WO2019041787A1 - Liquid crystal display device - Google Patents

Abstract

Provided is a liquid crystal display device capable of enhancing consistency of chromaticity coordinates of respective regions of a display screen. The liquid crystal display device comprises a liquid crystal panel (260), a light guide panel (220), a fluorescent film (230), a light source (210), a first reflective member (240), and a light attenuation layer (250). The light source (210) is arranged opposite to a light-entering surface (2201) of the light guide panel (220), and is used to emit source light. The light-entering surface (2201) is a surface where the source light emitted by the light source (210) enters the light guide panel (220). The fluorescent film (230) is arranged opposite to a light-exiting surface of the light guide panel (220), and is excited by the source light exiting from the light-exiting surface to generate excited light. The first reflective member (240) is arranged opposite to a first side surface (2202) of the light guide panel (220). The first side surface (2202) is a surface of the light guide panel (220) opposite to the light-entering surface (2201). The light attenuation layer (250) is provided between the first side surface (2202) and the first reflective member (240), and is used to absorb light exiting from the first side surface (2202). The liquid crystal panel (260) is arranged opposite to a light-exiting surface of the fluorescent film (230).

Description

Liquid crystal display device

The present application claims priority to Chinese Patent Application No. 200910778680.3, filed on Sep. 1, 2017, the entire disclosure of which is incorporated herein by reference. The content is incorporated herein by reference.

Technical field

The present disclosure relates to the field of display technologies, and in particular, to a liquid crystal display device.

Background technique

A gamut is the sum of colors that a technical system can produce. In general, the color gamut represents the range of colors that a device can express, that is, the range of colors that can be represented by various screen display devices, printers, or printing devices.

At present, in the liquid crystal display industry, in order to achieve a higher color gamut, a fluorescent material having a relatively narrow half-wave width is often used. Some fluorescent materials have a narrow half-wave width due to excitation. However, since the properties of the material cannot be directly placed in the Light Emitting Diode (LED), they need to be encapsulated in the optical film. Therefore, A backlight module with a fluorescent layer separation has appeared. However, the backlight module with such a fluorescent layer separation has a certain color cast problem in practical applications.

Summary of the invention

In a liquid crystal display device provided by some embodiments of the present disclosure, a first side of the light guide plate is a surface opposite to the light incident surface thereof, and a light is disposed between the first reflective sheet and the first side opposite to the first side surface. An attenuating layer that absorbs light from the first side, thereby improving the uniformity of color coordinates of various regions of the display screen.

One embodiment of the present disclosure provides a liquid crystal display device. The liquid crystal display device includes a liquid crystal panel, a light guide plate, a fluorescent film, a light source, a first reflection sheet, and a light attenuating layer. Wherein, the light source is disposed opposite to the light incident surface of the light guide plate for emitting light of the light source. The light incident surface is an incident surface of the light source light emitted from the light source on the light guide plate. The fluorescent film is disposed opposite to the light-emitting surface of the light guide plate for being excited by the light source emitted from the light-emitting surface to generate excitation light. The first reflective sheet is disposed opposite to the first side of the light guide plate. The first side is a surface of the light guide plate opposite to the light incident surface. The light attenuating layer is disposed between the first side and the first reflective sheet for absorbing light from the first side. The liquid crystal panel is disposed opposite to the light emitting surface of the fluorescent film.

DRAWINGS

In order to more clearly illustrate the embodiments of the present disclosure or the related art, the drawings to be used in the embodiments or the related art description will be briefly described below. Obviously, the drawings in the following description are only used for the drawings. One embodiment of the present disclosure is described, and other drawings may be obtained from those skilled in the art without departing from the drawings.

1A is a top plan view of a certain edge region of a backlight module of the related art;

FIG. 1B is a side view of a related art backlight module; FIG.

2 is a schematic structural diagram of a liquid crystal display device according to an embodiment of the present disclosure;

FIG. 3 is a schematic structural diagram of another liquid crystal display device according to this embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of another liquid crystal display device according to this embodiment of the present disclosure.

Detailed ways

The technical solutions in the embodiments of the present disclosure will be clearly and completely described in conjunction with the drawings in the embodiments of the present disclosure. It is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all implementable implementations. example. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure without departing from the inventive scope are the scope of the disclosure. It is to be noted that the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals indicate the same or similar components or components having the same or similar functions. The embodiments described below with reference to the drawings are illustrative, and are not intended to be construed as limiting. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in some embodiments.

