KR101274027B1 - Display panel and display apparatus having the same - Google Patents

Abstract

Disclosed are a display panel assembly capable of selectively adjusting a viewing angle and a display device having the same. The display panel assembly includes a first polarizing axis having a first polarizing plate, a second polarizing plate having a second polarizing axis perpendicular to the first polarizing axis, and a display panel interposed between the first and second polarizing axes. The display panel includes a first substrate having a first pixel electrode to which the first voltage is applied and a second pixel electrode to which the second voltage is applied, and a common electrode disposed to face the first substrate and to which the third voltage is applied. And a liquid crystal layer made of liquid crystal interposed between the second substrate and the first and second substrates. The liquid crystals of the liquid crystal layer are any of a horizontal mode arranged parallel to one of the first and second polarization axes, a vertical mode arranged perpendicularly to the first substrate, and an inclination mode disposed between the first and second polarization axes. It operates in one mode.

Wide viewing angle black, narrow viewing angle black

Description

 DISPLAY PANEL AND DISPLAY APPARATUS HAVING THE SAME [0002]

1 is a perspective view showing a display device according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view of the display device of FIG. 1 taken along line II ′ and illustrating a wide viewing angle black. FIG.

FIG. 2B is a plan view illustrating an arrangement relationship of liquid crystals in FIG. 2A.

FIG. 3A is a cross-sectional view of the display device of FIG. 1 taken along line II ′ and illustrating a narrow viewing angle black.

FIG. 3B is a plan view illustrating an arrangement relationship of liquid crystals in FIG. 3A.

FIG. 4A is a cross-sectional view of the display device of FIG. 1 taken along line II ′ and illustrating white implementation. FIG.

4B is a plan view illustrating an arrangement relationship of liquid crystals in FIG. 4A.

<Explanation of symbols for the main parts of the drawings>

DPA: Display Panel Assembly 100: Display Panel

110: first electrode 112: first pixel electrode

114: second pixel electrode 120: second substrate

122: common electrode 130: liquid crystal layer

200: first polarizing plate 210: first polarizing axis

300: second polarizing plate 310: second polarizing axis

BLA: Backlight Assembly

The present invention relates to a display panel assembly and a display device having the same, and more particularly, to a display panel assembly capable of selectively adjusting a viewing angle and a display device having the same.

Until now, liquid crystal displays have required wide viewing angle characteristics to recognize the same image at various locations. However, as personal information becomes more important and various portable electronic products appear, in some cases, narrow viewing angle characteristics are increasing. In particular, when there is a risk that information is leaked to people around, such as an ATM, a view angle related technology is further required.

Therefore, recently, an additional viewing angle control liquid crystal layer capable of adjusting the viewing angle is added to the existing liquid crystal display. That is, by adding a separate viewing angle control liquid crystal layer to the existing liquid crystal display, both wide viewing angle characteristics and narrow viewing angle characteristics are realized.

However, adding such a separate liquid crystal layer not only increases the thickness of the liquid crystal display but also causes a problem of increasing the product price. Accordingly, it is urgent to develop a liquid crystal display device that can adjust the viewing angle without increasing the thickness and price.

Accordingly, the technical problem of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a display panel assembly capable of adjusting the viewing angle with a single liquid crystal layer.

Another object of the present invention is to provide a display device having the above display panel assembly.

According to an aspect of the present invention, a display panel assembly includes a first polarization axis having a first polarization axis, a second polarization axis having a second polarization axis perpendicular to the first polarization axis, and the first and second polarization axes. And a display panel interposed between the polarization axes.

The display panel includes a first substrate, a second substrate, and a liquid crystal layer. The first substrate includes a first pixel electrode to which a first voltage is applied and a second pixel electrode to which a second voltage is applied. The second substrate is disposed to face the first substrate and includes a common electrode to which a third voltage is applied. The liquid crystal layer is composed of liquid crystals interposed between the first and second substrates, the horizontal liquid crystals are arranged in parallel with any one of the first and second polarization axes, the liquid crystals are the first substrate And a vertical mode arranged perpendicularly with respect to, and an oblique mode in which the liquid crystals are disposed between the first and second polarization axes.

