TW201824243A - Display panel structure - Google Patents

Abstract

A display panel structure includes a liquid crystal layer, a first optical modulation unit disposed at a side of the liquid crystal layer, a second optical modulation unit disposed at an opposite side of the liquid crystal layer, and a backlight unit disposed at a side of second optical modulation unit opposite to the liquid crystal layer. The first and/or second optical modulation units include a color gamut enhance polarizer, which contains a light-absorbing material. The light-absorbing material has a transmission rate at a wavelength range of 570-600 nm, which is 10%, and more preferably 15% lower than a transmission rate at a wavelength 450nm, and 15%, and more preferably 20% lower than a transmission rate at a wavelength 650nm.

Description

Display panel structure

The invention relates to a display panel structure, in particular to a wide color gamut display panel structure.

With the development of science and technology and people's increasing requirements for the color effect of display products, liquid crystal display panels have also developed in the direction of improving the color gamut, that is, increasing the color that can be recognized by the human eye. Wide represents the higher the color coverage that can be recognized by the human eye, so the wide color gamut has also become an indicator of the display quality of the display panel.

The method used to improve the color gamut of the panel in the conventional technology is to use a quantum dot film included in the backlight film to excite the quantum dot film with a blue LED to generate a narrow-band excitation light source to form a wide-band Optical performance of color gamut. However, because the general quantum dot film contains cadmium (Cd), it is toxic and harms the environment. Therefore, how to strike a balance between the demand for display technology with wide color gamut and the world trend of non-toxic and environmental protection, even a win-win situation is still in the industry. One of the goals of the effort.

Therefore, an object of the present invention is to provide a display panel that can obtain a wide color gamut performance without using a backlight quantum dot film.

The present invention specifically provides a display panel structure including: a backlight element; a liquid crystal layer; a first light modulation element, which is located on the opposite side of the liquid crystal layer from the backlight element, and is used to adjust its optical characteristics after the light enters the liquid crystal layer; The second light modulation element is located between the liquid crystal layer and the backlight element, and is used to adjust its optical characteristics before light enters the liquid crystal layer. Wherein, the first light modulating element and / or the second light modulating element includes a color gamut enhancement layer, and the color gamut enhancement layer includes at least one absorbing material, and the transmission spectrum of the absorbing material between the wavelengths of 570-600nm is greater than that of the wavelength between 450nm The transmission spectrum is more than 10% lower and more than 15% lower than the transmission spectrum between 650nm wavelength.

Preferably, the transmission spectrum of the absorbing material between the wavelengths of 570-600 nm is 20% lower than the transmission spectrum of the wavelengths of 450 nm and more than 25% lower than the transmission spectrum of the wavelengths of 650 nm.

According to an embodiment of the present invention, the first light modulation element includes a compensation film on the liquid crystal layer, and the color gamut enhancement polarizer is located on the compensation film, and the second light modulation element includes a metal wire grid polarizer. .

According to an embodiment of the present invention, the compensation film of the first light modulation element is a one-sided compensation film.

According to an embodiment of the present invention, the second light modulation element includes a compensation film on the liquid crystal layer, and the color gamut-enhancing polarizing plate is located on the compensation film, and the first light modulation element includes a metal wire grid polarizing plate. .

According to an embodiment of the present invention, the compensation film of the second light modulation element is a one-sided compensation film.

According to an embodiment of the present invention, the liquid crystal design parameter LC phase difference Delta_nd of the single-sided compensation film is in the range of 300-370nm, R0 is between 50-100nm, and Rth is between 200-350nm, where R0 = (nx-ny) × d; and Rth = ((nx + ny) / 2–nz) × d, where nx, ny and nz represent the three-dimensional spatial refractive index of the compensation film in the x-axis, y-axis, and z-axis, respectively, d Represents the thickness of the compensation film.

According to an embodiment of the present invention, the absorbing material is distributed in an adhesive layer material of the color gamut-enhancing polarizing plate.

According to another embodiment of the present invention, the absorbing material is distributed between an adhesive layer and a protective layer of the color gamut-enhancing polarizing plate.

Hereinafter, the present invention will be described in more detail by the following examples. It should be noted, however, that the following description of the preferred embodiments of the present invention is for the purpose of description and illustration only, and is not intended to limit the present invention.

