CN215575754U

CN215575754U - High-viewing-angle backlight module

Info

Publication number: CN215575754U
Application number: CN202121320079.8U
Authority: CN
Inventors: 山口勝; 見村知哉
Original assignee: Ways Electron Co ltd
Current assignee: Ways Electron Co ltd
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2022-01-18
Anticipated expiration: 2031-06-15

Abstract

The utility model discloses a high-visual-angle backlight module, which comprises: the light guide plate is provided with a first light emitting surface, a light guide surface and a light incident surface, wherein the first light emitting surface and the light guide surface are opposite to each other, and the light incident surface is connected between the light emitting surface and the light guide surface; the inverse prism is provided with a second light-emitting surface and a plurality of prism units which are arranged oppositely, the prism units are arranged right opposite to the first light-emitting surface, and a first lens array structure is arranged on the second light-emitting surface; the light source is configured on the light incident surface. This high field angle backlight unit under the condition that does not use ALCF, still can reach required optical characteristic, prevents that light from refracting to front windshield from upper and lower both sides and influencing driver's sight, reduce cost can realize accomplishing product thickness thinner moreover.

Description

High-viewing-angle backlight module

Technical Field

The utility model relates to the technical field of backlight modules, in particular to a high-viewing-angle backlight module.

Background

The backlight module provides a back light source component in a display product, the backlight quality determines important parameters of the display such as brightness, emergent light uniformity, color gradation and the like, and the light emitting effect of the display is determined to a great extent. Generally, the backlight module can be divided into a direct type backlight module and a side light type backlight module, and the side light type backlight module can make the product thinner, so the side light type backlight module is increasingly used by the existing display device.

Light emitted by the light source of the backlight module enters the light guide plate, is guided into the whole light guide plate, is refracted by the light emergent surface of the light guide plate, and then is emitted towards all directions through the optical film above the light guide plate. When the backlight module is used in some specific occasions such as an on-board central control display screen, light can be refracted to a front windshield from the upper side and the lower side of the display screen, and then the sight of a driver is influenced. In order to solve the technical problem, in the conventional backlight module, an ALCF (advanced Light Control Film) is usually disposed on the Light emitting surface of the Light guide plate, so as to reduce the range of the upper and lower emergent angles of Light and expand the range of the left and right emergent angles, as shown in fig. 1, the FWHM (Full width at half maximum) value of the backlight module is 54.3 °. However, the use of ALCF increases the cost of the backlight module, and the thickness of the backlight module is limited, which cannot be made thinner. Accordingly, there is a need for improvements in the art that overcome the deficiencies in the prior art.

Disclosure of Invention

The utility model provides a backlight module with a high viewing angle, which overcomes the defects of high cost and incapability of being thinner of the conventional backlight module.

The technical scheme adopted by the utility model for solving the technical problem is as follows: a high viewing angle backlight module comprises:

the light guide plate is provided with a first light emitting surface, a light guide surface and a light incident surface, wherein the first light emitting surface and the light guide surface are opposite to each other, and the light incident surface is connected between the light emitting surface and the light guide surface;

the inverse prism is provided with a second light-emitting surface and a plurality of arranged prism units, the second light-emitting surface is opposite to the first light-emitting surface, and the second light-emitting surface is provided with a first lens array structure;

the light source is configured on the light incident surface.

As a further improvement of the present invention, the first lens array structure includes a plurality of arc-shaped grooves arranged, and an extending direction of the arc-shaped groove arrangement is perpendicular to an extending direction of the prism unit arrangement.

As a further improvement of the utility model, the included angle formed by the tangents of the two ends of the arc-shaped groove is theta 1, and theta 1 is larger than or equal to 130 degrees and smaller than or equal to 160 degrees.

As a further improvement of the utility model, the prism units are in a prismatic structure, the included angle of the tips of the prism units is theta 2, and the theta 2 is more than or equal to 60 degrees and less than or equal to 70 degrees.

As a further improvement of the present invention, the light incident surface where the light source is located is perpendicular to the extending direction of the prism unit arrangement.

As a further improvement of the present invention, a second lens array structure is disposed on the light guide surface;

the second lens array structure comprises a plurality of arrayed reflector surfaces, the array extension direction of the reflector surfaces is consistent with the array extension direction of the prism units, and one end of the reflector surface, which is close to the light source, inclines towards the first light-emitting surface;

or the second lens array structure comprises a plurality of arranged spherical arc-shaped salient points.

