CN218064734U - Backlight module and display device - Google Patents

Abstract

The utility model relates to a backlight module and display device, backlight unit contain area source, grating diaphragm and accuse light diaphragm. The grating diaphragm is provided with a plurality of blocking parts and a plurality of light transmission parts arranged between the adjacent blocking parts. The light control film is provided with a first reference surface and a plurality of first prism structures arranged on the first reference surface. The blocking part, the light transmission part and the first prism structure extend in the same direction. Each first prism structure is provided with a first optical surface and a second optical surface, the first optical surface and the second optical surface respectively form a first inner included angle and a second inner included angle with the first reference surface, and the first inner included angle is an acute angle and smaller than the second inner included angle. Thereby deflecting light toward one side and suppressing the light-emitting rate of the other side.

Description

Backlight module and display device

The present application claims priority to chinese patent application No. 202221006003.2 entitled "backlight module and display device" filed on 28.4.2022, month and year, which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to an optical element, and more particularly to a backlight module and a display device capable of deflecting a light field.

Background

For a Display device for a vehicle, for example, a Central Information Display (CID), a viewing angle is required to be very wide in a horizontal direction so that passengers on both left and right sides can see Display contents of a screen.

However, the backlight module applied to the Central Information Display (CID) is difficult to be applied to a Display (Driver Information Display, DID) in front of the Driver seat or a Display (Co-Driver Display, CDD) in front of the passenger seat, because the large-angle light of the vehicle Display device may be reflected by the vehicle window to affect driving, and thus the conventional backlight module structure cannot meet the special viewing angle requirement of the vehicle Display device.

SUMMERY OF THE UTILITY MODEL

Therefore, an object of the present invention is to provide a backlight module with light field distribution capable of deviating to one side.

The backlight module comprises a surface light source, a grating diaphragm arranged on the light-emitting side of the surface light source and a light control diaphragm. The grating diaphragm is defined to have a first direction and a second direction which is not parallel to the first direction, the grating diaphragm is provided with a plurality of blocking parts which are arranged along the first direction at intervals and a plurality of light transmission parts which are arranged between the adjacent blocking parts, and the blocking parts and the light transmission parts extend along the second direction. The light control film sheet is provided with a first reference surface and a plurality of first prism structures arranged on the first reference surface along the first direction, each first prism structure extends along the second direction, each first prism structure is provided with a first optical surface and a second optical surface, a first inner included angle is formed between the first optical surface and the first reference surface, a second inner included angle is formed between the second optical surface and the first reference surface, the first inner included angle is an acute angle, and the first inner included angle is smaller than the second inner included angle.

Another technical means of the present invention is to provide the backlight module further comprising a prism sheet disposed between the surface light source and the grating membrane, wherein the prism sheet has a plurality of strip-shaped microstructures respectively extending along the first direction.

Another technical means of the present invention is to provide the backlight module further comprising a prism sheet disposed between the surface light source and the grating membrane, wherein the prism sheet has a plurality of strip-shaped microstructures extending along the second direction.

The other technical means of the present invention lies in that the first inner included angle of the light control film sheet is less than 45 degrees, and the second inner included angle is a right angle.

Another technical means of the present invention is to provide the first reference surface of the light control film back to the grating film.

The utility model discloses a second technical means lies in that this light control membrane still has the second reference surface for this first reference surface and sets up a plurality of second prism structures on this second reference surface along this first direction, each this second prism structure extends along this second direction, wherein, each this second prism structure has third optical surface and fourth optical surface, contained angle in having the third between this third optical surface and this second reference surface, contained angle in having the fourth between this fourth optical surface and this second reference surface, contained angle is the acute angle in this third, and contained angle is less than contained angle in this fourth in this third.

Another technical means of the present invention is to provide a light control diaphragm, wherein the first inner angle of the first prism structure and the third inner angle of the second prism structure face the same side of the light control diaphragm, the first inner angle and the third inner angle are both smaller than 45 degrees, and the second inner angle and the fourth inner angle are both larger than 45 degrees.

Another technical means of the present invention is to provide the first inner angle is larger than the third inner angle.

