KR20150081106A - Display device - Google Patents

Abstract

According to an embodiment of the present invention, a display device includes: a display panel which displays an image; and a liquid crystal lens panel on an upper side of the display panel. The liquid crystal lens panel includes: a lower substrate; a plurality of lower lens electrodes located on an upper side of the lower substrate; an upper substrate located to correspond to the lower substrate; an upper lens electrode located on a lower side of the upper substrate; an alignment layer located on the lower lens electrodes and the upper lens electrodes, respectively; and a liquid crystal layer existing between the upper substrate and the lower substrate. The liquid lens panel forms one Fresnel lens for each display panel. The display device appropriately adjusts a refractive index of light incident from the display panel according to the alignment of liquid crystal molecules located on the liquid crystal layer of a liquid crystal lens by applying voltages on the liquid crystal lens located on the display panel. Therefore, an image, same as an image on a curved display, can be obtained without actually bending the panel.

Description

Display device {DISPLAY DEVICE}

The present invention relates to a display device.

2. Description of the Related Art Liquid crystal displays (LCDs) are one of the most widely used display devices, and include two display units having field generating electrodes such as a pixel electrode and a common electrode, and a liquid crystal layer interposed therebetween. The liquid crystal display displays an image by applying a voltage to the electric field generating electrode to generate an electric field in the liquid crystal layer, thereby determining the direction of the liquid crystal molecules in the liquid crystal layer and controlling the polarization of the incident light.

A liquid crystal display device is used as a display device of a television receiver, and the size of the screen increases. As the size of the liquid crystal display device increases, there arises a problem that the visual difference increases depending on whether the viewer views the center of the screen or both sides of the screen.

In order to compensate for this visual difference, the display device may be curved in a concave or convex shape to form a curved surface. The display device may be a portrait type having a length longer than the horizontal length and being bent in the vertical direction based on the viewer's standard, a landscape type having a shorter vertical length than the horizontal length and being bent in the horizontal direction have.

However, when the liquid crystal display device is curved and formed into a curved surface shape, a shear stress is applied to the substrate located on the inner side of the curved surface among the two substrates. Accordingly, when the interval is not constant and the intervals of the liquid crystal display devices are not constant, the display quality is degraded.

SUMMARY OF THE INVENTION The present invention provides a display device that realizes the same image as a curved display without physical bending by appropriately driving a liquid crystal lens after locating the liquid crystal lens panel on a display panel without physically bending the substrate .

According to an aspect of the present invention, there is provided a display apparatus including a display panel for displaying an image, and a liquid crystal lens panel on the display panel, wherein the liquid crystal lens panel includes a lower substrate, A lower lens electrode, a lower lens electrode, and an upper lens electrode, the upper and lower lens electrodes, the upper substrate positioned in correspondence with the lower substrate, the upper lens electrode positioned on a lower surface of the upper substrate, And a liquid crystal layer existing between the lower substrates, wherein the liquid crystal lens panel forms one Fresnel lens per display panel.

The display panel may be a liquid crystal display panel, an electrophoretic display panel (EDP), an organic light-emitting display panel (OLED panel), and a plasma display panel display panel, PDP).

The width of the lower lens electrode may be reduced as the width of the lower lens electrode increases from one edge of the lower substrate toward the center, and the width of the lower lens electrode may decrease toward the opposite edge of the lower lens electrode.

The refractive index of the image transmitted through the liquid crystal lens panel changes and the distance from the focal point to the center and the edge of the liquid crystal lens panel can be visually recognized.

The display panel and the liquid crystal lens panel are planar, but an image transmitted through the liquid crystal lens panel can be visually recognized as a curved display having a certain curvature.

The curvature of the image transmitted through the liquid crystal lens panel can be changed according to the voltage applied to the liquid crystal lens panel.

The focus position of the image transmitted through the liquid crystal lens panel can be changed according to the voltage applied to the liquid crystal lens panel.

The liquid crystal lens panel may form a single focal point.

The focal point of the image transmitted through the liquid crystal lens panel may be located at the center of the display panel.

The focal point of the image transmitted through the liquid crystal lens panel may be located at one edge of the display panel.

