CN108873144B

CN108873144B - Light guide device, backlight module and liquid crystal display

Info

Publication number: CN108873144B
Application number: CN201710324724.5A
Authority: CN
Inventors: 武鹏; 李同; 张蕊蕊
Original assignee: Suzhou Institute of Nano Tech and Nano Bionics of CAS
Current assignee: Suzhou Institute of Nano Tech and Nano Bionics of CAS
Priority date: 2017-05-10
Filing date: 2017-05-10
Publication date: 2020-05-19
Anticipated expiration: 2037-05-10
Also published as: CN108873144A

Abstract

The invention discloses a light guide device, comprising a light-reflecting plate, a light-guiding plate and a collimating plate which are stacked in sequence; wherein, the light-guiding plate includes a first wedge-shaped plate and a second wedge-shaped plate, and the first wedge-shaped plate A wedge-shaped plate and the inclined surfaces of the second wedge-shaped plate are disposed opposite to each other with a first gap therebetween; the collimation plate includes a first sawtooth plate and a second sawtooth plate, the first sawtooth plate and the second sawtooth plate respectively There is a flat surface and a triangular saw tooth surface arranged oppositely, and the triangular saw tooth surfaces of the first saw tooth plate and the second saw tooth plate mesh with each other and have a second gap therebetween. The present invention also discloses a backlight module and a liquid crystal display including the above-mentioned light guide device. The light guide device can improve the collimation of the light provided by the backlight module, increase the utilization rate of the light source, and improve the display quality of the display.

Description

Light guide device, backlight module and liquid crystal display

Technical Field

The invention relates to the technical field of liquid crystal displays, in particular to a light guide device, a backlight module comprising the light guide device and a liquid crystal display.

Background

With the development of the photoelectric and semiconductor technologies, the development of Flat Panel displays (Flat Panel displays) is also increased, and among many Flat Panel displays, Liquid Crystal Displays (LCDs) have become the mainstream of the market due to their excellent characteristics, such as high space utilization efficiency, low power consumption, no radiation, and low electromagnetic interference. The lcd generally includes a Liquid Crystal Panel (Liquid Crystal Panel) and a backlight module (Black light module, BL). Since the lcd panel itself does not have the self-light emitting property, the backlight module must be disposed under the lcd panel to provide the surface light source required by the lcd panel, so that the lcd panel can display images by the surface light source provided by the backlight module.

A backlight module generally uses a Light Emitting Diode (LED) or a Cold Cathode Fluorescent Lamp (CCFL) as a light source, and light emitted from the light source is coupled into a display panel through a Light Guide Plate (LGP). However, the conventional light source has a large divergence angle, and the energy actually entering the light guide plate and utilized is less than 10%, which results in a reduction in the efficiency of the entire display. At present, many small-sized liquid crystal displays such as mobile phones, calculators, watches, etc. for personal use, which emphasize lightness, thinness, compactness, and low power consumption, have put higher demands on the structure of the backlight module, the light emitting angle of the light source, and the usage efficiency of the light source. On the other hand, the development of large-sized TVs, especially High Definition Televisions (HDTVs), has higher requirements for the contrast and the picture quality of the display, and the lcd panel has a high utilization rate for the paraxial light from the backlight module with the normal perpendicular to the display panel as the axis, so that if the divergence angle of the backlight is large, the utilization rate of the light source is reduced, and the large-angle off-axis light causes the problems of contrast reduction, light leakage, colorwashout, and the like.

Therefore, how to improve the collimation of the light provided by the backlight module and increase the utilization rate of the light source is a problem that needs to be solved urgently in the industry.

Disclosure of Invention

In view of the defects in the prior art, the present invention provides a light guide device, which is applied to a backlight module and a liquid crystal display, and can improve the collimation of light provided by the backlight module, increase the utilization rate of a light source, and improve the display quality of the display.

