WO2018113316A1

WO2018113316A1 - Direct backlight module and liquid crystal display device

Info

Publication number: WO2018113316A1
Application number: PCT/CN2017/096682
Authority: WO
Inventors: 李富琳; 金海洋; 袁光军
Original assignee: 青岛海信电器股份有限公司
Priority date: 2016-12-23
Filing date: 2017-08-09
Publication date: 2018-06-28
Also published as: CN106597741A

Abstract

A direct backlight module and a liquid crystal display device, the backlight module comprising a back plate (36), an LED light source (31), a reflecting sheet (32) and an optical conversion film (34), the back plate (36) comprising a bottom plate (362) and a side plate (361) disposed surrounding the bottom plate (362) and at an obtuse angle to the bottom plate (362), the LED light source being placed on the bottom plate (362), the reflecting sheet (32) comprising a main reflecting sheet (322) disposed on the bottom plate (362) and a side reflecting sheet (321) disposed on the side plate (361), the LED light source (31) emitting excitation light, so as to stimulate the optical conversion film (34) disposed on the reflecting sheet (32) to generate excited light, and the side reflecting sheet (321) having disposed thereon a material absorbing an excited light wavelength. In this manner, the portion of excited light incident to the side reflecting sheet (321) may be reduced, achieving the goal of the color of light exiting a peripheral location and a central location of a backlight module being consistent.

Description

Direct type backlight module and liquid crystal display device

Technical field

The present application relates to the field of liquid crystal display technology, and in particular, to a direct type backlight module and a liquid crystal display device.

Background technique

In the liquid crystal display device, the backlight module is used to provide a backlight for the liquid crystal display panel, so that the liquid crystal display panel displays the screen normally. The backlight module is divided into a side-in backlight module and a direct-lit backlight module according to the light source entrance position. The side-in backlight module means that the light source is disposed on the side of the backlight module, the light is incident on the light guide plate, and is converted into a uniformly distributed surface light source through the light guide plate and the optical film; the direct-lit backlight module refers to the light source is arranged according to the array manner. In the back plate of the backlight module, the light directly passes through the diffusion plate, the optical film, and the like to form a uniformly distributed surface light source.

At present, quantum dot technology is commonly used in direct-lit backlight modules to achieve high color gamut display. For example, a blue light-emitting diode (LED) light-emitting chip emits blue light, and the red and green quantum dot materials encapsulated in the quantum film are excited to generate yellow light, and the generated yellow light is mixed with partially transmitted blue light. For white light, up to 100% of the National Television Standards Committee (NTSC) color gamut.

Summary of the invention

The embodiments of the present application provide some technical solutions:

In a first aspect, the present application provides a direct type backlight module, including a back plate, an LED light source, a reflective sheet, and an optical conversion film, wherein the back plate includes a bottom plate at an edge of the bottom plate and at an angle with the bottom plate An obtuse-angled inclined side plate on which an LED light source is placed, the reflective sheet comprising a main reflection sheet placed above the bottom plate and a side reflection sheet placed above the side plate, the LED light source emitting excitation light, Exciting light is generated by exciting the optical conversion film disposed above the reflective sheet, wherein the side reflective plate is provided with a first material for absorbing the band of the excited light .

In a second aspect, the present application provides a direct type backlight module, including a back plate, an LED light source, a reflective sheet, and an optical conversion film, wherein the back plate includes a bottom plate at an edge of the bottom plate and at an angle with the bottom plate An obtuse-angled inclined side plate on which an LED light source is placed, the reflective sheet comprising a main reflection sheet placed above the bottom plate and a side reflection sheet placed above the side plate, the LED light source emitting excitation light, The excitation light is generated by exciting the optical conversion film disposed above the reflection sheet, wherein the main reflection plate is provided with a second material for absorbing the excitation light band.

In a third aspect, the present application further provides a liquid crystal display device including a display panel and the backlight module of the above first aspect.