The plurality of lower lens electrodes of the liquid crystal lens panel may include a plurality of first lens electrodes and a plurality of second lens electrodes electrically insulated by a protective layer.

The upper lens electrode of the liquid crystal lens panel may be a single plate.

The plurality of first lens electrodes and the plurality of second lens electrodes may be present in different layers spaced apart from the protective layer.

Different voltages are applied to the plurality of lower lens electrodes and the upper lens electrode, and different voltages are applied to the plurality of first lens electrodes and the plurality of second lens electrodes constituting the plurality of lower lens electrodes at regular intervals .

A voltage is not applied to the plurality of lower lens electrodes and the upper lens electrode of the liquid crystal lens panel, so that a plane image can be displayed.

A voltage is applied to the plurality of lower lens electrodes and the upper lens electrode of the liquid crystal lens panel so that liquid crystal molecules of the liquid crystal layer are oriented so that an image in which both ends are bent in the center direction with respect to the center can be displayed.

The displayed image can be bent to the left and right with respect to the center of the display device.

The displayed image can be bent up and down with respect to the center of the display device.

As described above, according to the display device of the present invention, a voltage is applied to a liquid crystal lens disposed on a display panel to properly adjust the refractive index of light incident from the display panel in accordance with the orientation of liquid crystal molecules located in the liquid crystal layer of the liquid crystal lens, It is possible to realize the same image as the curved display without bending. Accordingly, the present invention solves the problems of misalignment, color unevenness, and shrinkage in the case of forming a curved display by physically bending the panel.

Also, the curved display formed by bending the panel physically has a fixed curvature, so that it can not be changed. However, the display device of the present invention can freely change the curvature by adjusting the voltage applied to the liquid crystal lens.

1 shows a display device according to an embodiment of the present invention.
2 shows a display device according to another embodiment of the present invention.
FIG. 3A shows a structure of a general Fresnel lens, and FIG. 3B shows an enlarged view of a portion indicated by a dotted line in FIG. 3A. 3C illustrates a liquid crystal lens according to an embodiment of the present invention.
4A and 4B show one unit lens electrode.
5 schematically shows a cross section of the display device of the present invention.
6 schematically shows the upper surface of the display device of the present invention.
7 shows a display device and a liquid crystal lens according to a comparative example of the present invention.
8 shows a display device and a liquid crystal lens according to an embodiment of the present invention.
9 shows a curved display according to a comparative example of the present invention.
10 shows a display device according to an embodiment of the present invention.
11 to 13 show various embodiments of the display device of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. Like parts are designated with like reference numerals throughout the specification. It will be understood that when an element such as a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the element directly over another element, Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

Now, a display device according to an embodiment of the present invention will be described in detail with reference to the drawings.

1 shows a display device according to an embodiment of the present invention. Referring to FIG. 1, a display device according to an embodiment of the present invention includes a display panel 40 and a liquid crystal lens panel 50 disposed on the display panel.

As the display panel 40, a liquid crystal display panel, an electrophoretic display panel (EDP), an organic light-emitting display panel (OLED panel), and a plasma display panel a plasma display panel (PDP), or the like may be used. In the present embodiment, a liquid crystal display panel (LCD) will be described as an example of the display panel 40. FIG.

The display panel includes a first substrate 11 and a second substrate 21 facing each other, and a liquid crystal layer 3 positioned between the substrates. The liquid crystal molecules move according to the potential applied to the electrodes formed on the first substrate and the second substrate, and display images.

The first substrate has a plurality of pixel regions. Each pixel region is provided with a gate line (not shown) extending in a first direction, a data line (not shown) and a pixel electrode (not shown) extending in a second direction intersecting the first direction and insulated from the gate line do. In each pixel, a thin film transistor (not shown) electrically connected to the gate line and the data line and electrically connected to the pixel electrode is provided. The thin film transistor provides a driving signal provided to the corresponding pixel electrode side. In addition, a driver IC (not shown) may be provided on one side of the first substrate. The driver IC receives various signals from the outside, and outputs a driving signal for driving the display panel 40 to the thin film transistor side in response to input various control signals.

