WO2012036417A2 - Stereo image display - Google Patents

Abstract

The present invention relates to a stereo image display, and more specifically, to a stereo image display comprising a liquid crystal cell configured with a plurality of pixels having chromatic color sub-pixels of red, green, and blue and a white sub-pixel and a polarizing plate having a polarizer and a pattern retarder, wherein the pattern retarder is disposed such that the interface between neighboring patterns corresponds to a surface of the white sub-pixel, and the quantity of current applied to the white sub-pixel is controlled such that the white sub-pixel can implement black color, thereby improving cross talk generated by a small space between retarder patterns and thus widening the range of a viewing angle capable of stereo image implementation to enable the viewing of clear stereo images.

Description

Stereoscopic Display

The present invention relates to a display for stereoscopic images that can improve crosstalk caused by light leaking out of an incline through a pattern retarder by a narrow gap between retarder patterns.

In general, the eyes of a person are about 65 mm apart so that when looking at an object, each eye sees a slightly different side of the object. As a way of recognizing this, there is a slight difference between the shape of an object seen after covering one eye with a palm and the object seen after covering another.

This is called disparity due to the left and right binocular. This difference is synthesized in the brain and perceived as a three-dimensional image. This principle is a basic principle applied to stereoscopic image reproduction.

The stereoscopic image system includes a liquid crystal panel having a right eye image region (R) and a left eye image region (L), a polarizing plate disposed on the front surface of the liquid crystal panel, an electric field rotation direction of a right eye image and a left eye image disposed on the polarizing plate and passing through the polarizing plate. An image display portion including a patterned retarder that emits circularly polarized light opposite to each other is provided. In addition, it is provided with a polarized glasses for viewing the right eye image and the left eye image emitted from the stereoscopic image device as a stereoscopic image.

In the stereoscopic image, left circularly polarized light and right circularly polarized light incident on the polarizing glasses are converted into linearly polarized light, and the left and right eyes are separated and recognized, respectively.

The light incident to the front of the polarizing glasses is phase separated well, but the light incident to the slope is narrow between the patterns of the patterned retarder so that the light on the right side is incident on both the right and left eyes, or the light on the left side is incident on both the left and right eyes. Light leaks are generated. This light leakage causes a crosstalk phenomenon in which the left and right phases are not properly separated.

This phenomenon can be improved by widening the pattern spacing of the patterned retarder, but since the patterned retarder is designed in consideration of the size and arrangement of the pixels composed of the subpixels, the black matrix area of the pixel at the same time as the pattern spacing of the retarder The disadvantage is that the distance between the subpixels needs to be widened. Considering only one of these, the phenomenon that the phase is not separated from the front occurs. In addition, when the crosstalk is reduced by widening the black matrix area, optical characteristics such as panel brightness and contrast ratio may be degraded, resulting in deterioration of the display quality.

Meanwhile, a flat panel display device having a substrate in which a plurality of pixels are defined including subpixels arranged in the order of red, green, blue, and white has been proposed (Korean Patent Laid-Open No. 2008-58538). In order to improve the purity it is merely provided with a white sub-pixel.

SUMMARY OF THE INVENTION An object of the present invention is to provide a stereoscopic image display that can suppress crosstalk generation by widening the black matrix area of the pixel in a simple manner without changing the design of the patterning retarder and the pixel separately.

In addition, an object of the present invention is to provide a three-dimensional display for a three-dimensional image can be realized in a large space with a large viewing angle capable of realizing a three-dimensional image.

In order to achieve the above object, the stereoscopic image display includes a liquid crystal cell, a polarizer, and a patterned retarder for implementing a plurality of pixels including red, green, and blue colored subpixels and white subpixels. The patterning retarder includes a polarizing plate including a polarizing plate, and the patterned retarder is disposed to correspond to a center between adjacent patterns and a center of a white subpixel surface, and the average amount of current applied to the white subpixel is red, green, and blue, respectively. It should be less than 10% of the average amount of current applied to the pixel.