Please refer to FIG. 1. The display panel structure according to the present invention includes a color filter substrate (not shown) and a thin-film transistor substrate (not shown) sandwiching a liquid crystal layer 11, and the liquid crystal layer 11 is subjected to an applied electric field. Control to change the liquid crystal configuration to control the amount of light passing through different liquid crystal regions; the first light modulation element 12 is located on one side of the liquid crystal layer 11 to adjust its optical characteristics after the light enters the liquid crystal layer; the second light modulation The element 13 is located on the other side of the liquid crystal layer 11 and is used to adjust the optical characteristics of the light before it enters the liquid crystal layer 11, for example, to convert the passing light (polarized light having any direction) into polarized light of a specific direction. And a backlight element 14 located on the opposite side of the second light modulation element 13 from the liquid crystal layer 11 to provide a backlight for display. Wherein, the first light modulation element 12 and / or the second light modulation element 13 includes a color gamut enhancement layer, and the color gamut enhancement layer includes at least one absorbing material, which has a transmission spectrum between a wavelength of 570-600nm and a wavelength of between 450nm and 450nm. The transmission spectrum is more than 10% lower, that is, T (570nm ~ 600nm) <0.9 * T (450nm), preferably 15% lower, and more than 20% lower. And it is more than 15% lower than the transmission spectrum between the wavelengths of 650nm, that is, T (570nm ~ 600nm) <0.85 * T (650nm), preferably more than 20% lower, and more than 25% lower.

In an embodiment of the present invention, the color gamut enhancement layer further includes at least one absorbing material, and the main absorption wavelength of the absorbing material is 560 to 610 nm, more preferably 570 to 600 nm, and most preferably 580 to 590 nm. In addition, the absorbing material 36 may be, for example, a dye, a pigment, or another material capable of absorbing a light band.

The display panel of the present invention may be, for example, a twisted nematic (TN) display panel, a lateral electric field effect (IPS) display panel, or a vertical alignment (VA) display panel. Therefore, the liquid crystal layer 11 may be TN, IPS, or VA liquid crystal cell (Cell).

In the embodiment of the present invention, the backlight emitted by the backlight element 14 does not need to use blue light excited by the quantum dot film, and a general white light backlight source can be used. Of course, different backlight sources can also be used according to other design requirements, or combined with other technologies that help improve the color gamut. In one embodiment, the thin film transistor substrate is closer to the backlight element 14 than the color filter substrate.

FIG. 2 is a schematic cross-sectional view of a display panel structure according to an embodiment of the present invention. The first light modulation element 12 includes a compensation film 21 on the liquid crystal layer 11 and a color gamut enhancement polarizer (Color Gamut Enhance Polarizer). ) 22 is located on the compensation film 21. The second light modulation element 13 includes a polarizing plate 23. The color gamut-enhancing polarizing plate 22 is a polarizing plate containing an absorbing material as described in the description of FIG. 1 and has the functions of polarization and color gamut enhancement. The composition and structural details of the color gamut-enhancing polarizing plate 22 will be described later. It will be explained with reference to FIG. 3.

FIG. 3 shows a polarizing plate according to the present invention, including a polarizing substrate 30 for changing light from non-polarized light to polarized light; an upper protective layer 31 and a lower protective layer 32 for supporting and protecting a polarizing film; The surface protection film 33 is used to protect the polarizing film; an adhesive layer 34 is used to adhere the polarizing film to the liquid crystal layer; and a release film 35 is used to protect the adhesive. When in use, the surface protection film 33 and the release film 35 are peeled off, and adhered to the display panel through the adhesive layer 34.

In the above embodiment, the material of the polarizing substrate 30 may be a polyvinyl alcohol (PVA) resin film, which may be made by saponifying a polyvinyl acetate resin. The materials of the protective layers 31 and 32 are, for example, polymethylmethacrylate (PMMA), Triacetyl Cellulose (TAC), acrylic resin film, polyaromatic hydroxy resin film, polyether resin film, and cyclic polyolefin. Resin film (such as polynorbornene resin film), polyester (Polyethylene Terephthalate (PET), polypropylene (PP), Cyclo Olefin Polymer (COP), polycarbonate (Polycarbonate, PC) and the above A group consisting of any combination; the material of the surface protection film 33 is polyethylene (PE), polyethylene terephthalate (PET); the material of the release film 35 is polyethylene (PE), polyethylene terephthalate Ethylene formate (PET) and the like. The above examples of materials are for illustration purposes only, and those skilled in the art may make appropriate selections based on actual needs, without affecting or limiting the scope of implementation and protection of the present invention.

Among them, the absorbing material 36 in the color gamut-enhancing polarizing plate can be incorporated into the adhesive layer 34 together with the adhesive layer 34, as shown in FIG. 4A, or provided as an independent film layer in the adhesive. The layer 34 and the lower protective layer 32 are formed on the surface of the lower protective layer 32 by, for example, coating, spraying or other film forming methods, and then an adhesive layer 34 is added thereon, as shown in FIG. 4B. In addition to the two methods described above, the absorbing material 36 can also be incorporated into a suitable optical film layer in the polarizing plate when it is stretched into a film, such as the protective layer 31, 32 or the polarizing substrate 30 to achieve an improved color gamut. Effect. When incorporated into the adhesive layer 34 or other optical film layers, its concentration range (or weight percentage) is between 0.1% and 5.0%, preferably between 0.1% and 1.0%. If it is an independent film type, its thickness ranges between 0.1um ~ 5um, preferably between 0.1um ~ 1um.