In a fourth aspect, the present application further provides a liquid crystal display device including a display panel and the backlight module of the second aspect.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application, a brief description of the drawings to be used in the description of the embodiments will be briefly made. It is obvious that the drawings in the following description are some embodiments of the present application. Other drawings may also be obtained from those of ordinary skill in the art in view of the drawings.

1 is a schematic structural view of a direct type backlight module to which an optical conversion film is applied;

2 is a top plan view of a back plate portion of the direct type backlight module shown in FIG. 1;

3 is a front elevational view of the back plate portion of the direct type backlight module shown in FIG. 1;

4 is a schematic diagram of light propagation of a direct type backlight module using an optical conversion film according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a direct type backlight module according to an embodiment of the present application; FIG.

FIG. 5A illustrates an embodiment of the arrangement of the first material absorbing the band of excited light on the side reflection sheet provided by the embodiment of the present application; FIG.

FIG. 5B illustrates another embodiment of the arrangement of the first material absorbing the band of excited light on the side reflection sheet provided by the embodiment of the present application; FIG.

6 is a schematic view of a portion of a reflective sheet in the backlight module shown in FIG. 5;

FIG. 7 is a schematic diagram of light propagation of the backlight module shown in FIG. 5. FIG.

detailed description

The technical solutions in the embodiments of the present application are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present application. It is a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without creative efforts are within the scope of the present application.

It should be noted that the optical conversion film described in the present application may be a quantum film or a phosphor film, which is not limited in the present application. The quantum dot material may be encapsulated in the quantum film, and the phosphor powder may be encapsulated in the phosphor film.

The inventors have found that after applying a quantum film encapsulating red and green quantum dot materials, the edge position of the backlight module may be yellowish. For example, using a purple LED, the light emitting chip emits violet light, and the red, green and blue quantum dot materials encapsulated in the quantum film are excited to generate green light, and the generated green light is mixed with the partially transmitted violet light to emit white light. Up to 100% NTSC color gamut. However, after applying a quantum film encapsulating red, green, and blue quantum dot materials, the edge position of the backlight module may be greenish. The edge position of the backlight module is inconsistent with the color of the outgoing light at the intermediate position.

The embodiment of the present application is described below with the optical conversion film as a quantum film. The principle is similar for the optical conversion film as a phosphor film, and details are not described herein again. Since the quantum film is encapsulated with uniformly distributed red and green quantum dot materials, the ratio of the blue light emitted from each position of the quantum film and the yellow light excited by the blue light is constant, so that the color of the backlight module is uniform at each position. However, in the direct-type backlight module in which the quantum film is actually applied, the problem that the peripheral edge position of the backlight module is yellowish from the middle position is generated. The inventor has found through a lot of experimental research and analysis that the edge position of the backlight module is yellowish. The reason is as follows.

1 is a schematic structural view of a direct type backlight module using a quantum film, FIG. 2 is a top view of a back plate portion of the direct type backlight module shown in FIG. 1, and FIG. 3 is a back view of the direct type backlight module shown in FIG. The front view of the board section, which is the view when viewed from the side. As shown in FIG. 1-3, the backlight module includes a backing plate 12, a reflection sheet 13, an LED light source 11, and a quantum film 14 in order from bottom to top. Wherein the wavelength band of the excited light generated by the quantum dot material encapsulated in the quantum film is complementary to the wavelength band of the excitation light emitted by the LED light source, so that the excited light and the excitation light are mixed to form white light. . For example, the LED light source 11 can emit blue light by using a blue LED light emitting chip, and the red quantum dot material and the green quantum dot material encapsulated in the quantum film 14 are excited to generate yellow light, and the generated yellow light is mixed with the partially transmitted blue light to be white light. The LED light source 11 can also emit purple light by using a purple LED light emitting chip to excite the red quantum dot material, the green quantum dot material and the blue quantum dot material encapsulated in the quantum film 14 to generate green light, and the generated green light and partially transmitted violet light. Mix together for white light.

