WO2020082622A1

WO2020082622A1 - Backlight module for narrow-bezel display screen

Info

Publication number: WO2020082622A1
Application number: PCT/CN2019/071687
Authority: WO
Inventors: 郑净远
Original assignee: 惠州市华星光电技术有限公司
Priority date: 2018-10-23
Filing date: 2019-01-15
Publication date: 2020-04-30
Also published as: CN109375415B; CN109375415A

Abstract

A backlight module, wherein the side of a plastic frame (303) facing a light source (304) is provided with a light inlet (307) and a light outlet (306). The light inlet (307) is provided in the side of the plastic frame (303) facing the light source (304), and the light outlet (306) is correspondingly provided in the top of the plastic frame (303). The light inlet (307) communicates with the light outlet (306). The backlight module can ensure that the light from the light source (304) is reflected to a shadow area at the edge of the panel (301) through the light inlet (307) and the light outlet (306) in sequence, thereby improving dark zones existing at the peripheral edges of an operable area of a narrow-bezel screen.

Description

Backlight module for narrow frame display screen

Technical field

The invention relates to the field of display technology, in particular to the structure of a display screen, and in particular to a backlight module.

Background technique

In the current display field, the quality of the backlight module determines the quality of the display screen. In many large occasions, the splicing screen is used to display the picture to meet the needs of viewing by many people. However, because the main stitching of the splicing screen (that is, the distance from the operating area to the frame) is too narrow, only 3.5 mm, it will cause The edges around the operable area of the panel become dark bands due to the inaccessibility of light, thereby reducing the picture quality of the screen, as shown in Figures 1 and 2.

In summary, in the prior art, there is a dark band problem around the edges of the operable area of the narrow-frame screen, which affects the picture quality of the screen. Therefore, there is room for improvement in the prior art.

technical problem

The invention provides a backlight module with a narrow border, which is used to improve the dark band problem existing around the edges of the operable area of the narrow border screen and improve the human eye's picture quality experience at the seam of the screen.

Technical solution

In order to solve the above problems, the technical solution of the present invention provides a backlight module, at least including:

A plastic frame, a back plate provided at the bottom of the plastic frame, a diffusion plate provided at the top of the plastic frame, and a light source distributed between the back plate and the diffusion plate;

The diffusion plate includes a bright surface area, and an adhesive area located at an edge of the bright surface area, and the adhesive area of the diffusion plate is adhered and fixed to the surface of the plastic frame;

Wherein, the side of the plastic frame facing the light source is provided with a light inlet, and the top of the plastic frame is provided with a light outlet, and the light inlet is communicated with the light outlet to realize the light passage of the light source The inner wall of the plastic frame is reflected to the bonding area to enhance the brightness of the bonding area.

In the backlight module of the present application, the height of the light entrance is one-half the width of the bonding area, and the width of the light exit is one-half the width of the bonding area.

In the backlight module of the present application, the surface of the light inlet is perpendicular to the surface of the light source, and the vertical distance between the light inlet and the surface of the light source is a first distance. The vertical distance between the surfaces of the light entrance is a second distance, and the ratio of the first distance to the second distance is tan (30 ° ± 5 °).

In the backlight module of the present application, the light outlet is provided at any position where the top of the plastic frame is not in contact with the diffusion plate.

In the backlight module of the present application, the lengths of the light inlet and the light outlet are smaller than the lengths of the corresponding sides of the plastic frame.

In the backlight module of the present application, the plastic frame is a hollow frame body, and a diffuse reflection surface is provided inside the plastic frame.

In the backlight module of the present application, the plastic frame is a solid frame body, and an optical channel is provided in the plastic frame, one end of the optical channel is the light inlet, and the opposite end of the optical channel is The light outlet.

In the backlight module of the present application, the light channel in the solid frame is referred to as a linear channel, and the angle between the linear channel and the side of the top of the plastic frame facing the light source is an acute angle.