In one embodiment, the polarizing plate assembly may include other structural types of optical layers, such as optical gain, alignment, compensation, steering, orthogonal, diffusion, protection, anti-sticking, scratch resistance, anti-glare, and reflection suppression. Useful layers such as high refractive index, such as alignment liquid crystal layer with controlled viewing angle compensation or birefraction, etc., easy-to-bond treatment layer, hard coating layer, anti-reflection layer, anti-adhesion layer, diffusion Layer, anti-glare layer and other surface treatment layers.

In this embodiment, the polarizing plate 23 is a metal wire-grid polarizer (WGP), which has the functions of thinning, high transmittance, and increasing light utilization efficiency compared with the optical film polarizing plate. In addition, in order to comply with the characteristics of a metal fence polarizing plate, the compensation film 21 is preferably a single-sided compensation film, that is, the display panel structure of the present invention only needs to arrange a layer of compensation film in the first light modulation element 12, in other words, in the second light No other compensation film is disposed in the metal wire grid polarizing plate 23 of the modulation element 13 and the liquid crystal layer 11. Therefore, in the present invention, since only one-sided compensation film 21 is required, there is an effect of thinning the display panel structure.

As shown in Figure 5, the metal wire grid polarizing plate is made by arranging metal wires on a transparent substrate. The metal wires are arranged in parallel to form a grating. The electrons in the metal wire can only move along the wire. When light is irradiated on the metal wire When the grid polarizing plate is used, the vibration of the light wave electric vector in the direction of the metal wire will be absorbed by the electrons in the metal wire, and the light wave electric vector in the direction of the vertical metal wire can pass through, so that only the photons in the longitudinal direction of the wire are absorbed, and the horizontal photons are absorbed. It is not absorbed, thereby achieving a polarization effect. In addition to using metal wires to make gratings arranged in parallel and in parallel, optical etching can also be used to etch wires with a desired width on a substrate with a metal film deposited. In one embodiment, it can also be embossed with nanometers. Way to form metal wires. The pitch G of the metal lines 51 of the metal wire grid polarizing plate in this embodiment is in the nanometer range (10-200 nm). Its height H is 50-1000 nm. The metal used may be aluminum, silver, gold, lead, copper, etc., and aluminum is particularly preferred. The material of the transparent substrate 50 may be glass. In one embodiment, the metal wires may be formed on the thin film transistor substrate.

In addition, the material of the compensation film 21 is selected, and the vertical alignment (VA) liquid crystal design parameter LC Delta_nd is designed in a range of 300 to 370 nm, so that R0 is between 50 and 100 nm, preferably between 70 and 100 nm, and Rth is between 200 ~ 350nm, preferably 270-320nm. Among them, R0 = (nx-ny) × d; and Rth = ((nx + ny) / 2–nz) × d, where nx, ny, and nz represent the third degree of the compensation film 21 in the x-axis, y-axis, and z-axis, respectively. The spatial refractive index, d represents the thickness of the compensation film 21. At this time, it can have a viewing angle performance equivalent to or better than the original bilateral compensation film. The material of this single-sided optical compensation film 21 can be cellulose triacetate (TAC), cycloolefin polymer (COP), polymethyl methacrylate ( PMMA), polycarbonate (PC), liquid crystal or composite materials.

FIG. 6 is a schematic cross-sectional view of a display panel structure according to another embodiment of the present invention. The first light modulation element 12 includes a metal wire grid polarizing plate 61 on the liquid crystal layer 11, and the second light modulation element 13 includes a compensation film 62 and a color gamut enhancement polarizer 63. Is located on the compensation film 62. Among them, the color gamut-enhancing polarizing plate 63 is a polarizing plate containing an absorbing material as described in the description of FIG. 1, and has the functions of polarization and color gamut enhancement at the same time. As shown in FIGS. 4A and 4B, the design of the compensation film 62 can refer to the design of the compensation film 21 in the previous embodiment, and details are not described herein again. In one embodiment, the metal lines of the metal wire grid polarizing plate 61 may be formed on the color filter substrate.

FIG. 7 is a schematic diagram showing changes in the color gamut of the display panel of the present invention under various standards, where the x-axis is the chromaticity x and the y-axis is the chromaticity y. The display panel developed according to the present invention can effectively improve the color gamut by more than 10% without the need for a quantum dot film. For example, the NTSC color gamut can be increased by approximately 25%, the DCI-P3 color gamut can be increased by approximately 27%, and the BT2020 color gamut can be increased by approximately 19%. If CGEP and WGP are used as the upper and lower polarizers, in addition to effectively improving the color gamut by more than 10%, it can reach 30% penetration and wide viewing angle performance.

Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application.

11‧‧‧LCD layer

12‧‧‧The first light modulation element

13‧‧‧Second light modulation element

14‧‧‧ backlight

21‧‧‧Compensation film

22‧‧‧ color gamut enhanced polarizer

23‧‧‧ metal wire grid polarizer

30‧‧‧Polarized substrate

31‧‧‧ protective layer

32‧‧‧ protective layer

33‧‧‧Surface protection film

34‧‧‧Adhesive layer

35‧‧‧ release film

36‧‧‧ Absorbent material

50‧‧‧ transparent substrate

51‧‧‧metal wire

61‧‧‧metal wire grid polarizer

62‧‧‧Compensation film

63‧‧‧Color Gamut Enhancement Polarizer

FIG. 1 is a schematic diagram of a display panel structure according to the present invention; FIG. 2 is a schematic cross-sectional view of a display panel structure according to an embodiment of the present invention; and FIG. 3 is a cross-sectional view of a polarizer assembly structure providing a color gamut enhanced polarizer according to the present invention. Figure 4A is a schematic diagram of the distribution of an absorbent material in a display panel structure according to an embodiment of the present invention; Figure 4B is a schematic diagram of the distribution of an absorbent material in a display panel structure according to another embodiment of the present invention; Figure 5 A schematic cross-sectional view of an example of a metal wire grid polarizing plate that can be used in a display panel structure of the present invention; and FIG. 6 is a schematic cross-sectional view of a display panel structure according to another embodiment of the present invention; and FIG. 7 is a display of the present invention. Schematic diagram of panel structure color gamut enhancement effect.

no.

Claims (10)

A display panel structure includes: a backlight element; a liquid crystal layer; a first light modulation element located on an opposite side of the liquid crystal layer from the backlight element, and used to adjust optical characteristics after light enters the liquid crystal layer; Two light modulation elements are located between the liquid crystal layer and the backlight element, and are used to adjust the optical characteristics of light before the light enters the liquid crystal layer; wherein the first light modulation element and / or the second light modulation element Containing a color gamut enhancement layer, the color gamut enhancement layer includes at least one absorbing material, the transmission spectrum of the absorption material at a wavelength of 570-600nm is more than 10% lower than the transmission spectrum of a wavelength of 450nm, and the transmission spectrum of a wavelength of 650nm The transmission spectrum is lower than 15%. The display panel structure according to item 1 of the scope of patent application, wherein the transmission spectrum of the absorbing material between the wavelengths of 570-600nm is more than 20% lower than the transmission spectrum of the wavelengths of 450nm and is more than the transmission of the wavelengths of 650nm The spectrum is more than 25% lower. The display panel structure according to item 1 of the scope of patent application, wherein the first light modulation element includes a compensation film on the liquid crystal layer, and the color gamut enhancement layer is on the compensation film, and the first The two light modulation element includes a metal wire grid polarizing plate. The display panel structure according to item 3 of the scope of patent application, wherein the metal wire grid polarizing plate includes a plurality of metal lines and a transparent substrate, wherein the distance between the metal lines is 10-200 nm, and / or the metal lines The height is 50-1000nm. The display panel structure according to item 4 of the scope of patent application, wherein the materials of the metal wires are aluminum, silver, gold, lead, and copper. The display panel structure described in item 4 of the scope of patent application, wherein the material of the transparent substrate may be glass. The display panel structure according to item 3 of the scope of patent application, wherein the compensation film is a single-sided compensation film. The display panel structure described in item 3 of the scope of patent application, wherein the compensation film is designed in a vertical alignment (VA) liquid crystal design parameter LC Delta_nd in a range of 300 to 370 nm, R0 is between 50 to 100 nm, and Rth is 200 ~ 350nm, where R0 = (nx-ny) × d; and Rth = ((nx + ny) / 2–nz) × d, where nx, ny and nz represent the compensation film on the x-axis and y-axis, respectively The three-dimensional spatial refractive index with the z-axis, d represents the thickness of the compensation film. The display panel structure according to item 1 of the scope of patent application, wherein the absorbing material is distributed in an adhesive layer material of the color gamut-enhancing polarizing plate, or the absorbing material is distributed in a color gamut to enhance the adhesion of the polarizing plate. Between the agent layer and a protective layer, or the absorbing material is incorporated in the protective layer or the polarizing matrix. The display panel structure according to item 9 of the scope of the patent application, wherein the main absorption wavelength of the absorbing material is 560 to 610 nm, and / or the absorbing material is a dye, pigment, or other absorbing light band s material.