Another technical means of the present invention is to provide the fourth inner angle larger than the second inner angle, and the fourth inner angle is a right angle.

The other technical means of the present invention is to provide the first reference surface of the light control film back to the grating film, and the second reference surface faces the grating film.

The utility model discloses an another technical means lies in that this area light source includes light guide plate and lamp strip, and this light guide plate has the light-emitting side of going into the light side and connecting this light-emitting side of going into the light side, and this lamp strip sets up in this light-emitting side of this light guide plate, and this light-emitting side is to this grating diaphragm.

The utility model discloses a another technical means lies in that this lamp strip has circuit board and a plurality of illuminating part, and this circuit board extends along this first direction, and this a plurality of illuminating part then arrange along this first direction.

Another technical means of the present invention is to provide the surface light source comprising a circuit board parallel to the grating film and a plurality of light emitting members disposed on the circuit board.

Another technical means of the present invention is to provide the surface light source further comprising a diffusion plate, wherein the diffusion plate has a bottom surface and a top surface opposite to the bottom surface, the bottom surface faces the circuit board, and the top surface faces the grating diaphragm.

Another object of the present invention is to provide a display device, which includes the backlight module and the display panel disposed on the backlight module.

The utility model discloses an efficiency lies in, through the design of the first prism structure syntropy extension of the stop part of this grating diaphragm, printing opacity portion and this accuse light membrane piece, the angle design of this first interior contained angle of deuterogamy, and because the first prism structure of this accuse light diaphragm is the asymmetric microstructure of angle, so light when passing through this accuse light membrane piece, can be by its asymmetric microstructure of angle toward one side deflection, and make the light-emitting rate of opposite side can receive the suppression. Therefore, when the backlight module of the present invention is applied to a Display (Driver Information Display, DID) in front of the Driver seat or a Display (Co-Driver Display, CDD) in front of the front passenger seat, the light field distribution thereof can be deviated to one side and is not easily influenced by the glass reflection of the left/right side window.

Drawings

For a more complete understanding of the embodiments and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings.

Fig. 1 is an exploded perspective view of a backlight module according to a first preferred embodiment of the present invention, wherein the light source is a side-in light source;

FIG. 2 is a side view of FIG. 1 from another angle;

FIG. 3 is a partially enlarged view illustrating the structure of a light controlling diaphragm in the first preferred embodiment;

fig. 4 is a light field distribution diagram illustrating the distribution of the light field without the use of the light management film sheet of the present invention;

FIG. 5 is a light field distribution diagram illustrating the distribution of the light field when the microstructures of the light-controlling diaphragm and the microstructures of the grating diaphragm are perpendicular to each other;

FIG. 6 is a light field distribution diagram illustrating the light field distribution when the microstructures of the light-controlling film and the grating film are parallel to each other and the microstructures of the prism sheet and the light-controlling film are perpendicular to each other;

FIG. 7 is an exploded perspective view illustrating the micro structures of the light-controlling film, the grating film and the prism sheet being parallel to each other;

FIG. 8 is a light field distribution diagram illustrating the light field distribution formed by the structure of FIG. 7;

fig. 9 is a partial enlarged view of a partial structure of a light control film sheet in a second preferred embodiment of the backlight module of the present invention;

FIG. 10 is a light field distribution diagram illustrating the light field distribution formed by the structure of FIG. 9;

FIG. 11 is an exploded perspective view of another aspect of the first preferred embodiment, wherein the light source is a direct-illumination light source;

fig. 12 is an exploded perspective view of a backlight module according to a third preferred embodiment of the present invention;

FIG. 13 is a partial enlarged view of a portion of the light-controlling film in a third preferred embodiment of the backlight module of the present invention;

FIG. 14 is a light field distribution diagram illustrating the light field distribution formed by the structure of FIG. 13;

FIG. 15 is a graph quantifying light field distribution values for various embodiments; and

fig. 16 is a schematic diagram illustrating a light deflection range of the backlight module applied to the vehicle-mounted device according to the present invention.

Detailed Description

The features and technical content of the related applications of the present invention will become apparent from the following detailed description of the preferred embodiments with reference to the accompanying drawings. Before proceeding with the detailed description, it should be noted that like elements are identified with the same reference numerals.