In the backlight module of the present application, the light channel includes at least two ends of straight channels, the first straight channel is connected to the light outlet, and the first straight channel is perpendicular to the top of the plastic frame.

In the backlight module of the present application, the light channel includes at least one curved channel.

In addition, the technical solution of the present invention provides another backlight module, at least including:

Wherein, the side of the plastic frame facing the light source is provided with a light inlet, and the top of the plastic frame is provided with a light outlet, and the light inlet is communicated with the light outlet to realize the light passage of the light source The inner wall of the plastic frame is reflected to the bonding area to enhance the brightness of the bonding area;

The lengths of the light entrance port and the light exit port are greater than or equal to the length of their corresponding bonding areas.

Beneficial effect

The beneficial effects of the present invention are: a backlight module provided by the present invention. Compared with the prior art, the backlight module has the following differences:

The side of the plastic frame of the backlight module facing the light source is provided with a light inlet, the top of the plastic frame is provided with a light outlet, and the light inlet is in communication with the light outlet, wherein the height of the light inlet is The width of the bonding area is half, the width of the light outlet is half of the width of the bonding area, and the position of the light entrance is also required, and finally the light of the light source can be sequentially passed The light entrance and the light exit are thus reflected to the shadow area on the edge of the panel, thereby improving the brightness of the dark band area of the narrow border and reducing the width of the dark band area, thereby bringing a better picture experience to the user.

BRIEF DESCRIPTION

In order to more clearly explain the embodiments or the technical solutions in the prior art, the following will briefly introduce the drawings used in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only inventions. For some embodiments, those of ordinary skill in the art can obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic cross-sectional view of the structure of a direct type backlight module in the prior art.

FIG. 2 is a schematic diagram of the effect of the dark band area in the direct-lit backlight module in the prior art.

3 is a schematic cross-sectional view of a structure of a direct type backlight module provided by an embodiment of the present invention.

4 is a schematic cross-sectional view of a structure of a direct type backlight module provided by another embodiment of the present invention.

FIG. 5 is a schematic diagram of the effect of the dark band area in the direct backlight module provided by the embodiment of the present invention.

Best Mode of the Invention

The technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts fall within the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "upper", "lower", "inner", "outer", "surface", "vertical", etc. indicate the orientation or positional relationship based on the drawings. Orientation or positional relationship, where “upper” and “lower” are just surfaces above the object, specifically referring to directly above, diagonally above, and upper surface, as long as they are above the level of the object, while “surface” refers to The two objects are in direct contact with each other. The above orientation or positional relationship is only for the convenience of describing the present invention and simplifies the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, therefore It cannot be understood as a limitation to the present invention.

It should be noted that the terms "thickness", "width" and "length" are all neutral words, and do not mean that they are thick or thin, wide or narrow. The term "preset" is used here only to mean that there is a certain distance between objects Thickness, width or length, the value is uncertain, but will depend on the actual situation. In addition, the letters "H", "P", and "D" refer to a certain value. Due to the current ignorance, we can only use letters to represent them. The purpose is to represent the values between related objects or positions. Distance relationship.

In addition, it should be noted that the drawings only provide structures and / or steps that are closely related to the present invention, omitting some details that are not related to the invention, the purpose is to simplify the drawings and make the invention clear at a glance. It does not indicate that the actual device and / or method is exactly the same as the drawings, and is not intended to be a limitation of the actual device and / or method.

As shown in FIG. 1, a cross-sectional schematic diagram showing the structure of a direct type backlight module in the prior art. According to FIG. 1, we can find that the light emitted by the light source 104 on the back plate (not shown) of the plastic frame 103 is due to the side of the plastic frame 103 The blocking causes the light to be reflected to the middle part of the diffusion plate 102 that is not in contact with the plastic frame, that is, the light from the light source 106 is finally reflected evenly to the panel 101, and the part bonded to the plastic frame 103 around the diffusion plate 102 is due to The light cannot be reflected, and finally a dark band 105 of a certain width appears around the panel 101. For details, please refer to the schematic diagram of the effect of the dark band in the direct-lit backlight module shown in FIG. 2, where the edges are shallow The color indicates that the brightness is low, and it can be observed that the dark band 105 (that is, the light-colored area on the edge of FIG. 2) in the prior art has a large width and less light.

