WO2021128976A1

WO2021128976A1 - Backlight module and liquid crystal display

Info

Publication number: WO2021128976A1
Application number: PCT/CN2020/115941
Authority: WO
Inventors: 夏大学; 陈林; 谢仁礼
Original assignee: 深圳Tcl数字技术有限公司
Priority date: 2019-12-27
Filing date: 2020-09-17
Publication date: 2021-07-01
Also published as: CN211786494U

Abstract

The present disclosure provides a backlight module and liquid crystal display; the light-emitting assembly comprises a red primary color light-emitting element, a blue primary color light-emitting element, a first green primary color light-emitting element, and a second green primary color light-emitting element; the red primary color light-emitting element, blue primary color light-emitting element, first green primary color light-emitting element, and second green primary color light-emitting elements are arranged according to a certain rule. The present disclosure adds a primary color on the basis of a conventional three-primary-color display, significantly increasing the display color gamut of the display to nearly a full color gamut, achieving ultra-wide color gamut display of the display.

Description

Backlight module and liquid crystal display

priority

This disclosure requires the priority of a Chinese patent application filed with the Chinese Patent Office, application number "201922453632.4", and application name "a backlight module and liquid crystal display" on December 27, 2019, the entire content of which is incorporated by reference In this disclosure.

Technical field

The present disclosure relates to the field of display screen devices, in particular to a backlight module and a liquid crystal display.

Background technique

Displays have been widely used in industrial life and production, such as mobile phones, TVs, and computers. Existing displays generally adopt three colors of red (R), green (G), and blue (B) as primary colors to achieve color display. The existing liquid crystal display panel includes a thin film transistor (Thin Film Transistor) array, a color filter (Color Filter, CF) placed above and attached to the thin film transistor array, and a color filter (CF) located between the thin film transistor array and the color filter film. The working principle of the liquid crystal layer (Liquid Crystal Layer) is to control the rotation of the liquid crystal molecules of the liquid crystal layer by applying a driving voltage between the thin film transistor array and the color filter film, and refract the light from the backlight module to produce a picture. With the development of display technology, the color gamut coverage is gradually increasing, and the color performance of the display is further enriched, but there are still large areas that are not covered in the full color gamut.

The tongue-shaped color gamut diagram of CIE1931 (Commission Internationale de L'Eclairage) as shown in Figure 1 (where R is the red primary color, G is the green primary color, and B is the blue primary color). The display tilts to the right half. The main wavelength of green is close to 530-540nm. In the left half of the tongue, a large part of the color is not displayed by the display, which is difficult to meet and meet the requirements of users.

Therefore, the existing technology needs to be improved and developed.

Public content

In view of this, the present disclosure provides a backlight module and a liquid crystal display to improve the color rendering range of the existing display. In the full color gamut, there is still a problem that a large area is not covered.

The present disclosure provides a backlight module, including:

The backlight module includes a light-emitting component, wherein the light-emitting component includes a red primary color light-emitting component, a blue primary color light-emitting component, a first green primary color light-emitting component, and a second green primary color light-emitting component; a red primary color light-emitting component, and a blue primary color light-emitting component , The first green primary color light-emitting elements and the second green primary color light-emitting elements are arranged according to a certain rule.

A liquid crystal display, the liquid crystal display includes a backlight module and a liquid crystal display panel; the backlight module includes a light-emitting component, the light-emitting component includes a red primary color light-emitting component, a blue primary color light-emitting component, a first green primary color light-emitting component, and The second green primary color light-emitting element; the red primary color light-emitting element, the blue primary color light-emitting element, the first green primary color light-emitting element, and the second green primary color light-emitting element are arranged according to a certain rule;

The present disclosure greatly expands the range of the display color gamut of the display by adding a primary color on the basis of the three primary colors of red, green and blue of the traditional display, and increases the color performance capability of the display.

Description of the drawings

Figure 1 shows the tongue color gamut of CIE1931 (Commission Internationale de L'Eclairage).

Figure 2 is a comparison diagram of the color gamut display range with and without Local Dimming technology.

FIG. 3 is a schematic structural diagram of an embodiment of a liquid crystal display of the present disclosure.