The second substrate includes an RGB color filter for realizing a predetermined color using light provided from a backlight unit (not shown) on one surface, and a common electrode (not shown) formed on the RGB color filter and facing the pixel electrode . Here, the RGB color filter can be formed through a thin film process. In the present invention, a color filter is formed on the second substrate. However, the present invention is not limited thereto. For example, a color filter may be formed on the first substrate. In addition, a common electrode of the second substrate may be formed on the first substrate.

The liquid crystal layer 3 is arranged in a specific direction by voltages applied to the pixel electrodes and the common electrode, thereby adjusting the transmittance of light provided from the backlight unit so that the display panel 40 can display an image. When the backlight unit is not present, the image is displayed by adjusting the transmittance of the light incident on and reflected from the front surface of the display panel.

A liquid crystal lens panel 50 is positioned above the display panel 40. In the liquid crystal lens panel 50, the liquid crystal molecules of the liquid crystal lens panel 50 are aligned by applying a voltage, and one Fresnel liquid crystal lens is formed on the entire display panel. Such a Fresnel liquid crystal lens refracts an image incident from the lower display panel 40 so as to be viewed as the same image as the curved display.

The Fresnel lens forms a plurality of frames on the left and right around one center lens. In the present invention, in the liquid crystal lens, the panel implements one Fresnel liquid crystal lens on the entire display panel, and thus, a plurality of frames are formed on the left and right sides of the display panel. As shown in FIG. 1, the frame may have a symmetrical structure, and the size of individual frames may be reduced from the center to the edge of the display panel.

A detailed description of the structure of the liquid crystal lens panel 50 will be given later.

2 shows a display device according to another embodiment of the present invention. 2, the display device according to the present embodiment includes a liquid crystal lens panel 50, a display panel 40, and a gap keeping layer 60 disposed between the liquid crystal lens panel 50 and the display panel 40 do. The cavity-holding layer may be a space-holding plate 61 formed of transparent glass or plastic.

The lower surface of the gap maintaining plate 61 is fixed to the display panel 40 by an optical adhesive 62 and the upper surface thereof is fixed to the lower surface of the liquid crystal lens panel 50 by an optical adhesive 64. The optical adhesives 62 and 64 are arranged such that the refractive indices of the optical adhesives 62 and 64 are not substantially different from the refractive indexes of the display panel 40, the spacing plate 61 and the liquid crystal lens panel 50 And is made of an optically transparent material.

Hereinafter, the liquid crystal lens panel 50 of the display device of the present invention will be described.

FIG. 3A shows a structure of a general Fresnel lens, and FIG. 3B shows an enlarged view of a portion indicated by a dotted line in FIG. 3A. The stepped straight line shown in Figure 3B shows the ZONE PALTE phase distribution. 3C illustrates a liquid crystal lens according to an embodiment of the present invention.

In the present invention, the lens electrode comprises a lower lens electrode 300 formed of a plurality of discrete electrodes and an upper lens electrode 310 positioned facing the lower electrode. The upper lens electrode may be made of a plate, and both the upper lens electrode and the lower lens electrode are transparent. However, the upper lens electrode may have a separate electrode structure similar in shape to the lower electrode, not the transmissive plate.

4A is a cross-sectional view and a plan view of a lower lens electrode 300 of a liquid crystal lens according to an embodiment of the present invention. The lower lens electrode 300 has a plurality of branched electrodes (first lens electrode and second lens electrode) arranged in a stripe shape. The branched electrodes are repeatedly arranged in a predetermined pattern, and one same pattern constitutes one unit lens electrode group. That is, FIG. 4A shows one unit lens electrode group.

Referring to FIG. 4A, one unit lens electrode group has a shape in which the width of the individual lens electrodes increases toward the center. Such a unit lens functions as a zone plate type liquid crystal lens. The zone plate, also referred to as a Fresnel zone plate, implements a lensing effect using diffraction of light. In the liquid crystal lens of the present invention, different voltages are applied to a plurality of individual lens electrodes, and the degree of orientation of the liquid crystal molecules is changed, so that it functions as a Fresnel lens.

