit 10 includes a lamp 200 positioned to be perpendicular to the panel 230 and generating light, a lamp 200 housed in the lower portion of the lamp 200, A reflection plate 210 for reflecting light and a light diffusion plate 220 formed at a predetermined distance from the lamp 200 and scattering light to convert the light into a uniform plane light.

The direct-type backlight unit 20 can be installed directly under the panel 230 without limitation of the number of the panels 200 so as to correspond to the area of the panel, and is mainly used for a large-area liquid crystal display device requiring high brightness.

However, the direct-type backlight unit 20 prevents deformation of the light diffusion plate 220 due to heat generated in the lamp 200 and prevents a dark region between the lamp 200 and the lamp 200, It is difficult to provide a slim type backlight unit of about the edge type backlight unit 10 because a constant interval is required between the lamp 200 and the light diffusing plate 220 to provide uniform luminance distribution on the front side .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display having an auxiliary light guide for increasing the number of lamps so as to obtain a high luminance even when used in a large screen TV liquid crystal display device using a slimable edge type backlight unit, A light guide plate for an apparatus backlight unit and a liquid crystal display backlight unit including the same.

According to another aspect of the present invention, there is provided a liquid crystal display (LCD) backlight unit and a liquid crystal display (LCD) device including the light guide plate according to the present invention.

The technical objects to be achieved by the present invention are not limited to the technical matters mentioned above, and other technical subjects which are not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a light guide plate for a backlight unit for a liquid crystal display device, the light guide plate including a main light portion converting light incident from a side surface into a uniform surface light and emitting the light to a top surface, A second surface which is parallel to the first surface and has a height larger than the height of the first surface and in which light is incident adjacent to the light source portion, And an auxiliary light guiding portion having connection surfaces connecting the second surfaces.

A liquid crystal display backlight unit and a liquid crystal display device including the light guide plate according to the embodiment of the present invention are also provided.

The details of other embodiments are included in the detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

In the drawings, it is to be noted that the sizes of the constituent elements of the invention are exaggerated for clarity of description, and when it is described that any constituent element is present inside or connected to another constituent element, The element may be installed in contact with the other component, or may be installed with a predetermined distance therebetween, and when the component is installed at a distance, the third component for fixing or connecting the component to the other component The description of the means of FIG.

3 is a perspective view illustrating a light guide plate for a liquid crystal display backlight unit according to an embodiment of the present invention.

3, the light guide plate 30 for a liquid crystal display backlight unit according to an embodiment of the present invention includes a main light guide 300 and an auxiliary light guide 330, A light source unit 305 including a lamp housing 310 and a lamp housing 320 is installed.

When light is generated in the light source unit 305 located at the side, the side surface of the main light guide unit 300 tends to be brighter and it is used to convert the light into a uniform plane light as a whole. It is characterized by high strength and low cracking and deformation, light weight and high visible light transmittance.

The width of the main light guide part 300 is determined according to the width of the panel used. In general, the thickness of the main light guide part 300 is about 10 to 12 mm.

In addition, diffusion and refraction of light incident from the side of the main light-emitting portion 300 is promoted on the opposite surface (rear surface) of the surface (front surface) on which the light is emitted from the main light-emitting portion 300 to be converted into a more uniform type of surface light A dot having a prism shape for forming a dot may be formed.

The light source unit 305 includes a lamp 310 and a lamp housing 320.

The lamp 310 actually generates light. The lamp 310 may be of various types, but the lamp 310 used in a liquid crystal display device is a cold cathode fluorescent lamp (CCFL) Is used. In addition, light emitting diodes (LEDs) are also widely used in recent years in terms of high brightness and high brightness.

The cold cathode fluorescent lamp lamp used as the lamp 310 is advantageous in that it emits very bright white light with little heat dissipation, low power consumption, and can be made very thin with a diameter of about 2 to 3 mm, And is most often used as the lamp 310 of the device backlight unit.

The lamp housing 320 directs the light generated from the lamp 310 only in the lateral direction of the light guide plate 30 and reflects the light emitted in the other direction toward the light guide plate 30, It has a reflective surface like a glass surface inside for reflection of light.