The back plate 12 includes a bottom plate 122 and a side plate 121. The side plate 121 is obliquely disposed at a peripheral edge of the back plate 12 at an angle of an obtuse angle with the bottom plate 122. The LED light source 11 is disposed above the bottom plate 122, so that the position of the side plate 121 is corresponding. Part of the light is irradiated by the LED light source 11 on the bottom plate 122 at a long distance, so that the position is mostly a large angle of excitation light with a weak light intensity, and the light corresponding to the position of the bottom plate 122 is collectively illuminated by the plurality of LED light sources 11 compared to the side plate. The position stimulates light with fewer components.

The following is an example in which the excitation light emitted by the LED light is blue light, and the case where the excitation light emitted by the LED light is purple light or other light is similar, and will not be described herein.

Since the direction of the excited light in the light-emitting process of the excitation optical conversion film is toward the respective directions, the blue light emitted from the LED light source 11 at the position of the bottom plate 122 excites the optical conversion film 14 to generate yellow light in various directions. Among them, part of the yellow light incident Up to the corresponding reflective sheet 13 disposed above the side plate 121, it can be seen from the above analysis that the side plate 121 has less blue light component (the blue light component directly excites the optical conversion film) and is not enough to match and mix the yellow light to form white light. Therefore, the portion of the yellow light is reflected from the edge of the optical conversion film 14 after being reflected by the reflection sheet 13, so that when the ratio of the blue light and the yellow light is constant at the edge position and the intermediate position of the optical conversion film, the yellow light component at the edge position is excessive, and finally the backlight module is caused. The edge position does not match the color of the outgoing light at the intermediate position.

Taking the conversion rate of blue light as 50% as an example, the conversion rate of blue light is similar when it is other values, and will not be described here. 4 is a schematic diagram of light propagation of a direct type backlight module using a quantum film. As shown in FIG. 4, it is assumed that the blue light bj irradiated to the edge position of the quantum film by the LED light source is 50%, and the blue light bi which is irradiated to the intermediate position of the quantum film by the LED light source is 100%. It is assumed that 60% of the yellow light generated by blue light excitation is emitted from the quantum film, 20% is left-backed to convert yellow light, and 20% is right-backward to convert yellow light.

After 50% of the blue light bj at the edge position excites the quantum film, 50%×50%=25% of the yellow light is generated, and 25%×60%=15% of the yellow light yj1 emitted from the quantum film and 50%×50% of the transmission= When 25% of the blue light bj1 is mixed to form white light, the proportion of yellow light in the exiting light at the edge position is 15% / (15% + 25%) = 37.5%.

Further, after the central position 100% blue light bi-excites the quantum film, yellow light is generated 100%×50%=50%, wherein 50%×20%=10% left backward conversion yellow light yi is incident on the side plate position. Since the blue bj component of the position is insufficient to be mixed with the 10% left backward conversion yellow light yi to form white light, the 10% left backward conversion yellow light yi is reflected by the reflection sheet and then emitted from the edge of the quantum film to yellow light yi1 . At this time, the proportion of yellow light in the exiting light at the edge position is (15%+10%)/(15%+25%+10%)=50%>37.5%, so that blue light and yellow light are emitted at the edge position and the intermediate position of the quantum film. When the ratio is constant, the proportion of the yellow light at the edge position is significantly increased, and the edge position of the backlight module is yellowish.

When the LED light emitting chip emits violet light, the quantum film encapsulated with the green quantum dot material is excited by the violet light to generate green light. At this time, the edge position of the backlight module may be greenish, and the specific reason is similar to the above, and will not be described in detail herein. The violet light emitted by the LED light emitting chip may be formed by using an LED blue chip and a red phosphor.

