KR20120130869A

KR20120130869A - Liquid Crystal Display Device

Info

Publication number: KR20120130869A
Application number: KR1020110048896A
Authority: KR
Inventors: 임경호
Original assignee: 엘지디스플레이 주식회사
Priority date: 2011-05-24
Filing date: 2011-05-24
Publication date: 2012-12-04

Abstract

The present invention relates to a liquid crystal display device which improves the efficiency of light emitted from a lower polarizing plate by using a light collecting structure. The present invention relates to a liquid crystal display device comprising: a first substrate and a second substrate facing each other; and a pixel region intersecting with each other formed on the first substrate; A plurality of gate lines and data lines defined therein, a common line adjacent to and parallel to each of the gate lines, a black matrix layer covering the gate lines, the common lines, and the data lines on the second substrate; A color filter layer formed on the second substrate at least in correspondence with the pixel region; a liquid crystal layer formed between the first substrate and the second substrate; and positioned below the first substrate, the light being directed toward the first substrate. A backlight unit to transmit the light; And a light collecting part corresponding to the gate line and the common line on the backlight unit.

Description

Liquid Crystal Display Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device in which an efficiency of light emitted from a lower polarizing plate is improved by using a light collecting structure.

In the era of full-fledged informatization, the display field for visually expressing electrical information signals has been rapidly developed. In response, various flat display devices having excellent performance of thinning, light weight, and low power consumption have been developed. Device has been developed to quickly replace the existing cathode ray tube (CRT).

Specific examples of such a flat panel display include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electroluminescent display device. (Electro luminescence Display Device: ELD) and the like, these are commonly used as an essential component of a flat panel display panel that implements an image, a flat panel display panel has a pair of light emitting or polarizing material layer in between It has a configuration in which a transparent insulating substrate is faced and bonded together.

In a liquid crystal display device, an image is displayed by adjusting the light transmittance of a liquid crystal using an electric field. To this end, the image display apparatus includes a display panel having a liquid crystal cell, a backlight unit for irradiating the display panel with light, and a drive circuit for driving the liquid crystal cell.

Active LCD liquid crystal display (AMLCD) is the mainstream in the field of the liquid crystal display device, in which one thin film transistor (TFT) defines one pixel. One TFT controls the voltage level of the pixel as a switching element to change the light transmittance of the pixel to display an image.

A general liquid crystal display device includes a liquid crystal panel in which a plurality of TFTs are provided in a matrix form to display an image, a gate driver controlling input of a data signal to the liquid crystal panel, a data driver outputting a data signal to the liquid crystal panel, And a backlight controller for controlling the timing of each driver, and a backlight unit for irradiating light to the liquid crystal panel, the backlight unit being configured on a rear surface of the liquid crystal panel to perform visual display of data signals. And a backlight controller for controlling the backlight unit. In addition, the above configuration is supplied with driving power by a power supply unit for supplying suitable power required for driving, respectively, and each control unit is generally integrated on a printed circuit board (PCB).

The backlight unit may be one or more fluorescent lamps or a plurality of light emitting diodes (LEDs).

Meanwhile, the liquid crystal panel is divided into a display area in which two substrates are bonded to each other, a thin film transistor is formed to display an image, and a non-display area in which a driver and a signal wiring are formed.

More specifically, the display area is formed by crossing a plurality of gate lines and data lines in a matrix form, and a TFT (thin film transistor) is provided at a point where the gate lines and the data lines intersect.

The gate driver and the data driver receive a scan signal and a data signal from the outside and control the TFT of the display area through the gate line and the data line to change the light transmittance of the liquid crystal.

The timing controller and the power supply unit are mounted on a separate PCB substrate and connected to the gate driver and the data driver, and a backlight unit is provided on the rear surface of the liquid crystal panel.

However, there is a problem in that a light blocking portion that does not transmit light is absorbed in the lower substrate and the upper substrate constituting the liquid crystal panel, and the light transmitted from the lower backlight unit to the upper portion in the area occupied by the light blocking portion is not fully utilized.