4B is a cross-sectional view and a plan view of the lower lens electrode 300 of the liquid crystal lens according to another embodiment of the present invention

Referring to FIG. 4B, the lower individual lens electrode of the liquid crystal lens may be inclined in a certain direction in one entire panel. When the lower lens electrode of the liquid crystal lens is formed in such a tilted direction, the moire phenomenon can be reduced.

As shown in FIG. 3C, the liquid crystal lens of the present invention includes a lower substrate 110, an upper substrate 210 facing the lower substrate, and a liquid crystal layer 31 interposed between the lower substrate and the upper substrate.

The first substrate includes a lower substrate 110, a first insulating layer 181 formed on the lower substrate, a plurality of first lens electrodes 301, a second insulating layer 182, and a plurality of second lens electrodes 302, . Since the second insulating layer 182 is disposed between the first lens electrode 301 and the second lens electrode 302, the first lens electrodes and the second lens electrodes are formed in different layers, do.

The first lens electrode 301 and the second lens electrode 302 may include a transparent conductive oxide. For example, the first lens electrode 301 and the second lens electrode 302 may include indium tin oxide (ITO), indium zinc oxide (IZO), or the like.

The first insulating layer 181 and the second insulating layer 182 may include an insulating material that transmits light. For example, the first insulating layer 181 and the second insulating layer 182 may include silicon nitride (SiNx), silicon oxide (SiOx), and the like. The first insulating layer 181 is formed on the lower substrate and the first lens electrode 301 is formed on the first insulating layer 181. The first insulating layer 181 is formed on the first insulating layer 181, The second insulating layer 182 is formed on the first insulating layer 181 and the second lens electrode 302 is formed on the second insulating layer 182.

An upper lens electrode 310 is formed on the upper substrate 210. The upper lens electrode 310 may include a transparent conductive oxide material. For example, the upper lens electrode 310 may include indium tin oxide (ITO), indium zinc oxide (IZO), or the like. The upper lens electrode 310 rearranges the liquid crystal molecules of the liquid crystal layer together with the first lens electrode 301 and the second lens electrode 302. Accordingly, the first lens electrode 301 and the second lens electrode 302, the upper lens electrode 310, and the liquid crystal layer 31 constitute a unit lens.

The liquid crystal layer 31 may have a thickness of about 2 탆 to 5 탆. Since the liquid crystal layer 31 has a small thickness, high-speed switching according to the orientation of the liquid crystal molecules 32 is possible. The liquid crystal layer 3 may be oriented to have the refractive index of the Fresnel lens by the first lens electrode 301, the second lens electrode 302, and the upper lens electrode 310. [

When a drive voltage is applied to the liquid crystal lens, a potential is generated between the first lens electrode 301, the second lens electrode 302, and the upper lens electrode 310, The liquid crystal molecules 32 of the liquid crystal layer 31 interposed between the liquid crystal molecules 302 and the upper lens electrode 310 are rearranged. Accordingly, the unit lens can have the same phase difference as that of the Fresnel lens.

In the present invention, one unit lens electrode group is located on the display panel. In general, when the liquid crystal lens panel is placed on the display panel, the liquid crystal lens panel includes a plurality of unit lens electrode groups, that is, a plurality of Fresnel liquid crystal lenses. That is, the liquid crystal lens panel was repeated in many patterns as shown in Fig. The plurality of Fresnel liquid crystal lenses implement a 3D image by dispersing the focal point of the image input from the display panel into two.

However, in the liquid crystal lens of the present invention, there is only one Fresnel liquid crystal lens on one display panel, and a single focal point is realized. That is, the liquid crystal lens panel of the present invention has only one pattern shown in Fig. 4 across the display panel. The liquid crystal lens of the present invention forms a single focal lens by implementing a single Fresnel lens on one display panel, and exhibits the same effect as a curved display without bending another substrate. This will be described in detail below.

Fig. 5 schematically shows a cross section of a display device according to the present invention, and Fig. 6 schematically shows an upper surface of a display device according to the present invention.

Referring to FIG. 5, one unit lens electrode group is formed on the display panel. That is, as shown in FIG. 4, there is only one pattern in which a plurality of individual lens electrodes are aggregated so as to have a wider width toward the center.

