KR20080084527A - Liquid crystal display device including liquid crystal lens - Google Patents

Abstract

An LCD(Liquid Crystal Display) is provided to drive a liquid crystal layer through three electrodes, thereby freely controlling the change of phases by improving the structure and arrangement of the three electrodes. An LCD is composed of a liquid crystal lens(410) and an LCD panel(450) disposed below the liquid crystal lens. The LCD comprises a first substrate(420), second and third substrates(430,460) facing each other with the first substrate therebetween, a first liquid crystal layer(440) between the first substrate and the second substrate, and a second liquid crystal layer(480) between the first substrate and the third substrate. The first substrate functions as a substrate constituting the liquid crystal lens and the LCD panel. The liquid crystal lens is composed of the first substrate, the second substrate, and the first liquid crystal layer between the first and second substrates. A first electrode(422) is formed between the first substrate and the first liquid crystal layer. A first alignment layer(424) is formed on the first electrode. A plurality of second electrodes(432) are repeatedly formed on an inner surface of the second substrate. Each of the second electrodes has a first opening having a width corresponding to a first distance(d1). An insulating layer(434) is formed below the second electrodes. A plurality of third electrodes(436) are repeatedly formed below the insulating layer. Each of the third electrodes has a second opening having a width corresponding to a second distance(d2). A second alignment(438) is formed below the third electrodes. The first electrode, a pair of second electrodes, and a pair of third electrodes constitute one unit liquid crystal lens(ULL).

Description

Liquid crystal display device including a liquid crystal lens {Liquid Crystal Display Device Including Liquid Crystal Lens}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display including a liquid crystal lens, and a liquid crystal lens for driving a liquid crystal layer using three electrodes, and a liquid crystal display including the same.

In general, a liquid crystal display device is composed of two opposite electrodes and a liquid crystal layer formed therebetween. The liquid crystal molecules of the liquid crystal layer are driven by an electric field generated by applying a voltage to the two electrodes. Liquid crystal molecules have polarization property and optical anisotropy. Polarization property means that when liquid crystal molecules are placed in an electric field, charges in the liquid crystal molecules are concentrated on both sides of the liquid crystal molecules, and the direction of molecular arrangement changes according to the electric field. Refers to changing the path or polarization state of the emitted light differently according to the incident direction or the polarization state of the incident light due to the elongated structure of the liquid crystal molecules and the aforementioned molecular arrangement direction.

Accordingly, the liquid crystal layer may exhibit a difference in transmittance due to voltages applied to two electrodes, and may display an image by changing the difference for each pixel.

Recently, a liquid crystal lens having a liquid crystal layer acting as a lens using the characteristics of such liquid crystal molecules has been proposed.

That is, the lens is to control the path of the incident light by position using the difference in refractive index between the material constituting the lens and the air, the liquid crystal layer is driven by a different electric field for each position by applying different voltage to each position to the liquid crystal layer In this case, incident light incident on the liquid crystal layer may sense a different phase change for each position, and as a result, the liquid crystal layer may control the path of the incident light like an actual lens.

Such a liquid crystal lens will be described with reference to the drawings.

1A and 1B are a perspective view and a cross-sectional view of a general liquid crystal lens, respectively.

As shown in FIGS. 1A and 1B, the general liquid crystal lens 10 may include a liquid crystal layer 40 formed between the first and second substrates 20 and 30 facing each other and the first and second substrates 20 and 30. It is composed of The first electrode 22 is formed on the entire inner surface of the first substrate 20, and the second electrode 32 spaced apart from each other by the separation distance d is formed on the inner surface of the second substrate 30.

When voltage is applied to the first and second electrodes 22 and 32, an electric field is formed between the two electrodes 22 and 32, and the second electrode 32 is formed on the entire outer surface of the second substrate 30. Since it is not formed in the shape and has a separate form, a complete vertical electric field is not formed and is substantially perpendicular to the first and second substrates 20 and 30 in an area far from the separation section 32a of the second electrode 32. While the electric field is generated, an inclined electric field is generated in the first and second substrates 20 and 30 in the region close to the separation section 32a of the second electrode 32.

Therefore, the electric field generated by the first and second electrodes 22 and 32 changes in intensity and direction according to the distance from the separation section 32a of the second electrode 32, and as a result, the liquid crystal layer driven by the electric field. (40) also changes the phase of the incident light in accordance with the distance from the separation section 32a of the first and second electrodes 22, 32.

FIG. 2 is a graph illustrating a phase change of incident light when light passes through the liquid crystal lens of FIGS. 1A and 1B. Figure 2 also shows the phase change felt when the light passes through the actual lens for comparison.

In Fig. 2, the first, second, and third curves 40a, 40b, and 40c are curves showing the phase change of light passing through the liquid crystal lens having different configurations, respectively, and the fourth curve 40d is actually made of glass or the like. This curve shows the phase change of light passing through the lens. As can be seen from the first, second, and third curves 40a, 40b, and 40c, the phase change of light passing through the liquid crystal lens is separated from the separation intervals of the second electrode (32 in FIGS. 1A and 1B) (FIGS. 1A and 1B). It is symmetrical from left to right around 32a).

For example, the first, second, and third curves 40a, 40b, and 40c are curves when the distance (d in FIGS. 1a and 1b) of the second electrode (32 in FIGS. 1a and 1b) is gradually changed. Even if the separation distance (d in FIGS. 1A and 1B) is properly adjusted, there is a limit and thus the same result as the actual lens may not be obtained. That is, the first and second curves 40a and 40b generally have a smaller phase change than the fourth curve 40d, while the third curve 40c has a larger phase change than the fourth curve 40d.

This result is due to the small phase change control parameter of the liquid crystal lens, and it is possible to control the phase change in the liquid crystal lens because the separation distance of the second electrode (32 in FIGS. 1A and 1B) (see FIGS. 1A and 1B). Only the voltage applied to d) and the second electrode (32 in FIGS. 1A and 1B), and even if properly adjusted, it is difficult to obtain the same curve as the phase change in the actual lens.

Accordingly, the present invention has been made to solve the above problems, to provide a liquid crystal lens and a liquid crystal display device including the same that can be more freely adjusted by changing the phase by driving the liquid crystal layer using three electrodes. have.

In addition, the present invention provides a liquid crystal display device including a liquid crystal lens capable of switching the display of a two-dimensional planar image and a three-dimensional stereoscopic image even with an increased resolution by reducing the distance between the liquid crystal lens and the liquid crystal display panel. There is a purpose.

The present invention to achieve the above object, the first substrate; A second substrate facing and spaced apart from the first substrate; A first electrode formed on an inner surface of the first substrate; A plurality of second electrodes repeatedly formed on an inner surface of the second substrate, each of the second electrodes having a first opening having a width corresponding to the first distance; A first liquid crystal layer formed between the first electrode and the plurality of second electrodes; A third substrate disposed under the first substrate; A fourth substrate facing and spaced apart from the third substrate and in contact with the first substrate; A pixel electrode formed on an inner surface of the third substrate; The fourth substrate; A second liquid crystal layer formed between the third substrate and the fourth substrate; A first polarizing plate formed on an outer surface of the third substrate; A liquid crystal display device including a second polarizing plate formed on an outer surface of the second substrate is provided.

On the other hand, the present invention and the first substrate; Second and third substrates spaced apart from each other with the first substrate therebetween; A first electrode formed on one surface of the first substrate facing the second substrate; A plurality of second electrodes repeatedly formed on an inner surface of the second substrate, each of the second electrodes having a first opening having a width corresponding to the first distance; A first liquid crystal layer formed between the first electrode and the plurality of second electrodes; A pixel electrode formed on an inner surface of the third substrate; A second liquid crystal layer formed between the first substrate and the third substrate; A first polarizing plate formed on an outer surface of the third substrate; A liquid crystal display device including a second polarizing plate formed on an outer surface of the second substrate is provided.

The liquid crystal display of the present invention may further include a plurality of third electrodes formed repeatedly between the second electrode and the first liquid crystal layer, each having a second opening having a width corresponding to the second distance. .

In this case, each of the plurality of second electrodes and the plurality of third electrodes may be integrally formed in a rod shape.

When a voltage is applied to the first electrode, the plurality of second electrodes, and the plurality of third electrodes, a three-dimensional stereoscopic image is displayed, and the first electrode, the plurality of second electrodes, and the plurality of third electrodes are displayed. When no voltage is applied to the display, a two-dimensional planar image is displayed. The pixel electrode is formed in a plurality of spaced apart from each other on the inner surface of the third substrate to define a plurality of image pixels, and the liquid crystal display device the three-dimensional stereoscopic image. When displaying, the plurality of image pixels alternately display the first and second images.