FIG. 4 is a schematic diagram of an arrangement structure of a pixel unit in an embodiment of the liquid crystal display of the present disclosure.

5 is a schematic diagram of the arrangement structure of the color filter film in an embodiment of the liquid crystal display of the present disclosure.

FIG. 6 is a schematic diagram of an arrangement structure of a pixel unit in another embodiment of the liquid crystal display of the present disclosure.

FIG. 7 is a schematic diagram of the arrangement structure of the color filter film in another embodiment of the liquid crystal display of the present disclosure.

In the figure: 100, backlight plate; 200, light-emitting component; 210, red primary color light-emitting element; 220, first green primary color light-emitting element; 230, blue primary color light-emitting element; 240, second green primary color light-emitting element; 300, pixel unit; 310. Red sub-pixel; 320, first green sub-pixel; 330, blue sub-pixel; 340, second green sub-pixel; 400, liquid crystal molecular layer; 500, color filter film; 510, red primary color filter film; 520, green primary color filter film; 530, blue primary color filter film; 540, first green primary color filter area; 550, second green primary color filter area.

Detailed ways

In order to make the objectives, technical solutions, and advantages of the present disclosure clearer and clearer, the present disclosure will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, but not used to limit the present disclosure.

In a conventional liquid crystal display, a light-emitting assembly 200 is provided on the backlight plate 100 to form a backlight module. The light-emitting assembly 200 in the backlight module is used to provide sufficient brightness and uniformly distributed light sources for the display to display images normally. The light-emitting assembly 200 includes a plurality of red primary color light-emitting elements 210, a plurality of first green primary color light-emitting elements 220, a plurality of blue primary color light-emitting elements 230, a red primary color light-emitting element, a first green primary color light-emitting element, and a blue primary color light-emitting element. The light is the three primary colors of red, green, and blue, and the colors of the three primary colors of red, green, and blue are added in different proportions to produce a variety of colors. In the specific implementation process, each primary color light-emitting element in the light-emitting assembly 200 adopts LED lamp beads, and the LED lamp beads emit corresponding primary color light. It is easy to think that the light-emitting assembly 200 can also use other light-emitting elements that can emit light of the desired color.

As shown in FIG. 3, this embodiment provides a backlight module. In addition to the red primary color light-emitting element 210, the first green primary color light-emitting element 220, and the blue primary color light-emitting element 230, the light-emitting assembly 200 in the backlight module further includes At least one second green primary color light-emitting element 240, the light-emitting color of the second green primary color light-emitting element 240 is different from the light-emitting colors of the red primary color light-emitting element 210, the first green primary color light-emitting element 220, and the blue primary color light-emitting element 230, that is, The light-emitting elements of different types of the light-emitting assembly 200 have different light-emitting colors, and the dominant wavelengths of the light-emitting elements are all different. The second green primary color light-emitting element 240 can also be multiple light-emitting elements that emit light of different colors, that is, the primary color types of the light-emitting assembly 200 can be set to four or more according to actual conditions to meet user requirements.

In the specific implementation process, the backlight module of this solution also includes a backlight controller (not shown in the figure) that independently controls the backlight of each primary color. The backlight controller that independently controls the backlight of each primary color adopts the backlight driving technology of Local Dimming. Local Dimming refers to local backlight adjustment. The backlight composed of hundreds of LEDs is used to replace the CCFL backlight, so that the backlight LED can be adjusted according to the brightness of the image. The brightness of the bright part of the image can be maximized, while the dark part can be reduced or even turned off to achieve the best contrast. In this way, the reduction of the brightness of the dark area reduces the power consumption of the backlight. Broadly speaking, Local Dimming can be roughly divided into three categories, namely 0D, 1D, and 2D dimming. Among them, 2D dimming can maximize local dimming technology. If Localdimming technology is not added, only four primary colors are displayed, and the expansion effect of the color gamut is worse than that of using Localdimming, as shown in Figure 2 (where R is the red primary color, G1 is the first green primary color, and G2 is the local Dimming technology's second green primary color light-emitting element, G2' is the luminous primary color of the second green primary color light-emitting element that does not use Local Dimming technology, B is the blue primary color), the color gamut display range of the display using Local Dimming technology is G2BRG1 display If the local Dimming technology is not used, the G2 point may go to the G2' point, so that the color gamut area is only the display area of G2'BRG1. Under the same other conditions, the display color gamut display range using Local Dimming technology (The display area of G2BRG1) is obviously larger than the display area without Local Dimming technology (the display area of G2'BRG1). Local dimming is an existing technology, which can enrich the color display of the display, and will not be described in detail here.