The conventional liquid crystal display device has the following problems.

Structurally, the wiring region of the thin film transistor array of the lower substrate or the black matrix layer portion of the upper substrate is a region where the light is transmitted from the backlight unit. In this case, the transmittance is low, the light efficiency of the backlight unit is lowered, there is a problem of increased power consumption according to the decrease in brightness.

The present invention has been made to solve the above problems, and an object thereof is to provide a liquid crystal display device which improves the efficiency of light emitted from the lower polarizing plate by using a light collecting structure.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a first substrate and a second substrate facing each other; a plurality of gate lines and data lines defining pixel regions crossing each other formed on the first substrate; And a common line adjacent to and parallel to each of the gate lines; and a black matrix layer covering the gate line, the common line, and the data line on the second substrate; A color filter layer formed on a second substrate; a liquid crystal layer formed between the first substrate and the second substrate; and a backlight unit positioned below the first substrate and transmitting light to the first substrate; And a light collecting part corresponding to the gate line and the common line on the backlight unit.

First and second polarizing plates may be further attached to the lower side of the first substrate and the upper side of the second substrate, respectively. The light collecting part may be included in the first polarizing plate. In this case, the light collecting part may be included inside the outer protective film forming the first polarizing plate.

In addition, an optical film may be further included between the lower portion of the first polarizing plate and the backlight unit. In this case, the light collecting part may be included in the optical film. In more detail, the light collecting part may be included inside the base film of the optical film.

The light collecting part may be formed of a reflective film or a diffraction grating pattern. When the light collecting part is a reflective film, it may include silver (Ag) or silicon (Si).

The light collecting part may correspond to an area including the gate line and the common line and a spaced area between the gate line and the common line.

The light converging portion may be equal to or smaller than the width of the black matrix layer in a horizontal direction.

Another liquid crystal display of the present invention for achieving the same object includes: a first substrate and a second substrate facing each other, and a gate line and a data line crossing each other formed on the first substrate to define pixel regions; And a black matrix layer covering the gate line and the data line on the second substrate; a color filter layer formed on the second substrate corresponding to at least the pixel region; and the first substrate and the second substrate. A liquid crystal layer formed between the substrates and a backlight unit positioned below the first substrate to transmit light to the first substrate; And a light collecting part formed on the backlight unit to correspond to the gate line.

The liquid crystal display of the present invention as described above has the following effects.

By arranging a light collecting structure using a reflective structure or a diffraction grating structure at a portion corresponding to the light blocking portion of the first substrate, the light path is adjusted to be diffracted or reflected by adjusting the path of the light shielded so that light can be transmitted back to the pixel, thereby providing a substantial aperture ratio. Can improve. As a result, the transmittance of the pixel region is improved, and the luminance can be improved, thereby improving the power consumption.

1 is a plan view showing a second substrate of the liquid crystal display of the present invention;
FIG. 2 is a plan view illustrating a first substrate corresponding to FIG. 1.
3 is a plan view of one pixel of the liquid crystal display of the present invention;
4 is a cross-sectional view taken along the line of the data line of FIG.
5 is a cross-sectional view of a liquid crystal display according to a first exemplary embodiment of the present invention.
6 and 7 are detailed cross-sectional views showing an application example of the first embodiment of the present invention.
8 is a cross-sectional view of a liquid crystal display according to a second exemplary embodiment of the present invention.
9 and 10 are detailed cross-sectional views showing an application example of the second embodiment of the present invention.

Hereinafter, the liquid crystal display of the present invention will be described in detail with reference to the accompanying drawings.

1 is a plan view illustrating a second substrate of a liquid crystal display of the present invention, and FIG. 2 is a plan view illustrating a first substrate corresponding to FIG. 1.

As shown in FIG. 1, in the liquid crystal display device of the present invention, a color filter layer 202 is formed on the second substrate corresponding to the non-pixel region and corresponding to the black matrix layer 201 and at least the pixel region. The components on the second substrate are collectively called a color filter array.