The light field distribution diagram disclosed by the invention is obtained by observing the luminance of the light-emitting surface in the 360-degree direction from the forward direction (vertical to the light-emitting plane) of the backlight module, so that the light field distribution diagram is circular, and the scale on the periphery of the circle is an angle. The scales marked by the inner concentric circles represent the inclination angle between the observation direction and the positive direction of the backlight module.

Referring to fig. 1 and 2, a backlight module according to a first preferred embodiment of the present invention includes a surface light source 2, a prism sheet 3, a grating film 4 and a light control film 5. A display panel (not shown) is disposed in the light emitting direction of the light control film sheet 5, which is a display device.

The grating film 4 is defined to have a first direction X and a second direction Y not parallel to the first direction X, in this embodiment, the second direction Y is perpendicular to the first direction X, but the invention is not limited thereto. The grating diaphragm 4 has a plurality of blocking portions 41 arranged at intervals along the first direction X and a plurality of light-transmitting portions 42 arranged between adjacent blocking portions 41, wherein each blocking portion 41 and each light-transmitting portion 42 extend along the second direction Y.

Referring to fig. 2 and 3, the light-controlling film 5 has a first reference surface 51 facing away from the grating film 4 and a plurality of first prism structures 52 disposed on the first reference surface 51 along the first direction X. Each of the first prism structures 52 extends along the second direction Y, that is, the blocking portion 41 and the light-transmitting portion 42 of the grating diaphragm 4 are disposed parallel to the first prism structure 52 of the light-controlling diaphragm 5. Each first prism structure 52 has a first optical surface 521 and a second optical surface 522, and the first optical surface 521, the second optical surface 522 and the first reference surface 51 together form a triangle, so that each first prism structure 52 has a triangular cross section. As shown in fig. 3, a first inner included angle θ 1 is formed between the first optical surface 521 and the first reference surface 51, a second inner included angle θ 2 is formed between the second optical surface 522 and the first reference surface 51, the first inner included angle θ 1 is an acute angle, and the first inner included angle θ 1 is smaller than the second inner included angle θ 2. In the first preferred embodiment of the present invention, first included angle θ 1 is 20 ° and second included angle θ 2 is 80 °, such that each first prism structure 52 is a cross section of a triangle in which both first included angle θ 1 and second included angle θ 2 are not symmetrical.

In the backlight module disclosed in this embodiment, the grating diaphragm 4 is firstly utilized to change the light field distribution of the surface light source 2 into a single direction, and then the first prism structure 52 of the light-controlling diaphragm 5 having the same extending direction as the blocking portion 41 of the grating diaphragm 4 is utilized to adjust the light field distribution in the single direction, and since the first prism structure 52 of the light-controlling diaphragm 5 has an asymmetric microstructure having a first inner included angle θ 1 smaller than a second inner included angle θ 2, when light passes through the light-controlling diaphragm 5, the light can be effectively deflected to a specific side direction to emit light by the asymmetric microstructure, so that the light-emitting efficiency at the other side is effectively suppressed. Therefore, when the Display device is applied to a Display (DID) in front of a Driver seat or a Display (Co-Driver Display, CDD) in front of a passenger seat, the light field distribution can be deviated to one side and is not easily influenced by the glass reflection of the left/right side windows.

As shown in fig. 4, which is a distribution diagram of the light field without using the light-controlling film 5 of the present invention, it can be seen that the dark color range thereof is located at the very center, and no polarization is generated. In addition, as shown in fig. 5, even if the light control film 5 of the present invention is used, since the extending direction of the first prism structure 52 of the light control film 5 is perpendicular to the extending direction of the blocking portion 41 and the light transmitting portion 42 of the grating film 4, the polarization effect is not generated, and a large amount of noise is generated on both sides. Therefore, as shown in fig. 1, the light control film 5 and the grating film 4 must be used together, and the extending direction of the first prism structure 52 of the light control film 5 and the extending direction of the blocking portion 41 and the light transmitting portion 42 of the grating film 4 must be parallel to each other, so that the dark color range deviates from the center as shown in fig. 6, and the desired polarization effect is generated.