In addition, when the liquid crystal display displays the 3D stereoscopic image, the first liquid crystal layer changes the optical path for one selected polarized light and does not change the optical path for other polarized light.

The liquid crystal display device includes: a first alignment layer formed between the first electrode and the liquid crystal layer; A second alignment layer formed between the third electrode and the liquid crystal layer; It may further include an insulating film formed between the second electrode and the third electrode.

A first voltage, a second voltage, and a third voltage are respectively applied to the first electrode, the plurality of second electrodes, and the plurality of third electrodes, and at least one of the first to third voltages is an AC voltage. In particular, the first voltage may be a DC voltage, and the second and third voltages may be AC voltages having the same frequency and different magnitudes.

The first distance may be smaller than the second distance.

The present invention according to another embodiment, the first substrate; A second substrate facing and spaced apart from the first substrate; A first electrode formed on an inner surface of the first substrate; A second electrode formed on an inner surface of the second substrate; An insulating layer formed under the second electrode and having a semi-cylindrical concave portion; A first liquid crystal layer formed between the first electrode and the insulating layer to fill the recess; A third substrate disposed under the first substrate; A fourth substrate facing and spaced apart from the third substrate and in contact with the first substrate; A pixel electrode formed on an inner surface of the third substrate; A second liquid crystal layer formed between the third substrate and the fourth substrate; A first polarizing plate formed on an outer surface of the third substrate; A liquid crystal display device including a second polarizing plate formed on an outer surface of the second substrate is provided.

The present invention according to another embodiment, the first substrate; A second substrate facing the first substrate and spaced apart from each other above the first substrate; A plate-shaped first electrode formed on an upper surface of the first substrate; A plate-shaped second electrode formed on the lower surface of the second substrate; An insulating layer formed under the second electrode and having a semi-cylindrical concave portion; A first liquid crystal layer formed between the first electrode and the insulating layer to fill the recess; A third substrate facing and spaced apart from each other under the first substrate and in contact with the first substrate; A pixel electrode formed on an inner surface of the third substrate; A second liquid crystal layer formed between the first substrate and the third substrate; A first polarizing plate formed on an outer surface of the third substrate; A liquid crystal display device including a second polarizing plate formed on an outer surface of the second substrate is provided.

In this case, the insulating layer is characterized in that the refractive index has the same value as the long-axis refractive index of the liquid crystal molecules constituting the first liquid crystal layer, characterized in that the liquid crystal forming the first liquid crystal layer has a vertical alignment or horizontal alignment characteristics. .

A first alignment layer may be further formed between the first electrode and the first liquid crystal layer, and a second alignment layer may be further formed between the insulating layer having the concave portion and the first alignment layer.

The first electrode and the second electrode is formed in the plate shape on the front surface of the first substrate and the second substrate, respectively.

In the case of including four substrates among all liquid crystal display devices according to the present invention, a common electrode may be further formed on an inner surface of the fourth substrate, and the second liquid crystal layer may be formed between the pixel electrode and the common electrode. .

In the case of including all three substrates among the liquid crystal display according to the present invention, a common electrode is further formed on one surface of the first substrate facing the third substrate, and the second liquid crystal layer includes the pixel electrode and the It may be formed between the common electrode.

The liquid crystal lens according to the present invention generates an electric field using three electrodes and drives the liquid crystal layer with the electric field, or as an insulating layer having two plate-shaped electrodes and semi-cylindrical recesses and a liquid crystal layer filling the recesses. By constructing an electric field by the plate-shaped electrode to drive the semi-cylindrical liquid crystal layer can implement a liquid crystal lens substantially the same as an optical lens, the liquid crystal display device comprising the liquid crystal lens, By controlling the voltage applied to the liquid crystal lens there is an advantage that can be displayed by switching between the 2D image and the 3D image.

In addition, by minimizing the separation distance between the liquid crystal lens and the liquid crystal display panel it is possible to smoothly display a three-dimensional stereoscopic image under high resolution.

In addition, the first and second polarizing plates are disposed on the outer surface of the substrate positioned at the outermost part of the liquid crystal display panel and the liquid crystal lens, respectively, so that the path of the light incident on the liquid crystal lens is out of the display area by the diffusing action of the polarizing plate. There is an effect of preventing the display quality degradation caused.

In addition, manufacturing the liquid crystal lens and the liquid crystal display panel using a total of three substrates has the effect of reducing the manufacturing cost.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

<First Embodiment>

3 is a cross-sectional view schematically showing a liquid crystal lens according to a first embodiment of the present invention.

As shown in FIG. 3, the liquid crystal lens 110 according to the first exemplary embodiment of the present invention faces the first and second substrates 120 and 130 and the first and second substrates 120 and 130 spaced apart from each other. It consists of a liquid crystal layer 140 formed between. The first electrode 122 is formed on the entire surface of the first substrate 120, and the first alignment layer 124 is formed on the first electrode 122.

On the inner surface of the second substrate 130, a second electrode 132 having a first opening having a width corresponding to the first distance d1 is formed around the center of the second substrate 130. An insulating film 134 is formed under the electrode 132. A third electrode 136 having a second opening having a width corresponding to the second distance d2 is formed at the center of the second substrate 130 below the insulating layer 134. ), A second alignment layer 138 is formed below. The second and third electrodes 132 and 136 are electrically insulated from each other by the insulating layer 134 and are disposed to partially overlap each other. Although not shown, in plan view, the second and third electrodes 132 and 136 may be connected to each other at the ends of the first and second openings.

The liquid crystal layer 140 is formed between the first and second alignment layers 124 and 138. In some cases, the first and second alignment layers 124 and 138 may be omitted. In the present exemplary embodiment, the second alignment layer 138 is formed in contact with the third electrode 136, but in another embodiment, a protective film made of an insulating material may be formed between the third electrode 136 and the second alignment layer 138. have. In addition, the first, second, and third electrodes 122, 132, and 136 may be made of a transparent conductive material.

In the liquid crystal lens 110 having such a structure, an electric field is generated by the first, second, and third voltages applied to the first, second, and third electrodes 122, 132, and 136, respectively, and the liquid crystal layer 140 is formed by the generated electric field. ) Is driven. At this time, the generated electric field is controlled by the magnitudes of the first, second, and third voltages and the first and second distances d1 and d2. You can produce more details.

The variation in the size and direction of the generated electric field by position means the diversity of the phase change curve in the liquid crystal layer 140, and appropriately adjusts the first, second and third voltages and the first and second distances d1 and d2. Thus, the same phase shift curve as that of the actual lens can be realized. That is, in the liquid crystal lens 110 according to the first exemplary embodiment of the present invention, the refractive index of the liquid crystal layer 140 is finely adjusted for each position by the generated electric field, and thus the fine light felt by the incident light passing through the liquid crystal layer 140 is sensed. The phase change shows the same optical path changing effect as in the actual lens.

Looking at the driving of the liquid crystal lens 110, the first, second, and third voltages applied to the first, second, and third electrodes, respectively, may have different voltages, and may be a direct current (DC) voltage or an alternating current (AC). Voltage. When the electric field by DC voltage is continuously applied to the liquid crystal layer 140, since the liquid crystal layer 140 may be deteriorated by accumulation of charge in one direction, at least one of the first, second, and third voltages may be It would be desirable to have an alternating voltage. For example, a DC voltage may be applied to the first electrode 122, and an AC voltage having different magnitudes may be applied to the second and third electrodes 132 and 136 at the same frequency.

In addition, although the first distance d1 is smaller than the second distance d2 in this embodiment, in another embodiment, the first distance d1 may be greater than or equal to the second distance d2 as necessary.

On the other hand, since the liquid crystal lens functions as a lens or a simple transmissive layer depending on the voltage applied to the electrode, the liquid crystal lens may be applied to the liquid crystal display panel to display the 2D planar image and the 3D stereoscopic image. .

Second Embodiment

4 is a cross-sectional view of a liquid crystal display including a liquid crystal lens according to a second embodiment of the present invention. The description of the same parts as the liquid crystal lens of FIG. 3 with respect to the liquid crystal lens of FIG. 4 will be omitted.

As shown in FIG. 4, the liquid crystal display device 201 according to the second embodiment of the present invention includes a liquid crystal display 210 and a liquid crystal display panel 250 formed under the liquid crystal lens 210.

The liquid crystal lens 210 includes first and second substrates 220 and 230 facing each other and spaced apart from each other, and a first liquid crystal layer 240 formed between the first and second substrates 220 and 230. The first electrode 222 is formed on the entire surface of the first substrate 220, and the first alignment layer 224 is formed on the first electrode 222.