The auxiliary light guide portion 330 is disposed between the side surface of the main light guide portion 300 and the light source portion 305.

The light source unit 305 is formed to be longer than the light source unit of the conventional liquid crystal display device because the light source unit 305 is formed in close contact with the side surface of the light guide plate 30 without the auxiliary light guide unit 330 The thickness of the light source unit 305 must be determined by the thickness of the light guide plate 30 in the present invention. However, in the present invention, the light source unit 305 may not be formed in close contact with the main light guide 30, It is possible to form the light source unit 305 thicker than the thickness of the light guide plate 300 by newly adding a member that is not present in the prior art as the auxiliary light guide unit 330. [

Although the auxiliary light guiding part 330 is described as a separate member physically separated from the main light guiding part 300 in the above description, the auxiliary guiding part 330 may be physically coupled to the main light guiding part 300, It may be integrated.

Hereinafter, the auxiliary light guide portion 330 will be described in detail.

FIG. 4 is a view illustrating the auxiliary light-guiding part 330 separated from the auxiliary light-guiding part 330 in FIG. 3 in order to explain the auxiliary light-guiding part 330 in more detail.

Secondary FIG portion 330 has a greater height than the height (h ₁₎ of the first surface 331, a first side parallel to the to the 331 first side 331 adjacent the side surface of the main portion 300 ( h ₂₎ to have a light source 305, a second side 332, and first surface 331 and second surface 332 adjacent to which the light generated from the lamp 310 of light source 305 is incident on And connecting surfaces 333 and 334 for connecting.

The first surface 331 is a surface that contacts the side surface of the main light guide 300 and transmits the light incident through the second surface 332 to the side surface of the main light guide 300. The first surface 331 is the same as the side surface of the main light guide 300 Or substantially the same thickness.

3, the first surface 331 and the main light emitting portion 300 (see FIG. 3) may be formed as a single body, as shown in FIG. 3. However, in the case where the main light emitting portion 300 and the auxiliary light emitting portion 330 are integrally formed, The side does not exist.

The second surface 332 is disposed parallel to the first surface 331 and is a surface on which the light generated from the light source unit 305 is incident on the light source unit 305. The second surface 332 has a height h ₂ Is formed to be higher than the height h ₁ of the first surface 331.

In this way the light source 305 and the contact with the by forming the height of the second side 332 above the first surface 331, the height of the light source part 305 in contact with the second surface 332 (h ₃₎ also the second face (H < ₂ >) of the _first electrode 332.

When the height h ₃ of the light source unit 305 is increased, the number of the lamps 310 installed in the light source unit 305 increases.

In other words, conventionally, the thickness of the light source part is formed to correspond to the light guide part having a thickness of about 12 mm. In this case, considering that the thickness of the generally used lamp 310 is about 3 mm, Only a maximum of three lamps 310 could be mounted in consideration of the interval.

However, when the auxiliary light guiding part 330 is provided as in the present invention, the height h ₂ of the second surface 332 of the auxiliary light guiding part 330, which is in contact with the light source part 305, The height h _{3 of the} light source unit 305 is set to be larger than the height h ₁ of the first surface 331 in contact with the light source unit ₃₀₀ , The height of the side surface of the main light guide portion 300 can be made higher than the height of the side surface of the main light guide portion 300.

Accordingly, it is possible to increase the number of the lamps 310 inserted into the light source unit 305, thereby increasing the brightness according to the increase in the number of the lamps 310 in the liquid crystal display device.

The second surface 332 on which the light is incident from the light source unit 305 in the auxiliary light guide unit 330 and the first surface 331 that transmits the incident light to the side surface of the main light guide unit 300 can easily transmit light And if light leaks to the connection surfaces (333 and 334 in FIG. 4) connecting the other first surface 331 and the second surface 332, the amount of light may be reduced And the connection surfaces 333 and 334 are preferably provided with a light reflecting surface, that is, a metal surface treatment such as a mirror surface or aluminum.