It should be noted that the prism sheet 3 is disposed between the surface light source 2 and the grating film 4 to help converge the light field distribution of the surface light source 2, so that the light can enter the grating film 4 above the prism sheet 3 more intensively, thereby avoiding the light energy loss. In addition, the prism sheet 3 has a plurality of strip-shaped microstructures 31, and the strip-shaped microstructures 31 may extend along the first direction X as shown in fig. 1, and the optical field distribution thereof is as shown in fig. 6, which may produce a good polarization effect. The bar-shaped microstructures 31 can also extend along the second direction Y as shown in fig. 7, and the optical field distribution thereof is as shown in fig. 8, which can also produce good polarization effect. As can be seen from comparing fig. 6 and 8, the extending direction of the strip-shaped microstructures 31 of the prism sheet 3 does not affect the polarization effect.

Referring to fig. 9, a second preferred embodiment of the backlight module of the present invention is different from the first preferred embodiment in that: the first inner included angle of the light control film 5 is smaller than 45 degrees, and the second inner included angle is a right angle. In FIG. 9, first included angle θ 1 is 10 ° and second included angle θ 2 is 90 °, such that each first prism structure 52 has a right-angled triangle cross section. However, the second inner included angle θ 2 may also be an acute angle, so as to improve the problem that the film mold is not easy to release during the right-angle design. As can be seen from the light field distribution diagram of fig. 10, the polarization effect can be generated as well, and compared with fig. 6, the light stripe area on the left side is obviously reduced, which means that the energy dissipation can be effectively reduced, and a better light-emitting deviation effect is generated.

Referring to fig. 1 and 2, in the first preferred embodiment, the surface light source 2 is of a side-in type, and includes a light guide plate 21, a diffusion film 22 and a light bar 23. The light guide plate 21 has a light incident side 211 and a light exiting side 212 connected to the light incident side 211, the diffusion film 22 is disposed on the light exiting side 212 of the light guide plate 21, the light bar 23 is disposed on the light incident side 211 of the light guide plate 21, and the light exiting side 212 faces the grating film 4. The light bar 23 has a circuit board 231 (not shown in fig. 2) and a plurality of light emitting elements 232, wherein the circuit board 231 extends along the first direction X, and the light emitting elements 232 are arranged along the first direction X. Therefore, the arrangement direction of the circuit board 231 and the light emitting member 232 is different from the extension direction of the blocking portion 41 of the grating diaphragm 4 and the first prism structure 52 of the light control diaphragm 5, and is perpendicular to each other in the present embodiment. In this way, the light can be effectively deflected and guided to the specific side to emit light, and the light emitting efficiency of the other side is effectively suppressed, and if the arrangement direction of the circuit board 231 and the light emitting member 232 is the same as the extending direction of the blocking portion 41 of the grating film 4 and the first prism structure 52 of the light control film 5, the light emitting phenomenon of the other side still occurs and cannot be suppressed.

In practical implementation, as shown in fig. 11, the surface light source 2 may be a direct-type surface light source, and includes a circuit board 231 parallel to the grating film 4, a plurality of light emitting elements 232 disposed on the circuit board 231, and a diffusion plate 24. The diffusion plate 24 has a bottom surface 241 and a top surface 242 opposite to the bottom surface 241, the bottom surface 241 faces the circuit board 231, and the top surface 242 faces the grating membrane 4. In the present invention, the surface light source 2 can be either a side-incident type or a direct type.

Referring to fig. 12, a backlight module according to a third preferred embodiment of the present invention includes a surface light source 2, a prism sheet 3, a grating film 4 and a light control film 5. The difference from the first preferred embodiment is that: the light-controlling membrane 5 further has a plurality of second prism structures 54 arranged along the first direction X toward the grating membrane 4. Each first prism structure 52 and each second prism structure 54 extend along the second direction Y.