In the specific implementation process, four light-emitting elements with different primary colors are used in this embodiment, that is, only one second green primary color light-emitting element 240 is added. The light-emitting assembly 200 includes a red primary color light-emitting element 210, a first green primary color light-emitting element 220, and a blue primary color light-emitting element. The primary color light-emitting element 230 and the second green primary color light-emitting element 240. The light emitted by the second green primary color light-emitting element 240 is another green light that is different from the green light emitted by the first green primary color light-emitting element 220, and its main wavelength is in the blue primary color. Within the main wavelength range of the green primary color, that is, the dominant wavelength of the light emitted by the second green primary color light emitting element 240 is around 520nm, and the light emitted by the second green primary color light emitting element 240 is different from the traditional red, green, and blue light, as the fourth Base color. The red primary color light-emitting elements, the first green primary color light-emitting elements, the blue primary color light-emitting elements, and the second green primary color light-emitting elements are evenly arranged according to certain rules. The arrangement rule is that the red primary color light-emitting elements form a matrix, and the blue primary color light-emitting elements The light-emitting elements form a matrix, the first green primary color light-emitting elements form a matrix, and the second green primary color light-emitting elements form a matrix, which are arranged circularly in the matrix, wherein the number of light-emitting elements in each matrix is the same. For example: 1X1 matrix, a single light emitting element is arranged in a circular order, such as red-first green-blue-second green-red-first green-blue... or red-blue-first green-second green- Red-Blue-First Green-Second Green...; for example, a 10*10 matrix or a 5*5 matrix, which is arranged circularly in order with the matrix as the unit. The fourth primary color (second green primary color) is inserted into the traditional arrangement of light-emitting elements, and the above arrangement makes the light-emitting elements of each primary color evenly distributed. It is easy to think that the arrangement can be adjusted according to the specific situation to adapt to the use environment. Each light-emitting component 200 or the light-emitting matrix composed of several light-emitting components 200 can be individually controlled by the backlight driving technology of local dimming.

This embodiment also provides a liquid crystal display, which includes the above-mentioned backlight module and a liquid crystal display panel. The liquid crystal display panel includes a thin film transistor array (TFT array) arranged on the light-emitting side of the light-emitting component 200, and the light-emitting component The light-emitting side of 200 is the side where light-emitting elements of various colors are attached. The thin film transistor array forms a plurality of pixel units 300, each of the pixel units 300 includes a red sub-pixel 310, a first green sub-pixel 320, and a blue sub-pixel 330 , And the second green sub-pixel 340. Moreover, the red sub-pixel 310, the first green sub-pixel 320, the blue sub-pixel 330, and the second green sub-pixel 340 respectively correspond to the light-emitting colors of the light-emitting elements on the light-emitting assembly 200. The red sub-pixel 310, the first green sub-pixel 320, the blue sub-pixel 330, and the second green sub-pixel 340 are arranged according to a certain rule to form a pixel unit 300. It is easily conceivable that when there are multiple second green primary color light-emitting elements 240, there are also multiple corresponding second green sub-pixels 340.

The liquid crystal display panel further includes a color filter film 500. The color filter film 500 (CF) is arranged on the side of the thin film transistor array facing away from the light-emitting component 200. The color filter film 500 is an optical film that expresses colors. Filter film, it can accurately select the small range of light waves to be passed, and reflect other undesired wavebands to control the color display of the display. The color filter film 500 includes a red primary color filter film 510, a green primary color filter film 520, and a blue primary color filter film 530. The arrangement structure of the red primary color filter film 510, the green primary color filter film 520, and the blue primary color filter film 530 corresponds to the arrangement position of each color sub-pixel of the pixel unit 300 of the thin film transistor array, wherein the green primary color filter The film 520 corresponds to the arrangement position of the first green sub-pixel 320 and the second green sub-pixel 340.