The average amount of current applied to the white subpixel may be 0% of the average amount of current applied to the red, green, and blue subpixels.

In addition, the subpixels may be arranged in a stripe form, respectively.

In addition, the subpixels may have the same area.

In addition, the sub-pixels may be arranged so that the interval between them is the same.

In addition, the white subpixel may have an area greater than or equal to the interval between the subpixels.

Further, the spacing between adjacent patterns of the patterned retarder may be narrower than the size including the width of the white subpixel and the spacing between the white subpixel and the adjacent subpixels.

In addition, the area of the white subpixel may be 0.3 to 2.5 times the area of each chroma subpixel.

In addition, the patterned retarder may be in the form of a stripe.

In addition, the subpixels may be formed by periodically repeating a chroma subpixel and a white subpixel.

Further, the sub pixels may be red-green-blue-white, red-blue-green-white, green-red-blue-white, green-blue-red-white, blue-red-green-white or blue-green- Red-white may be formed by periodically repeating arrangement.

The display for stereoscopic images of the present invention can improve crosstalk due to a narrow gap between retarder patterns, thereby enabling a clear stereoscopic image.

In addition, the stereoscopic image display according to the present invention has a wider viewing angle at which stereoscopic images are implemented, so that a large number of people can view stereoscopic images of the same quality in a large space.

In addition, when the pixel used in the stereoscopic image display of the present invention is applied to a 2D display, high color purity, high brightness and high contrast ratio can be realized by applying a current to the white sub-pixel.

1A and 1B are block diagrams of subpixels according to the present invention;

2A and 2B show a subpixel and a patterned retarder arranged according to the present invention, where (a) is a voltage application, (b) is a voltage free application,

3 shows an example of a crosstalk measuring apparatus.

The present invention relates to a display for stereoscopic images that can improve crosstalk caused by light leaking out of an incline through a pattern retarder by a narrow gap between retarder patterns.

Hereinafter, the present invention will be described in detail.

A stereoscopic image spherical display according to the present invention includes a polarizing plate including a liquid crystal cell that implements a plurality of pixels including red, green, and blue colored subpixels and white subpixels, and a polarizer and a patterned retarder.

The patterned retarder is disposed such that the boundary between adjacent patterns and the center of the surface of the white subpixel correspond. The average amount of current applied to the white subpixel is 10% or less of the average amount of current applied to the red, green, and blue subpixels.

The liquid crystal cell includes a liquid crystal layer injected between the first and second glass substrates bonded to each other with a predetermined space.

The first glass substrate (TFT array substrate) includes a plurality of gate lines arranged in one direction at a predetermined interval; A plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines; And a plurality of thin film transistors which are switched by a plurality of pixel electrodes formed in a matrix form in each pixel region defined by crossing each of the gate lines and the data lines and signals of the gate lines to transfer signals of the data lines to each pixel electrode. Is formed.

The second glass substrate (color filter substrate) may include a light shielding layer for blocking light of portions except the pixel region; A color filter layer comprising red, green, and blue colored colors and white for expressing a color color; And a common electrode for realizing the image.

The pixel of the present invention includes red, green, and blue colored subpixels and white subpixels, and the colored subpixels and the white subpixels may be repeatedly arranged in a periodic manner. Specifically, the subpixels are red-green-blue-white, red-blue-green-white, green-red-blue-white, green-blue-red-white, blue-red-green-white or blue-green-red -Can be arranged periodically in white order.

In one pixel according to the present invention, as shown in FIGS. 1A and 1B, subpixels arranged in the order of red, green, blue, and white are arranged. Each subpixel implements a predetermined color in the pixel according to the voltage value applied thereto.

The red, green, blue, and white subpixels are arranged in a stripe form, respectively. The area of each subpixel is divided by a black matrix layer.

Each sub pixel has the same area, and it is preferable to arrange so that the space | interval between them may be the same.