In the direct-type backlight module in which the optical conversion film is applied, in order to solve the problem that the color of the edge of the backlight module is inconsistent with the color of the light emitted from the intermediate position, the embodiment of the present application provides a direct-lit backlight module, wherein the corresponding one of the side plates The side reflector piece is provided with a material for absorbing the band of the excited light to absorb the portion of the excited light incident on the edge of the backlight module, thereby solving the problem of color cast of the position at the intermediate position, and emitting the light at the edge position and the intermediate position of the backlight module. The colors tend to be consistent.

FIG. 5 is a schematic structural diagram of a direct type backlight module according to an embodiment of the present application, and FIG. 6 is a schematic diagram of a portion of a reflective sheet in the backlight module shown in FIG. 5. As shown in FIGS. 5 and 6, the backlight module may include: a back plate 36, placed on the back The LED light source 31 and the reflection sheet 32 above the plate 36, and the diffusion plate 33, the optical conversion film 34, and the optical film 35 which are sequentially placed above the reflection sheet 32.

The LED light source 31 generates excitation light. After passing through the diffusion plate 33, the excitation optical conversion film 34 generates excited light. The excited light and the partially transmitted excitation light are between the reflection sheet 32, the diffusion plate 33 and the optical film 35. After secondary refraction or reflection, the mixture forms a white light. The backing plate 36 includes a bottom plate 362, and side plates 361 located at the peripheral edges of the bottom plate 362 and at an obtuse angle to the bottom plate 362. An LED light source 31 is placed above the bottom plate 362. The side plate 361 supports the diffusion plate 33, and the reflection sheet 32 includes a side reflection sheet 321 disposed above the side plate 361. As an embodiment, the side reflection sheet 321 may be disposed in parallel with the side plate 361 and attached to the side plate 361. As an embodiment, the main reflective sheet 322 can be disposed in parallel with the bottom plate 362 and attached to the bottom plate 362. The first reflective material is disposed on the side reflective sheet 321 . The first material is used to absorb the band of excited light. The function of the first material absorbing the band of the excited light is to selectively absorb the excited light incident on the side reflection sheet, thereby ensuring that the color of the emitted light at each position of the backlight module tends to be uniform.

Wherein, the first material may be a dye, and may be coated or bonded on the side reflection sheet. The first material may also be a pigment as long as the pigment or dye satisfies the condition of selectively absorbing the band of the excited light on the side reflection sheet, which is not limited in the present application.

When the excitation light emitted by the LED light source is blue light and the excited light generated by the optical conversion film is yellow light, the first material may be a material for absorbing the yellow light band, for example, a yellow dye for absorbing the yellow light band. When the excitation light emitted by the LED light source is purple light and the excited light generated by the optical conversion film is green light, the first material may be a material for absorbing the green light band, for example, for absorbing green light band Green dye.

In some embodiments of the present application, the first material may selectively absorb the band of the excited light or selectively absorb the band of the excitation light. The case where the excited light is yellow light and the excitation light is blue light is taken as an example. The case where the excited light is green light or other light, and the excitation light is purple light or other light is similar, and will not be described here. For example, a pigment coating may be disposed on the side reflection sheet, and the pigment coating layer comprises a yellow dye and a blue dye, respectively, selectively absorbing the blue light band incident on the side reflection sheet and the yellow light excited by the blue light. Band; in some embodiments of the present application, the ratio of the absorption of yellow light to blue light can be controlled by adjusting the mass percentage of the yellow dye and the blue dye in the dye coating to achieve the edge position and the intermediate position of the backlight module. The color of the light tends to be consistent.

FIG. 5A illustrates an embodiment of the arrangement of the first material absorbing the band of excited light on the side reflection sheet provided by the embodiment of the present application, wherein the first material may be dot-shaped, and FIG. 5A is exemplarily represented by a solid dot. First material, The larger the solid point, the greater the absorption rate of the first material and/or the larger the dot area. A person skilled in the art may also express the dot-shaped first material in other manners, which is not limited in this application.