As a further improvement of the utility model, the inclination angle of the reflecting mirror surface is theta 3, and the theta 3 is more than or equal to 0.5 degrees and less than or equal to 5 degrees.

As a further improvement of the utility model, the included angle formed by the tangents of the two ends of the section of the salient point is theta 4, and the theta 4 is more than or equal to 160 degrees and less than or equal to 175 degrees.

As a further improvement of the present invention, the light guide plate further includes a reflection sheet disposed on the light guide surface.

As a further improvement of the present invention, a fourth lens array structure is disposed on the first light emitting surface, and the fourth lens array structure includes a plurality of arranged convex pillar units or prism units, and an extending direction of the arrangement of the fourth lens array structure is perpendicular to an extending direction of the arrangement of the prism units.

The utility model has the beneficial effects that: the utility model provides a high visual angle backlight module, which is characterized in that a reverse prism is arranged on a first light-emitting surface of a light guide plate, a first lens array structure vertical to a prism unit is arranged on a second light-emitting surface of the reverse prism, and under the action of an arc-shaped groove of the first lens array structure, the angle of refracted light on an X axis is increased and diffused, so that a display device using the backlight module is in an oblique view state, particularly used on a vehicle-mounted display screen, and a driver and passengers can be ensured to watch pictures; meanwhile, under the action of the prism unit, the angle of the refracted light on the Y axis is reduced and gathered in a certain angle range, the required optical characteristics can still be achieved under the condition that the ALCF is not used, the light is prevented from being refracted to the front windshield from the upper side and the lower side to affect the sight of a driver, the cost is reduced, and the product thickness can be thinner.

Drawings

FIG. 1 is a diagram of a conventional backlight module using ALCF;

FIG. 2 is a perspective view of the present invention;

FIG. 3 is an enlarged view of A of FIG. 2 according to the present invention;

FIG. 4 is a front view of the present invention;

FIG. 5 is an enlarged view of B of FIG. 4 in accordance with the present invention;

FIG. 6 is a side view of the present invention;

FIG. 7 is an enlarged view of C of FIG. 6 in accordance with the present invention;

FIG. 8 is an enlarged view of D of FIG. 6 in accordance with the present invention;

FIG. 9 is a simulated chromatogram of the present invention.

The following description is made with reference to the accompanying drawings:

1-light guide plate; 101-light emitting surface;

102-light guide surface; 1021-mirror surface;

103-incident surface; 2-inverse prism;

201-a second light-emitting surface; 2011-arc groove;

202-prism unit; 3-light source;

4-reflecting sheet.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to fig. 2, the present invention provides a high viewing angle backlight module, including: the light guide plate 1, the inverse prism 2 and the light source 3 are arranged on the top of the light guide plate 1 along the Z-axis direction, with the long side of the light guide plate 1 as the X-axis, the short side as the Y-axis and the high side as the Z-axis.

Referring to fig. 3 to 4, the light guide plate 1 has a first light emitting surface 101 and a light guiding surface 102 opposite to each other, and a light incident surface 103 connected between the light emitting surface 101 and the light guiding surface 102. The inverse prism 2 has an opposite second light emitting surface 201 and a plurality of prism units 202, the prism units 202 are disposed opposite to the first light emitting surface 101, the individual prism units 202 each extend along the X-axis direction, and the plurality of prism units 202 are arranged in series along the Y-axis direction. The second light emitting surface 201 is provided with a first lens array structure, the first lens array structure includes a plurality of continuously arranged arc grooves 2011, the separate arc grooves 2011 extend along the Y axis direction, the plurality of arc grooves 2011 are continuously arranged along the X axis direction, that is, the extending direction of the arc grooves 2011 is perpendicular to the extending direction of the prism unit 202. The light source 3 is disposed on the light incident surface 103, the light incident surface 103 where the light source 3 is located is perpendicular to the extending direction of the arrangement of the prism units 202, and the light source 3 includes a plurality of LEDs arranged at intervals along the X axis.