The area of the white subpixel according to the present invention preferably has an area greater than or equal to the interval between the subpixels, and more preferably 0.3 to 2.5 times the area of each colored subpixel in consideration of stereoscopic image implementation and color reproducibility. Do.

In this case, the area of the subpixel and the interval between the subpixels are not limited to the size applicable to the display of the related art.

In the present invention, each subpixel is an area maintaining one color of red, green, blue, and white, and a gap between the subpixels is a width of an area not maintaining one of the colors of red, green, blue, and white. Means. In addition, each pattern is a region where the phase difference value and the axial direction are kept constant, and the interval between the patterns means the width of the region where the phase difference value or the axial direction is not kept constant.

Red, green, blue, and white color filter layers are formed on the upper substrate corresponding to the red, green, blue, and white subpixels, respectively. The lower substrate is formed with a pixel electrode facing the red, green, and blue color filter layers, and a gate line and a data line surrounding the horizontal and vertical peripheries of the pixel electrode are formed, and at the intersection of the gate line and the data line. A thin film transistor for driving the pixel electrode is formed.

In addition, the upper substrate may include a black matrix layer covering a portion corresponding to the gate line and the data line; Red, green, blue and white color filter layers; And an overcoat layer for forming the top of these layers in front. Column spacers are formed in a portion corresponding to the black matrix layer on the overcoat layer.

The color filter layer may be selectively patterned by an exposure and development process after applying a color filter of each color, or may be formed by an inkjet printing method or the like only on a specific portion. The color spacer is formed by coating a photosensitive resin on the entire surface of the substrate and then selectively exposing and developing the photosensitive resin.

In the present invention, when the liquid crystal cell and the polarizer are bonded together, as shown in FIG. 2, the white subpixel plane and the patterned retarder are disposed to correspond to the interface between adjacent patterns. 2A and 2B show a subpixel and a patterned retarder arranged according to the present invention, where (a) is a voltage application and (b) is a voltage free application.

At this time, the subpixel and the pattern retarder are preferably arranged such that their long sides coincide with each other. 2A shows that the long sides of the subpixels and the pattern retarder are vertical, and FIG. 2B shows the long sides of the subpixels and the pattern retarder horizontal.

The subpixels and the pattern retarder are generally arranged in the same shape, and preferably, may be in the form of stripes.

In addition, by controlling the amount of current applied to the white sub-pixel to perform the role of a black matrix. The pattern of the patterned retarder is typically designed to be the same size as the pixel including the red, green, blue and white subpixels.

When the white subpixel serves as a black matrix, the distance between the patterns of the retarder is widened, and since the overlapping of images does not occur even on the inclined surface, the viewing angle for realizing a stereoscopic image is enlarged.

The spacing between adjacent patterns of the patterned retarder is preferably narrower than the size including the width of the white subpixel and the spacing between the white subpixel and the adjacent subpixels.

The average amount of current applied to the white subpixel is preferably 10% or less, preferably 0%, of the average amount of current applied to the red, green and blue subpixels.

The polarizer includes a polarizer and a patterned retarder for converting light passing through the polarizer into circularly polarized light.

The polarizer is generally used in the art and is not particularly limited as long as it can perform a polarizing function. Specifically, stretched polyvinyl alcohol, a wire grid and carbon nanotubes using a dichroic compound may be used.

Among these, the stretched polarizer of which the form-type polarizer is easy to process into a film form is a dichroic dye adsorbed and oriented to the stretched polyvinyl alcohol-based film. The polyvinyl alcohol-based resin constituting the polarizer can be produced by saponifying a polyvinyl acetate-based resin.

As an example of polyvinyl acetate type resin, the copolymer etc. with vinyl acetate and the other monomer copolymerizable with this besides the polyvinyl acetate which is a homopolymer of vinyl acetate are mentioned. Specific examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ethers, acrylamides having an ammonium group, and the like. In addition, the polyvinyl alcohol-based resin may be modified, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The degree of saponification of the polyvinyl alcohol-based resin may be 85 to 100 mol%, preferably 98 mol% or more. In addition, the degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

The polarizer may be bonded to the transparent protective film on any one or more surfaces.