In the description of the present disclosure, it is to be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "straight", The orientation or positional relationship of the indications of "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is merely for convenience of description of the present disclosure and simplified description. It is not intended or implied that the device or component that is referred to has a particular orientation, is constructed and operated in a particular orientation, and therefore is not to be construed as limiting.

Moreover, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" or "second" may include one or more features either explicitly or implicitly. In the description of the present disclosure, the meaning of "a plurality" is two or more unless specifically and specifically defined otherwise.

In the present disclosure, the terms "installation", "connected", "connected", "fixed", and the like, are to be understood broadly, and may be either a fixed connection or a detachable connection, unless explicitly stated or defined otherwise. , or integrated; can be mechanical or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two components or the interaction of two components. The specific meaning of the above terms in the present disclosure can be understood by one of ordinary skill in the art based on the specific circumstances.

In the related art, a backlight module in which a fluorescent layer is separated, for example, an LED light source uses a blue light chip and a red fluorescent substance, and a green fluorescent substance is disposed in the optical film. The LED light source emits blue light and red light (mixed in magenta). After the light reaches the green fluorescent film, part of the blue light is absorbed by the green fluorescent material to generate green light, and part of it is directly transmitted, and the red light is not absorbed by the green fluorescent substance. Light is generated and transmitted directly, and finally a mixture of blue light, green light and red light produces white light.

In the practical application, the backlight module with the phosphor layer separation needs to be provided with a quantum dot film or a phosphor film, and there is a certain color cast problem. For example, when the backlight module adopts a green quantum film or a phosphor film, there is a color difference between the color coordinate point of the middle region and the color coordinate point of the peripheral edge position, and the position of the periphery of the screen is magenta, which affects the display effect.

There are two main reasons for this phenomenon:

The first aspect is that the divergence angle of the light emitted by the light guide plate is less than a certain threshold, but the divergence angle of the light generated by the quantum dot film is large, so the color of the white point in the central region of the screen is light from a small area (including from The light emitted by the LED light source after being conducted by the light guide plate has a small light divergence angle; and includes a partial fluorescence of the quantum dot film excited at the small region, a large divergence angle of the fluorescence) and a large area of light ( That is, the quantum dot film around the small area or the fluorescence generated by the excitation of the fluorescent film is mixed. For example, if the LED uses blue light to excite the red phosphor, the quantum dot film is a green quantum dot film, and the small area contributes blue, red and blue light to the green color generated by the quantum film, and the small area mainly contributes green to the surrounding large area (ie, The large area around the small area contributes to the small area mainly by green fluorescence), and the green of this part of the crosstalk is generated by the blue light of the non-small area. For a point close to the edge position, the light of the small area remains unchanged, and the green light component from the periphery of the small area is reduced, resulting in a mixed color of magenta (a mixed color of blue light and red light).

As shown in FIG. 1A and FIG. 1B , a top view and a side view of a backlight module 100 of the related art are respectively shown. Since no blue light is emitted on the right side of the light guide plate 110 or blue light is reduced, the green light generated by the fluorescent film 120 is reduced. The edge position is magenta, so there is a color difference between the color coordinate point of the middle area and the color coordinate point of the surrounding edge position. That is, the display has a different degree of magenta from the peripheral edge to the center. The closer to the edge, the deeper the magenta is, which is a gradual process.

Based on this, some embodiments of the present disclosure provide a side-entry backlight module and a liquid crystal display device. The embodiment will be further described in detail below with reference to the accompanying drawings. It is to be understood that the embodiments described herein are for the purpose of illustration and illustration

One embodiment of the present disclosure provides a liquid crystal display device. As shown in FIG. 2, the liquid crystal display device includes a light source 210, a light guide plate 220, a fluorescent film 230, a first reflective sheet 240, a first light attenuating layer 250, and a liquid crystal panel 260.

The light guide plate 220 includes a light incident surface 2201 , a first side surface 2202 opposite to the light incident surface 2201 , and a light exit surface. The light incident surface 2201 is an incident surface of the light source light emitted from the light source 210 on the light guide plate 220. The light source 210 is disposed opposite to the light incident surface 2201 of the light guide plate 220 for emitting light of the light source. The fluorescent film 230 is disposed opposite to the light-emitting surface of the light guide plate 220, and is excited by the light source emitted from the light-emitting surface to generate excitation light. The first reflective sheet 240 is disposed opposite to the first side surface 2202 of the light guide plate 220. The first light attenuating layer 250 is disposed between the first side surface 2202 and the first reflective sheet 240 for absorbing light source light emitted from the first side surface 2202. The liquid crystal panel 260 is disposed opposite to the light emitting surface of the fluorescent film 230.