As shown in FIG. 3, a schematic cross-sectional view showing the structure of a direct type backlight module provided by an embodiment of the present invention. ), A diffusion plate 302 provided on the top of the plastic frame 303, and a light source 304 distributed between the back plate and the diffusion plate, a panel 301 is installed above the diffusion plate 302, and the length of the panel 301 around Both exceed the length of the diffusion plate 302 around.

The area where the diffusion plate 302 is bonded to the top surface of the plastic frame 303 is defined as the bonding area, and the other areas of the diffusion plate 302 are defined as the bright area.

As shown in FIG. 3, the plastic frame 303 in the figure is a hollow frame, and each side of the plastic frame 303 has a certain thickness. Compared with the prior art in this embodiment, in the plastic frame 303 A light inlet 307 is opened on the side facing the light source, and a light outlet 306 is opened on the top of the plastic frame, wherein each light inlet 307 and light outlet 306 are in one-to-one correspondence.

Wherein, for any of the shadow strips 305 (adhesion area), assuming that the width of the shadow strip 305 (adhesion area) is D, the height of the light entrance 307 should be set as the shadow strip One-half of the width of 305 (adhesion area), the width of the light outlet 306 is one-half of the width of the shadow zone 305 (adhesion area). Here, if the height of the light inlet 307 and the width of the light outlet 306 are greater than D / 2, the edge brightness will be too high, and if it is smaller than D / 2, the effect of shading may be poor, so here the light inlet 307 Setting the height and the width of the light outlet 306 to D / 2 is a better choice. Such a size design changes the originally completely opaque area (0%) of the dark band 307 into at least a slight fill light (+ 20%) , The actual improvement effect will be much greater than 20%.

In particular, the position of the light inlet 307 on the plastic frame 303 is specified as follows:

The plastic frame 303 has several vertical surfaces, and any one of the vertical surfaces is provided with a light inlet 307, and the surface of the light inlet 307 and the surface of the light source 304 are perpendicular to each other. For a certain light entrance 307, it is assumed that the shortest vertical distance from the plane of the light entrance 307 among all the light sources 304 is defined as P, and the face of the light entrance 307 and the light source 304 is located The vertical distance of is defined as H, then the above H and P should satisfy H / P = tan (30 ° ± 5 °).

Similarly, for this backlight module, the position of each light inlet 307 and the corresponding H and P should comply with the above regulations.

In addition, the light outlet 306 is provided at any position on the top of the plastic frame 303 where the diffusion plate 302 and the plastic frame 303 are not in contact, because in practice the width of the edges of the panel 301 and the diffusion plate 302 The difference is very small, only about 3.5 mm, so the distance between the light exit 306 and the diffusion plate 302 need not be considered.

It should be understood that, in order to allow the light from the light source 306 to pass through the light inlet 307 and the light outlet 306 in order to be reflected to the dark band 305 (bonding area), the light inlet 307 and the light outlet The thickness of 306 should be based on the thickness of the side wall passing through the corresponding plastic frame 303.

It should be noted that FIG. 3 is only a schematic cross-sectional view of the structure of a direct type backlight module provided by an embodiment of the present invention. In practice, the light entrance 307 and the light exit 306 have a certain length, and the light entrance The length of the port 307 and the light exit port 306 must be greater than or equal to the length of the corresponding dark band 305 (bonding area) to ensure that the brightness of the entire dark band 305 (bonding area) length can be improved; and, the light entrance port The lengths of 307 and the light outlet 306 are smaller than the corresponding lengths of the sides of the plastic frame 303, otherwise the side frames of the plastic frame 303 are split into multiple separate parts by the light inlet 307 and the light outlet 306, It should be understood that the normal plastic frame 303 cannot be formed to realize the functions of reflection and the like of the normal plastic frame 303.