Therefore, one Fresnel liquid crystal lens is formed on the display panel 40 in the present invention. In the entire substrate of the display panel 40, the width of each individual lower lens electrode is increased from one edge of the lower substrate toward the center, and decreased toward the opposite edge. That is, there is only one such pattern in the present invention.

6 schematically shows the upper surface of the display device of the present invention. Referring to FIG. 6, it can be seen that the width of the individual lower lens electrode increases from the substrate edge of the display panel toward the center, and the width decreases again from the center toward the opposite edge. That is, the liquid crystal lens of the display device of the present invention has a structure in which both sides are symmetrical with respect to the center of the display panel.

7 shows a display device and a liquid crystal lens according to a comparative example of the present invention. 8 shows a display device and a liquid crystal lens according to an embodiment of the present invention.

Referring to Fig. 7, a plurality of Fresnel liquid crystal lenses are formed on the display panel 40. Fig. That is, a plurality of lower lens electrode groups are located on the display panel 40. Normally, two lower lens electrode groups are placed on nine pixels. Thus, two Fresnel liquid crystal lenses are formed for every nine pixels.

However, referring to FIG. 8, one Fresnel liquid crystal lens is formed on all the pixels of the display panel 40 according to the embodiment of the present invention. That is, one Fresnel liquid crystal lens corresponds to all the pixels of the display panel of the display device. Therefore, the liquid crystal lens according to the comparative example of the present invention generates a binocular parallax to realize a stereoscopic image without glasses, while the liquid crystal lens of the present invention forms one focus.

In the display device according to the embodiment of the present invention, the liquid crystal lens panel can control the refraction of light according to the voltage applied to the liquid crystal lens electrode. Accordingly, when the voltage applied to the liquid crystal lens electrode is appropriately adjusted, a curved display can be realized without additional bending.

9 shows a curved display according to a comparative example of the present invention. Referring to FIG. 9, misalignment occurs due to the difference in size between the upper substrate and the lower substrate due to bending of the substrate. Therefore, mura is generated on the screen. In addition, there is also a problem that the panel is reduced in size by bending during bending. However, the display device of the present invention can solve the above-described problem by realizing a curved display without substantially bending the substrate.

10 shows a display device according to an embodiment of the present invention. Referring to FIG. 10, a display device according to an embodiment of the present invention includes a display panel and a liquid crystal lens panel on the display panel. As shown in Fig. 10, the display device according to the present invention applies the voltage to the liquid crystal lens electrode, aligns the liquid crystal molecules of the liquid crystal lens, and appropriately regulates the refraction of light so that the same image as the curved display Can be displayed.

9, the curved display of the comparative example of the present invention has the same distance d from the focal point to the center of the panel and the distance d from the focal point to the edge of the panel according to the bending of the panel. Referring to Fig. 10, the display device according to the embodiment of the present invention differs in the distance dc from the focus to the center of the panel and the distance de from the focus to the edge of the panel because the panel is not bent substantially.

However, the display device according to the embodiment of the present invention functions as a Fresnel liquid crystal lens by adjusting the refractive index through the application of the voltage of the liquid crystal lens, so that the distance dc to the center of the panel and the distance from the focal point to the edge of the panel Is recognized by the change of the refractive index at the time of passing through the liquid crystal lens. Therefore, a curved display can be realized without bending another substrate.

In addition, although the curved display formed by bending the panel physically has a fixed curvature, the display device according to the embodiment of the present invention can freely adjust the curvature according to the adjustment of the voltage applied to the liquid crystal lens. That is, a voltage is applied only when necessary and used as a curved display, and if a voltage is not applied to the liquid crystal lens, it can be used as a normal flat display.

11 to 13 show various embodiments of the display device of the present invention. Referring to FIG. 11, the focal point of the display device of the present invention may be located at the center of the display device. Fig. 11 shows a driving form of the Fresnel liquid crystal lens when the focal point of the display device is set at the center. Fig. 12 shows a driving form of the Fresnel liquid crystal lens when the focal point of the display device is set to the right edge, and Fig. 13 shows a driving form of the Fresnel liquid crystal lens when the focal point of the display device is set to the left edge .