The dot-shaped first material may be laid on the side reflection sheet in a dot pattern. The dot-shaped first material may be disposed on the side reflection sheet in such a manner that the density of the dot-shaped first material becomes larger as the direction away from the main reflection sheet is larger; and/or the above-mentioned dot shape The first material may be disposed on the side reflection sheet in such a manner that the absorptivity of the point first material is larger and larger as the direction away from the main reflection sheet. The increase in absorbance can be achieved by adjusting the dot material or expanding the dot area.

FIG. 5B illustrates another embodiment of the arrangement of the first material absorbing the band of excited light on the side reflection sheet provided by the embodiment of the present application, wherein the first material may be strip-shaped, and FIG. 5B is exemplarily dark. The strip indicates the first material, and the wider the width of the dark strip, the greater the absorbance of the first material. A person skilled in the art may also express the strip-shaped first material in other manners, which is not limited in this application.

The strip-shaped first material may be disposed on the side reflection sheet in a manner parallel to a boundary line between the main reflection sheet and the side reflection sheet. In detail, each side reflection sheet and the main reflection sheet have a boundary line, and the strip material on the side reflection sheet and the boundary line between the reflection sheet and the main reflection sheet are parallel to each other, and the strip-shaped first material can be The density of the strip-shaped first material is disposed on the side reflection sheet in such a manner that the direction away from the main reflection sheet is larger and larger; and/or the absorption rate of the first material in the strip shape is away from The direction in which the main reflection sheet is larger and larger is disposed on the side reflection sheet.

In the embodiment of the present application, the first material absorbing the band of the excited light is disposed on the side reflection sheet to absorb the portion of the excited light beam incident on the position, thereby reducing the excited light component at the position, thereby solving the edge position of the backlight module. Compared with the middle position color cast problem, the edge position of the backlight module is consistent with the color of the outgoing light at the intermediate position.

The excitation light emitted by the LED light source 31 is blue light, and the excited light generated by the quantum dot material encapsulated in the blue light excitation quantum film 34 is yellow light, and finally the yellow light and the partially transmitted blue light are mixed into white light, and the first material absorbs the yellow light band. The material is described in detail as an example. For the excitation light to be purple or other light, the excited light is green light or other light. The first material is a material that absorbs the green light band or a material that absorbs other light bands. The detailed process is similar and will not be described here.

FIG. 7 is a schematic diagram of light propagation of the backlight module shown in FIG. 5. FIG. As shown in FIG. 7 , since the LED light source 31 is not disposed above the side plate 361 and is located at the edge of the backlight module, the light bj component is less in the light incident on the side plate 361, and the blue light bj component directly excites the quantum film 34 to generate yellow. The light yj1 is mixed with the partially transmitted blue light bj1 to form white light, and there is no excess ratio of incident blue light and a portion of the left rearward conversion yellow light yi incident on the side reflection sheet 321 (the area adjacent to the region on the quantum dot film is affected by The backward light generated after the excitation is mixed to form white light, resulting in the edge position of the backlight module being yellow. More light components. Therefore, the first reflective material 321 is provided with a first material that absorbs the yellow light band, such that a portion of the left rearward-converted yellow light yi incident on the side reflective sheet 321 is absorbed, so that blue light is emitted at the edge position and the intermediate position of the quantum film. When the ratio of the yellow light is constant, the yellow light component at the position is reduced, thereby solving the problem that the edge position of the backlight module is yellowish from the middle position, and the edge position of the backlight module is consistent with the color of the outgoing light at the intermediate position.

Example 2, as in the first example above, 10% of the left rearward conversion yellow light yi incident on the side reflection sheet, assuming that the material absorbing yellow light can absorb 6% left backward conversion yellow light yi, then there is 4% left rear The yellow light is reflected from the edge of the quantum film after being reflected by the side reflection sheet. At this time, the proportion of yellow light in the exiting light at the edge position is (15%+4%)/(15%+25%+4%)=43%< 50%, so that when the ratio of the blue light and the yellow light is constant at the edge position and the intermediate position of the quantum film, the proportion of the yellow light at the edge position is significantly reduced, and the problem of the color position of the edge of the backlight module is improved, so that the edge position of the backlight module is The color of the outgoing light in the middle position tends to be the same.