In order to achieve the purpose, the invention adopts the following technical scheme:

a light guide device is used for conducting divergent light emitted by a light source to form collimated parallel light, and comprises a reflecting plate, a light guide plate and a collimating plate which are sequentially arranged; the light guide plate comprises a first wedge plate and a second wedge plate, wherein inclined planes of the first wedge plate and the second wedge plate are oppositely arranged, a first gap is formed between the inclined planes of the first wedge plate and the second wedge plate, the end faces, with larger thicknesses, of the first wedge plate and the second wedge plate are respectively arranged as light incident faces of the light guide plate, a straight face of the first wedge plate is arranged towards the light reflecting plate, and a straight face of the second wedge plate is arranged as a light emergent face of the light guide plate and arranged towards the collimation plate; the collimation plate comprises a first sawtooth plate and a second sawtooth plate, the first sawtooth plate and the second sawtooth plate are respectively provided with a straight surface and a triangular sawtooth surface which are oppositely arranged, the triangular sawtooth surfaces of the first sawtooth plate and the second sawtooth plate are mutually meshed and have a second gap therebetween, the straight surface of the first sawtooth plate is arranged as the light incident surface of the collimation plate, and the straight surface of the second sawtooth plate is arranged as the light emergent surface of the collimation plate.

Preferably, in the first wedge-shaped plate and the second wedge-shaped plate, an included angle between the inclined surface and the straight surface is not more than 5 °.

Preferably, the end face with the smaller thickness of the first wedge-shaped plate is provided with a first reflection film, and/or the end face with the smaller thickness of the second wedge-shaped plate is provided with a second reflection film.

Preferably, the first wedge-shaped plate and the second wedge-shaped plate in the light guide plate are of an integrally formed structure, the end with the smaller thickness of the first wedge-shaped plate is integrally connected with the end with the larger thickness of the second wedge-shaped plate, and the end with the larger thickness of the first wedge-shaped plate is integrally connected with the end with the smaller thickness of the second wedge-shaped plate.

Preferably, the end face of the first wedge-shaped plate with the larger thickness is set as the light incident face of the light guide plate, and is used for receiving light rays emitted by the light source; the light guide device further comprises a reflecting mechanism, the reflecting mechanism is arranged adjacent to the end face with the larger thickness of the second wedge-shaped plate, and the reflecting mechanism is used for reflecting the light emitted from the end face with the smaller thickness of the first wedge-shaped plate towards the end face with the larger thickness of the second wedge-shaped plate.

Preferably, the light guide device further includes a transmission lens, the transmission lens is disposed on a side of the reflector plate away from the light guide plate, a first end of the transmission lens receives a part of light emitted from the light source, the part of light is transmitted by the transmission lens and then emitted from a second end of the transmission lens, and the reflection mechanism reflects the light emitted from the second end of the transmission lens toward an end face of the second wedge plate with a larger thickness.

Preferably, the reflecting mechanism includes a reflecting surface, the reflecting surface includes a first reflecting inclined surface and a second reflecting inclined surface that intersect to form an included angle, the first reflecting inclined surface reflects the light emitted from the second end of the transmission lens toward the second reflecting inclined surface, and the second reflecting inclined surface reflects the light emitted from the first reflecting inclined surface toward the end surface of the second wedge-shaped plate that is thicker.

The invention also provides a backlight module which comprises a first light guide mechanism and a light source mechanism arranged on the side surface of the first light guide mechanism, wherein the first light guide mechanism adopts the light guide device.

Preferably, the light source mechanism includes a light source and a second light guide mechanism, the second light guide mechanism adopts the light guide device, the second light guide mechanism conducts divergent light emitted by the light source to form collimated parallel light in a first dimension direction, and the first light guide mechanism conducts light emitted by the second light guide mechanism to form collimated parallel light in a second dimension direction.

Another aspect of the present invention provides a liquid crystal display, which includes a liquid crystal panel and a backlight module, wherein the liquid crystal panel and the backlight module are disposed opposite to each other, and the backlight module provides a display light source to the liquid crystal panel to enable the liquid crystal panel to display an image, and the backlight module is the backlight module as described above.

According to the light guide device provided by the embodiment of the invention, the structure of the light guide plate and the collimating plate is improved, so that the collimation degree of the emitted light is improved. The light source is applied to the backlight module and the liquid crystal display, and can improve the collimation of light provided by the backlight module, increase the utilization rate of the light source and improve the display quality of the display. In a preferred embodiment, the backlight module includes a first light guide mechanism and a second light guide mechanism of the light guide device having the above structure, and the first light guide mechanism and the second light guide mechanism respectively adjust the collimation degree of the light source from the first dimension direction and the second dimension direction, so that the light provided by the backlight module to the liquid crystal display has good collimation property in the two dimension directions in a plane, and the display quality of the display is further improved.

