KR101637877B1 - Liquid Crystal Display Device - Google Patents

Abstract

The liquid crystal display device includes a lower substrate, an upper substrate, and a liquid crystal layer formed between the both substrates. The liquid crystal display device includes a first sub pixel region driven in a mode for adjusting a viewing angle, And a second sub-pixel region driven in a mode for displaying the first sub-pixel region, wherein the first sub-pixel region is provided with a light blocking portion for blocking light transmission in the active region,

According to the present invention, since the light blocking portion is formed in the active region of the first sub-pixel region driven by the mode for adjusting the viewing angle for information protection, the light leakage generated in the front direction can be minimized, The image quality in a state in which the viewing angle for protection is adjusted is improved.

Information protection, viewing angle, light blocking part

Description

[0001] The present invention relates to a 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 suitable for use in protecting information from a person in a side seat in a moving means.

Liquid crystal display devices have a wide range of applications ranging from mobile phones, notebook computers, monitors, spacecrafts and aircraft to the advantage of low operating voltage and low power consumption and being portable.

The liquid crystal display device includes a lower substrate, an upper substrate, and a liquid crystal layer formed between the two substrates. The arrangement of the liquid crystal layers is adjusted according to whether an electric field is applied or not, .

Meanwhile, in recent years, a liquid crystal display device to which a specific function has been added to meet various demands of a consumer has been developed. As one of them, a liquid crystal display device capable of adjusting a viewing angle to protect information from a person in a side seat is being developed when a notebook or the like is used in a moving means such as a train or an airplane.

That is, in general, a liquid crystal display device has been developed to have a wide viewing angle capable of viewing images not only in the front direction but also in the left and right side directions. However, recently, in order to protect privacy, A liquid crystal display device has been developed which has a function of making it possible to see the liquid crystal display device.

In the conventional liquid crystal display device having the function of allowing the image to be viewed only on the front surface as described above, the ECB (Electronically Controlled Birefringence) mode is additionally provided in the pixel together with the existing mode so that the viewing angle is adjusted It is designed to be able to view images only in the front direction.

More specifically, when the ECB mode does not operate, an image is displayed according to a conventional mode so that an image can be seen not only in the front direction but also in the left and right side directions. However, when the ECB mode operates, So that the image can be seen according to the conventional mode and light leakage occurs in the left and right side directions, so that the image can not be seen.

However, in such a conventional liquid crystal display device, when the ECB mode is operated, predetermined light leakage occurs even in the frontal direction, and the quality of the image in the frontal direction is deteriorated. That is, when a user views an image in the front direction of a liquid crystal display device, a vertical viewing angle is maintained with respect to the central portion of the image, but the vertical state is not maintained with respect to the corner portion of the image, Therefore, due to such an influence, predetermined light leakage occurs in the frontal direction and the quality of the image is deteriorated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display device capable of adjusting a viewing angle in order to protect information from a person in a side seat in a moving means, It is an object of the present invention to provide a liquid crystal display device in which quality of an image is improved by preventing light leakage occurring in a front direction.

In order to achieve the above object, the present invention provides a liquid crystal display device including a lower substrate, an upper substrate, and a liquid crystal layer formed between the two substrates, wherein the liquid crystal display device includes a first And a second sub-pixel region driven in a mode for displaying an image, wherein the first sub-pixel region is provided with a light shielding portion in the active region for shielding light transmission, A display device is provided.

A black matrix for defining the active region and a first electrode for forming an electric field are formed on the upper substrate of the first sub-pixel region, and a first electrode for applying a signal to the lower substrate of the first sub- 1 wiring and a second electrode for forming a vertical electric field together with the first electrode are formed.

A black matrix for defining the active region and a color filter for implementing color are formed on the upper substrate of the second sub pixel region and a second color pixel for applying a signal is formed on the lower substrate of the second sub pixel region, A third electrode and a fourth electrode for forming wiring and a horizontal electric field are formed.

The light blocking portion included in the first sub-pixel region may be formed on the upper substrate. In particular, the light blocking portion may be formed of the same material as the black matrix. In addition, the light blocking portion may be formed as a straight line or a curved straight line at the central portion of the active region.