In some embodiments of the present application, the amount of the first material absorbing the yellow light band on the side reflection sheet may be adjusted to control the proportion of the side reflection sheet absorbing yellow light, thereby improving the degree of color shift of the edge position of the backlight module relative to the intermediate position. problem. For example, in the above example, the mass of the material absorbing yellow light band can be adjusted so that the ratio of absorbing yellow light is 5%, 6%, 8%, and the like.

The embodiment of the present application further provides a direct type backlight module, which is shown in FIG. 5, wherein a second material is disposed on the main reflector 322, and the second material is used to absorb the excitation light. Band. The function of the second material absorbing the band of the excited light is to selectively absorb the excitation light incident on the main reflection sheet, thereby ensuring that the color of the emitted light at each position of the backlight module tends to be uniform.

Wherein, the second material may be a dye, which may be coated or bonded on the main reflection sheet. The second material may also be a pigment as long as the pigment or dye satisfies the condition of selectively absorbing the excitation light band on the main reflection sheet, which is not limited in the present application.

When the excitation light emitted by the LED light source is blue light and the excited light generated by the optical conversion film is yellow light, the second material may be a material for absorbing the blue light band, for example, a blue dye for absorbing a blue light band; When the excitation light emitted by the LED light source is violet light and the excited light generated by the optical conversion film is green light, the first material may be a material for absorbing the violet light band, for example, a purple dye for absorbing violet light.

Similar to FIG. 5A, in some embodiments of the present application, the second material may be dot-shaped, and the dot-shaped second material may be laid on the main reflective sheet in a dot pattern. The dot-shaped second material may be disposed on the main reflection sheet in such a manner that the density of the second material of the dot-like shape becomes smaller as the direction away from the center of the main reflection sheet is smaller; and/or the above point The second material of the shape may be disposed on the main reflection sheet in such a manner that the absorption rate of the second material of the dot-like shape becomes smaller as the direction away from the center of the main reflection sheet becomes smaller.

Similar to FIG. 5B, in some embodiments of the present application, the second material may be strip-shaped, and the strip-shaped second material may be parallel to the boundary between the main reflective sheet and the side reflective sheet. A line is arranged on the main reflection sheet. The strip-shaped second material may be disposed on the main reflection sheet in such a manner that the density of the strip-shaped second material becomes smaller as the distance from the center of the main reflection sheet is smaller; and/or according to the strip The absorptivity of the second material is disposed on the main reflection sheet in such a manner that the distance from the center of the main reflection sheet becomes smaller.

In the embodiment of the present application, by providing a second material that absorbs the excitation light band on the main reflection sheet to absorb the excitation light incident on the main reflection sheet portion, the excitation light component at the position is reduced, so that the excitation light of the main reflection sheet portion is relatively The problem is that the color position of the edge of the backlight module is more than that of the middle position, and the color of the edge of the backlight module is consistent with the color of the light emitted from the middle position.

The embodiment of the present application further provides a liquid crystal display device, including a display panel and the backlight module shown in FIG. 5 disposed under the display panel, wherein the side reflection sheet of the backlight module may be provided with a first material, The first material is used to absorb the wavelength band of the excited light, and/or the main reflective sheet of the backlight module may be provided with a second material for absorbing the wavelength band of the excitation light to display the liquid crystal display device. The color of the emitted light at each position of the panel is the same.

The above liquid crystal display device may be any product or component having a display function such as a liquid crystal television, a tablet computer, a portable personal computer or the like.

Other configurations and the like of the liquid crystal display device of the embodiment of the present application are well known to those skilled in the art, and reference may be made to the prior art in the art, and will not be described in detail herein.