Through the above embodiments, on the basis of the existing red, green, and blue primary color displays, adding another primary color, changing the arrangement of sub-pixels in the pixel unit 300, can display the color range that cannot be covered by the existing display screen. , To achieve ultra-wide color gamut display.

The liquid crystal display in this embodiment also includes an independently controlled liquid crystal molecular layer 400 located between the pixel unit 300 of the thin film transistor array (TFT array) and the color filter film 500 (CF). The liquid crystal molecular layer 400 is a kind of The organic compound layer between the solid and the liquid applies an electric field to the liquid crystal, which will change its molecular arrangement. With the color filter film 500, by changing the voltage applied to the liquid crystal, the light transmittance of a certain color can be changed. How much, that is, changing the voltage across the liquid crystal can change its transmittance. In this embodiment, the liquid crystal molecules can be individually controlled to change the transmittance of a local location.

In the specific implementation process, there are two different implementation modes for each corresponding pixel unit 300 and color filter film 500. The specific implementation is as follows:

Example one:

As shown in FIG. 4, a plurality of pixel units 300 are uniformly distributed on the thin film transistor array, and each pixel unit 300 includes a red sub-pixel 310, a first green sub-pixel 320, a blue sub-pixel 330, and a second green sub-pixel. 340. The second green sub-pixel 340 is a fourth-color sub-pixel. In a pixel unit 300 (the pixel unit is a square), four sub-pixels are arranged according to a certain rule, and the size and arrangement of the four sub-pixels can be adjusted according to actual conditions. In order to adapt to the existing color filter film 500 (Color Filter) structure, in this embodiment, as shown in FIG. 4, the size and arrangement of the sub-pixels are set: the pixel area of the red sub-pixel 310 is compared with that of the blue sub-pixel 310. The pixel areas of the color sub-pixels 330 are the same, the area of the first green sub-pixel 320 is the same as the area of the second green sub-pixel 340, and the sum of the areas of the first green sub-pixel 320 and the second green sub-pixel 340 is equal to the red sub-pixel 310 or the area of the blue sub-pixel 330. The first green sub-pixel 320 and the second green sub-pixel 340 are arranged in a row, horizontally or vertically side by side, forming a combined color sub-pixel with the same shape and area as the red sub-pixel 310 and the blue sub-pixel 330, and the red sub-pixel 310 The blue sub-pixels 330 are arranged on both sides of the combined color sub-pixels to form a pixel unit. That is, on the basis of the pixel units of the existing three-primary-color transistor array, the existing first green sub-pixel 320 is equally divided into the first green sub-pixel 320 and the second green sub-pixel 340. All the pixel units 300 of the thin film transistor array have the same arrangement of sub-pixels and the same area size. This arrangement is compatible with the existing color filter film 500.

As shown in FIG. 5, the color filter film 500 includes a red primary color filter film 510, a green primary color filter film 520, and a blue primary color filter film corresponding to the arrangement structure and area size of each pixel unit 300 of the thin film transistor array. 530. In this embodiment, the light emitted by the first green primary color light-emitting element 220 and the light emitted by the second green primary color light-emitting element 240 are single monochromatic lights with no overlapping spectra, but both can pass through the green primary color filter film 520 at the same time. The first green sub-pixel 320 and the second green sub-pixel 540 use the same green primary color filter film 520 to filter light, that is, the green primary color filter film 520 simultaneously treats the first green sub-pixel 320 and the second green sub-pixel. The 340's backlight is filtered. The size and arrangement of the sub-pixels in this embodiment are set to be compatible with the structure of the existing color filter film 500. Therefore, the color filter film 500 used in this embodiment is an existing common structure and is adapted to The structure of the color filter film 500 is commonly used, and the color filter film 500 does not need to be specially produced in the liquid crystal display production process, which simplifies the process of the liquid crystal display, reduces the manufacturing difficulty, and saves the production cost.

When the main wavelength of the light emitted by the second green primary color light emitting element 240 is close to the main wavelength of the green primary color, the backlight LED can be adjusted according to the brightness of the image through the backlight driving technology of local dimming. As shown in Figure 2, under the same other conditions, the color gamut display range (display area of G2BRG1) of the monitor using Local Dimming technology is obviously larger than the display range without Local Dimming technology (display area of G2'BRG1). Further broaden the range of the display color gamut.