By adopting the structural design, when the light source 3 is turned on, the emitted light is refracted by the light incident surface 103 and enters the light guide plate 1, and is totally reflected in the light guide plate 1, and is continuously close to the critical angle of the light guide plate 1 until the incident angle of the light on the first light emitting surface 101 is smaller than or equal to the critical angle, the light is refracted by the first light emitting surface 101 and then emitted, and the light is refracted by the prism unit 202 of the inverse prism 2 and emitted from the second light emitting surface 201. The arc-shaped groove 2011 of the second light-emitting surface 201 can increase the angle of the refracted light on the X axis by taking a perpendicular line perpendicular to the second light-emitting surface 201 as a reference, and continuously diffuse the refracted light on the X axis while emitting the light; meanwhile, under the action of the prism unit 202, the angle of the refracted light on the Y axis is reduced, and the light is converged within a certain angle range while being emitted, so that the FWHM value of the light is about 60 degrees, thereby achieving the optical characteristics (as shown in fig. 9) similar to ALCF and reducing the cost.

In this embodiment, the light guide plate 1 is a mirror reflection type light guide plate, and the light guide plate 1 may be made of a transparent resin material, a PMMA (Polymethyl methacrylate) material, an optical material COP (COP), a COC (copolymer of cyclic olefin copolymer) material, an optical grade PC (polycarbonate) material, or the like, and preferably made of a PC material having a reflection critical angle of 39.2 °. After the light emitted from the light source 3 is refracted by the light incident surface 103 and enters the light guide plate 1, the light with the incident angle exceeding 39.2 ° is totally reflected and propagated inside the light guide plate 1, and when the incident angle is lower than the critical angle of 39.2 °, the light can be refracted to the outside through the first light emitting surface 101. When the light guide plate 1 made of another material is used, the critical angle thereof may be changed.

Referring to fig. 4 and 5, the cross section of the arc-shaped groove 2011 is arc-shaped, an included angle formed by tangents at two ends of the arc-shaped groove 2011 is θ 1, preferably, θ 1 is larger than or equal to 130 degrees and smaller than or equal to 160 degrees, so that the light can be diffused in a larger angle on the X axis, and a display device using the backlight module can still view pictures in an oblique view state, particularly on a vehicle-mounted display screen.

Referring to fig. 6 and 7, the prism unit 202 has a triangular prism structure with tips disposed toward the first light emitting surface 101 at an included angle θ 2, preferably 60 ° θ 2 ≦ 70 °. By setting the angle of the prism unit 202 within this interval, the emitted light can be concentrated in the range of 0 ° to 10 ° on the Y axis to achieve the desired emission angle characteristic.

Referring to fig. 6 and 8, the light guide surface 102 is provided with a second lens array structure, the second lens array structure includes a plurality of arrayed mirror surfaces 1021, and the mirror surfaces 1021 are arrayed and extended along the Y axis direction and are consistent with the extending direction of the arrayed prism units 202. One end of the reflector 1021 near the light source 3 inclines towards the first light emitting surface 101, and light emitted from the light source 3 enters the light guide plate 1 through the light incident surface 103 and is totally reflected on the reflector 1021, so that the incident angle of the light is continuously reduced until the incident angle of the light on the reflector 1021 is smaller than or equal to the critical angle, and then the light is refracted out through the first light emitting surface 101. In addition, the inclination angle of the reflecting mirror 1021 is theta 3, theta 3 is more than or equal to 0.5 degrees and less than or equal to 5 degrees, and the time for the light to reach the critical angle can be adjusted by changing the size of theta 3. The second lens array structure can also be a plurality of arranged spherical arc-shaped salient points (not shown in the figure), the included angle formed by tangent lines at two ends of the cross section of each salient point is theta 4, and the theta 4 is more than or equal to 160 degrees and less than or equal to 175 degrees, and the same effect can be achieved.

Referring to fig. 2, the backlight module further includes a reflective sheet 4, and the reflective sheet 4 is disposed on the light guide surface 102. As the reflection sheet 4, 3M materials is used, but it is needless to say that the utility model is not limited thereto, and any medium having reflection characteristics may be used as the reflection sheet 4.

Referring to fig. 3, a fourth lens array structure is disposed on the first light emitting surface 101, and the fourth lens array structure includes a plurality of convex pillar units or prism units arranged along the X axis, and an extending direction of the arrangement of the fourth lens array structure is perpendicular to an extending direction of the arrangement of the prism units 202, and the arrangement of the fourth lens array structure may be continuous or spaced. In this embodiment, the fourth lens array structure employs convex pillar units arranged at intervals.