The connecting surfaces 333 and 334 may connect the first surface 331 and the second surface 332 in a planar shape (see 333 in FIG. 4) (See 334 in FIG. 4).

However, the scope of the present invention is not limited by the number of the connection surfaces 333 and 334, and the present invention is not limited thereto. And an auxiliary light guiding part 330 having a second surface 332 contacting the light source part 305 formed higher than the first surface 331 contacting the side surface of the light part 300. In this case, And the scope of the invention is not limited by the shape or the number of the other connection surfaces 333 and 334, and the like.

Figs. 5A and 5B show various embodiments of the auxiliary light guide portion 330. Fig.

5A shows that the connecting surfaces connecting the first surface 331 and the second surface 332 are all planar and only one connecting surface is perpendicular to the first surface 331 and the second surface 332 And the other connecting surface meets with the first surface 331 and the second surface 332 in an inclined form.

5B has two connecting surfaces, all of which are in the form of a plane, and meet the first surface 331 and the second surface 332 in an inclined manner.

5C has two connecting surfaces, both of which are in the form of curved surfaces curving inward of the auxiliary light-guiding portion 330. [

6 is a view for explaining the progress of light in a backlight unit of a liquid crystal display device according to an embodiment of the present invention. In Fig. 6, the arrow (?) Indicates the traveling direction of the light.

In the light guide plate 30 for a backlight unit for a liquid crystal display device having an auxiliary light guide according to an embodiment of the present invention, light generated when light is generated in the lamp 310 of the light source unit 305 is scattered in all directions, So that most of the light is incident on the auxiliary light guiding part 330.

The light incident from the light source unit 305 is incident through the second surface 332 of the auxiliary light guide unit 330 and is transmitted to the main light guide unit 300 through the first surface 331. At this time, The light transmitted to the connection surfaces 333 and 334 of the auxiliary light guide portion 330 is reflected and refracted at the reflection surfaces formed on the connection surfaces 333 and 334 and finally transmitted to the main light guide portion 300.

The light transmitted through the auxiliary light guide portion 330 is converted into a relatively uniform surface light in the main light guide portion 300 and emitted in a direction in which the panel portion of the liquid crystal display device is positioned (upward in FIG. 6).

7 and 8 are views showing a light guide plate for a liquid crystal display backlight unit according to another embodiment of the present invention.

In Figs. 7 and 8, the same reference numerals as those in Fig. 3 denote the same members. Therefore, a description thereof will be made with reference to FIG.

The backlight unit of FIGS. 7 and 8 is different from the backlight unit of FIG. 3 in that the height h ₂ of the second surface 332 adjacent to the light source unit 305 in the auxiliary light guide unit 330 is larger than the height h ₂ in that same height (h ₁₎ and 331) differ.

That is, the auxiliary light guiding part 330 is disposed between the main light guiding part 300 and the light source part 305, but the total thickness of the auxiliary light guiding part 330 is the same as the thickness of the main light guiding part 300 And the first surface 331 adjacent to the side surface of the main light guide 300 is parallel to the side surface of the main light guide 300 and the second surface 331 adjacent to the light source 305 The width w of the second surface 332 is longer than the height h ₁ of the first surface 331. The first surface 331 and the second surface 332 are inclined with respect to each other.

As a result, since the light source unit 305 is formed adjacent to the second surface 332 having a width w that is longer than the height h ₁ of the first surface 331, .

7 is different in that the sectional shape of the auxiliary light guiding portion 330 is a trapezoidal shape and that of the auxiliary light guiding portion 330 is a triangular shape. And the sectional shape of the auxiliary light guide portion 330 is not limited to the above-mentioned trapezoidal or triangular shape, but may be formed in the form of a figure including various types of polygons or curves.

7 and 8, the auxiliary light guiding portion 330 and the main light guiding portion 300 are physically separated so that the side surface of the main light guiding portion 300 and the first surface 331 of the auxiliary light guiding portion 330 are adjacent to each other The present invention is not limited to this and the first surface 331 of the auxiliary light-guiding portion 330 does not exist on the side surfaces of the main light-guiding portion 300 and the auxiliary light- 330 may be integrally formed.