The width of the first wiring formed on the lower substrate of the first sub-pixel region may be greater than the width of the second wiring formed on the lower substrate of the second sub-pixel region. In addition, the first wiring formed on the lower substrate of the first sub-pixel region may extend to the inside of the active region.

The third electrode and the fourth electrode formed on the lower substrate of the second sub-pixel region may be alternately arranged in parallel with each other, and may be spaced apart with an insulating layer interposed therebetween.

A color filter may be additionally formed on the upper substrate of the first sub-pixel region.

According to the present invention as described above, the following effects can be obtained.

According to the present invention, since the light blocking portion is formed in the active region of the first sub-pixel region driven by the mode for adjusting the viewing angle for information protection, the light leakage generated in the front direction can be minimized, The image quality in a state in which the viewing angle for protection is adjusted is improved.

In addition, according to the present invention, since the first wiring formed in the first sub-pixel region is extended to the inside of the active region, the light leakage in the front direction is prevented while adjusting the viewing angle for information protection, do.

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

1A and 1B are schematic sectional views of a liquid crystal display device according to an embodiment of the present invention. FIG. 1A shows a state in which a viewing angle for information protection is adjusted. FIG. 1B shows a state in which a viewing angle is not adjusted Respectively.

1A and 1B, a liquid crystal display according to an exemplary embodiment of the present invention includes an upper substrate 100, a lower substrate 300, and a liquid crystal layer 500 formed between the substrates 100 and 300, .

The liquid crystal display according to an embodiment of the present invention includes a first sub-pixel region driven in a mode for adjusting a viewing angle for information protection and a second sub-pixel region driven in a mode for displaying an image, The first sub-pixel region and the second sub-pixel region each include the lower substrate 100, the upper substrate 300, and the liquid crystal layer 500.

Hereinafter, a general configuration of a liquid crystal display device according to an embodiment of the present invention will be described, and then, the first sub pixel area and the second sub pixel area will be separately described.

First, the overall configuration of a liquid crystal display device according to an embodiment of the present invention will be described.

An upper polarizer 110 is formed on one surface of the upper substrate 100 and a lower polarizer 310 is formed on a lower surface of the lower substrate 300.

Each of the upper polarizer 110 and the lower polarizer 310 is formed to have a predetermined optical axis. The optical axis of the upper polarizer 110 and the optical axis of the lower polarizer 310 may be perpendicular to each other.

A black matrix 120 is formed on the other surface of the upper substrate 100. The black matrix 120 serves to prevent light from leaking to an area other than the active area, and the black matrix 120 defines an active area. Herein, the term 'active area' refers to an area defined by the black matrix 120, that is, an area inside the black matrix 120.

A color filter 130 is formed in the active region defined by the black matrix 120. The color filter 130 may be made of red (R), green (G), or blue (B) pigments.

In addition, the light blocking portion 200 is formed in the active region defined by the black matrix 120. Since the light shield 200 is formed in the active area, the quality of the image can be improved by preventing the light leakage in the front direction while the viewing angle for information protection is adjusted. The description will be given later. The light shielding part 200 may be formed of the same material as the black matrix 120.

An overcoat layer 140 is formed on the entire other surface of the upper substrate 100 including the black matrix 120 and a first electrode 150 is formed on the overcoat layer 140. The first electrode 150 forms a vertical electric field together with the second electrode 330 formed on the lower substrate 300 to be described later.

An element layer 320 is formed on the other surface of the lower substrate 300. Wirings 321 and 322 for applying a signal are formed in the device layer 320. The wirings 321 and 322 include a gate wiring for applying a gate signal and a data wiring for applying a data signal. Though not shown, a thin film transistor is formed in the element layer 320 as a switching element. The thin film transistor includes a gate electrode, a semiconductor layer, a source electrode, and a drain electrode.

A second electrode 330, a third electrode 340, and a fourth electrode 350 are formed on the device layer 320.

The second electrode 330 forms a vertical electric field together with the first electrode 150 formed on the upper substrate 100. The third electrode 340 and the fourth electrode 350 form a horizontal electric field.