Meanwhile, when the first, second and third voltages are all the same, the liquid crystal layer is operated in the horizontal mode, the first and second voltages are the same, and the third voltage is the first voltage. And when the second voltage is different from the second voltage, the liquid crystal layer is operated in the vertical mode, when the first and second voltages are different from each other, and the third voltage is equal to any one of the first and second voltages. The liquid crystal layer is preferably operated in the tilt mode.

According to another aspect of the present invention, a display device includes a display panel assembly displaying an image and a backlight assembly providing light to the display panel assembly.

The display panel assembly includes a first polarization axis having a first polarization plate, a second polarization plate having a second polarization axis perpendicular to the first polarization axis, and a display panel interposed between the first and second polarization axes.

The display panel includes a first substrate having a first pixel electrode to which a first voltage is applied and a second pixel electrode to which a second voltage is applied, and a common electrode disposed to face the first substrate and to which a third voltage is applied. A horizontal mode comprising a second substrate having a second liquid crystal interposed between the first and second substrates, wherein the liquid crystals are arranged in parallel with one of the first and second polarization axes, and the liquid crystals being And a liquid crystal layer operated in any one of a vertical mode arranged perpendicularly to the first substrate, and an inclined mode in which the liquid crystals are disposed between the first and second polarization axes.

According to the present invention, as the liquid crystal layer interposed between the first and the second substrate not only changes the light transmittance but also the viewing angle, an additional liquid crystal layer is added to control the viewing angle, thereby increasing thickness and cost. Can be prevented.

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

1 is a perspective view showing a display device according to an embodiment of the present invention.

Referring to FIG. 1, the display device according to the present exemplary embodiment includes a display panel assembly DPA for displaying an image and a backlight assembly disposed under the display panel assembly DPA to provide light to the display panel assembly DPA. BLA).

First, the display panel assembly DPA includes a display panel 100, a first polarizer 200, and a second polarizer 300. In this case, the display panel 100 is disposed between the first polarizer 200 and the second polarizer 300.

The first polarizer 200 is disposed under the display panel 100 and has a first polarization axis 210 that polarizes light in a first direction.

The second polarizer 300 is disposed on the display panel 100 and has a second polarization axis 310 that polarizes light in a second direction perpendicular to the first direction.

The display panel 100 includes a first substrate 110, a second substrate 120 disposed to face the first substrate 110, and a liquid crystal interposed between the first substrate 110 and the second substrate 130. Layer 130.

The first substrate 110 is disposed on the first polarizer 200. The first substrate 110 includes a first pixel electrode 112, a second pixel electrode 114, a thin film transistor (not shown), and a signal line (not shown).

The first pixel electrode 112 and the second pixel electrode 114 are made of a transparent conductive material. For example, the first pixel electrode 112 and the second pixel electrode 114 may be, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or amorphous indium oxide. Tin Oxide, a-ITO).

For example, the first pixel electrode 112 and the second pixel electrode 114 are elongated in a third direction, and a plurality of first and second pixel electrodes 112 and 114 are alternately arranged in a fourth direction different from the third direction. In this case, the third and fourth directions are preferably perpendicular to each other.

On the other hand, the third and fourth directions have a direction different from the first and second directions. Preferably, the third direction is inclined at 45 degrees with respect to the first direction.

The thin film transistor is electrically connected to the first pixel electrode 112 and the second pixel electrode 114 to apply a driving voltage to the first pixel electrode 112 and the second pixel electrode 114. The thin film transistor includes a gate electrode, a source electrode, a drain electrode, and a channel layer.

The signal line is electrically connected to the thin film transistor to control the thin film transistor. That is, the signal line includes a gate wire electrically connected to the gate electrode to apply a gate signal, and a data wire electrically connected to the source electrode to apply a data signal.

The second substrate 120 is disposed to face the first substrate 110. The second substrate 120 includes a color filter (not shown) formed to correspond to the first pixel electrode 112 and the second pixel electrode 114, and a common electrode 122 formed on the entire surface of the substrate.

The color filter includes, for example, a red color filter, a green color filter, and a blue color filter. The color filter may be formed on the first substrate 110 instead of on the second substrate 120.