Drawings

Fig. 1 is a schematic structural diagram of a light guide device provided in embodiment 1 of the present invention;

fig. 2 is a schematic structural diagram of a light guide plate provided in embodiment 1 of the present invention;

FIG. 3 is a schematic diagram of the light path of a portion of light transmitted in the light guide plate of FIG. 2;

FIG. 4 is a schematic structural diagram of a collimation plate provided in embodiment 1 of the present invention;

FIG. 5 is a schematic diagram of the path of a portion of light rays traveling in a collimating plate as in FIG. 4;

FIG. 6 is a schematic diagram of another light path of light transmitted in the light guide plate of FIG. 2;

fig. 7 is a schematic structural view of a light guide device provided in embodiment 2 of the present invention;

fig. 8 is a schematic structural view of a light guide device provided in embodiment 3 of the present invention;

FIG. 9 is a schematic diagram of the light path of a portion of light transmitted in the light guide device of FIG. 8;

fig. 10 is a schematic structural diagram of a backlight module and a liquid crystal display provided in embodiment 4 of the invention;

fig. 11 is a schematic structural diagram of a backlight module and a liquid crystal display provided in embodiment 5 of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the invention shown in the drawings and described in accordance with the drawings are exemplary only, and the invention is not limited to these embodiments.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the scheme according to the present invention are shown in the drawings, and other details not so relevant to the present invention are omitted.

Example 1

The embodiment provides a light guide device which is used for guiding divergent light emitted by a light source to form collimated parallel light. As shown in fig. 1, the light guide device 10 includes a light reflection plate 1, a light guide plate 2, and a collimating plate 3, which are sequentially disposed. Fig. 1 also shows a light source (first light source 4) disposed on the side of the light guide device 10, and light emitted by the first light source 4 is guided through the light guide plate 2 and the collimating plate 3 to form collimated parallel light, and then is emitted from above the collimating plate 3.

As shown in fig. 1 and fig. 2, the light guide plate 2 includes a first wedge plate 21 and a second wedge plate 22, the

inclined surfaces

211, 221 of the first wedge plate 21 and the second wedge plate 22 are disposed opposite to each other with a first gap 23 therebetween, the

end surfaces

212, 222 of the first wedge plate 21 and the second wedge plate 22 having a larger thickness may be disposed as the light incident surfaces of the light guide plate 2, the flat surface 213 of the first wedge plate 21 is disposed toward the light reflection plate 1, and the flat surface 223 of the second wedge plate 22 is disposed as the light exit surface of the light guide plate 2 and disposed toward the collimation plate 3. More specifically, in the present embodiment, the

inclined surfaces

211, 221 of the first and

second wedge plates

21, 22 are oppositely disposed, and the outer peripheral profile of the light guide plate 2 formed by the combination of the first and

second wedge plates

21, 22 has an approximately parallelepiped structure.

Fig. 3 shows a schematic diagram of a light path of a part of light rays transmitted through the light guide plate 2, and referring to fig. 2 and 3, the light rays incident from the light incident surface (the

end surfaces

212 and 222 of the first wedge plate 21 and the second wedge plate 22 with larger thickness) are reflected by the first wedge plate 21 and the second wedge plate 22 for multiple times, and then exit from the light exiting surface (the flat surface 223 of the second wedge plate 22), such as light rays L11 and L12 in fig. 3. Part of the light rays are emitted from the flat surface 213 of the first wedge plate 21, reflected back into the light guide plate 2 by the reflector 1, and finally emitted from the light emitting surface, as shown by light ray L13 in fig. 3. The first wedge plate 21 and the second wedge plate 22 are configured to converge the divergent light with a large angle from the light source into a light beam with a small divergent angle near the critical angle of total reflection by multiple total reflections and emit the light beam.

As shown in fig. 4, the collimating plate 3 includes a first sawtooth plate 31 and a second sawtooth plate 32, the first sawtooth plate 31 has a flat surface 311 and a triangular sawtooth surface 312 which are oppositely arranged, the second sawtooth plate 32 also has a flat surface 321 and a triangular sawtooth surface 322 which are oppositely arranged, and the cross sections of the first sawtooth plate 31 and the second sawtooth plate 32 are of a structure having a flat substrate and a plurality of isosceles triangles arranged in an array on the flat substrate. Wherein, first serration plate 31 with the

triangle serration surface

312, 322 of second serration plate 32 are engaged with each other, first serration plate 31 with second serration plate 32 has second clearance 33 between the

triangle serration surface

312, 322, second clearance 33 follows the surface extension of

triangle serration surface

312, 322. The flat surface 311 of the first sawtooth plate 31 is disposed such that the light incident surface of the collimating plate 3 faces the light emitting surface of the light guide plate 2, and the flat surface 321 of the second sawtooth plate 32 is disposed such that the light emitting surface of the collimating plate 3.