A column spacer 204 is formed on the horizontal line of the black matrix layer 201 to maintain the cell gap of the liquid crystal layer between the first and second substrates.

Here, the black matrix layer 201 may be formed such that horizontal lines correspond to horizontal metal lines on opposite first substrates such as gate lines and common lines, and vertical lines may face first substrates. It is formed corresponding to the data line of the image.

The shape of the black matrix layer 201 is different from the vertical lines in one direction in a state in which the vertical lines of the black matrix layer 201 are bent at the center of each pixel region. The vertical line of the black matrix layer 201 is along the shape of the data line on the first substrate and may be changed according to the shape of the data line. In this case, the data line has a shape that is bent at the center for each pixel area, and is used to secure a wide viewing angle useful for both the upper and lower portions.

As shown in Fig. 2, the liquid crystal display device of the present invention is characterized in that the light collecting portion using the light reflection effect or the diffraction effect is positioned in the horizontal metal line forming portion 10. Here, the horizontal metal line forming portion 10 corresponds to the horizontal line of the black matrix layer formed on the second substrate.

Here, the reason why the light collecting part is disposed in a region corresponding to the horizontal metal lines formed on the first substrate is that the width of the portion has a wider width by focusing on a region smaller than the metal lines in the vertical direction. This is because the effect of misalignment with the light collecting portion is small and the light collecting efficiency is high.

For example, referring to the IPS model illustrated in FIG. 3, the area of the data line occupies about 10.6% of the entire pixel, and the area covering the gate line and the common line is about 13%. It can be seen that the area corresponding to the common line is larger.

In FIG. 2, reference numeral 20, which is not described in FIG. 2, is a region excluding a metal line of a horizontal line, and includes a pixel region and a data line forming portion in a vertical line direction.

On the other hand, the light collecting unit is positioned between the backlight unit below the first substrate. In this case, it may be included in the polarizing plate positioned below the first substrate, and preferably included in the optical film on the backlight unit. However, in some cases, the light collecting portion may be located on the back side of the first substrate, or may be located on the first substrate before the thin film transistor array is formed.

Hereinafter, specific examples of the liquid crystal display device of the present invention will be described.

3 is a plan view of one pixel of the liquid crystal display of the present invention, and FIG. 4 is a cross-sectional view taken along the data line of FIG. 3.

3 and 4, the liquid crystal display of the present invention crosses the first substrate 100 and the second substrate (see 200 in FIG. 5) that are opposed to each other, and are formed on the first substrate 100. On the second substrate 200, a plurality of gate lines 101 and data lines 102 defining a pixel area, a common line 111 adjacent to and parallel to each of the gate lines 101, and the second substrate 200. A black matrix layer (see 201 of FIG. 1) covering the gate line, the common line and the data line, a color filter layer (see 202 of FIG. 1) formed on the second substrate 200 at least corresponding to the pixel region; The liquid crystal layer 150 formed between the first substrate 100 and the second substrate 200 and a backlight unit positioned below the first substrate 100 to transmit light to the first substrate 100. A light concentrator 310 corresponding to the gate line and the common line is included on the backlight unit 400 and the backlight unit 400. Than it has done.

The illustrated model shows the IPS mode, in which the pixel electrode 103 and the common electrode 122 are alternately arranged in parallel with the data line in the pixel area. Here, the pixel electrode 103 and the common electrode 122 are made of a transparent electrode formed on the same layer.

At the intersection of the gate line 101 and the data line 102, the gate electrode 101a protruding from the gate line 101 and the semiconductor layers 113a and 113 covering the gate electrode 101a and A thin film transistor including a same layer), a source electrode 102a protruding from the data line 102, and a drain electrode 102b spaced apart from the source electrode 102a.