On the inner surface of the second substrate 230, a plurality of second electrodes 232 having a first opening having a width corresponding to the first distance d1 are repeatedly formed, and the plurality of second electrodes 232 are formed. An insulating film 234 is formed below. A plurality of third electrodes 236 having a second opening having a width corresponding to the second distance d2 are repeatedly formed below the insulating film 234, and a second alignment layer is formed below the third electrode 236. 238 is formed. The plurality of second electrodes and the plurality of third electrodes 232 and 236 are electrically insulated from each other by the insulating film 234, and are disposed to partially overlap each other. Although not shown, the second electrode 232 and the third electrode 236 formed in one unit liquid crystal lens ULL may have a bar shape extending in a direction perpendicular to the drawing in plan view. The second opening may be connected to each other.

The liquid crystal lens 210 acts as one lens by applying a voltage to each electrode as described in FIG. 3. The first electrode 222, the pair of second electrodes 232, and the pair of third electrodes Reference numeral 236 constitutes one unit liquid crystal lens ULL. That is, the unit liquid crystal lens ULL is one cylindrical lens by applying the first, second, and third voltages to the first electrode 222, the pair of second electrodes 232, and the pair of third electrodes 236, respectively. It acts as a cylindrical lens, and the entire liquid crystal lens 210 serves as a plurality of connected cylindrical lenses.

Although the second and third electrodes 232 and 236 are shown as being separated for each unit liquid crystal lens ULL in FIG. 4, the optical characteristics such as the refractive index of the unit liquid crystal lens ULL are designed to be the same. Since the same voltage is applied to each of the second and third electrodes 232 and 236 of the unit liquid crystal lens ULL, each of the second and third electrodes 232 and 236 of the adjacent unit liquid crystal lens ULL is integrally connected. Can be.

An electric field is generated by the first, second, and third voltages applied to the first, second, and third electrodes 222, 232, and 236, respectively, and the first liquid crystal layer 240 is driven by the generated electric field. The generated electric field is controlled by the magnitudes of the first, second, and third voltages and the first and second distances d1 and d2, and consequently, the phase change curve of the first liquid crystal layer 240 is obtained. The shape is controlled.

The first, second, and third voltages may be voltages having different sizes, and may be a direct current (DC) voltage or an alternating current (AC) voltage, and at least one of the first, second, and third voltages may be an AC voltage. desirable. For example, a DC voltage may be applied to the first electrode 222, and an AC voltage having different magnitudes may be applied to the second and third electrodes 232 and 236 at the same frequency.

The liquid crystal display panel 250 includes third and fourth substrates 260 and 270 facing each other and spaced apart from each other, and a second liquid crystal layer 280 formed between the third and fourth substrates 260 and 270. The pixel electrode 262 is formed on the inner surface of the third substrate 260 to correspond to each of the image pixels P1 and P2, and the common electrode 272 is formed on the entire surface of the second substrate 270. The second liquid crystal layer 280 is formed between the pixel electrode 262 and the common electrode 272 to change the polarization state and transmittance of incident light according to the voltage applied to the pixel electrode 262 and the common electrode 272. Display the video.

Accordingly, first and second polarizing plates 292 and 294 are formed on outer surfaces of each of the third and fourth substrates 260 and 270. The polarization axes of the first and second polarizing plates 292 and 294 may be configured to be orthogonal to each other, and the second liquid crystal layer 280 may change the polarization state of incident light incident on the first polarizing plate 292 according to an applied voltage. The image is displayed by determining whether the second polarizing plate 292 passes.

In this case, the first and second image pixels P1 and P2 that display the first and second images IM1 and IM2, respectively, are sequentially and repeatedly arranged in the liquid crystal display panel 250.

When the liquid crystal lens 210 acts as an optical lens by applying the first, second, and third voltages to the first, second, and third electrodes 222, 232, and 236, the first and second electrodes of the liquid crystal display panel 250 are provided. The two images IM1 and IM2 are transmitted to the first and second viewing zones VZ1 and VZ2 by the liquid crystal lens 210, respectively. If the distance between the first and second viewing zones VZ1 and VZ2 is designed as the distance between two eyes of a person, the user may display the first and second images transmitted to the first and second viewing zones VZ1 and VZ2, respectively. IM1 and IM2) are synthesized to recognize stereoscopic 3D images.

The first, second, and third electrodes 222, 232, and 236 do not apply the first, second, and third voltages, so that the liquid crystal lens 210 serves as a simple transparent layer. And the second images IM1 and IM2 pass through the liquid crystal lens 210 without refraction. Therefore, the first and second images IM1 and IM2 are transmitted to the user without the visual field classification, and the user recognizes the 2D image.

 In conclusion, the liquid crystal display device including the liquid crystal lens according to the second exemplary embodiment of the present invention may display the 2D planar image and the 3D stereoscopic image by switching between the 2D planar image and the 3D stereoscopic image depending on the voltage applied to each electrode of the liquid crystal lens.

Although not shown in FIG. 4, the liquid crystal display panel 250 includes gate and data wirings intersecting with each other and a thin film transistor connected to the gate and data wirings between the third substrate 260 and the pixel electrode 262. The thin film transistor may be connected to the pixel electrode 262 and serve to switch a voltage applied to the pixel electrode. In addition, a black matrix corresponding to the gate wiring and the data wiring and a color filter layer below the black matrix may be formed between the fourth substrate 270 and the common electrode 272. In addition, third and fourth alignment layers may be formed between the pixel electrode 262 and the second liquid crystal layer 280, and between the common electrode 272 and the second liquid crystal layer 280.

However, as the trend for higher resolution is required, the size of the pixels of the liquid crystal display panel is reduced, and accordingly, the first and second image pixels P1 and P2 which display the first and second images IM1 and IM2, respectively. ), The pitch of the video pixels is also reduced. However, since the parallax of both eyes is constant at about 65 mm, the liquid crystal display device having a reduced distance between the reduced first and second image pixels P1 and P2 is used to smoothly display three-dimensional stereoscopic images. The first separation distance L1 (the distance between the center plane of the first liquid crystal layer and the center plane of the second liquid crystal layer) between the liquid crystal display panels 250 should also be reduced.

For example, when the pitch of the image pixel of the liquid crystal display panel 250 is about 50 μm, the first separation distance L1 between the liquid crystal lens 210 and the liquid crystal display panel 250 should be about 0.5 mm so that the first and the first It is possible to display three-dimensional stereoscopic images by smoothly separating the two images IM1 and IM2.

The main factor determining the first separation distance L1 between the liquid crystal lens 210 and the liquid crystal display panel 250 is the thickness of the first substrate 220, the second polarizing plate 294, and the fourth substrate 270. Even if the thickness of each substrate is reduced, a polarizing plate having a thickness of about 2 mm may become an obstacle.

Hereinafter, the liquid crystal display device provided by the present invention to solve such a problem will be described.

Third Embodiment

5 is a cross-sectional view of a liquid crystal display device including a liquid crystal lens according to a third embodiment of the present invention. The description of the same parts as the liquid crystal lens of FIG. 3 with respect to the liquid crystal lens of FIG. 5 will be omitted.

As shown in FIG. 5, the liquid crystal display device 360 according to the third exemplary embodiment of the present invention includes a liquid crystal display panel 350 disposed below and in contact with the liquid crystal lens 310. .

The liquid crystal lens 310 includes a first liquid crystal layer 340 formed between the first and second substrates 320 and 330 spaced apart from each other, and the first and second substrates 320 and 330. The first electrode 322 is formed on the entire surface of the first substrate 320, and the first alignment layer 324 is formed on the first electrode 322.

A plurality of second electrodes 332 are repeatedly formed on an inner surface of the second substrate 330, each having a first opening having a width corresponding to the first distance d1, and a plurality of second electrodes 332. An insulating film 334 is formed below. A plurality of third electrodes 336 are repeatedly formed under the insulating layer 334, each having a second opening having a width corresponding to the second distance d2, and below the third electrode 336. 338 is formed. The plurality of second electrodes and the plurality of third electrodes 332 and 336 are electrically insulated from each other by the insulating film 334, and are disposed to overlap with each other. Although not shown, the second electrode 332 and the third electrode 336 may have a rod shape extending in a direction perpendicular to the drawing, and may be connected to ends of the first and second openings, respectively.

As described above with reference to FIG. 3, the liquid crystal lens 310 acts as a single lens by applying a voltage to each electrode. The first electrode 322, the pair of second electrodes 332, and the pair of third electrodes Reference numeral 336 constitutes one unit liquid crystal lens ULL. That is, the unit liquid crystal lens ULL is one cylindrical lens by applying the first, second and third voltages to the first electrode 322, the pair of second electrodes 332, and the pair of third electrodes 336, respectively. It serves as a cylindrical lens, and the entire liquid crystal lens 310 serves as a plurality of connected cylindrical lenses.