As described above, in the embodiment of FIG. 3, most of the light emitted by the light source 304 on the back plate of the plastic frame 303 directly hits the diffuser plate 302 or is reflected by the inner surface of the plastic frame 303 to the diffuser plate 302. A part of the light from the nearest LED point light source 304 is reflected by the light inlet 307 and the light outlet 306 to the dark area 307 at the edge of the panel 301 in turn, that is, the light part where the light intensity is high is transferred to the weak light intensity Area to improve the picture quality of the dark zone 307 of the panel. For the specific improvement of the light in the shadow zone 307, refer to FIG. 5. In FIG. 5, the gray scale becomes darker, indicating that the brightness is increased, that is, the intensity of light becomes larger, so that the image quality around the final screen is improved.

FIG. 4 is a schematic cross-sectional view showing the structure of a direct type backlight module provided by another embodiment of the present invention. Compared with the backlight module in FIG. 3, this backlight module differs from the backlight module in FIG. The plastic frame 403 is a solid frame. Next, the difference between the embodiment of FIG. 4 and the embodiment of FIG. 3 will be highlighted.

In FIG. 4, the area where the diffusion plate 402 is bonded to the top surface of the plastic frame 403 is defined as the bonding area, and the other area of the diffusion plate 402 is defined as the bright surface area.

The backlight module is also provided with a light inlet 407 and a light outlet 406 on the plastic frame 403. Since the plastic frame 403 is solid, an optical channel is provided inside the plastic frame 403. One end of the light channel is the light inlet 407, and the opposite end of the light channel is the light outlet 406.

The size and position of the light inlet 407 and the light outlet 406 are the same as those in the embodiment corresponding to FIG. 3.

The light channel in FIG. 4 is configured as two straight-line channels, the first straight-line channel is connected to the light outlet 406, the first straight-line channel is perpendicular to the top of the plastic frame 403, and the second straight-line channel is connected该光光口 407。 The light entrance 407.

As described above, the light from the light source 404 passes through the light inlet 407 and the light outlet 406 in sequence, and the light undergoes multiple reflections on the inner wall of the light channel and is finally reflected to the dark band 405 (bonding area) of the panel 401 .

For the case where the plastic frame is solid, in addition to the embodiment described in FIG. 4, the light channel may also be set as a linear channel, wherein the linear channel and the top of the plastic frame face the side of the light source The included angle is an acute angle; the light channel can also be set as one or more curved channels or a channel in which straight lines and curves are mixed and matched.

It should be understood that regardless of the shape and path of the light channel, the principle is to use multiple reflections of light to transfer part of the light from the light source 404 to the dark band 405 (bonding area) on the panel 401, In this way, the dark bands existing around the edges of the operable area of the narrow bezel screen are improved.

When the plastic frame is solid, the effect diagrams produced by using the foregoing embodiments are shown in FIG. 5.

The structure and position relationship of a narrow-frame backlight module provided by the embodiments of the present invention have been described in detail above, and specific examples have been used in this paper to explain the principles and implementations of the present invention. To help understand the technical solutions of the present invention and its core ideas; those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or equivalently replace some of the technical features; and these Modifications or substitutions do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

A backlight module includes at least:

A plastic frame, a back plate provided at the bottom of the plastic frame, a diffusion plate provided at the top of the plastic frame, and a light source distributed between the back plate and the diffusion plate;

The diffusion plate includes a bright surface area, and an adhesive area located at an edge of the bright surface area, and the adhesive area of the diffusion plate is adhered and fixed to the surface of the plastic frame;