Embodiment two:

In the specific implementation process, the structure of the pixel unit 300 and the color filter film 500 are modified.

A plurality of pixel units 300 are uniformly distributed on the thin film transistor array, and each pixel unit 300 includes a red sub-pixel 310, a first green sub-pixel 320, a blue sub-pixel 330, and a second green sub-pixel 340. In a pixel unit, the four sub-pixels are arranged according to certain rules, and the size and arrangement of the four sub-pixels can be adjusted according to actual conditions. In order to make the arrangement structure of the sub-pixels simpler and reduce the difficulty in fabricating the thin film transistor array, the arrangement and size of the sub-pixels are set as shown in FIG. 6, the red sub-pixel 310, the first green sub-pixel 320, and the blue sub-pixel are set as shown in FIG. The pixel areas of the color sub-pixel 330 and the second green sub-pixel 340 are the same. The second green sub-pixel 340 and the first green sub-pixel 320 are respectively located at diagonal positions of the pixel unit 300, and the red sub-pixel 310 and the blue sub-pixel 330 are respectively located at another diagonal position of the pixel unit 300 to form a pixel unit 300. This arrangement only requires that the second green sub-pixel 340 and the first green sub-pixel 320 are located at diagonal positions, so that the sub-pixels are evenly distributed. It is easily conceivable that the position of each sub-pixel can be adjusted according to the actual situation while ensuring that the second green sub-pixel 340 and the first green sub-pixel 320 are located at diagonal positions. The arrangement and area size of the sub-pixels in each pixel unit 300 in the thin film transistor array are the same. The arrangement of the sub-pixels in this embodiment is simpler than other types of arrangement, which can simplify the operation of producing the thin film transistor array, reduce the difficulty of production, and improve the production efficiency.

As shown in FIG. 7, the structure of the color filter film 500 is adjusted according to the arrangement of the sub-pixels of each color. The color filter film 500 includes the red primary color filter corresponding to the arrangement structure and area size of the sub-pixels of each color of the thin film transistor array. The film 510, the green primary color filter film 520, the blue primary color filter film 530, the green primary color filter film 520 includes a first green primary color filter area 540 and a second green primary color filter area 550; that is, the red primary color filter film Corresponding to the arrangement structure and area size of the red sub-pixels, the blue primary color filter film corresponds to the arrangement structure and area size of the blue sub-pixels, and the first green primary color filter area corresponds to the The arrangement structure of the first green sub-pixels corresponds to the area size, and the second green primary color filter region corresponds to the arrangement structure and area size of the second green sub-pixels. In this embodiment, the light emitted by the first green primary color light-emitting member 220 and the light emitted by the second green primary color light-emitting member 240 are single monochromatic lights, and the spectrum does not overlap. The light emitted by the second green primary color light-emitting member 240 is made according to the light emitted by the second green primary color light-emitting member 240. The corresponding primary color filter film enables the first green primary color filter area 540 to individually filter the backlight emitted by the first green primary color light-emitting element 220, and the second green primary color filter area 550 individually filters the second green primary color light-emitting element 240 The emitted backlight is filtered. In order to adapt to the arrangement of the sub-pixels of each color, the first green primary color filter region 540 and the second green primary color filter region 550 in the color filter film 500 are arranged diagonally, and the red primary color filter film 510 and the blue primary color filter are arranged diagonally. The film 530 is arranged diagonally, so that the position and area size of each primary color filter film correspond to the position and area size of the sub-pixel, and the color filter film 500 can correctly filter the color light that should be filtered.