7 and 8, there is a technical idea that the width w of the second surface 332, which is the surface in contact with the light source unit 305, is widened.

FIG. 9 is a perspective view illustrating an LCD TV to which a light guide plate for a liquid crystal display backlight unit according to an embodiment of the present invention shown in FIG. 3 is applied.

9, the LCD TV includes a light source unit 305 including a lamp 310 and a lamp housing 320, a light guide plate 30 including a main light guide 300 and an auxiliary light guide 330, a light guide plate, A liquid crystal panel unit 900 and an LDI unit (LCD Driving IC) 910.

However, since the light source unit 305 and the light guide plate 30 are the same as the light guide plate 30 of FIG. 3, a description thereof will be made with reference to FIG. 3.

The liquid crystal panel unit 900 and the LDI unit 910 are also the same as those used in the conventional liquid crystal display device.

FIG. 9 is a view for explaining a possible embodiment when the light guide plate according to the embodiment of the present invention is actually applied to an LCD TV. Since the auxiliary light guide part 330 is formed longer than the main light guide part 300, A predetermined space is formed on the back surface of the LCD panel 900 where the liquid crystal panel unit 900 is positioned. Even if the light source unit 305 is long, if the LDI unit 910 is placed in the space, Thickness is thinner than the conventional direct lowering method.

 While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is to be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

According to the LCD backlight unit according to the embodiment of the present invention, the height of the light source unit for generating light can be increased, and the number of lamps installed in the light source unit can be increased. As a result, the luminance can be increased with the increase of the lamp. This makes it possible to apply the edge type backlight unit which can be slim rather than the direct-down type to a large-screen liquid crystal display for TV while maintaining a high luminance.

Claims (13)

A main light portion for converting the light incident from the side surface into a uniform surface light and emitting the light to an upper surface; And A first surface adjacent to a side surface of the main light emitting portion, a second surface parallel to the first surface and having a height larger than a height of the first surface, And an auxiliary light guiding part having a second surface to be incident and connection surfaces connecting the first surface and the second surface. A main light portion for converting the light incident from the side surface into a uniform surface light and emitting the light to an upper surface; And A first surface adjacent to a side surface of the main light emitting portion and a second surface adjacent to the light source portion and having an inclination with respect to the first surface and a width larger than a height of the first surface, And an auxiliary light guiding part having a second surface to be incident, and connection surfaces connecting the first surface and the second surface. 3. The method according to claim 1 or 2, And the connection surfaces of the auxiliary light guide portions are subjected to a reflection surface treatment for reflecting light. 3. The method according to claim 1 or 2, Wherein a dot is formed on a lower surface of the main light guide portion facing the upper surface, and a figure having a predetermined shape is formed in the dot. 5. The method of claim 4, Wherein the figure is a prism-shaped light guide plate. 3. The method according to claim 1 or 2, Wherein the connection surfaces of the auxiliary light guide portion are formed of a flat or curved surface or a combination thereof. 3. The method of claim 2, Wherein a cross section of the auxiliary light guide portion is one of a triangle, a trapezoid, a polygon, or a curved line. 3. The method according to claim 1 or 2, Wherein a side surface of the main light guide part and a first surface of the auxiliary light guide part are physically separated from each other. 3. The method according to claim 1 or 2, Wherein a side surface of the main light guide part and a first surface of the auxiliary light guide part are physically coupled to each other. delete A light guide plate comprising a main light guide part and an auxiliary light guide part according to claim 1 or 2; And a light source disposed on a side surface of the light guide plate. 12. The method of claim 11, Wherein the light source unit comprises a lamp of one of a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED). A light guide plate comprising a main light guide part and an auxiliary light guide part according to claim 1 or 2; A light source unit disposed on a side surface of the auxiliary light guide; A liquid crystal panel part provided so as to face a front part of the main light emitting part through which light is emitted; And And an LDI (LCD Driving IC) portion provided in a space between the auxiliary light-guiding portions under the main light-emitting portion.

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