In the liquid crystal display device provided in this embodiment, since the first light attenuating layer 250 is disposed between the first side surface 2202 and the first reflective sheet 240 for absorbing the light source light emitted from the first side surface 2202, the light source can be lightened. Or eliminating the color cast phenomenon caused by the reflection of the light of a specific color incident on the first reflection sheet 240.

In an embodiment of the above embodiment, the light source 210 is a light-emitting diode (LED) light source.

In some embodiments of the above embodiments, the light source light is blue light, the fluorescent film 230 is used to be excited by the blue light emitted from the light exiting surface to generate red and green excitation light, and the first light attenuating layer 250 is used for absorption from the first The blue light emitted from the side 2202.

In some embodiments of the above embodiments, the source light is blue light and red light, and the fluorescent film 230 is used to be excited by blue light emitted from the light exit surface to generate green excitation light; the first light attenuation 250 is used for absorption from the first side The red light exiting 2202 is either for absorbing blue light emerging from the first side 2202 or for absorbing red and blue light emerging from the first side 2202.

The light source 210 is an LED light source, which emits blue light and red light, that is, the light source light is blue light and blue light, and the fluorescent film 230 is excited by blue light emitted from the light exiting surface to generate green excitation light, as shown in FIG. The light source 210 may include a blue chip 2102 and a red phosphor 2101. The blue chip 2102 emits blue light, and the red phosphor 2101 is packaged around the blue chip 2102, and is excited by the blue light emitted by the blue chip 2102 to generate red light. The red phosphor 2101 may be a nitride phosphor, a fluoride phosphor or a sulfide phosphor or the like. Therefore, the light emitted by the LED light source 210 behaves as a magenta (mixed light of blue light and red light). The material for forming the fluorescent film 230 may be a green phosphor or a green quantum dot material. After the blue light and the red light emitted from the light exit surface of the light guide plate 220 are incident on the fluorescent film 230, a part of the blue light is directly transmitted, and most of the blue light excitation fluorescent film 230 generates green light, and the red light completely passes through the fluorescent film 230, red light, blue light and The green light is mixed to cause the liquid crystal panel 260 to display white.

In an embodiment of the above embodiment, as shown in FIG. 3, the liquid crystal display device further includes a second light attenuating layer 270 and a second reflective sheet 280. The second reflection sheet 280 is disposed opposite to the bottom surface of the light guide plate 220, and the bottom surface of the light guide plate 220 is a surface of the light guide plate 220 opposite to the light exit surface. The second light attenuating layer 270 is disposed between the bottom surface and the second reflective sheet 280 for absorbing light from the bottom surface.

In some embodiments of the above embodiments, the source light is blue light and the second light attenuating layer 270 is for absorbing blue light emerging from the bottom surface.

In some embodiments of the above embodiments, the source light is blue light and red light, and the second light attenuating layer 270 is for absorbing red light emitted from the bottom surface, or for absorbing blue light emitted from the bottom surface, or for absorbing from the bottom surface. Red and blue light.

In an embodiment of the above embodiment, the bottom surface of the light guide plate 220 is divided into a color cast area 2203. The color cast area 2203 is adjacent to the first side surface 2202 and is an area on the light guide plate 220 corresponding to a region where a color cast phenomenon occurs at the edge of the liquid crystal panel 260.

In one embodiment of the above embodiment, as shown in FIG. 3, the second light attenuating layer 270 is disposed on the edge region of the color cast region 2203 adjacent to the first side surface 2202.

In an embodiment of the above embodiment, as shown in FIG. 4, the second light attenuating layer 270 is disposed on a side of the second reflective sheet 280 facing the bottom surface and an edge region of the first coloring portion 2203 adjacent to the first side surface 2202. Relative position.

In some embodiments of the above embodiments, the second light attenuating layer 270 is in the shape of a dot. The color cast of the liquid crystal panel 260 is increased in the direction from the light incident surface 2201 to the first side surface 2202 of the light guide plate 220, and the color cast phenomenon is the most serious at the position closest to the first side surface 2202 of the light guide plate 220. In order to more effectively eliminate or mitigate different degrees of color cast, the volume and/or density of each dot in the second light attenuating layer 270 may be uniform in the direction from the light incident surface 2201 of the light guide plate 220 to the first side surface 2202. increase. For example, as shown in FIG. 3-4, the closer to the first side surface 2202, the denser the distribution of the dots in the second light attenuating layer 270, the larger the volume; and the farther away from the first side 2202, the first The thinner the distribution of the dots in the two light attenuating layers 270, the smaller the volume.