As the transparent protective film, a film excellent in transparency, mechanical strength, thermal stability, moisture shielding, and isotropy may be used. Specific examples include polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate and polybutylene terephthalate; Cellulose resins such as diacetyl cellulose and triacetyl cellulose; Polycarbonate resins; Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene resins such as polystyrene and acrylonitrile-styrene copolymers; Polyolefin-based resins such as polyethylene, polypropylene, cyclo-based or norbornene-structured polyolefins, ethylene-propylene copolymers; Vinyl chloride-based resins; Amide resins such as nylon and aromatic polyamides; Imide resin; Polyether sulfone resin; Sulfone resins; Polyether sulfone resin; Polyether ether ketone resins; Sulfided polyphenylene resins; Vinyl alcohol-based resins; Vinylidene chloride-based resins; Vinyl butyral resin; Allyl resins; Polyoxymethylene resin; And films composed of thermoplastic resins such as epoxy resins, and the like, and films composed of blends of the above thermoplastic resins may also be used. Moreover, you may use the film which consists of thermosetting resins or ultraviolet curable resins, such as (meth) acrylic-type, urethane type, acrylurethane type, epoxy type, and silicone type.

The content of the thermoplastic resin in the transparent protective film is 50 to 100% by weight, preferably 50 to 99% by weight, more preferably 60 to 98% by weight, most preferably 70 to 97% by weight. If the content is less than 50% by weight, it may not sufficiently express the original high transparency possessed by the thermoplastic resin.

Such a transparent protective film may be one containing an appropriate one or more additives. As an additive, a ultraviolet absorber, antioxidant, a lubricating agent, a plasticizer, a mold release agent, a coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment, a coloring agent, etc. are mentioned, for example.

The pattern retarder is composed of a phase difference layer arranged so that two or more distinct areas have different phase or slow axis directions.

The present invention may also be used to form a pattern retarder generally used in the art, for example, a film retarder pattern, a retarder pattern from which the alignment film is removed, and the like, but is not particularly limited thereto.

The present invention uses a substrate film, an alignment film on the substrate film, a pattern retarder in which a liquid crystal coating layer is formed on the alignment film.

Characteristics and specific types of the base film are the same as the contents of the transparent protective film. The base film may have a thickness of 5 to 100 μm, preferably 15 to 60 μm. If the thickness is less than 5 μm, the mechanical strength of the base film is weak, and if the thickness exceeds 100 μm, there is a problem that the thickness of the polarizing plate is not easy.

The alignment film formed on the base film is generally used in the art and is not particularly limited, but an organic alignment film is preferably used.

The organic alignment film is formed using an alignment film composition containing an acrylate-based, polyimide-based or polyamic acid. The polyamic acid is a polymer obtained by reacting diamine and dianhydride, and the polyimide is obtained by imidating the polyamic acid, and their structure is not particularly limited.

It is important to maintain an appropriate viscosity of the alignment film composition. When the viscosity is too high, it is difficult to form an alignment film having a uniform thickness because it does not easily flow even when pressure is applied. When the viscosity is too low, the spreadability is good, but it is difficult to control the thickness of the alignment film. For example, it is preferable that it is 8-13 cP.

In addition, it is good to consider the surface tension, the solid content and the volatility of the solvent. In particular, since the content of solid content affects the viscosity and surface tension, it is good to adjust the thickness and curing characteristics of the alignment film in consideration of the same.

If the solid content is too high, the viscosity is high, the thickness of the alignment film is thick, if it is too low, there is a problem that a high proportion of the solvent causes a stain after drying the solution. For example, it is preferable that content of solid content is 0.1 to 10 weight%.

The alignment film composition is preferably in the form of a solution in which solid content such as acrylate, polyimide, or polyamic acid is dissolved in a solvent. The solvent is not particularly limited as long as it can dissolve the solid content. Specifically, butyl cellosolve, gamma-butyrolactone, N-methyl-2-pyrrolidone and dipropylene glycol monomethyl ether may be used.