Although each of the second and third electrodes 332 and 336 is illustrated as being separated for each unit liquid crystal lens ULL in FIG. 5, the optical characteristics such as the refractive index of each unit liquid crystal lens ULL are designed to be the same. Since the same voltage is applied to each of the second and third electrodes 332 and 336 of each unit liquid crystal lens ULL, the second and third electrodes 332 and 336 of the adjacent unit liquid crystal lens ULL are integrally connected. Can be formed.

An electric field is generated by the first, second, and third voltages applied to the first, second, and third electrodes 322, 332, and 336, respectively, and the first liquid crystal layer 340 is driven by the generated electric field. The generated electric field is adjusted in magnitude and direction by the magnitudes of the first, second, and third voltages, and the first and second distances d1 and d2. As a result, the phase change curve of the first liquid crystal layer 340 is changed. The shape is controlled.

The first, second, and third voltages may be voltages having different sizes, and may be a direct current (DC) voltage or an alternating current (AC) voltage, and at least one of the first, second, and third voltages may be an AC voltage. desirable. For example, a DC voltage may be applied to the first electrode 322, and an AC voltage having different magnitudes may be applied to the second and third electrodes 332 and 336 at the same frequency.

The liquid crystal display panel 350 includes third and fourth substrates 360 and 370 facing and spaced apart from each other, and a second liquid crystal layer 380 formed between the third and fourth substrates 360 and 370. The pixel electrode 362 is formed on the inner surface of the third substrate 360 to correspond to each of the image pixels P1 and P2, and the common electrode 372 is formed on the entire surface of the fourth substrate 370. The second liquid crystal layer 380 is formed between the pixel electrode 362 and the common electrode 372 to change the polarization state and transmittance of incident light according to the voltage applied to the pixel electrode 362 and the common electrode 372. Display the video.

In this case, in order to minimize the distance between the liquid crystal lens 310 and the liquid crystal display panel 350, the first substrate 320 of the liquid crystal lens 310 and the fourth substrate 370 of the liquid crystal display panel 350 are in contact with each other. The first and second polarizing plates 392 and 394, which are disposed in contact with each other and are in close contact with each other, are required on the outer surfaces of the third and second substrates 360 and 330, respectively.

As a result, the second separation distance L2 between the liquid crystal lens 310 and the liquid crystal display panel 350 of the liquid crystal display device 360 according to the third embodiment of the present invention is the liquid crystal according to the second embodiment of the present invention. The environment having an increased resolution is reduced from the first separation distance L1 of the liquid crystal lens (210 of FIG. 4) and the liquid crystal display panel 250 of FIG. 4 (201 of FIG. 4). ) Can be expressed in 3D stereoscopic image smoothly.

Meanwhile, polarization axes of the first and second polarizing plates 392 and 394 may be configured to be orthogonal to each other, and the second liquid crystal layer 380 may change the polarization state of incident light incident on the first polarizing plate 392 according to an applied voltage. The image is displayed by determining whether or not the second polarizing plate 392 passes by changing or maintaining the same.

In the liquid crystal display panel 350, first and second image pixels P1 and P2 for displaying the first and second images, respectively, are sequentially and repeatedly arranged.

When the liquid crystal lens 310 acts as an optical lens by applying the first, second, and third voltages to the first, second, and third electrodes 322, 332, and 336, the first and second electrodes of the liquid crystal display panel 350 are formed. The second image is transmitted to the first and second viewing areas by the liquid crystal lens 310, respectively, and when the distance between the first and second viewing areas is designed as the distance between two eyes of a person, the user may move to the first and second viewing areas. The first and second images respectively transmitted are synthesized to recognize a 3D image by stereographics.

The first, second, and third electrodes 322, 332, and 336 do not apply the first, second, and third voltages, and thus, when the liquid crystal lens 310 serves only as a transparent layer, the first of the liquid crystal display panel 350 And the second image is passed through the liquid crystal lens 310 as it is without refraction, and is transmitted to the user as it is without visual field division, and the user recognizes the 2D image.

 In conclusion, the liquid crystal display including the liquid crystal lens according to the third exemplary embodiment of the present invention may display the 2D planar image and the 3D stereoscopic image by switching between the 2D planar image and the 3D stereoscopic image according to the presence or absence of voltage applied to each electrode of the liquid crystal lens.

Although not shown in FIG. 5, the liquid crystal display panel 350 includes gate and data wirings intersecting with each other and a thin film transistor connected to the gate and data wirings between the third substrate 360 and the pixel electrode 362. The thin film transistor may be connected to the pixel electrode 362 to switch a voltage applied to the pixel electrode. In addition, a black matrix corresponding to the gate wiring and the data wiring and a color filter layer below the black matrix may be formed between the fourth substrate 370 and the common electrode 372. In addition, third and fourth alignment layers may be formed between the pixel electrode 362 and the second liquid crystal layer 380 and between the common electrode 372 and the second liquid crystal layer 380.

Next, a liquid crystal display device provided by the present invention that can more smoothly display three-dimensional stereoscopic images in response to increased resolution will be described.

Fourth Embodiment

6 is a cross-sectional view of a liquid crystal display device including a liquid crystal lens according to a fourth embodiment of the present invention. The description of the same parts as the liquid crystal lens of FIG. 3 with respect to the liquid crystal lens of FIG. 6 will be omitted.

As shown in FIG. 6, the liquid crystal display device 460 according to the fourth exemplary embodiment of the present invention includes a liquid crystal display panel 450 which is integrally formed with the liquid crystal lens 410 and the liquid crystal lens 410. do. That is, the liquid crystal display 460 may include the first substrate 420, the second and third substrates 430 and 460 facing each other with the first substrate 420 therebetween, and the first and second substrates 420. When the first liquid crystal layer 440 between 420 and 430 and the second liquid crystal layer 480 between the first and third substrates 420 and 460 are formed, the first substrate 420 may be a liquid crystal lens ( 410 and the liquid crystal display panel 450 serves as a substrate.

The liquid crystal lens 410 is composed of first and second substrates 420 and 430 facing each other and spaced apart from each other, and a first liquid crystal layer 440 formed between the first and second substrates 420 and 430. The first electrode 422 is formed on the entire surface between the first substrate 420 and the first liquid crystal layer 440, and the first alignment layer 424 is formed on the first electrode 422.

On the inner surface of the second substrate 430, a plurality of second electrodes 432 having a first opening having a width corresponding to the first distance d1 are repeatedly formed, and a plurality of second electrodes 432 is formed. An insulating film 434 is formed below. A plurality of third electrodes 436 having a plurality of second openings each having a width corresponding to the second distance d2 is repeatedly formed below the insulating layer 434, and a second alignment layer is formed below the third electrode 436. 438 is formed. The plurality of second electrodes and the plurality of third electrodes 432 and 436 are electrically insulated from each other by the insulating layer 434, and are disposed to partially overlap each other. Although not shown, the second electrode 432 and the third electrode 436 may have a rod shape extending in a direction perpendicular to the drawing, and may be connected to ends of the first and second openings, respectively.

The liquid crystal lens 410 acts as a single lens by applying a voltage to each electrode as described in FIG. 3. The first electrode 422, a pair of second electrodes 4332, and a pair of third electrodes 436 constitutes one unit liquid crystal lens ULL. That is, the unit liquid crystal lens ULL is one cylindrical lens by applying the first, second, and third voltages to the first electrode 422, the pair of second electrodes 432, and the pair of third electrodes 436, respectively. It acts as a cylindrical lens, and the entire liquid crystal lens 410 serves as a plurality of connected cylindrical lenses.

Although each of the second and third electrodes 432 and 436 is illustrated as being separated for each unit liquid crystal lens ULL in FIG. 5, the optical characteristics such as the refractive index of each unit liquid crystal lens ULL are designed to be the same. If the same voltage is applied to each of the second and third electrodes 432 and 436 of each unit liquid crystal lens ULL, the second and third electrodes 432 and 436 of the adjacent unit liquid crystal lens ULL are connected to each other. It can be formed as.

An electric field is generated by the first, second, and third voltages applied to the first, second, and third electrodes 422, 432, and 436, respectively, and the first liquid crystal layer 440 is driven by the generated electric field. The generated electric field is controlled by the magnitudes of the first, second and third voltages and the first and second distances d1 and d2, resulting in the phase change curve of the first liquid crystal layer 440. The shape is controlled.