In an embodiment of the above embodiment, the first light attenuating layer 250 is a light absorbing layer for absorbing the light source light emitted from the first side surface 2202 and passing light having a wavelength band different from that of the light source light; The light attenuating layer 270 is an optical compensation layer for exciting light of the same color as that of the excitation light by the light source emitted from the bottom surface.

Wherein, the light source light may be blue light, the fluorescent film 230 is used to be excited by the blue light emitted from the light exiting surface to generate red and green excitation light, and the first light attenuating layer 250 (light absorbing layer) is used for absorbing from the first side 2202 The emitted blue light, the second light attenuating layer 270 (optical compensation layer) is used to generate green and red excitation light, or yellow light, by blue light emitted from the bottom surface.

Alternatively, the source light may be blue light and red light, the fluorescent film 230 is used to be excited by blue light emitted from the light exit surface to generate green excitation light; and the first light attenuation 250 (light absorbing layer) is used for absorption from the first side 2202 The red light is used to absorb red light and blue light emitted from the first side 2202; the second light attenuating layer 270 (light compensation layer) is used to generate green excitation light by being excited by blue light emitted from the bottom surface.

For example, when the light source 210 emits red light and blue light, the light absorbing layer may be coated between the first side 2202 of the light guide plate 220 and the first reflective sheet 240, made of a material for absorbing red light, or used for absorption. Made of red and blue light materials. The material for fabricating the light absorbing layer has the following characteristics: high absorption rate for red light or red light and blue light, and high transmittance for light of other colors, so as to include red light or red light and blue light. When the light beam is incident on the light absorbing layer, red light or red light and blue light are absorbed by the light absorbing layer, and light energy of other wavelength bands is transmitted through the light absorbing layer without being affected. For example, the material for fabricating the light absorbing layer is an lanthanoid pigment, a flower lanthanum pigment, a diammonium pigment, or a square-like pigment, and may also be a specific microstructured metal nanoparticle such as a side length of 30 to 90 nm and a triangle. Structure of Ag nanostructured materials. The material for fabricating the photo-compensation layer may be a green phosphor or a green quantum dot material which is excited to generate green light after absorbing blue light, and performs green light compensation on the edge region of the liquid crystal panel 260. The light compensation layer may also include dots made of a fluorescent material.

In an embodiment of the above embodiment, the first light attenuating layer 250 is a light compensation layer for absorbing the light source light emitted from the first side surface 2202 to stimulate the light of the same color as the excitation light; the second light attenuation Layer 270 is a light absorbing layer for absorbing light from the source that exits the bottom surface.

Wherein, the light source light may be blue light, the fluorescent film 230 is used to be excited by the blue light emitted from the light exiting surface to generate red and green excitation light; the first light attenuating layer 250 (light compensation layer) is used to receive from the first side 2202 The emitted blue light is excited to generate green and red excitation light, or yellow light; the second light attenuating layer 270 (light absorbing layer) is used to absorb blue light emitted from the bottom surface.

Alternatively, the source light may be blue light and red light, and the fluorescent film 230 is used to be excited by blue light emitted from the light exit surface to generate green excitation light; the first light attenuation 250 (light compensation layer) is used to be emitted from the first side 2202 The blue light excitation produces green excitation light; the second light attenuating layer 270 (light absorbing layer) is used to absorb red light emitted from the bottom surface, or to absorb red light and blue light emitted from the bottom surface.

The fluorescent compensation layer may be disposed in the light compensation layer and applied between the first side surface 2202 of the light guide plate 220 and the first reflection sheet 240. The light absorbing layer may include dots formed of a light absorbing material.

In the above embodiment, the light absorbing layer and the light compensation layer are provided at a position close to the first side surface 2202 of the light guide plate. The light absorbing layer is configured to absorb the light source light that is emitted toward the first reflective sheet 240 or the second reflective sheet 280, thereby reducing or eliminating the partial light generated by the reflected light generated by the specific color of the light passing through the reflective sheet. Color phenomenon. The light compensation layer is excited to generate excitation light of a specified color, further reducing or eliminating the color cast phenomenon caused by the reduction of the excitation light of the specified color at the edge of the display screen. Wherein, the light of a specific color absorbed by the light absorbing layer may be red light or red light and blue light, and the excitation light of the specified color generated by the light compensation layer may be green light; or a specific color absorbed by the light absorbing layer. The light may be blue light, and the excitation light of the specified color generated by the excitation of the light compensation layer may be green light and red light. Thus, the liquid crystal display device provided by the embodiment of the present disclosure, by combining the optical compensation layer and the light absorbing layer, interacts to absorb the excitation light of the second specific color while absorbing the first specific color spectrum, thereby Better solve the problem of color cast on the display.