Such solvents are suitably mixed so as to form a uniform alignment film in consideration of solubility, viscosity, surface tension, and the like.

In addition to the alignment layer composition, a crosslinking agent and a coupling agent may be further mixed to form an effective alignment layer.

The alignment film is prepared by applying the alignment film composition to one side of the polymer base film.

The application is not particularly limited as long as it is a method commonly used in the art. For example, application of the alignment layer composition may be carried out using a flow casting method and a method of applying an air knife, gravure, reverse roll, kiss roll, spray, or blade. It can be formed by applying directly in a suitable development manner.

In order to improve the coating efficiency of the alignment film composition, a drying process may be further performed.

Drying is not particularly limited and can be generally carried out using a hot air dryer or a far infrared heater, and the drying temperature is usually 30 to 100 ° C, preferably 50 to 80 ° C, and the drying time is usually 30 to 600 seconds, preferably It is preferable that it is 120 to 600 seconds.

Orientation is provided to the alignment film formed after this. Orientation provision methods include a rubbing method, a photo-alignment method and the like, and is not particularly limited.

For example, after providing the entire alignment property to the formed alignment film, the alignment film patterned to have different alignment directions may be manufactured by an exposure process using a photo mask. In addition, after performing the first exposure process by aligning the first photo mask having the light transmitting portion and the light blocking portion on the formed alignment layer, the second photo mask in which the positions of the light transmitting portion and the light blocking portion of the first photo mask are reversed is aligned. The exposure process may be performed to fabricate an alignment film patterned to have different optical axes.

The light used for the exposure is not particularly limited, but for example, polarized ultraviolet irradiation, ion beam or plasma beam irradiation, radiation irradiation, or the like can be used. For example, it is preferable to irradiate polarized ultraviolet rays.

A liquid crystal coating layer is formed on the oriented alignment film.

The liquid crystal coating layer forms a patterned retarder by coating the liquid crystal coating composition on the patterned alignment layer. The method for forming the liquid crystal coating composition and the liquid crystal coating layer is the same as the vertically aligned liquid crystal layer.

The polarizing plate of the present invention may be further laminated with a surface treatment layer such as a hard coat layer, an antireflection layer or an antifouling layer, a diffusion layer, an antiglare layer, etc. without departing from the object of the present invention.

The stereoscopic image spherical display of the present invention can enjoy a stereoscopic image using polarizing glasses generally used in the art. For example, the polarizing glasses include a λ / 4 retardation layer for converting light passing through the display into linearly polarized light and a polarizer for passing light emitted from the λ / 4 retardation layer.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

Example 1

The lower substrate on which the gate wiring, the data wiring, and the thin film transistor were formed, and the upper substrate on which the black matrix layer, the color filter layer, and the common electrode were formed were bonded at regular intervals. A liquid crystal cell was prepared by injecting a liquid crystal between the bonded upper and lower substrates.

The upper substrate includes a plurality of pixels of red, green, blue, and white subpixels. The subpixels have the same area and spacing, respectively. The black matrix layer was formed to correspond to regions other than the pixel region on the upper substrate and the gate line data line region of the lower substrate. Corresponding to each of the sub-pixel areas divided by the black matrix layer, a red color filter layer, a green color filter layer, a blue color filter layer, and a white color filter layer were formed in turn. Each of the color filter layers was applied and then exposed and selectively patterned. An overcoat layer was formed on the entire surface of the substrate including the red, green, blue, and white subpixels. After the photosensitive resin was applied to the entire surface of the substrate, it was selectively exposed to form column spacers, and the column spacers were formed on an overcoat layer corresponding to the black matrix layer.