The first, second, and third voltages may be voltages having different sizes, and may be a direct current (DC) voltage or an alternating current (AC) voltage, and at least one of the first, second, and third voltages may be an AC voltage. desirable. For example, a DC voltage may be applied to the first electrode 422, and an AC voltage having different magnitudes may be applied to the second and third electrodes 432 and 436 at the same frequency.

The LCD panel 450 includes third and first substrates 460 and 420 facing each other and spaced apart from each other, and a second liquid crystal layer 480 formed between the third and first substrates 460 and 420. The pixel electrode 462 is formed on the inner surface of the third substrate 460 to correspond to each of the image pixels P1 and P2, and the common electrode 472 is formed between the first substrate 420 and the second liquid crystal layer 480. It is formed on the front. The second liquid crystal layer 480 is formed between the pixel electrode 462 and the common electrode 472 to change the polarization state and transmittance of incident light according to the voltage applied to the pixel electrode 462 and the common electrode 472. Display the video.

In this case, in order to minimize the distance between the liquid crystal lens 410 and the liquid crystal display panel 450, the first substrate 420 is a component of the liquid crystal lens 410 and a component of the liquid crystal display panel 450. The first and second polarizing plates 492 and 494 necessary for displaying an image of the panel 450 are formed on the outer surfaces of the third and second substrates 460 and 430, respectively.

As a result, the third separation distance L3 between the liquid crystal lens 410 and the liquid crystal display panel 450 of the liquid crystal display 460 according to the fourth embodiment of the present invention is the liquid crystal according to the third embodiment of the present invention. The environment having an increased resolution is further reduced than the second separation distance (L2 in FIG. 5) between the liquid crystal lens (310 in FIG. 5) and the liquid crystal display panel (350 in FIG. 5) of the display device (301 in FIG. 5). In 3), 3D stereoscopic images can be more smoothly represented.

Meanwhile, polarization axes of the first and second polarizing plates 492 and 494 may be configured to be orthogonal to each other, and the second liquid crystal layer 480 may change the polarization state of incident light incident on the first polarizing plate 492 according to an applied voltage. The image is displayed by determining whether or not the second polarizing plate 492 passes by changing or maintaining the same.

In the liquid crystal display panel 450, first and second image pixels P1 and P2 displaying the first and second images, respectively, are sequentially and repeatedly arranged.

When the liquid crystal lens 410 acts as an optical lens by applying the first, second, and third voltages to the first, second, and third electrodes 422, 432, and 436, the first and second electrodes of the liquid crystal display panel 450 are formed. The second image is transmitted to the first and second viewing areas by the liquid crystal lens 410, respectively, and when the distance between the first and second viewing areas is designed as the distance between two eyes of a person, the user moves to the first and second viewing areas. Each of the first and second images to be transmitted are synthesized to recognize a 3D image by stereographics.

The first, second, and third electrodes 422, 432, and 436 do not apply the first, second, and third voltages, and thus, when the liquid crystal lens 410 serves as a simple transparent layer, the first of the liquid crystal display panel 450 And the second image is passed through the liquid crystal lens 410 as it is without refraction and is transmitted to the user as it is without visual field division, and the user recognizes the 2D image.

 In conclusion, the liquid crystal display device including the liquid crystal lens according to the fourth exemplary embodiment of the present invention may display the 2D planar image and the 3D stereoscopic image by switching between the 2D planar image and the 3D stereoscopic image according to the voltage applied to each electrode of the liquid crystal lens.

Although not shown in FIG. 6, the liquid crystal display panel 450 includes a gate wiring and a data wiring crossing between the third substrate 460 and the pixel electrode 462, and a thin film transistor connected to the gate wiring and the data wiring. The thin film transistor may be connected to the pixel electrode 462 to switch a voltage applied to the pixel electrode. In addition, a black matrix corresponding to the gate wiring and the data wiring and a color filter layer below the black matrix may be formed between the first substrate 420 and the common electrode 472. In addition, third and fourth alignment layers may be formed between the pixel electrode 462 and the second liquid crystal layer 480, and between the common electrode 472 and the second liquid crystal layer 480.

Next, the operation of the liquid crystal display device including the liquid crystal lens according to the fourth embodiment of the present invention will be described with reference to the polarization state of the incident light.

7A and 7B are schematic views showing optical paths and polarization states of incident light when the liquid crystal lenses of the liquid crystal display according to the fourth exemplary embodiment of the present invention are turned off and on, respectively. 7A and 7B illustrate only the polarizing plate and the liquid crystal layer, which are optical elements that affect the optical path and the polarization state of incident light among the components of the liquid crystal display.

As shown in Figs. 7A and 7B, the off and on states of the liquid crystal lens (410 in Fig. 6) are defined as the off state when the liquid crystal lens serves as a simple transparent layer and the on state when the liquid crystal lens serves as an optical lens. Irrespective of the incident light, the incident light emitted from the backlight (not shown) below the liquid crystal display panel 450 (see FIG. 6) passes through the first polarizing plate 492 to become the first polarized light and enter the second liquid crystal layer 480. do.

Thereafter, the first polarized light passes through the second liquid crystal layer 480, and the polarization state thereof changes according to the on / off state of the liquid crystal display panel 450 (FIG. 6). In the normally black mode, when no voltage is applied to the pixel electrode 462 of FIG. 6 and the common electrode 472 of FIG. 6, a black image is displayed and the pixel electrode (FIG. When a voltage is applied to 462 of 6 and the common electrode 472 of FIG. 6, a white image is displayed.

That is, when the first polarized incident light passes through the second liquid crystal layer 480 corresponding to the image pixel displaying the black image, the incident light is emitted as the first polarized light without changing the polarization state, while the white image When passing through the second liquid crystal layer 480 corresponding to the image pixel indicating the polarization state is changed and is emitted as the second polarization (↔).

In addition, since there is no change in the optical path while the light emitted from the backlight passes through the first polarizing plate 492 and the second liquid crystal layer 480, the light emitted from the backlight goes straight out of the second liquid crystal layer 480. .

The emitted light of the liquid crystal display panel 450 of FIG. 6 is then passed through the first liquid crystal layer 440 and the second polarizing plate 494 of the liquid crystal lens 410 of FIG. 6, wherein the optical path and polarization state are Since it changes differently according to the off and on states of the lens 410 of FIG. 6, it demonstrates separately.

As shown in FIG. 7A, when the liquid crystal lens 410 of FIG. 6 is in an off state, the first liquid crystal layer 440 simply serves as a transparent layer for incident light in all polarization states, so that the liquid crystal display panel 450 in FIG. The first and second polarizations (ⓧ, ↔) emitted from the second liquid crystal layer 480 of the first pass through the first liquid crystal layer 440 without changing the optical path and polarization state to reach the second polarizing plate 494. do.

Since the second polarizing plate 494 has a polarization axis different from that of the first polarizing plate 492, the first polarized light is the second polarizing plate among the emitted light of the first liquid crystal layer 440 of the liquid crystal lens 410 of FIG. 6. The black image is not displayed because the display panel 449 does not pass, and the second polarized light ↔ passes through the second polarizing plate 494 to display a white image. In this case, since the optical paths of the first and second polarizations do not change and thus do not generate separate viewing areas, when the liquid crystal lens 461 of FIG. 6 is in an off state, the liquid crystal display device 460 of FIG. 6 is a two-dimensional plane. The image will be displayed.

Meanwhile, as shown in FIG. 7B, when the liquid crystal lens 410 of FIG. 6 is in an on state, the first liquid crystal layer 440 serves as an optical lens according to the polarization state of incident light.

That is, it serves as an optical lens for changing the optical path for the polarized light selected from the incident light of the liquid crystal lens (410 of FIG. 6) and serves as a simple transparent layer that does not change the optical path for the other polarized light.

Here, the incident light of the liquid crystal lens (410 of FIG. 6) is used as an optical lens for the second polarization and a simple transparent layer for other polarizations, but in another embodiment, the first liquid crystal layer ( 440 can be designed.

Accordingly, the first polarized light passes through the first liquid crystal layer 440 without change in the optical path and polarization state, and reaches the second polarizing plate 494, while the second polarized light ↔ is changed in the polarization state. However, the optical path is changed to reach the second polarizing plate 494.

Since the second polarizing plate 494 has a polarization axis different from that of the first polarizing plate 492, the first polarized light is the second polarizing plate among the emitted light of the first liquid crystal layer 440 of the liquid crystal lens 410 of FIG. 6. The black image is not displayed because the display panel does not pass 494, and the second polarized light ↔ whose optical path is changed is passed through the second polarizing plate 494 to display a white image. In this case, the first polarized light is a component that does not contribute to the viewing performance because the optical path is not changed, but is blocked by the second polarizing plate 494, so that the first polarized light does not interfere with the 3D stereoscopic image display of the liquid crystal display, and the second polarized light is not. (↔) generates a viewing area through the second polarizing plate 494 with the optical path changed, and when the liquid crystal lens 461 of FIG. 6 is turned on, the liquid crystal display device 460 of FIG. The image will be displayed.