The common electrode 122 is made of the same transparent and conductive material as the first pixel electrode 112 and the second pixel electrode 114. A reference voltage is applied to the common electrode 122, while a voltage equal to or different from the reference voltage is applied to the first pixel electrode 112 and the second pixel electrode 114. For example, 0 V is applied to the common electrode 122, while voltages such as 0 V, + 5 V, and −5 V are applied to the first pixel electrode 112 and the second pixel electrode 114. As a result, an electric field is formed between each of the common electrode 122, the first pixel electrode 112, and the second pixel electrode 114.

The liquid crystal layer 130 is interposed between the first substrate 110 and the second substrate 120 and consists of a plurality of liquid crystals 132. The arrangement of the liquid crystals 132 of the liquid crystal layer 130 is changed by the common electrode 122, the first pixel electrode 112, and the second pixel electrode 114. As such, when the arrangement of the liquid crystals 132 is changed, the transmittance of light incident on the liquid crystal layer 130 is changed to display an image.

Meanwhile, the liquid crystal layer 130 has a horizontal mode in which liquid crystals 132 are arranged in parallel with one of the first polarization axis 210 and the second polarization axis 310, and the liquid crystals 132 are formed on the first substrate 110. The vertical mode arranged vertically with respect to the liquid crystal and the liquid crystals 132 are operated in any one of the gradient modes disposed between the first polarization axis 210 and the second polarization axis 310. In this case, a detailed description of each liquid crystal mode will be described later.

Meanwhile, the backlight assembly BLA is disposed under the display panel assembly PDA. The backlight assembly BLA includes a light source (not shown) for generating light and an optical sheet (not shown) for improving optical characteristics of the light generated by the light source. Examples of the light source include a cold cathode fluorescent lamp (CCFL), a light emitting diode (LED), and the like.

The backlight assembly BLA preferably generates linear light traveling in a direction perpendicular to the first substrate 110. This is because when the light generated by the backlight assembly BLA is straight light perpendicular to the first substrate 110, it helps to accurately implement each liquid crystal mode of the liquid crystal layer 130.

Hereinafter, each liquid crystal mode of the liquid crystal layer 130 will be described using separate drawings.

FIG. 2A is a cross-sectional view of the display device of FIG. 1 taken along line II ′ and illustrating a wide viewing angle black. FIG. FIG. 2B is a plan view illustrating an arrangement relationship of liquid crystals in FIG. 2A.

First, referring to FIGS. 2A and 2B, when the liquid crystal layer 130 is operated in the horizontal mode, the liquid crystals 132 are parallel to either one of the first polarization axis 210 and the second polarization axis 310. Are arranged. For example, in the present exemplary embodiment, the liquid crystals 132 are arranged in parallel with the first polarization axis 210.

Here, in order to operate the liquid crystal layer 130 in the horizontal mode, the same voltage is applied to all of the common electrode 122, the first pixel electrode 112, and the second pixel electrode 114. For example, 0 V is applied to all of the common electrode 122, the first pixel electrode 112, and the second pixel electrode 114. As such, when the same voltage is applied to the common electrode 122, the first pixel electrode 112, and the second pixel electrode 114, no electric field is formed, so that the liquid crystals 132 of the liquid crystal layer 130 Keep the original array. That is, the liquid crystals 132 maintain the shape arranged in parallel with the first polarization axis 210.

Meanwhile, when the liquid crystal layer 130 is operated in the horizontal mode, the display panel assembly DPA realizes a wide viewing angle black image. The process of implementing such a wide viewing angle black image is briefly described as follows.

The unpolarized light generated by the backlight assembly BLA is changed into light polarized in a direction parallel to the first polarization axis 210 while passing through the first polarizer 200. The polarized light is transmitted through the liquid crystal unit 130 operating in the horizontal mode, and is refracted at a predetermined angle without a phase change. That is, the light passing through the liquid crystal part 130 is refracted at a predetermined angle without changing the polarization axis to increase the viewing angle. The transmitted light is blocked by the second polarizer 300 having the second polarization axis 310 perpendicular to the first polarization axis 210 to implement a wide viewing angle black image.

FIG. 3A is a cross-sectional view of the display device of FIG. 1 taken along line II ′ and illustrating a narrow viewing angle black. FIG. 3B is a plan view illustrating an arrangement relationship of liquid crystals in FIG. 3A.