Wherein, the side of the plastic frame facing the light source is provided with a light inlet, and the top of the plastic frame is provided with a light outlet, and the light inlet is communicated with the light outlet to realize the The inner wall of the plastic frame is reflected to the bonding area to enhance the brightness of the bonding area.
The backlight module according to claim 1, wherein the height of the light entrance is half of the width of the bonding area, and the width of the light exit is half of the width of the bonding area One.
The backlight module according to claim 1, wherein the surface of the light inlet is perpendicular to the surface of the light source, and the vertical distance between the light inlet and the surface of the light source is a first distance, The vertical distance between the light source and the surface where the light entrance is located is a second distance, and the ratio of the first distance to the second distance is tan (30 ° ± 5 °).
The backlight module according to claim 1, wherein the light outlet is provided at any position where the top of the plastic frame is not in contact with the diffusion plate.
The backlight module according to claim 1, wherein the lengths of the light inlet and the light outlet are smaller than the length of the corresponding side of the plastic frame.
The backlight module according to any one of claims 1 to 5, wherein the plastic frame is a hollow frame body, and a diffuse reflection surface is provided inside the plastic frame.
The backlight module according to any one of claims 1 to 5, wherein the plastic frame is a solid frame body, and an optical channel is provided in the plastic frame, and one end of the optical channel is the light inlet. The opposite end of the light channel is the light exit port.
The backlight module according to claim 7, wherein the light channel is provided as a straight channel, and the angle between the straight channel and the side of the top of the plastic frame facing the light source is an acute angle.
The backlight module according to claim 7, wherein the light channel comprises at least two straight-line channels, the first straight-line channel is connected to the light outlet, the first straight-line channel and the top of the plastic frame vertical.
The backlight module according to claim 7, wherein the light channel includes at least one curved channel.
A backlight module includes at least:

A plastic frame, a back plate provided at the bottom of the plastic frame, a diffusion plate provided at the top of the plastic frame, and a light source distributed between the back plate and the diffusion plate;

The diffusion plate includes a bright surface area, and an adhesive area located at an edge of the bright surface area, and the adhesive area of the diffusion plate is adhered and fixed to the surface of the plastic frame;

Wherein, the side of the plastic frame facing the light source is provided with a light inlet, and the top of the plastic frame is provided with a light outlet, and the light inlet is communicated with the light outlet to realize the light passage of the light source The inner wall of the plastic frame is reflected to the bonding area to enhance the brightness of the bonding area;

The lengths of the light entrance port and the light exit port are greater than or equal to the length of their corresponding bonding areas.
The backlight module according to claim 11, wherein the height of the light entrance is half of the width of the bonding area, and the width of the light exit is half of the width of the bonding area One.
The backlight module according to claim 11, wherein the surface of the light inlet is perpendicular to the surface of the light source, and the vertical distance between the light inlet and the surface of the light source is a first distance, The vertical distance between the light source and the surface where the light entrance is located is a second distance, and the ratio of the first distance to the second distance is tan (30 ° ± 5 °).
The backlight module according to claim 11, wherein the light outlet is provided at any position where the top of the plastic frame is not in contact with the diffusion plate.
The backlight module according to claim 11, wherein the lengths of the light inlet and the light outlet are smaller than the length of the corresponding side of the plastic frame.
The backlight module according to any one of claims 11 to 15, wherein the plastic frame is a hollow frame body, and a diffuse reflection surface is provided inside the plastic frame.
The backlight module according to any one of claims 11 to 15, wherein the plastic frame is a solid frame body, and an optical channel is provided in the plastic frame, and one end of the optical channel is the light inlet. The opposite end of the light channel is the light exit port.
The backlight module according to claim 17, wherein the light channel is provided as a straight channel, and the angle between the straight channel and the side of the top of the plastic frame facing the light source is an acute angle.
The backlight module according to claim 17, wherein the light channel comprises at least two linear channels, the first linear channel is connected to the light outlet, the first linear channel and the top of the plastic frame vertical.
The backlight module of claim 17, wherein the light channel includes at least a curved channel.