In the above embodiment, the case where the liquid crystal display panel 450 of FIG. 6 is normally black mode has been described as an example, but the case where the liquid crystal display panel 450 of FIG. 6 is normally white mode is also described. The same operation is performed except that the luminance and voltage application of the displayed image are opposite to those of the normally black mode, and the liquid crystal display device 460 of FIG. 6 switches between displaying the 2D flat image and the 3D stereoscopic image. can do.

In addition, the liquid crystal display 301 shown in FIG. 5 is formed by forming the liquid crystal lens 310 and the liquid crystal display panel 350, and then attaching the first and fourth substrates 320 and 370 using an adhesive or the like. In the liquid crystal display 401 illustrated in FIG. 6, the first electrode 422 and the common electrode 472 are formed on both surfaces of the first substrate 420, and the second and third electrodes 432 are formed. And the second substrate 430 having the 436 formed thereon to be bonded to the first substrate 420 via the first liquid crystal layer 440 and then the third liquid crystal layer having the third substrate 460 having the pixel electrode 462 formed thereon. It may be formed by bonding through 480, or by changing the bonding order of the second and third substrates (430, 460).

Fifth Embodiment

8 is a cross-sectional view of a liquid crystal display device including a liquid crystal lens according to a fifth embodiment of the present invention.

First, the liquid crystal lens used in the fifth embodiment of the present invention will be described.

The liquid crystal lens 510 used in the liquid crystal display device 501 according to the fifth embodiment of the present invention may be formed of a plate shape without the need for configuring a plurality of spaced apart electrodes as in the first to fourth embodiments described above. By forming the first and second electrodes 522 and 537 and applying a voltage to the two electrodes 522 and 537 to form a vertical electric field, a plurality of semi-cylindrical first liquid crystal layers 540 exposed to the vertical electric field are formed. It is characterized in that it is simply implemented to serve as a lenticular lens having a semi-cylindrical convex portion.

That is, in the liquid crystal lens according to the first to fourth embodiments, the liquid crystal layer forming the lens forms a plate shape, and thus the liquid crystal layer of the plate shape is formed by a plurality of electrodes formed at predetermined intervals above or below the liquid crystal layer. Although configured to act as a convex lens, the liquid crystal lens 510 according to the fifth embodiment of the present invention has a plurality of semi-cylindrical recesses formed of a transparent material in which the first liquid crystal layer 540 itself acts as a lens. Formed by the insulating layer 539, the bottom surface is flat with the top surface of the first substrate 520 positioned substantially below it, as shown by itself, and the top portion has a plurality of convex semi-cylinders. It is characterized by having a form. In this case, the insulating layer 539 having the plurality of semi-cylindrical recesses has a refractive index value equal to the refractive index in the major axis direction of the liquid crystal molecules constituting the first liquid crystal layer 540.

In this case, a flat plate-like first alignment layer 524 is formed below the first liquid crystal layer 540 having a plurality of semi-cylindrical shapes, and a plurality of half of the semi-cylindrical forms are arranged along the curvature of the first liquid crystal layer 540. The second alignment layer 538 is further formed in a cylindrical shape.

In addition, a first electrode 522 is formed under the first alignment layer 524 in a plate shape on the front surface thereof, and the upper portion of the insulating layer 539 having the concave portion corresponds to the first electrode 522. Similarly to the first electrode 522, a plate-shaped second electrode 537 is formed on the front surface thereof.

In addition, a first substrate 520 is formed of a transparent material under the first electrode 522, and a second substrate 530 is formed of a transparent material above the second electrode 537.

Accordingly, the liquid crystal lens 510 used in the liquid crystal display according to the fifth exemplary embodiment of the present invention may include the first substrate 510 between the first substrate 520 and the second substrate 530 facing each other. The first electrode 522 in the form of a plate, the first alignment layer 524 in the form of a plate, the first liquid crystal layer 540 having a plurality of semi-cylindrical forms, and a plurality of capturing the first liquid crystal layers, An insulating layer 539 having a semi-cylindrical recess and having a specific refractive index (refractive index in the long axis direction of the liquid crystal molecules constituting the first liquid crystal layer 540), and a plurality of semi-cylindrical second alignment films 538. ) And a plate-shaped second electrode 537 are laminated.

An operation of the liquid crystal lens 510 according to the fifth embodiment having the above configuration will be described with reference to FIGS. 9A and 9B, which illustrate changes in the first liquid crystal layer when the power is turned on / off. . In this case, in the liquid crystal forming the first liquid crystal layer 540, when the voltage is not applied to the first and second electrodes 522 and 537, the horizontal alignment of the liquid crystals is arranged in parallel with the first alignment layer 540. It is preferable that the liquid crystal has a vertical alignment characteristic in which the long axis is vertically aligned with respect to the first alignment layer 540.

In the drawing, when no voltage is applied, a horizontally oriented liquid crystal having a feature in which the major axis thereof is arranged in parallel with respect to the first alignment layer 540 is used. The insulating layer 539 having the plurality of semi-cylindrical recesses is horizontal. It shows that a material made of a material having a refractive index value of the same size as the refractive index value in the long axis direction of the liquid crystal molecules 541 having the property to be oriented.

As shown in FIG. 9A, a vertical electric field is sufficiently strong between the first and second electrodes 522 and 537 by applying different voltages to the first and second electrodes 522 and 537 of the liquid crystal lens 510. When formed, the liquid crystal molecules 541 in the plurality of semi-cylindrical first liquid crystal layers 540 are formed by the vertical electric field between the first and second electrodes 522 and 537 so that their major axes are parallel to the vertical electric field. Are arranged.

On the other hand, the light emitted from the lower backlight unit passes through the first liquid crystal layer 540 in which the liquid crystal molecules as described above are arranged vertically by applying a vertical electric field, and thus the light is emitted in the long axis direction of the liquid crystal molecules 541. Advancement occurs, and in this case, the light feels the refractive index (called n _e ) in the major axis direction of the liquid crystal molecules 541.

In this case, the insulating layer 539 having the plurality of semi-cylindrical recesses has a refractive index value equal to the refractive index in the long axis direction of the liquid crystal molecules 541 constituting the first liquid crystal layer 540. When the light passes through the first liquid crystal layer 540 and enters the insulating layer 539, the light is not refracted and the light travels straight. Thus, the first liquid crystal layer 540 has a semi-cylindrical lens (lenticular). Lens).

As shown in FIG. 9B, when no voltage is applied to the first and second electrodes 522 and 537, a vertical electric field does not occur between the first and second electrodes 522 and 537. The liquid crystal molecules 541 in the first liquid crystal layer 540 having a semi-cylindrical shape have a long axis parallel to the first alignment layer 540. In this state, when the light emitted from the lower backlight unit is incident on the first liquid crystal layer 540, the light may feel a refractive index (hereinafter referred to as n _o ) of the liquid crystal molecule 541. Thus, the light passing through the first liquid crystal layer 540 having the refractive index n _{o in} the minor axis direction has the same refractive index as the refractive index n _{e in} the major axis direction of the liquid crystal molecule 541 ( 539), refraction occurs at the boundary due to the difference in refractive index. In this case, since the refractive index n _{e in} the long axis direction of the liquid crystal molecule 541 has a value smaller than the refractive index n _{o in the} short axis direction, Snell The first liquid crystal layer 540 acts as a lenticular lens because the first liquid crystal layer 540 is refracted by a larger angle with respect to the normal at the point where the light is incident.

As a comparative example, when the refractive index of the insulating layer having the semi-cylindrical concave portion has a uniaxial refractive index of the liquid crystal molecules of the first liquid crystal layer, when no voltage is applied, the liquid crystal molecules in the first liquid crystal layer have a long axis. The light passing through the first liquid crystal layer from the lower portion to the upper portion of the first alignment layer is parallel to the first alignment layer, and the refractive index of the insulating layer is the same as the refractive index of the insulating layer. Without passing through the insulating layer. On the other hand, when the voltage is applied to the first and second electrodes in the same state, the long axis of the liquid crystal molecules is arranged perpendicular to the first and second alignment layer, in this case the light passing through the first liquid crystal layer The refractive index in the long axis direction is felt. In this state, when the light penetrating the first liquid crystal layer is incident on the insulating layer having the refractive index in the uniaxial direction of the liquid crystal, refraction occurs at the boundary due to the difference in refractive index. However, the liquid crystal having a horizontal alignment characteristic has a refractive index in the uniaxial direction of the liquid crystal molecules larger than the refractive index in the long axis direction, and when light is incident from a material having a small refractive index into a material having a large refractive index, it is normal at the interface between materials. It proceeds with an angle of refraction less than the angle of incidence for. Therefore, in this case, the light passing through the first liquid crystal layer is incident on the insulating layer, and the light spreads as if the light passes through the scattering layer. Although not known, the first liquid crystal layer does not serve as a lenticular lens.