The first electrode 150 and the fourth electrode 350 function as a common electrode and the second electrode 340 and the third electrode 340 serve as pixel electrodes The first electrode 150, the second electrode 330, the third electrode 340 and the fourth electrode 350 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO) ZnO (Zinc Oxide), or the like.

Next, the first sub-pixel region and the second sub-pixel region included in the liquid crystal display device according to an embodiment of the present invention will be described.

The first sub-pixel region is driven in a mode for adjusting a viewing angle for information protection, for example, an ECB (Electronically Controlled Birefringence) mode.

A black matrix 120 is formed on the upper substrate 100 of the first sub pixel region and a light blocking portion 200 is formed in an active region defined by the black matrix 120, An overcoat layer 140 is formed on the matrix 120 and the light shielding part 200 and a first electrode 150 is formed on the overcoat layer 140. As described above, although no color filter is formed on the upper substrate 100 of the first sub-pixel region, a color filter is not necessarily formed, but a color filter is formed on the upper substrate 100 of the first sub-pixel region It is possible.

An element layer 320 including a first wiring 321 and a thin film transistor (not shown) is formed on the lower substrate 300 of the first sub pixel region, and a second electrode 330 are formed. The second electrode 330 is connected to the thin film transistor and functions as a pixel electrode.

The second sub-pixel region is driven in a mode for displaying an image, for example, an IPS (In-Plane Switching) mode.

A black matrix 120 is formed on the upper substrate 100 of the second sub pixel region and a color filter 130 is formed in an active region defined by the black matrix 120, An overcoat layer 140 is formed on the transparent substrate 130. In general, in order to display an image, one pixel region is required which is constituted by a combination of a red (R) sub pixel region, a green (G) sub pixel region, and a blue (B) sub pixel region, The second sub-pixel region shows only one sub-pixel region of the pixel region for displaying an image.

An element layer 320 including a second wiring 322 and a thin film transistor (not shown) is formed on the lower substrate 300 of the second sub-pixel region. A third electrode 340 and a fourth electrode 350 are formed. The third electrode 340 is connected to the thin film transistor to function as a pixel electrode. Although the third electrode 340 and the fourth electrode 350 are formed in the same layer in the drawing, the third electrode 340 and the fourth electrode 350 are not necessarily formed in the same layer. The third electrode 340 and the fourth electrode 350 may be formed in different layers, The third electrode 340 and the fourth electrode 350 may be variously modified according to the IPS mode of the IPS mode.

A method of controlling the viewing angle for information protection through the operation of the liquid crystal display device according to the present invention will be described below.

1A shows a state in which a viewing angle for information protection is adjusted. That is, FIG. 1A shows a state in which both a first sub-pixel area driven in a mode for adjusting a viewing angle for information protection and a second sub-pixel area driven in a mode for displaying an image are on .

A horizontal electric field is generated between the third electrode 340 and the fourth electrode 350 formed on the lower substrate 300 when the second sub pixel region driven in the mode for displaying an image is turned on, So that the liquid crystal layer 500 is arranged in the horizontal electric field direction. When the liquid crystal layer 500 is arranged in the horizontal electric field direction as described above, the polarized light is transmitted through the lower polarizer 310 and the phase retarded light is transmitted through the upper polarizer 110 having the optical axis orthogonal to the lower polarizer 310 And the image is displayed.

On the other hand, when the first sub-pixel region driven in a mode for controlling the viewing angle for information protection is turned on, the first electrode 150 formed on the upper substrate 100 and the first substrate 150 formed on the lower substrate 300 A vertical electric field is formed between the second electrodes 330 formed on the liquid crystal layer 500 and the liquid crystal layer 500 is arranged in the vertical electric field direction. When the liquid crystal layer 500 is arranged in the vertical electric field direction as described above, the light transmittance varies depending on the viewing angle. Specifically, since the phase of the light incident on the long axis of the liquid crystal is not retarded due to the nature of the ECB (Electically Controlled Birefringence) liquid crystal, the polarized light transmitted through the lower polarizer 310 in the front direction is transmitted through the upper polarizer 110 The polarized light passes through the upper polarizer 110 while passing through the lower polarizer 310 in the right and left directions, and light leakage occurs.