Fig. 5 shows a schematic optical path diagram of a part of light rays transmitted by the collimating plate 3, and referring to fig. 4 and 5, the light rays L21, L22 forming a large angle incidence with the light incident surface (the flat surface 311 of the first sawtooth plate 31) are refracted at the light incident surface. After entering the first sawtooth plate 31, the light rays L21, L22 reach the interface of the second gap 33, passing through the parallel air gap (second gap 33) with an angle of incidence less than the critical angle for total reflection, without changing the angle. After entering the second sawtooth plate 32, the light rays L21, L22 are totally reflected when entering the interface of the second gap 33 from the second sawtooth plate 32, and exit in a direction perpendicular or approximately perpendicular to the light exit surface (the flat surface 321 of the second sawtooth plate 32). The first serrated plate 31 and the second serrated plate 32 are configured to change the incident light with a small divergence angle of a large incident angle in two directions emitted from the light guide plate 2 into the incident light with a small divergence angle emitted approximately perpendicular to the light emitting surface, thereby realizing an approximately collimated parallel light beam with a small divergence angle.

It should be noted that, regarding the structure of the triangular saw teeth of the first sawtooth plate 31 and the second sawtooth plate 32, that is, the isosceles triangle in the foregoing, the height and the angle of the vertex angle thereof are determined and selected according to the exit angle of the light emitted from the light guide plate 2. According to the exit angle of the light emitted from the light guide plate 2, the height and the vertex angle of the isosceles triangular sawtooth structure are determined so that the light meets the condition of total reflection when entering the interface of the second gap 33 from the second sawtooth plate 32 and is emitted in the direction perpendicular or approximately perpendicular to the light exit surface.

In this embodiment, referring to fig. 1 and fig. 2, the end surface 212 of the first wedge-shaped plate 21 with the larger thickness is configured as a light incident surface of the light guide device 10, and is used for receiving light emitted by an external light source (for example, the first light source 4 in fig. 1). The light guide device 10 further includes a reflection mechanism 5, the reflection mechanism 5 is disposed adjacent to the end surface 222 with the larger thickness of the second wedge plate 22, the reflection mechanism 5 is configured to reflect the light emitted from the end surface 214 with the smaller thickness of the first wedge plate 21 toward the end surface 222 with the larger thickness of the second wedge plate 22, that is, the reflection mechanism 5 reflects the light emitted from the end surface 214 with the smaller thickness of the first wedge plate 21 back into the light guide device 10. By arranging the reflecting mechanism 5, the loss of light can be reduced, and the utilization rate of a light source is improved.

in this embodiment, referring to fig. 2, the first wedge plate 21 and the second wedge plate 22 have the same structure, and the included angle α between the

inclined surfaces

211, 221 and the

straight surfaces

213, 223 in the first wedge plate 21 and the second wedge plate 22 is not greater than 5 °.

further, in this embodiment, referring to fig. 2, the first wedge plate 21 and the second wedge plate 22 in the light guide plate 2 are integrally formed, the end with the smaller thickness of the first wedge plate 21 is integrally connected with the end with the larger thickness of the second wedge plate 22, and the end with the larger thickness of the first wedge plate 21 is integrally connected with the end with the smaller thickness of the second wedge plate 22. it can be understood that, as shown in fig. 2, the outer contour of the light guide plate 2 is a straight parallelepiped, the cross section of the straight parallelepiped is a parallelogram, and then a gap structure is hollowed in the middle of the straight parallelepiped with the outer contour, the gap structure is also the first gap 23, the gap structure is a long and narrow parallelogram and is obliquely arranged, and the included angle between the gap structure and the upper and lower surfaces of the straight parallelepiped is α.