Accordingly, in order for the first liquid crystal layer 540 to serve as a semi-cylindrical lens, that is, a lenticular lens, the insulating layer 539 having the plurality of semi-cylindrical recesses may have a refractive index in the long axis direction of the liquid crystal molecules 541. It should be formed to have a refractive index n _e of the same size as.

As a modification of the fifth embodiment, a case in which a semi-cylindrical first liquid crystal layer is formed using a liquid crystal having a property that its major axis is vertically aligned with respect to the alignment film will be described without drawing. Also in this case, the insulating layer having the concave portion of the semi-cylinder was configured to have a refractive index value of the same size as the refractive index in the long axis direction of the vertically aligned liquid crystal.

In the liquid crystal lens according to the modified example of the fifth embodiment, when voltage is applied to the first and second electrodes, the liquid crystal molecules in the first liquid crystal layer are horizontally aligned with respect to the first and second alignment layers. The refractive index of the liquid crystal layer and the insulating layer has a difference, and since the refractive index of the inside of the first liquid crystal layer is larger than that of the insulating layer, the first liquid crystal layer serves as a semi-cylindrical lens (lenticular lens).

On the other hand, when no voltage is applied to the liquid crystal lens according to the modification of the fifth embodiment, the semi-cylindrical first liquid crystal layer has a vertical alignment characteristic, so that the liquid crystal molecules therein are perpendicular to the first alignment layer. In this case, the light passing through the first liquid crystal layer feels the refractive index in the long axis direction of the liquid crystal, which is the same as the refractive index of the insulating layer having the semi-cylindrical concave portion. As the light proceeds straight without being refracted, the semi-cylindrical first liquid crystal layer does not function as a lens.

Accordingly, the liquid crystal lens provided in the liquid crystal display device according to the fifth embodiment and the modified example also functions as a lens or simply as a transparent layer depending on whether voltage is applied to the liquid crystal lens, thereby providing a liquid crystal display device having the same. In addition, 3D or 2D video can be viewed.

Hereinafter, the overall configuration of the liquid crystal display according to the fifth exemplary embodiment of the present invention, in which the liquid crystal lens having the above-described configuration will be described with reference to FIG. 8 again.

The liquid crystal display device 501 according to the fifth embodiment of the present invention includes a liquid crystal lens including a first liquid crystal layer 540 having a plurality of semi-cylindrical shapes and an insulating layer 539 having a plurality of semi-cylindrical recesses. 510 and a liquid crystal display panel 550 integrally formed below the liquid crystal lens 510.

In this case, the liquid crystal lens 510 including the plurality of semi-cylindrical first liquid crystal layers 540 is the same as the above-described configuration, and the liquid crystal display panel 550 disposed under the liquid crystal lens 510 having such a configuration. Is composed of the third and fourth substrates 560 and 570 facing each other and the second liquid crystal layer 580 formed between the third and fourth substrates 560 and 570. In this case, a pixel electrode 562 is formed on an inner surface (upper surface) of the third substrate 560 to correspond to each of the image pixels P1 and P2, and is common to an inner surface (lower surface) of the fourth substrate 570. An electrode 572 is formed on the entire surface. Although not shown in the drawing, an initial arrangement of liquid crystal molecules in the second liquid crystal layer 580 positioned between the two electrodes 562 and 572 is disposed on the pixel electrode 562 and the lower portion of the common electrode 572. The third and fourth alignment layers (not shown) are further formed to keep the constant. In this case, the second liquid crystal layer 580 is formed between the pixel electrode 562 and the common electrode 572, more specifically, between the third and fourth alignment layers (not shown), so that the pixel electrode 562 and the common electrode ( The polarization state, transmittance, and the like of incident light are changed according to the voltage applied to 572 to display an image.

Meanwhile, in order to minimize the distance between the liquid crystal lens 510 and the liquid crystal display panel 550, the first substrate 520 of the liquid crystal lens 510 and the fourth substrate 570 of the liquid crystal display panel 550 may be formed. The first and second polarizing plates 592 and 594, which are disposed in close contact with each other to be in contact with each other, and which are required for displaying an image of the liquid crystal display panel 550, are the third substrate 560 that is a weather plate of the liquid crystal display panel 550. And an outer surface of the second substrate 530 which is a weather plate of the liquid crystal lens 510. At this time, the polarization axes of the first and second polarizing plates 592 and 594 are configured to be perpendicular to each other.

The first polarizing plate 592 and the second polarizing plate 594 are configured on the outer surfaces of the substrates 530 and 560 located at the outermost sides of the liquid crystal lens 510 and the liquid crystal display panel 510, respectively. The polarizing plate 594 is positioned between the liquid crystal display panel 550 and the liquid crystal lens 510 to prevent the display quality from being deteriorated due to the diffusion of the light path.

FIG. 10 is a view schematically illustrating a path of light for one pixel area positioned at the outermost part of a display area in a liquid crystal display device in which a polarizer is disposed between a liquid crystal display panel and a liquid crystal lens as another comparative example of the fifth embodiment. . At this time, only the components that influence the path of light by simplifying the components are shown, and the same reference numerals are given to the fifth embodiment.

Typically, the polarizers 592 and 594 themselves have a property of diffusing light transmitted therethrough (particularly for wide viewing angle implementation), and the third polarizers 592 and 594 constituting the liquid crystal display panel 550 have such characteristics. And a light having a specific path among light incident on the liquid crystal lens 510 by the light diffusion function of the polarizing plates 592 and 594 when formed on the outer surfaces of the fourth substrates 560 and 570 (a large number of semi-cylinders). If the light incident on the outermost side of the first liquid crystal layer 540 having the shape, the light of the path ① is normal, the front of the front face of the user viewed from the front of the liquid crystal lens 510 through the liquid crystal lens 510 is normal. The light of a path (path ②) that is to be focused on a specific area but passes to the side of the liquid crystal display 501 after passing through the liquid crystal lens 510 by the diffusion phenomenon of the second polarizing plate 594. This will occur.

Accordingly, the first and second polarizers 592 and 594 to prevent light leakage caused by the polarizer 594 being positioned between the liquid crystal display panel 550 and the liquid crystal lens 510 and deterioration of display quality. More precisely, the second polarizing plate 594 is formed on the outer surface of the second substrate 530 constituting the liquid crystal lens 510.

Although not shown in the drawing, the liquid crystal display panel 550 includes a gate wiring and a data wiring crossing between the third substrate 560 and the pixel electrode 562, and a thin film transistor connected to the gate wiring and the data wiring. The thin film transistor may be connected to the pixel electrode 562 to switch a voltage applied to the pixel electrode 562. In addition, a black matrix corresponding to the gate wiring and the data wiring and a color filter layer below the black matrix may be formed between the first substrate 520 and the common electrode 572.

Sixth Embodiment

 11 is a cross-sectional view of a liquid crystal display device including a liquid crystal lens according to a sixth embodiment of the present invention.

The liquid crystal display device 601 according to the sixth embodiment of the present invention also has a first liquid crystal layer 640 having a plurality of semi-cylindrical shapes and a plurality of liquid crystal lenses similar to the liquid crystal lens of the liquid crystal display device according to the fifth embodiment. It consists of a liquid crystal lens 610 and a liquid crystal display panel 650 including an insulating layer 639 having a structure having a semi-cylindrical concave portion to capture the first liquid crystal layer, and differs only from the fifth embodiment. The point is that a total of three substrates are used. Other components have the same configuration as that of the fifth embodiment described above, and the same components are assigned by adding 100 to the reference numerals given to the fifth embodiment.

In the sixth embodiment of the present invention, the first and second substrates 520 and 530 of the first and second substrates 520 and 530 of the liquid crystal lens shown in FIG. 520 is replaced with a fourth substrate 570 of FIG. 8 that forms an upper substrate of the liquid crystal display panel 550 of FIG. 8.

That is, according to the sixth exemplary embodiment of the present invention, the fourth substrate 670 may be one substrate constituting the liquid crystal display panel 650 and one substrate constituting the liquid crystal lens 610 disposed thereon. .