Referring to fig. 13, in more detail, the light control film sheet 5 further has a second reference surface 53 facing the grating film 4 and opposite to the first reference surface 51, and a plurality of second prism structures 54 arranged on the second reference surface 53 along the first direction X. Each first prism structure 52 has a first optical surface 521 and a second optical surface 522, a first inner included angle θ 1 is formed between the first optical surface 521 and the first reference surface 51, a second inner included angle θ 2 is formed between the second optical surface 522 and the first reference surface 51, the first inner included angle θ 1 is an acute angle, and the first inner included angle θ 1 is smaller than the second inner included angle θ 2. Each second prism structure 54 has a third optical surface 541 and a fourth optical surface 542, a third inner included angle θ 3 is formed between the third optical surface 541 and the second reference surface 53, a fourth inner included angle θ 4 is formed between the fourth optical surface 542 and the second reference surface 53, the third inner included angle θ 3 is an acute angle, and the third inner included angle θ 3 is smaller than the fourth inner included angle θ 4. The first included angle θ 1 of the first prism structure 52 and the third included angle θ 3 of the second prism structure 54 face the same side of the light-controlling film 5. The first inner included angle theta 1 and the third inner included angle theta 3 are both smaller than 45 degrees, the second inner included angle theta 2 and the fourth inner included angle theta 4 are both larger than 45 degrees, the first inner included angle theta 1 is larger than the third inner included angle theta 3, the fourth inner included angle theta 4 is larger than the second inner included angle theta 2, and the fourth inner included angle theta 4 is a right angle. In this embodiment, the first inner angle θ 1 is 20 °, the second inner angle θ 2 is 80 °, the third inner angle θ 3 is 10 °, and the fourth inner angle θ 4 is 90 °. As can be seen from the light field distribution diagram of fig. 14, the polarization effect can be generated as well, and compared with fig. 6, the dark color range is more deviated from the center, and the light-emitting shift effect is larger. In short, in order to perform detail adjustment of the light field deflection effect, the light field deflection effect generated by the first prism structure 52 with only one surface can be changed by fine angle adjustment by the design of the second prism structure 54 of the light control film 5 on the second reference surface 53, so as to meet different use conditions or customer requirements. In addition, the first prism structure 52 and the second prism structure 54 are convex structures, but in practice, concave structures may be adopted, and the light field deflection effect is basically the same or similar, so the description of the present embodiment should not be taken as a limitation.

Referring to the graph of fig. 15, the values of the respective light field distributions are quantified. The dot line represents the control group using only the grating diaphragm 4, the dotted line represents the first preferred embodiment, the long and short dot chain line represents the second preferred embodiment, and the solid line represents the third preferred embodiment. As can be seen from fig. 15, compared to the control group, the third preferred embodiment can suppress the light output most effectively at the viewing angle of-30 ° to-15 °, and can shift the light output to the viewing angle of 15 ° to 30 °, thereby effectively suppressing the single-side light output and generating the polarization effect. It should be noted that the angles of the inner angles of the light-controlling films 5 can be adjusted to adjust the light deflection range according to different application environments, so as to obtain the best polarization effect.

With the above-described configuration, when the backlight module according to the present invention is applied to an in-vehicle device, as shown in fig. 16 (a), an image of an in-vehicle instrument panel 91 located on the front driver seat side may be projected to the positions of the front driver seat and the front passenger seat, but may not be reflected by a window on the front driver seat side, or as shown in fig. 16 (b), an image of a display screen 92 located on the front passenger seat side may be projected to the positions of the front driver seat and the front passenger seat, but may not be reflected by a window on the front passenger seat side, thereby reducing interference due to reflection of the images.

In summary, the backlight module of the present invention can deflect light toward one side and suppress the light extraction rate of the other side by the design that the grating film and the light control film are mutually matched and the blocking portion and the light transmitting portion of the grating film and the first prism structure of the light control film extend in the same direction and the design of the angles of the inner included angles are combined, so that the backlight module can be applied to the use environment requiring an anisotropic light field.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the scope of the invention, which is defined by the appended claims and their equivalents, and all changes and modifications that are within the scope of the claims and the contents of the specification are intended to be embraced therein.