The common line 111 may be formed at a lower boundary and / or an upper boundary of the pixel area. In the illustrated figure, a common line 111 is illustrated at a lower boundary of the pixel region, and a common electrode branch pattern 123 connecting the common electrode 103 is formed at an upper boundary of the pixel region. Here, the common line 111 is a metal line on the same layer as the gate line 101, and the common electrode branch pattern 123 is a transparent electrode component integrated with the common electrode 122. For the electrical connection between the common line 111, the common electrode branch pattern 123, and the common electrode 122, the common light blocking pattern 121 overlapping the edge of the data line 102 is formed at both boundaries of the pixel area. Is formed more. The common light blocking pattern 121 is integrally connected to the common line 111, overlaps with one side of the common electrode branch pattern 123, and has an electrical connection through the first contact hole 125a.

The common electrode 122 is branched from the common line 111, and the pixel electrode 103 is formed in contact with the drain electrode 102b and alternately positioned with the common electrode 103. In this case, the pixel electrode 103 may partially overlap the common line 111.

Meanwhile, a pixel electrode branch pattern 133 is formed to partially cover the upper portion of the common line 111 and branch the pixel electrode 103.

The semiconductor layer 113 is further formed under the data line 102 by using the same mask.

A redundancy pattern 123a is further formed on both sides of the data line 102 and overlaps with the common light blocking pattern 123, and has a width wider than that of the common light blocking pattern 121.

In addition, a gate insulating layer 105 is formed on the first substrate 100 to cover the gate line 101, the common line 111, and the common light blocking pattern 121.

The semiconductor layer 113, the data line 102, and the source / drain electrodes 102a and 102b are formed on the gate insulating layer 105, and the interlayer insulating layer 106 covering them is formed.

The common electrode branch pattern 123 is formed on the interlayer insulating layer 106 so that the pixel electrode 103 made of a transparent electrode and the common electrode 122 alternate with each other, and branch the common electrode 122. A pixel electrode branch pattern 133 is formed to branch the pixel electrode 103. In addition, a redundancy pattern 123a overlapping the common light blocking pattern 121 is further formed on the same layer.

The liquid crystal display of the present invention corresponds to a metal line in a horizontal direction adjacent to each other such as the common line 111 and the gate line 101, and has a light collecting portion. It may be included anywhere in the first substrate 100, the polarizing plate or the optical film.

The above-described liquid crystal display is implemented in the IPS mode, but is not necessarily limited thereto. The TN mode, the VA mode, or the FFS mode may be changed. In addition, as a mode using light emitted from the backlight unit, any type of structure may be used to increase the light collection efficiency corresponding to the light blocking portion.

The light converging portion corresponds to a region including the common line, the gate line, and a region therebetween. In this case, when there is one common line for each pixel, the light collecting unit occupies a substantial area in the width between the gate lines spaced apart from each other and the non-adjacent outer edge lines of the common line, and the common line is disposed above and below the pixel area. If each is disposed at the boundary, it occupies a considerable area in the width between the gate line and the edge line of both adjacent common lines. In any case, it is assumed that the common line is made of a metal line.

5 is a cross-sectional view illustrating a liquid crystal display device according to a first embodiment of the present invention.

As shown in FIG. 5, the liquid crystal display according to the first exemplary embodiment of the present invention includes a light collecting part 310 in the first polarizing plate 161 disposed under the first substrate 100. In the liquid crystal display according to the first exemplary embodiment, a first polarizing plate 161 and a second polarizing plate 162 are attached to the rear surfaces of the first and second substrates 100 and 200, respectively.

In this case, the light collecting part 310 corresponds to the horizontal metal line forming part 10 on the first substrate 100. The black matrix layer 201 corresponds to the second metal substrate 200 corresponding to the horizontal metal line forming unit 10.

In addition, an optical film 350 and a backlight unit 400 are disposed under the first polarizing plate 161 including the light collecting part 310.

Here, the light source used in the backlight unit 400 is not limited to LEDs, fluorescent lamps, etc., the arrangement form can also be used in both edge type or direct type.

6 and 7 are specific sectional views showing an application example of the first embodiment of the present invention.