Therefore, the image displayed in the second sub-pixel area is displayed as it is because there is no influence due to the first sub-pixel area in the front direction, but light leakage occurs due to the first sub-pixel area in the left and right directions, The image displayed in the two sub-pixel areas is not displayed. As a result, the user can see the image in the front direction but can not see the image in the left and right side directions.

1B shows a state in which the viewing angle for information protection is not adjusted. That is, in FIG. 1B, a first sub-pixel area driven in a mode for controlling a viewing angle for information protection is off, and a second sub-pixel area driven in a mode for displaying an image is on, FIG.

When the first sub-pixel area driven by the mode for adjusting the viewing angle for information protection is turned off, the liquid crystal layer 500 is arranged while maintaining the initial alignment state. In this case, since the light incident from the front direction and the light incident from the left and right side directions are not phase retarded, the polarized light transmitted through the lower polarizer 310 can not transmit through the upper polarizer 110, do.

Therefore, since there is no influence by the first sub-pixel area in both the front direction and the left and right side directions, the image displayed in the second sub-pixel area is displayed as it is. As a result, the user can view the image in both the front direction and the left and right side directions.

On the other hand, as shown in FIG. 1A, in the most ideal case where the viewing angle for information protection is adjusted, light leakage occurs in the first sub pixel area in the right and left directions, So that a predetermined light leakage is actually generated in the front direction, thereby deteriorating the image quality.

That is, when the user views the image in the front direction, the vertical viewing angle is maintained with respect to the central portion of the image, but the vertical state is not maintained with respect to the mother portion of the image and the predetermined inclination angle is formed. For this reason, Light leakage occurs.

However, according to the present invention, since the light blocking part 200 is formed in the active area of the first sub-pixel area, the light leakage generated in the front direction can be minimized, thereby adjusting the viewing angle for information protection The image quality in one state is improved.

A concrete formation of the light blocking portion 200 will be described below.

2A to 2C are schematic plan views showing formation of a light shielding part 200 according to various embodiments of the present invention.

2A to 2C, a black matrix 120 is formed on the upper substrate 100 to define an active region, and the active region includes red (R), green (G), and blue (B) And a color filter 130 are formed. On the other hand, in the active area where the color filter 130 is not formed, the light blocking part 200 is formed.

A first sub-pixel region including the active region in which the light blocking portion 200 is formed is formed and the color filters 130 of red (R), green (G), and blue (B) And the first sub-pixel region and the three second sub-pixel regions are combined to constitute one pixel region. The first sub-pixel region and the second sub-pixel region are combined to form one pixel region.

Although the active region is shown as being curved in the drawing, the active region is not necessarily limited thereto, and the active region may be formed in various shapes known in the art, such as a rectangle.

The light blocking portion 200 is formed in the active region of the first sub-pixel region, in particular, at the central portion of the active region.

2A, the light blocking portion 200 may be formed to extend in the vertical direction of the active region in a curved straight line similar to the shape of the active region, or may be formed in a straight line shape as shown in FIG. Or may extend in the vertical direction of the active region in a straight line shape as shown in FIG. 2C. The light blocking portion 200 may be formed in various shapes at the central portion of the active region, and is not limited to the shapes shown in FIGS. 2A to 2C.

As described above, in the present invention, since the light blocking portion 200 is formed in the active region of the first sub-pixel region, the light leakage in the front direction can be prevented and the image quality can be improved while the viewing angle for information protection is adjusted. In addition, by using the wiring 321 formed on the lower substrate 300 of the first sub-pixel region, the light leakage prevention effect in the front direction can be improved. This will be described below.

3 is a schematic cross-sectional view of a liquid crystal display according to an embodiment of the present invention for enhancing the light leakage prevention effect in the front direction by using a wiring 321 formed on the lower substrate 300. Referring to FIG.

3, a black matrix 120 is formed on the upper substrate 1000 to define an active region, and a first wiring 321 and a second wiring 322 are formed on the lower substrate 300. As shown in FIG.

At this time, the width d1 of the first wiring 321 formed in the first sub-pixel region is formed to be larger than the width d2 of the second wiring 322 formed in the second sub-pixel region.

In addition, the second wiring 322 formed in the second sub-pixel region is not formed inside the active region, but the first wiring 321 formed in the first sub-pixel region extends to the inside of the active region.