[ List of reference numerals ]

2. Area light source

21. Light guide plate

211. Side of incident light

212. Light emitting side

22. Diffusion film

23. Light bar

231. Circuit board

232. Luminous element

24. Diffusion plate

241. Bottom surface

242. Top surface of the container

3. Prism sheet

31. Strip-shaped microstructure

4. Grating diaphragm

41. Blocking part

42. Light transmission part

5. Light control diaphragm

51. First reference surface

52. First prism structure

521. First optical surface

522. Second optical surface

53. Second reference plane

54. Second prism structure

541. Third optical surface

542. Fourth optical surface

91. Vehicle instrument board

92. Display screen

X first direction

Y second direction

Theta 1 first inner included angle

Theta 2 second inner included angle

Theta 3 third inner included angle

And theta 4 a fourth inner included angle.

Claims (15)

1. A backlight module, comprising:

a surface light source;

the grating diaphragm is arranged on the light outlet side of the surface light source, and is defined to have a first direction and a second direction which is not parallel to the first direction, the grating diaphragm is provided with a plurality of blocking parts which are arranged at intervals along the first direction and a plurality of light transmission parts which are arranged between the adjacent blocking parts, and the blocking parts and the light transmission parts extend along the second direction; and

the light control film comprises a first reference surface and a plurality of first prism structures arranged on the first reference surface along the first direction, each first prism structure extends along the second direction, each first prism structure comprises a first optical surface and a second optical surface, a first inner included angle is formed between the first optical surface and the first reference surface, a second inner included angle is formed between the second optical surface and the first reference surface, the first inner included angle is an acute angle, and the first inner included angle is smaller than the second inner included angle.

2. The backlight module of claim 1, further comprising a prism sheet disposed between the surface light source and the grating film, wherein the prism sheet has a plurality of stripe-shaped microstructures extending along the first direction.

3. The backlight module of claim 1, further comprising a prism sheet disposed between the surface light source and the grating film, wherein the prism sheet has a plurality of stripe-shaped microstructures respectively extending along the second direction.

4. The backlight module as claimed in claim 1, wherein the first inner included angle of the light-controlling film is less than 45 degrees, and the second inner included angle is a right angle.

5. A backlight module according to claim 1, wherein the first reference surface of the light control film faces away from the grating film.

6. The backlight module according to claim 1, wherein the light-controlling film further has a second reference surface opposite to the first reference surface and a plurality of second prism structures arranged on the second reference surface along the first direction, each of the second prism structures extends along the second direction, each of the second prism structures has a third optical surface and a fourth optical surface, a third included angle is formed between the third optical surface and the second reference surface, a fourth included angle is formed between the fourth optical surface and the second reference surface, the third included angle is an acute angle, and the third included angle is smaller than the fourth included angle.

7. The backlight module according to claim 6, wherein the first inner included angle of the first prism structure and the third inner included angle of the second prism structure face to the same side of the light-controlling film, the first inner included angle and the third inner included angle are both smaller than 45 degrees, and the second inner included angle and the fourth inner included angle are both larger than 45 degrees.

8. The backlight module according to claim 6, wherein the first inner included angle is larger than the third inner included angle.

9. The backlight module according to claim 8, wherein the fourth inner included angle is larger than the second inner included angle, and the fourth inner included angle is a right angle.

10. The backlight module according to claim 6, wherein the first reference surface of the light-controlling film faces away from the grating film, and the second reference surface faces toward the grating film.

11. The backlight module according to any one of claims 1-10, wherein the surface light source comprises a light guide plate and a light bar, the light guide plate has a light incident side and a light emergent side connected to the light incident side, the light bar is disposed on the light incident side of the light guide plate, and the light emergent side faces the grating film.

12. The backlight module according to claim 11, wherein the light bar has a circuit board and a plurality of light emitting elements, the circuit board extends along the first direction, and the plurality of light emitting elements are arranged along the first direction.

13. The backlight module according to any one of claims 1 to 10, wherein the surface light source comprises a circuit board parallel to the grating film and a plurality of light emitting members disposed on the circuit board.

14. A backlight module according to claim 13, wherein the surface light source further comprises a diffuser plate having a bottom surface facing the circuit board and a top surface opposite to the bottom surface, the top surface facing the grating film.

15. A display device, comprising the backlight module as claimed in any one of claims 1 to 14, and a display panel disposed on the backlight module.

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