The above embodiments are only used to explain the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that they can still implement the foregoing embodiments. The technical solutions described in the examples are modified, or some or all of the technical features are equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present application.

Claims

A direct type backlight module includes a back plate, an LED light source, a reflection sheet and an optical conversion film, the back plate includes a bottom plate, and an inclined side plate located at an outer edge of the bottom plate and having an obtuse angle with the bottom plate. An LED light source is disposed above the bottom plate, the reflective sheet includes a main reflective sheet disposed above the bottom plate, and a side reflective sheet disposed above the side plate, the LED light source emitting excitation light to excite the placement The optical conversion film above the reflective sheet generates excited light, wherein the side reflective sheet is provided with a first material for absorbing the band of the excited light.
The direct type backlight module of claim 1, wherein the first material is a dye.
The direct type backlight module according to claim 1, wherein the first material is coated or bonded on the side reflection sheet.
The direct type backlight module according to claim 1, wherein the first material is dot-shaped, and the dot-shaped first material is disposed on the side reflection sheet in a dot shape.
The direct type backlight module according to claim 4, wherein the dot-shaped first material has a density which is larger in a direction away from the main reflection sheet according to a density of the first material in a dot shape. The method is disposed on the side reflection sheet.
The direct type backlight module according to claim 4, wherein the dot-shaped first material has a larger absorption rate of the first material in a point shape as it goes away from the main reflection sheet. The manner is disposed on the side reflection sheet.
The direct type backlight module according to claim 1, wherein the first material is strip-shaped, and the strip-shaped first material is parallel to the main reflection sheet and the side reflection sheet. The boundary line is disposed on the side reflection sheet.
The direct type backlight module according to claim 7, wherein the strip-shaped first material has a density of the strip-shaped first material that is larger and larger in a direction away from the main reflection sheet. The method is disposed on the side reflection sheet.
The direct type backlight module according to claim 7, wherein the strip-shaped first material has an absorption rate of the strip-shaped first material that is larger and larger as it goes away from the main reflection sheet. The manner is disposed on the side reflection sheet.
The direct-lit backlight module of claim 1 , wherein the excitation light emitted by the LED light source is blue light, and when the excited light generated by the optical conversion film is yellow light, the first material is used for absorption. The material of the yellow light band.
The direct type backlight module of claim 1 , wherein the excitation light emitted by the LED light source is violet light, and when the excited light generated by the optical conversion film is green light, the first material is used The material that absorbs the green light band.
A direct type backlight module includes a back plate, an LED light source, a reflection sheet and an optical conversion film, and the back plate includes a bottom plate, an inclined side plate at an edge of the bottom plate and an obtuse angle with the bottom plate, An LED light source is disposed above the bottom plate, the reflective sheet includes a main reflective sheet disposed above the bottom plate and a side reflective sheet disposed above the side plate, the LED light source emitting excitation light to excite the reflection The optical conversion film above the sheet generates an excitation light, characterized in that the main reflection sheet is provided with a second material for absorbing the excitation light band.
The direct type backlight module according to claim 12, wherein the second material is a dye.
The direct type backlight module according to claim 12, wherein the second material is coated or bonded to the main reflection sheet.
The direct type backlight module according to claim 12, wherein the second material is dot-shaped, and the dot-shaped second material is disposed on the main reflection sheet in a dot pattern.
The direct type backlight module according to claim 12, wherein the first material is strip-shaped, and the strip-shaped second material is parallel to the main reflection sheet and the side reflection sheet. The manner of the boundary line is disposed on the main reflection sheet.
The direct type backlight module according to claim 12, wherein the excitation light emitted by the LED light source is blue light, and when the excited light generated by the optical conversion film is yellow light, the second material is used for absorption. The material of the blue light band.
A liquid crystal display device comprising a display panel, further comprising the backlight module of claim 1.