In this embodiment, referring to fig. 2 and 6, the end surface 214 of the first wedge plate 21 with the smaller thickness is provided with a first reflective film 215, and the end surface 224 of the second wedge plate 22 with the smaller thickness is provided with a second reflective film 225. The first and second

reflective films

215 and 225 may be metal plated or otherwise adhered dielectric reflective films. The first reflective film 215 is used to reflect the light rays propagating in the first wedge plate 21 and reaching the end face 214 toward the second wedge plate 22 (for example, light ray L31 in fig. 6), and the second reflective film 225 is used to reflect the light rays propagating in the second wedge plate 22 and reaching the end face 224 toward the first wedge plate 21, so as to reduce the loss of the light rays and improve the utilization rate of the light source. Of course, the end surface 214 with the smaller thickness of the first wedge plate 21 and the end surface 224 with the smaller thickness of the second wedge plate 22 may be provided with a reflective film only on one end surface selected according to actual conditions. For example, in the present embodiment, the end face 212 with the larger thickness of the first wedge-shaped plate 21 is set as the light incident face of the light guide device 10, and receives the external light source, and at this time, the probability that the light ray is transmitted to the end face 214 with the smaller thickness of the first wedge-shaped plate 21 and exits from the end face 214 is high, so the first reflective film 215 is selectively set on the end face 214 with the smaller thickness of the first wedge-shaped plate 21; the probability that the light rays after multiple reflections reach the end surface 224 with the smaller thickness of the second wedge plate 22 and exit from the end surface 214 is low, so that the second reflective film 225 may be omitted from the end surface 224 with the smaller thickness of the second wedge plate 22.

The light guide device provided by the above embodiment first uses the structures of the first wedge plate and the second wedge plate to converge the divergent light with a large angle emitted by the light source into a light beam with a small divergent angle near the critical angle of total reflection through multiple total reflections, and then uses the structures of the first sawtooth plate and the second sawtooth plate to change the incident light with a small divergent angle with a large incident angle in two directions emitted from the light guide plate into the incident light with a small divergent angle approximately perpendicular to the light emitting surface to be emitted, so as to obtain the approximately collimated parallel light beam with a small divergent angle.

Example 2

The difference between this embodiment and embodiment 1 is that the light guide device 10 in this embodiment is provided with two light incident surfaces for receiving external light sources. Specifically, referring to fig. 7, the end surfaces 212 and 222 of the first wedge plate 21 and the second wedge plate 22 with larger thickness are both configured as the light incident surface of the light guide device 10. Fig. 7 also shows two light sources (first light source 4 and second light source 6) arranged on the sides of the light guide 10, as can be understood: as in embodiment 1, the end surface 212 of the first wedge-shaped plate 21 with a larger thickness is set as an incident surface of the light guide device 10, and is used for receiving light emitted by the external first light source 4; unlike embodiment 1, the reflecting mechanism 5 in embodiment 1 is removed, and the end surface 222 with the larger thickness of the second wedge plate 22 is set as another light incident surface of the light guide device 10, and is used for receiving the light emitted by the external second light source 6.

Other structures in this embodiment are the same as those in embodiment 1, and are not described again here. In this embodiment, the light guide device 10 has two light incident surfaces for receiving external light sources, so as to receive more external light, and the light guide device is used in a backlight module to improve backlight power.

Example 3

The difference between this embodiment and embodiment 1 is that, as shown in fig. 8, the light guide device 10 further includes a transmission lens 7, and the transmission lens 7 is disposed on a side of the light reflection plate 1 facing away from the light guide plate 2. The first end 71 of the transmission lens 7 extends towards the end where the first light source 4 is arranged, and the second end 72 extends towards the end where the reflecting mechanism 5 is arranged. A part of the light emitted by the first light source 4 enters from the first end 71 of the transmission lens 7, is transmitted by the transmission lens 7 and then exits from the second end 72 of the transmission lens 7, and the reflection mechanism 5 reflects the light exiting from the second end 72 of the transmission lens 7 toward the end surface with the larger thickness of the second wedge plate 22. The transmission lens 7 is a straight parallelepiped and includes a light incident surface (first end 71) and a light emitting surface (second end 72), the upper surface and the lower surface opposite to each other are all provided as total reflection surfaces, referring to fig. 8 and 9, a light ray L41 incident from the light incident surface is reflected from the light emitting surface after being totally reflected for multiple times, and reaches the reflection mechanism 5, and the reflection mechanism 5 reflects the light ray emitted from the light emitting surface and enters the second wedge plate 22. Generally, for the backlight power, the size of the light source is large, but the thickness of the light guide plate 2 is small, the light emitted by the large-sized light source cannot be completely coupled into the light incident surface of one wedge-shaped plate (for example, the end surface 212 of the first wedge-shaped plate 21), and at this time, by arranging the transmission lens 7, a part of the light is transmitted to be incident from the light incident surface of another wedge-shaped plate (for example, the end surface 222 of the second wedge-shaped plate 22), so that the problem that some light sources are too large to couple all light energy into the light guide plate is solved, and the energy utilization rate of the light sources is improved.