In summary, the solution of the present disclosure provides a liquid crystal display. On the basis of the existing red, green and blue primary color displays, one other primary color is added to change the arrangement of sub-pixels and color filters in the pixel unit 300. The structure of the film 500, through the regional dynamic backlight control, makes the light become independent and separated primary colors when passing through the color filter film 500, avoiding the mixing and superimposition of different primary color spectra, thereby improving the color saturation of each primary color, which is more traditional The uncovered color range realizes a good display, and a liquid crystal display with an ultra-wide color gamut is realized.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present disclosure, but not to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions recorded in the embodiments are modified, or some of the technical features are equivalently replaced; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

A backlight module comprising a light-emitting component, wherein the light-emitting component includes a red primary color light-emitting element, a blue primary color light-emitting element, a first green primary color light-emitting element, and a second green primary color light-emitting element; and a red primary color light-emitting element The blue primary color light-emitting components, the first green primary color light-emitting components, and the second green primary color light-emitting components are arranged according to a certain rule.
The backlight module of claim 1, wherein, in the light-emitting assembly, the red primary color light-emitting elements form a matrix, the blue primary color light-emitting elements form a matrix, and the first green primary color light-emitting elements form a matrix , The second green primary color light-emitting elements form a matrix, which is arranged in a circle in sequence with the matrix as a unit, wherein the number of light-emitting elements in each matrix is the same.
A liquid crystal display, wherein the liquid crystal display includes a backlight module and a liquid crystal display panel; the backlight module includes a light-emitting component, and the light-emitting component includes a red primary color light-emitting component, a blue primary color light-emitting component, and a first green primary color light-emitting component , And the second green primary color luminous element;

The red primary color light-emitting elements, the blue primary color light-emitting elements, the first green primary color light-emitting elements, and the second green primary color light-emitting elements are arranged according to a certain rule;

The liquid crystal display panel includes a plurality of pixel units, and each pixel unit includes a red sub-pixel, a blue sub-pixel, a first green sub-pixel, and a second green sub-pixel.
3. The liquid crystal display of claim 3, wherein the area of the first green sub-pixel and the area of the second green sub-pixel are the same.
4. The liquid crystal display of claim 4, wherein the area of the red sub-pixel is equal to the area of the blue sub-pixel.
5. The liquid crystal display of claim 5, wherein the sum of the areas of the first green sub-pixel and the second green sub-pixel is equal to the area of the red sub-pixel or the area of the blue sub-pixel.
7. The liquid crystal display of claim 6, wherein the first green sub-pixel and the second green sub-pixel are located in the middle of the pixel unit, and the red sub-pixel and the blue sub-pixel are located in the first Positions on both sides of the green sub-pixel and the second green sub-pixel.
3. The liquid crystal display of claim 3, wherein the area of the red sub-pixel, the area of the blue sub-pixel, the area of the first green sub-pixel and the area of the second green sub-pixel are all the same .
8. The liquid crystal display of claim 8, wherein the first green sub-pixel and the second green sub-pixel are located at diagonal positions of the pixel unit, and the red sub-pixel and the blue sub-pixel They are respectively located at the other diagonal position of the pixel unit.
The liquid crystal display according to claim 3, wherein the liquid crystal display panel further comprises a color filter film, and a red primary color filter film corresponding to the red sub-pixel is arranged on the color filter film. The blue primary color filter film corresponding to the blue sub-pixel and the green primary color filter film corresponding to the first green sub-pixel and the second green sub-pixel.
The liquid crystal display according to claim 3, wherein the liquid crystal display panel further comprises a color filter film, and a red primary color filter film corresponding to the red sub-pixel is arranged on the color filter film. The blue primary color filter film corresponding to the blue sub-pixel, the first green primary color filter area corresponding to the first green sub-pixel, and the second green primary color filter region corresponding to the second green sub-pixel Area.
11. The liquid crystal display of claim 11, wherein the red primary color filter film corresponds to an arrangement structure and an area size of the red sub-pixels, and the blue primary color filter film and the blue sub-pixels are arranged The structure corresponds to the area size, the first green primary color filter area corresponds to the arrangement structure and area size of the first green sub-pixel, and the second green primary color filter area corresponds to the second green sub-pixel The arrangement structure corresponds to the size of the area.
11. The liquid crystal display of claim 12, wherein the first green primary color filter region and the second green primary color filter region are diagonally disposed, and the red primary color filter film and the blue primary color filter film Set diagonally.
3. The liquid crystal display of claim 3, wherein the light-emitting components are individually controlled by Local Dimming's backlight driving technology.
3. The liquid crystal display according to claim 3, wherein the light emitted by the first green primary color light-emitting member and the light emitted by the second green primary color light-emitting member are monochromatic light with non-overlapping spectra.