As shown in FIG. 6, the light collecting part 310 may be provided with a diffraction grating pattern.

Here, the first polarizing plate 161, in order from the bottom, the protective film 1616, the diffraction grating pattern layer 1610, the first TAC 1611, the PVA 1612, the second TAC 1613, and the adhesive layer 1614. ) Is laminated. In the first polarizing plate 161, a release film (not shown) is protected on the adhesive layer 1614 before being attached to the lower side of the first substrate 100. The adhesive layer 1614 is attached to the back surface of the first substrate 100 directly.

Here, the PVA 1612 is actually an optical layer that has a transmission axis optically and has a polarization function, and the first and second TACs 1611 and 1613 function as an optical protective layer that protects the PVA 1612 up and down.

In addition, the diffraction grating pattern layer 1610 is positioned inside the passivation layer 1616. In particular, the diffraction grating pattern is disposed corresponding to the horizontal metal line forming unit 10 so that the light passing through the diffraction grating pattern among the light transmitted from the lower backlight unit 400 to the upper part is not the linear light 20. The path of light is increased to increase the light efficiency used in the pixel unit 20.

7 shows another embodiment of the first embodiment of the present invention, in order from the bottom, the protective film 1626, the reflective film 1620, the first TAC 1621, the PVA 1622, the second TAC 1623, The adhesive layer 1624 is laminated. 6, the reflective film 1620 is disposed in the first polarizing plate 161 instead of the diffraction grating pattern layer. In this case, the reflective structure of the reflective film 1620 corresponds to the horizontal metal line forming portion 10. For example, the reflective structure may have a texture of irregularities that can adjust an optical path of light. It may be patterned or may be achieved by arranging the material with a reflective material. For example, the material included in the reflective structure may be silver (Al), silicon (Si), or the like, and may be formed using a reflective metal.

8 is a cross-sectional view of a liquid crystal display according to a second exemplary embodiment of the present invention.

As shown in FIG. 8, the liquid crystal display according to the second exemplary embodiment of the present invention arranges the light collecting part 310 on the optical film 350 on the backlight unit 400 as compared with the first exemplary embodiment described above. . In this case, the light collecting part 310 may be included in a portion of one sheet of the various sheets included in the optical film 350, or may be separately arranged to add a sheet having a reflection or diffraction grating function. Can be.

Specific embodiments will be described with reference to the drawings of FIGS. 9 and 10. The illustrated figure shows a form in which the light collecting part is added in the form of a sheet.

The description of the unexplained signs will be the same as the description of the above-described first embodiment.

9 and 10 are specific sectional views showing an application example of the second embodiment of the present invention.

As shown in FIG. 9, an application example of the second embodiment of the present invention shows a form in which a diffraction grating pattern 3512 is provided on a base film 350 in correspondence with the metal wiring in the horizontal direction of the first substrate. . A protective film 3313 is further formed on the base film 350 including the diffraction grating pattern 3512 to protect the diffraction grating pattern 3512 from the outside.

Another application of the second embodiment of the present invention of FIG. 10 is to replace the reflective structure 3352 at the portion corresponding to the diffraction grating pattern 3512 compared to FIG. 9. Here, the remaining portions except the reflective structure 3352 may be filled with a transparent adhesive layer or a transparent layer may be positioned. The reflective structure 3352 is formed using a structure and a material forming the reflective film 1620 of FIG. 7.

As described above, the light converging portion of the present invention includes a diffraction grating structure or a reflective structure to include a polarizing plate or an optical film, and further includes a separate layer, and corresponds to a region partially corresponding to metal wiring in a component included in the liquid crystal display device. In this case, part of the light blocked by the metal wiring by the diffraction or reflection effect of the light is diffracted or reflected back to the pixel region. As a result, the light efficiency can be improved, and at least 50% or more of light can be recycled, corresponding to the light converging region, thereby improving transmittance, thereby reducing power consumption according to brightness.