In this case, the liquid crystal display panel 650 and the liquid crystal lens 610 are not manufactured and attached to each other, and the liquid crystal display panel 650 is first manufactured using the third and fourth substrates 660 and 670, and then the liquid crystal A first alignment layer 622 is formed on an outer surface of the fourth substrate 670 that forms an upper substrate of the display panel 650, and the plurality of second alignment layers 622 are formed on the second substrate 630, which is an upper substrate of the liquid crystal lens 610. After forming up to an insulating layer 639 having a semi-cylindrical concave portion, it can be completed by bonding and injecting or dropping the liquid crystal to form the first liquid crystal layer 640 having a semi-cylindrical shape in the plurality of concave portions. .

In this case, the liquid crystal display device 601 including the liquid crystal lens 610 may be manufactured using three substrates (second, third, and fourth substrates 630, 660, and 670) to reduce manufacturing costs. .

Other components have the same configuration as that of the fifth embodiment described above, and thus description thereof will be omitted.

On the other hand, in the liquid crystal display device according to the second to sixth embodiments described above, in the case of the liquid crystal display panel as a component thereof, the pixel electrode and the common electrode face each other with the liquid crystal layer interposed therebetween, The liquid crystal display panel is not limited to this configuration and may be variously changed according to the driving mode of the liquid crystal display panel. For example, when driven in a transverse electric field method, the common electrode may be formed on the same substrate on which the pixel electrode is formed to be alternately spaced apart from the pixel electrode.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

1A and 1B are a perspective view and a cross-sectional view of a general liquid crystal lens, respectively.

2 is a graph showing a phase change of incident light when light passes through the liquid crystal lens of FIGS. 1A and 1B;

3 is a sectional view schematically showing a liquid crystal lens according to the first embodiment of the present invention;

4 is a cross-sectional view of a liquid crystal display device including a liquid crystal lens according to a second embodiment of the present invention.

5 is a cross-sectional view of a liquid crystal display device including a liquid crystal lens according to a third embodiment of the present invention.

6 is a cross-sectional view of a liquid crystal display device including a liquid crystal lens according to a fourth embodiment of the present invention.

7A and 7B are schematic views showing an optical path and a polarization state of incident light of a liquid crystal display including a liquid crystal lens according to a fourth embodiment of the present invention.

8 is a cross-sectional view of a liquid crystal display device including a liquid crystal lens according to a fifth embodiment of the present invention.

9A and 9B illustrate changes in the first liquid crystal layer when the power is turned on / off with respect to the operation of the liquid crystal lens 510 according to the fifth embodiment.

FIG. 10 is a view schematically illustrating a path of light for one pixel area positioned at an outermost part of a display area in a liquid crystal display device having a polarizing plate disposed between a liquid crystal display panel and a liquid crystal lens as another comparative example of the fifth embodiment;

 11 is a cross-sectional view of a liquid crystal display device including a liquid crystal lens according to a sixth embodiment of the present invention.

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

410 liquid crystal lens 420 first substrate

422: first electrode 424: first alignment layer

430: second substrate 432: second electrode

434: insulating layer 436: third electrode

438: second alignment layer 440: first liquid crystal layer

450: liquid crystal display panel 460: third substrate

480: second liquid crystal layer 462: pixel electrode

472: common electrode 492: first polarizing plate

494: second polarizing plate

Claims (20)

A first substrate; A second substrate facing and spaced apart from the first substrate; A first electrode formed on an inner surface of the first substrate; A plurality of second electrodes repeatedly formed on an inner surface of the second substrate, each of the second electrodes having a first opening having a width corresponding to the first distance; A first liquid crystal layer formed between the first electrode and the plurality of second electrodes; A third substrate disposed under the first substrate; A fourth substrate facing and spaced apart from the third substrate and in contact with the first substrate; A pixel electrode formed on an inner surface of the third substrate; The fourth substrate; A second liquid crystal layer formed between the third substrate and the fourth substrate; A first polarizing plate formed on an outer surface of the third substrate; A second polarizing plate formed on an outer surface of the second substrate Liquid crystal display comprising a. A first substrate; Second and third substrates spaced apart from each other with the first substrate therebetween; A first electrode formed on one surface of the first substrate facing the second substrate; A plurality of second electrodes repeatedly formed on an inner surface of the second substrate, each of the second electrodes having a first opening having a width corresponding to the first distance; A first liquid crystal layer formed between the first electrode and the plurality of second electrodes; A pixel electrode formed on an inner surface of the third substrate; A second liquid crystal layer formed between the first substrate and the third substrate; A first polarizing plate formed on an outer surface of the third substrate; A second polarizing plate formed on an outer surface of the second substrate Liquid crystal display comprising a. The method according to claim 1 or 2, And a plurality of third electrodes repeatedly formed between the second electrode and the first liquid crystal layer, each having a second opening having a width corresponding to the second distance. The method of claim 3, wherein And the plurality of second electrodes and the plurality of third electrodes each have a rod shape. The method of claim 3, wherein And the plurality of second electrodes and the plurality of third electrodes are integrally formed with each other. The method of claim 3, wherein When a voltage is applied to the first electrode, the plurality of second electrodes, and the plurality of third electrodes, a three-dimensional stereoscopic image is displayed, and the first electrode, the plurality of second electrodes, and the plurality of third electrodes are displayed. 2. A liquid crystal display that displays a two-dimensional planar image when no voltage is applied. The method of claim 6, The pixel electrode is formed in a plurality of spaced apart from each other on the inner surface of the third substrate to define a plurality of image pixels, when the liquid crystal display device displays the three-dimensional stereoscopic image, the plurality of image pixels are first and second 2 Liquid crystal display for displaying images alternately. The method of claim 6, And the first liquid crystal layer does not change the optical path for one selected polarized light and does not change the optical path for other polarized light when the liquid crystal display displays the 3D stereoscopic image. The method of claim 3, wherein A first alignment layer formed between the first electrode and the first liquid crystal layer; A second alignment layer formed between the third electrode and the first liquid crystal layer; An insulating film formed between the second electrode and the third electrode Liquid crystal display further comprising. The method of claim 3, wherein A first voltage, a second voltage, and a third voltage are respectively applied to the first electrode, the plurality of second electrodes, and the plurality of third electrodes, and at least one of the first to third voltages is an AC voltage. Display. The method of claim 10, Wherein the first voltage is a DC voltage, and the second and third voltages are AC voltages having the same frequency and different magnitudes. The method of claim 3, wherein And the first distance is smaller than the second distance. A first substrate; A second substrate facing and spaced apart from the first substrate; A first electrode formed on an inner surface of the first substrate; A second electrode formed on an inner surface of the second substrate; An insulating layer formed under the second electrode and having a semi-cylindrical concave portion; A first liquid crystal layer formed between the first electrode and the insulating layer to fill the recess; A third substrate disposed under the first substrate; A fourth substrate facing and spaced apart from the third substrate and in contact with the first substrate; A pixel electrode formed on an inner surface of the third substrate; A second liquid crystal layer formed between the third substrate and the fourth substrate; A first polarizing plate formed on an outer surface of the third substrate; A second polarizing plate formed on an outer surface of the second substrate Liquid crystal display comprising a. A first substrate; A second substrate facing the first substrate and spaced apart from each other above the first substrate; A plate-shaped first electrode formed on an upper surface of the first substrate; A plate-shaped second electrode formed on the lower surface of the second substrate; An insulating layer formed under the second electrode and having a semi-cylindrical concave portion; A first liquid crystal layer formed between the first electrode and the insulating layer to fill the recess; A third substrate facing and spaced apart from each other under the first substrate and in contact with the first substrate; A pixel electrode formed on an inner surface of the third substrate; A second liquid crystal layer formed between the first substrate and the third substrate; A first polarizing plate formed on an outer surface of the third substrate; A second polarizing plate formed on an outer surface of the second substrate Liquid crystal display comprising a. The method according to claim 13 or 14, And said refractive index has the same refractive index as that of the long-axis refractive index of the liquid crystal molecules forming the first liquid crystal layer. The method according to claim 13 or 14, The liquid crystal of the first liquid crystal layer is characterized in that the vertical alignment or horizontal alignment characteristics. The method according to claim 13 or 14, A liquid crystal display device further comprising a first alignment layer between the first electrode and the first liquid crystal layer, and a second alignment layer further formed between the insulating layer having the recess and the first alignment layer. The method according to claim 13 or 14, And the first electrode and the second electrode are formed in front of the first substrate and the second substrate in the form of a plate. The method according to claim 1 or 13, A common electrode is further formed on an inner surface of the fourth substrate, and the second liquid crystal layer is formed between the pixel electrode and the common electrode. The method according to claim 2 or 14, The common electrode is further formed on one surface of the first substrate facing the third substrate, and the second liquid crystal layer is formed between the pixel electrode and the common electrode.

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