The polarizing plate bonded to the said liquid crystal cell in order of a triacetyl cellulose (TAC) protective film, a polarizer, and a pattern retarder was bonded by the upper plate. On the lower plate, a polarizing plate laminated in the order of a triacetyl cellulose (TAC) protective film, a PVA polarizer, and a triacetyl cellulose (TAC) protective film was bonded. The pattern retarder is designed to be 45 ° and -45 ° when the slow axis of the adjacent pattern is counterclockwise in the positive (+) direction with respect to the right horizontal direction of the viewer side, and the spacing between adjacent patterns is white subpixel. Narrower than the size including the width and the distance between the white sub-pixels and the sub-pixels next to it was used. The patterned retarder was bonded to each other such that the interface between adjacent patterns and the center of the white subpixel plane correspond to each other to produce a stereoscopic image display.

The three-dimensional image display manufactured later was implemented by setting the average amount of current applied to the white subpixel as 0% of the average amount of current applied to the red, green, and blue subpixels.

Example 2

In the same manner as in Example 1, the average current applied to the white subpixels was 10% of the average current applied to the red, green, and blue subpixels.

Comparative Example 1

In the same manner as in Example 1, a display for a stereoscopic image was manufactured using a liquid crystal cell including a plurality of pixels including subpixels arranged in the order of red, green, and blue.

Comparative Example 2

In the same manner as in Example 1, the average current applied to the white subpixels was 20% of the average current applied to the red, green, and blue subpixels.

Experimental Example

The degree of crosstalk generation of the stereoscopic image display manufactured in the above Examples and Comparative Examples was measured using the light intensity measuring apparatus (manufactured by TOPCON, SR3) of FIG. At this time, the crosstalk generation degree at 15 °, 20 °, 25 ° and 30 ° in the upward direction based on the front side was measured.

The degree of crosstalk generation is measured by the ratio of the light leakage portion of the black state of the stereoscopic image display and the transmission portion of the white state, as identified by the flat glasses, as shown in Equation 1 below.

[Equation 1]

Cross talk (C / T) = (light blocking part in the dark state) / (light transmitting part in the bright state)

TABLE 1

As shown in Table 1, Examples 1 and 2 it was confirmed that the generation of cross-talk is significantly lower than 20 ° in the upward direction relative to the front compared to Comparative Examples 1 and 2.

Claims (11)

1. A polarizing plate including a liquid crystal cell implementing a plurality of pixels including red, green, and blue colored subpixels and white subpixels, and a polarizer and a patterned retarder,

   The patterned retarder is disposed such that a boundary between adjacent patterns and a center of a white subpixel plane correspond to each other.

   An average current amount applied to a white subpixel is 10% or less of an average current amount applied to each of the red, green, and blue subpixels.
2. The display of claim 1, wherein an average amount of current applied to the white subpixel is 0% of an average amount of current applied to the red, green, and blue subpixels.
3. The display for a stereoscopic image of claim 2, wherein the subpixels are each arranged in a stripe shape.
4. The display for a stereoscopic image according to claim 3, wherein the subpixels each have the same area.
5. The display for a stereoscopic image according to claim 4, wherein the sub-pixels are arranged such that intervals between them are equal.
6. The display for a stereoscopic image according to claim 3, wherein the white subpixel has an area greater than or equal to a gap between the subpixels.
7. The display for a stereoscopic image of claim 1, wherein an interval between adjacent patterns of the patterned retarder is smaller than a size including a width of a white subpixel and an interval between the white subpixel and a subpixel adjacent to the white subpixel.
8. The display of claim 3, wherein an area of the white subpixel is 0.3 to 2.5 times the area of each chroma subpixel.
9. The display of claim 3, wherein the patterned retarder is in the form of a stripe.
10. The display for a stereoscopic image of claim 1, wherein the subpixels are formed by periodically repeating a chroma subpixel and a white subpixel.
11. The method of claim 10, wherein the subpixels are red-green-blue-white, red-blue-green-white, green-red-blue-white, green-blue-red-white, blue-red-green-white or blue A display for stereoscopic images formed by periodically repeating arrangement of green-red-white.

Images