Since the first wiring 321 formed in the first sub-pixel region extends to the inside of the active region, the light leakage in the front direction is prevented and the image quality is improved in a state in which the viewing angle for information protection is adjusted .

As a result, according to the present invention, in the first sub-pixel region, light leakage is prevented by the light blocking portion 200 at the central portion of the active region, and light leakage is prevented by the first wiring 321 at the side portion of the active region .

4 is a schematic cross-sectional view of a liquid crystal display according to another embodiment of the present invention, except that the second sub-pixel region is configured to operate in an FFS (Fringe Field Switching) mode, Device. Therefore, the same reference numerals are assigned to the same components, and a detailed description of the same components will be omitted.

Referring to FIG. 4, a third electrode 340 and a fourth electrode 350 formed in the second sub-pixel region are spaced apart from each other with an insulating layer 360 therebetween. Accordingly, the alignment state of the liquid crystal layer 500 is controlled through a fringe field between the third electrode 340 and the fourth electrode 350.

Although the third electrodes 340 are patterned at a predetermined interval on the insulating layer 360 and the fourth electrodes 350 are formed long under the insulating layer 360, The third electrode 340 may be formed long under the insulating layer 360 and the fourth electrode 350 may be patterned at a predetermined interval on the insulating layer 360, The third electrode 340 and the fourth electrode 350 may be variously formed according to a known FFS mode.

1A and 1B are schematic sectional views of a liquid crystal display device according to an embodiment of the present invention. FIG. 1A shows a state in which a viewing angle for information protection is adjusted. FIG. 1B shows a state in which a viewing angle is not adjusted Respectively.

2A to 2C are schematic plan views illustrating formation of a light intercepting portion according to various embodiments of the present invention.

3 is a schematic cross-sectional view of a liquid crystal display device according to an embodiment of the present invention for improving the light leakage prevention effect in the front direction by using a wiring formed on a lower substrate.

4 is a schematic cross-sectional view of a liquid crystal display device according to another embodiment of the present invention.

DESCRIPTION OF THE REFERENCE SYMBOLS

100: upper substrate 120: black matrix

150: first electrode 200: light blocking portion

300: lower substrate 321: first wiring

322: second wiring 330: second electrode

340: third electrode 350: fourth electrode

Claims (10)

A liquid crystal display comprising a lower substrate, an upper substrate, and a liquid crystal layer disposed between the both substrates, Wherein the liquid crystal display comprises a first sub-pixel region driven in a mode for adjusting a viewing angle and a second sub-pixel region driven in a mode for displaying an image, The first sub-pixel region includes a light intercepting portion provided in the active region for blocking light transmission and a first interconnection for applying a signal, A second wiring for applying a signal to the second sub-pixel region, Wherein a width of the first wiring is larger than a width of the second wiring. The method according to claim 1, A black matrix for defining the active region and a first electrode for forming an electric field are provided on the upper substrate of the first sub pixel region and on the lower substrate of the first sub pixel region, A second electrode for forming a vertical electric field together with one electrode is provided, A black matrix for defining the active region and a color filter for implementing color are provided on the upper substrate of the second sub pixel region and the second wiring and the horizontal electric field are formed on the lower substrate of the second sub pixel region, And a third electrode and a fourth electrode for forming the second electrode. 3. The method of claim 2, And a light blocking portion provided in the first sub-pixel region is disposed on the upper substrate. The method of claim 3, And the light blocking portion provided in the first sub-pixel region is made of the same material as the black matrix. The method of claim 3, And the light blocking portion provided in the first sub-pixel region is formed as a straight line or a curved straight line at the center of the active region. delete 3. The method of claim 2, And the first wiring provided on the lower substrate of the first sub pixel region extends to the inside of the active region. 3. The method of claim 2, And the third electrode and the fourth electrode provided on the lower substrate of the second sub-pixel region are alternately arranged in parallel with each other. 3. The method of claim 2, And a third electrode and a fourth electrode provided on the lower substrate of the second sub-pixel region are spaced apart with an insulating layer interposed therebetween. The method according to claim 1, And a color filter is further provided on the upper substrate of the first sub-pixel region.

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