In particular, in the case of the reflective structure, the efficiency of 90% or more of the light collecting area is recyclable. For example, when the opening ratio is 63% in the IPS structure as shown in FIG. 3, the recyclable efficiency of the horizontal wiring formation area corresponding to about 13% of the area becomes 90% or more when using the reflective structure, thereby improving the opening ratio of 11.7%. Have Therefore, when the liquid crystal display device of the present invention is applied, the aperture ratio is approximately 74.7%.

On the other hand, the numerical values of the aperture ratios presented above are for specific models only, and not all effects of the present invention are attributed thereto. It is meaningful to improve the light efficiency by turning the path of the light absorbed into the light-shielded area by forming the light collecting part of the present invention to transmit the light to the pixel area by reflection or diffraction.

The above-described liquid crystal display device can be used for all types of LCD structure including a backlight unit under the first substrate, and there are no limitations on the size of the application that can be used, and can be used for mobile, notebook, monitor, TV, and public display. It can be used for both.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

10: horizontal metal line forming portion 20: pixel region
100: first substrate 101: gate line
111: common line 102: data line
161: first polarizing plate 162: second polarizing plate
200: second substrate 201: black matrix layer
202: color filter layer 310: light collecting part
350: optical sheet 400: backlight unit

Claims

A first substrate and a second substrate facing each other;
A plurality of gate lines and data lines intersecting each other formed on the first substrate to define a pixel area;
A common line adjacent and parallel to each gate line;
A black matrix layer covering the gate line, the common line and the data line on the second substrate;
A color filter layer corresponding to at least a pixel area and formed on the second substrate;
A liquid crystal layer formed between the first substrate and the second substrate;
A backlight unit positioned below the first substrate to transmit light to the first substrate; And
And a light collecting part corresponding to the gate line and the common line on the backlight unit.

The method of claim 1,
A first and a second polarizing plate are further attached to the lower side of the first substrate and the upper side of the second substrate, respectively.

The method of claim 2,
And the light collecting part is included in the first polarizing plate.

The method of claim 2,
And a further optical film between the lower part of the first polarizing plate and the backlight unit.

5. The method of claim 4,
And the light collecting part is included in the optical film.

The method of claim 1,
And the light collecting part is a reflective film.

The method according to claim 6,
The reflective film includes silver (Ag) or silicon (Si).

The method of claim 1,
And the light collecting part is formed of a diffraction grating pattern.

The method of claim 3,
And the light collecting part is included inside an outer passivation layer forming the first polarizing plate.

6. The method of claim 5,
The light converging unit is included in the base film of the optical film.

The method of claim 1,
And the light collecting part corresponds to an area including the gate line and the common line, and a spaced area between the gate line and the common line.

The method of claim 1,
And the light collecting part is equal to or smaller than a width in a horizontal direction of the black matrix layer.

A first substrate and a second substrate facing each other;
A gate line and a data line crossing each other formed on the first substrate to define a pixel area;
A black matrix layer covering the gate line and the data line on the second substrate;
A color filter layer corresponding to at least a pixel area and formed on the second substrate;
A liquid crystal layer formed between the first substrate and the second substrate;
A backlight unit positioned below the first substrate to transmit light to the first substrate; And
And a light collecting part formed on the backlight unit to correspond to the gate line.

The method of claim 13,
A first and a second polarizing plate are further attached to the lower side of the first substrate and the upper side of the second substrate, respectively.

The method of claim 14,
And the light collecting part is included in the first polarizing plate.

The method of claim 14,
And a further optical film between the lower part of the first polarizing plate and the backlight unit.

17. The method of claim 16,
And the light collecting part is included in the optical film.

The method of claim 13,
And the light collecting part is a reflective film.

19. The method of claim 18,
The reflective film includes silver (Ag) or silicon (Si).

The method of claim 13,
And the light collecting part is formed of a diffraction grating pattern.

16. The method of claim 15,
And the light collecting part is included inside an outer passivation layer forming the first polarizing plate.

18. The method of claim 17,
The light converging unit is included in the base film of the optical film.