The above detailed description of the embodiments, the technical solutions and the beneficial effects of the embodiments of the present disclosure are further described in detail, and the above is only the specific embodiments of the embodiments of the present disclosure, and is not intended to limit the present disclosure. The scope of the protection, all modifications, equivalents, improvements, etc., made within the scope of the present disclosure are intended to be included within the scope of the disclosure.

Claims (17)

A liquid crystal display device, comprising: a liquid crystal panel, a light guide plate, a fluorescent film, a light source, a first reflective sheet and a light attenuating layer; among them, The light source is disposed opposite to the light incident surface of the light guide plate for emitting light source light; the light incident surface is an incident surface of the light source light emitted by the light source on the light guide plate; The fluorescent film is disposed opposite to the light emitting surface of the light guide plate for being excited by the light source emitted from the light emitting surface to generate excitation light; The first reflective sheet is disposed opposite to the first side surface of the light guide plate; the first side surface is a surface of the light guide plate opposite to the light incident surface; The light attenuating layer is disposed between the first side surface and the first reflective sheet for absorbing the light source light emitted from the first side surface; The liquid crystal panel is disposed opposite to a light emitting surface of the fluorescent film. A liquid crystal display device according to claim 1, wherein The light attenuating layer is a light absorbing layer for absorbing the light source light emitted from the first side surface and passing light having a wavelength band different from a wavelength band of the light source light. The liquid crystal display device of claim 2, further comprising: a light compensation layer and a second reflective sheet; among them, The second reflective sheet is disposed opposite to the bottom surface of the light guide plate, and the bottom surface is a surface of the light guide plate opposite to the light exiting surface; The light compensation layer is disposed between the bottom surface and the second reflection sheet for exciting light of the light source emitted from the bottom surface to generate light of the same color as the excitation light. A liquid crystal display device according to claim 3, wherein said light compensation layer is provided on an edge of said bottom surface close to said first side. The liquid crystal display device according to claim 3, wherein the light compensation layer is provided on an edge of the second reflection sheet facing the bottom surface and close to the first side surface. A liquid crystal display device according to any of claims 3-5, wherein said light compensation layer comprises dots formed of a fluorescent material. A liquid crystal display device according to claim 6, wherein a volume of each dot in said light compensation layer is uniformly increased in a direction along said light incident surface to said first side surface. A liquid crystal display device according to claim 6, wherein a density of each dot in said light compensation layer is uniformly increased in a direction along said light incident surface to said first side surface. A liquid crystal display device according to claim 1, wherein The light attenuating layer is a light compensation layer; and the light compensation layer is provided with a fluorescent substance for absorbing the light source light emitted from the first side surface to generate light of the same color as the excitation light. The liquid crystal display device of claim 9, further comprising: a light absorbing layer and a second reflective sheet; among them, The second reflective sheet is disposed opposite to the bottom surface of the light guide plate, and the bottom surface is a surface of the light guide plate opposite to the light exiting surface; The light absorbing layer is disposed between the bottom surface and the second reflective sheet for absorbing the light source light emitted from the bottom surface. A liquid crystal display device according to claim 10, wherein said light absorbing layer is provided on an edge of said bottom surface close to said first side. The liquid crystal display device according to claim 10, wherein the light absorbing layer is provided on an edge of the first reflection sheet facing the bottom surface and close to the first side surface. A liquid crystal display device according to claims 9-12, wherein said light absorbing layer comprises dots formed of a light absorbing material. The liquid crystal display device according to claim 13, wherein the volume of each dot in the light absorbing layer is uniformly increased in a direction along the light incident surface to the first side surface. The liquid crystal display device according to claim 13, wherein the density of each dot in the light absorbing layer is uniformly increased in a direction along the light incident surface to the first side surface. A liquid crystal display device according to any one of claims 1 to 15, wherein The light source is blue light; the fluorescent film is used to excite blue light emitted by the light exiting surface to generate red and green excitation light; and the light attenuating layer is configured to absorb blue light emitted from the first side. A liquid crystal display device according to claim 3 or 10, wherein The light source light is red light and blue light; the fluorescent film is used to be excited by blue light emitted from the light exiting surface to generate green excitation light; the light absorbing layer is used to absorb the emitted red light, or to absorb and emit Red and blue light; the light compensation layer is used to be excited by the emitted blue light to produce green excitation light.

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