3A and 3B, when the liquid crystal layer 130 is operated in the vertical mode, the liquid crystals 132 are vertically arranged with respect to the first substrate 110.

Here, in order for the liquid crystal layer 130 to operate in the vertical mode, the same arbitrary voltage is applied to the first pixel electrode 112 and the second pixel electrode 114, and the arbitrary voltage is applied to the common electrode 122. A voltage different from is applied.

For example, +5 V or −5 V is applied to the first pixel electrode 112 and the second pixel electrode 114, and 0 V is applied to the common electrode 122. As such, when the voltages are applied to the common electrode 122, the first pixel electrode 112, and the second pixel electrode 114, the electric field is formed in a direction perpendicular to the first substrate 110. As a result, the liquid crystals 132 are vertically arranged with respect to the first substrate 110.

Meanwhile, when the liquid crystal layer 130 is operated in the vertical mode, the display panel assembly DPA realizes a narrow viewing angle black image. The process of implementing the narrow-view angle black image is briefly described as follows.

The unpolarized light generated by the backlight assembly BLA is changed into light polarized in a direction parallel to the first polarization axis 210 while passing through the first polarizer 200. When the polarized light is transmitted through the liquid crystal layer 130 operated in the vertical mode, the polarized light is transmitted without change in phase and refraction. The transmitted light is blocked by the second polarizer 300 having the second polarization axis 310 to implement a narrow viewing angle black image.

FIG. 4A is a cross-sectional view of the display device of FIG. 1 taken along line II ′ and illustrating white implementation. FIG. 4B is a plan view illustrating an arrangement relationship of liquid crystals in FIG. 4A.

Finally, referring to FIGS. 4A and 4B, when the liquid crystal layer 130 is operated in the inclined mode, the liquid crystals 132 are arranged to be inclined between the first polarization axis 210 and the second polarization axis 310. Preferably, the liquid crystals 132 are inclined at an angle of 45 degrees with respect to the first polarization axis 210 when viewed in a plan view.

Here, in order to operate the liquid crystal layer 130 in the inclined mode, different voltages are applied to the first pixel electrode 112 and the second pixel electrode 114, and the first pixel electrode () is applied to the common electrode 122. The same voltage as that applied to any one of 112 and the second pixel electrode 114 is applied.

For example, 0 V is applied to the common electrode 122, + 5 V or − 5 V is applied to the first pixel electrode 112, and 0 V is applied to the second pixel electrode 114. As such, when the voltage is applied to the common electrode 122, the first pixel electrode 112, and the second pixel electrode 114, the first pixel electrode 112 and the second pixel electrode 114 formed adjacent to each other. An electric field is formed between them. At this time, the direction formed in the electric field is formed to face between the first polarization axis 210 and the second polarization axis 310 when viewed in plan view, preferably, inclined at an angle of 45 degrees with respect to the first polarization axis 210. It is preferably formed. As a result, the liquid crystals 132 are inclined at an angle of 45 degrees with respect to the first polarization axis 210 by the electric field.

Meanwhile, when the liquid crystal layer 130 is operated in the tilt mode, the display panel assembly DPA implements a white image. The process of implementing such a white image is briefly described as follows.

The unpolarized light generated by the backlight assembly BLA is changed into light polarized in a direction parallel to the first polarization axis 210 while passing through the first polarizer 200. The polarized light is transmitted through the liquid crystal layer 130 operating in the inclined mode, and the phase is retarded by 90 degrees to be refracted at a predetermined angle. That is, the light transmitted through the liquid crystal layer 130 has a polarization axis rotated by 90 degrees and is refracted at a predetermined angle to increase the viewing angle. The transmitted light passes through the second polarizing plate 300 having the second polarization axis 310 to implement a white image.

According to the present embodiment, as the liquid crystal layer 130 interposed between the first substrate 110 and the second substrate 120 is operated by moving between the vertical mode, the horizontal mode, and the inclined mode in some cases, A viewing angle black image, a narrow viewing angle black image, and a white image may be implemented.

Meanwhile, when the wide viewing angle and the narrow viewing angle are adjusted through the black image, the brightness ratio CR may vary depending on the position of the image. For example, when the display device implements a narrow-viewing-angle black image, the brightness ratio may be increased in front of the display device, and the image may be distinguished from the side of the display device.