Therefore, the high-visual-angle backlight module is characterized in that the inverse prism is arranged on the first light-emitting surface of the light guide plate, the first lens array structure perpendicular to the prism unit is arranged on the second light-emitting surface of the inverse prism, and the angle of refracted light on an X axis is increased and diffused under the action of the arc-shaped groove of the first lens array structure, so that a display device using the backlight module is in an oblique view state, particularly used for a vehicle-mounted display screen, and a driver and passengers can be ensured to watch pictures; meanwhile, under the action of the prism unit, the angle of the refracted light on the Y axis is reduced and gathered in a certain angle range, the required optical characteristics can still be achieved under the condition that the ALCF is not used, the light is prevented from being refracted to the front windshield from the upper side and the lower side to affect the sight of a driver, the cost is reduced, and the product thickness can be thinner.

In the previous description, numerous specific details were set forth in order to provide a thorough understanding of the present invention. The foregoing description is only a preferred embodiment of the utility model, which can be embodied in many different forms than described herein, and therefore the utility model is not limited to the specific embodiments disclosed above. And that those skilled in the art may, using the methods and techniques disclosed above, make numerous possible variations and modifications to the disclosed embodiments, or modify equivalents thereof, without departing from the scope of the claimed embodiments. Any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A high viewing angle backlight module, comprising:

the light guide plate (1) is provided with a first light emitting surface (101), a light guide surface (102) and a light incident surface (103) connected between the light emitting surface (101) and the light guide surface (102), wherein the first light emitting surface and the light guide surface are opposite;

the inverse prism (2) is provided with a second opposite light emitting surface (201) and a plurality of prism units (202) which are arranged, the prism units (202) are arranged right opposite to the first light emitting surface (101), and a first lens array structure is arranged on the second light emitting surface (201);

and a light source (3) disposed on the light incident surface (103).

2. The high viewing angle backlight module of claim 1, wherein: the first lens array structure comprises a plurality of arrayed arc grooves (2011), and the extending direction of the arrayed arc grooves (2011) is perpendicular to the extending direction of the arrayed prism units (202).

3. The high viewing angle backlight module of claim 2, wherein: the included angle formed by tangents at two ends of the arc-shaped groove (2011) is theta 1, and the theta 1 is more than or equal to 130 degrees and less than or equal to 160 degrees.

4. The high viewing angle backlight module of claim 1, wherein: the prism unit (202) is of a prismatic structure, the included angle of the tip end of the prism unit is theta 2, and the theta 2 is more than or equal to 60 degrees and less than or equal to 70 degrees.

5. The high viewing angle backlight module of claim 1, wherein: the light incident surface (103) where the light source (3) is located is perpendicular to the extending direction of the arrangement of the prism units (202).

6. The high viewing angle backlight module of claim 5, wherein: a second lens array structure is arranged on the light guide surface (102);

the second lens array structure comprises a plurality of arranged reflecting mirror surfaces (1021), the extending direction of the arrangement of the reflecting mirror surfaces (1021) is consistent with the extending direction of the arrangement of the prism units (202), and one end, close to the light source (3), of each reflecting mirror surface (1021) inclines towards the first light-emitting surface (101);

7. The high viewing angle backlight module of claim 6, wherein: the inclination angle of the reflecting mirror surface (1021) is theta 3, and theta 3 is more than or equal to 0.5 degrees and less than or equal to 5 degrees.

8. The high viewing angle backlight module of claim 6, wherein: the included angle formed by tangent lines at two ends of the section of the salient point is theta 4, and the theta 4 is more than or equal to 160 degrees and less than or equal to 175 degrees.

9. The high viewing angle backlight module of claim 1, wherein: the light guide plate further comprises a reflecting sheet (4), and the reflecting sheet (4) is arranged on the light guide surface (102).

10. The high viewing angle backlight module of claim 1, wherein: the first light emitting surface (101) is provided with a fourth lens array structure, the fourth lens array structure comprises a plurality of arrayed convex column units or prism units, and the array extension direction of the fourth lens array structure is perpendicular to the array extension direction of the prism units (202).