As described above, according to the display apparatus of the present invention, the voltage is applied to the liquid crystal lens disposed on the display panel to properly adjust the refractive index of the light incident from the display panel in accordance with the orientation of the liquid crystal molecules located in the liquid crystal layer of the liquid crystal lens, It can function like a curved display. Accordingly, problems such as misalignment, color unevenness, and shrinkage caused by bending the panel to form a curved display have been solved.

Also, the curved display formed by bending the panel physically has a fixed curvature, so that it can not be changed. However, the display device of the present invention can freely change the curvature by adjusting the voltage applied to the liquid crystal lens.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

11: first substrate 21: second substrate
3: liquid crystal layer 40: display panel
50: liquid crystal lens panel 60:
61: spacing plate 62, 64: optical adhesive
110: lower substrate 181, 182: insulating layer
210: upper substrate 300: lower lens electrode
301: first lens electrode 302: second lens electrode
310: upper lens electrode 31: liquid crystal layer
32: liquid crystal molecule

Claims (18)

A display panel for displaying an image,
And a liquid crystal lens panel above the display panel,
The liquid crystal lens panel
A lower substrate,
A plurality of lower lens electrodes positioned above the lower substrate,
An upper substrate positioned in correspondence with the lower substrate,
An upper lens electrode positioned on a lower surface of the upper substrate,
An alignment film disposed on the lower lens electrode and the upper lens electrode, respectively, and
And a liquid crystal layer present between the upper substrate and the lower substrate,
Wherein the liquid crystal lens panel forms one Fresnel lens per display panel. The method of claim 1,
The display panel may include a liquid crystal display panel, an electrophoretic display panel (EDP), an organic light-emitting display panel (OLED panel), and a plasma display panel a display panel, a PDP) 3. The method of claim 2,
Wherein the plurality of lower lens electrodes are formed such that the width of each of the lower lens electrodes is increased from one edge of the lower substrate toward the center, and is decreased from the lower edge toward the opposite edge. 4. The method of claim 3,
Wherein a refractive index of the image transmitted through the liquid crystal lens panel is changed so that the distance from the focal point to the center and the edge of the liquid crystal lens panel is visually recognized. 5. The method of claim 4,
The display panel and the liquid crystal lens panel are flat,
Wherein the image transmitted through the liquid crystal lens panel is viewed as a curved display having a predetermined curvature. The method of claim 1,
Wherein a curvature of an image transmitted through the liquid crystal lens panel is changeable according to a voltage applied to the liquid crystal lens panel. The method of claim 1,
Wherein the focus position of an image transmitted through the liquid crystal lens panel is changeable according to a voltage applied to the liquid crystal lens panel. 8. The method of claim 7,
Wherein the liquid crystal lens panel forms a single focal point. 9. The method of claim 8,
And the focal point of the image transmitted through the liquid crystal lens panel is located at the center of the display panel. 9. The method of claim 8,
And the focal point of the image transmitted through the liquid crystal lens panel is located at one edge of the display panel. The method of claim 1,
Wherein the plurality of lower lens electrodes of the liquid crystal lens panel include a plurality of first lens electrodes electrically insulated by a protective layer and a plurality of second lens electrodes. 12. The method of claim 11,
Wherein the upper lens electrode of the liquid crystal lens panel is a single plate. 12. The method of claim 11,
Wherein the plurality of first lens electrodes and the plurality of second lens electrodes are spaced apart from each other and are present in different layers. The method of claim 13,
Wherein the plurality of lower lens electrodes and the upper lens electrode are applied with different voltages,
Wherein different voltages are applied to the plurality of first lens electrodes and the plurality of second lens electrodes constituting the plurality of lower lens electrodes at regular intervals. The method of claim 14,
Wherein no voltage is applied to the plurality of lower lens electrodes and the upper lens electrode of the liquid crystal lens panel to display a plane image. The method of claim 14,
A voltage is applied to the plurality of lower lens electrodes and the upper lens electrode of the liquid crystal lens panel,
Wherein the liquid crystal molecules of the liquid crystal layer are oriented so as to display an image in which both ends are bent in the center direction with respect to the center. 17. The method of claim 16,
Wherein the displayed image is curved right and left with respect to the center of the display device. 17. The method of claim 16,
Wherein the displayed image is bent up and down with respect to the center of the display device.

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