In addition, as the wide viewing angle is adjusted using only the liquid crystal layer 130 disposed between the first substrate 110 and the second substrate 120, the additional viewing angle adjusting member is not added to increase thickness and cost. It can prevent.

According to the present invention, as the liquid crystal layer interposed between the first substrate and the second substrate is operated by moving between the vertical mode, the horizontal mode and the inclined mode in some cases, wide viewing angle black image, narrow viewing angle black image And a white image.

In addition, only the liquid crystal layer disposed between the first substrate and the second substrate may adjust the transmittance and the wide viewing angle, thereby preventing an increase in thickness and cost by a separate viewing angle adjusting member.

While the present invention has been described in connection with what is presently considered to be practical and exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

A display panel assembly comprising a first polarizing axis having a first polarizing plate, a second polarizing plate having a second polarizing axis perpendicular to the first polarizing axis, and a display panel interposed between the first and second polarizing axes. The display panel A first substrate having a first pixel electrode to which a first voltage is applied and a second pixel electrode to which a second voltage is applied; A second substrate disposed to face the first substrate and having a common electrode to which a third voltage is applied; And A horizontal mode in which the liquid crystals are interposed between the first and second substrates, the liquid crystals arranged in parallel with one of the first and second polarization axes, and the liquid crystals perpendicular to the first substrate. An arrayed vertical mode, and a liquid crystal layer operated in any one of an oblique mode in which the liquid crystals are disposed between the first and second polarization axes, And the liquid crystals are arranged to be inclined at 45 degrees with respect to the first polarization axis when in the inclined mode. The liquid crystal layer of claim 1, wherein when the magnitudes of the first, second, and third voltages are the same, the liquid crystal layer is operated in the horizontal mode, When the magnitudes of the first and second voltages are the same and the magnitudes of the third voltages are different from the first and second voltages, the liquid crystal layer is operated in the vertical mode. Wherein when the magnitudes of the first and second voltages are different from each other and the magnitude of the third voltage is the same as any one of the first and second voltages, the liquid crystal layer is operated in the inclined mode. Panel assembly. The liquid crystal layer of claim 2, wherein when the first, second, and third voltages are all 0 V, the liquid crystal layer is operated in the horizontal mode, When the first and second voltages are 5 V and the third voltage is 0 V, the liquid crystal layer is operated in the vertical mode, And one of the first and second voltages is 5 V, the other is 0 V, and the third voltage is 0 V, wherein the liquid crystal layer is operated in the inclined mode. delete The display panel assembly of claim 2, wherein the first and second pixel electrodes are elongated in a first direction, and a plurality of the first and second pixel electrodes are alternately disposed along a second direction different from the first direction. The display panel assembly of claim 5, wherein the first and second directions are perpendicular to each other. The display panel assembly of claim 6, wherein the first direction is inclined at 45 degrees with respect to the first polarization axis. The display panel assembly of claim 2, wherein the wide viewing angle black is implemented in the horizontal mode, the narrow viewing angle black is implemented in the vertical mode, and the white is implemented in the inclined mode. A display panel assembly including a first polarizing axis having a first polarizing plate, a second polarizing plate having a second polarizing axis perpendicular to the first polarizing axis, and a display panel interposed between the first and second polarizing axes, and the display panel A display device comprising a backlight assembly disposed under the assembly to provide light to the display panel. The display panel A first substrate having a first pixel electrode to which a first voltage is applied and a second pixel electrode to which a second voltage is applied; A second substrate disposed to face the first substrate and having a common electrode to which a third voltage is applied; And A horizontal mode in which the liquid crystals are interposed between the first and second substrates, the liquid crystals arranged in parallel with one of the first and second polarization axes, and the liquid crystals perpendicular to the first substrate. An arrayed vertical mode, and a liquid crystal layer operated in any one of an oblique mode in which the liquid crystals are disposed between the first and second polarization axes, And the liquid crystals are arranged to be inclined at 45 degrees with respect to the first polarization axis when in the inclined mode. The display device of claim 9, wherein the backlight assembly generates straight light perpendicular to the first substrate.

Images