Specifically, referring to fig. 8 and 9, the reflecting mechanism 5 in this embodiment includes a reflecting surface, and the reflecting surface includes a first reflecting inclined surface 51 and a second reflecting inclined surface 52 intersecting to form an included angle, where the first reflecting inclined surface 51 is disposed corresponding to an end surface of the second end 72 of the transmission lens 7, and the second reflecting inclined surface 52 is disposed corresponding to an end surface of the second wedge plate 22 having a larger thickness. The first reflecting inclined surface 51 reflects the light emitted from the second end 72 of the transmission lens 7 toward the second reflecting inclined surface 52, and the second reflecting inclined surface 52 reflects the light emitted from the first reflecting inclined surface 51 toward the end surface 222 of the second wedge plate 22 with a larger thickness. In the present embodiment, the reflecting mechanism 5 is a straight heptahedron having a cross section of a pentagon formed by a rectangle in which a triangle having one side of the rectangle (a side adjacent to the end faces of the transmission lens 7 and the second wedge plate 22) as a base is removed inward. The surfaces formed by the two sides except the base of the removed triangle are optical reflection surfaces, and light emitted from the transmission lens 7 enters the second wedge plate 22 after being reflected by the two optical reflection surfaces.

In other embodiments, the reflecting mechanism 5 may include a reflecting surface, or may be a reflecting surface having another shape, for example, a circular arc surface or a curved surface similar to the circular arc surface, or may include a larger number (more than 3) of reflecting inclined surfaces that are sequentially spliced together.

Example 4

As shown in fig. 10, the present embodiment provides a liquid crystal display, which includes a liquid crystal panel 100 and a backlight module 200, wherein the liquid crystal panel 100 and the backlight module 200 are disposed opposite to each other, and the backlight module 200 provides a display light source to the liquid crystal panel 100, so that the liquid crystal panel 100 displays an image.

The backlight module 200 includes a first light guide mechanism 101 and a light source mechanism 102 disposed on a side surface of the first light guide mechanism 101.

The first light guide mechanism 101 is the light guide device 10 provided in

embodiments

1 and 2 or 3 of the present invention. When the first light guide mechanism 101 adopts the light guide device 10 as provided in

embodiment

1 or 3, one end of the first light guide mechanism 101 is provided with the light source mechanism 102, and the other end is provided with the light reflecting mechanism. When the light guide device 10 provided in embodiment 2 is used as the first light guide mechanism 101, one light source mechanism 102 is disposed at each end of the first light guide mechanism 101.

According to the backlight module and the liquid crystal display, light provided by the backlight module has good collimation, the utilization rate of a light source is increased, and the display quality of the display is improved.

Example 5

The difference between this embodiment and embodiment 4 is that, as shown in fig. 11, the light source mechanism 102 in this embodiment includes a light source 102a and a second light guide mechanism 102b, and the second light guide mechanism 102b adopts the light guide device 10 provided in

embodiments

1 and 2 or embodiment 3 of the present invention.

The second light guide mechanism 102b conducts the divergent light emitted by the light source 102a to form a first-dimension-direction collimated parallel light to be emitted (see the content of embodiment 1 for the transmission principle), the light emitted by the second light guide mechanism 102b faces the light incident surface of the first light guide mechanism 101, and the first light guide mechanism 101 conducts the light emitted by the second light guide mechanism 102b to form a second-dimension-direction collimated parallel light to be emitted (see the content of embodiment 1 for the transmission principle), and the second-dimension-direction collimated parallel light is provided to the liquid crystal panel 100.

Compare in embodiment 4, in the backlight unit of this embodiment, adopt first light guide mechanism and second light guide mechanism to adjust the collimation degree of light source light from first dimension direction and second dimension direction respectively for backlight unit all has good collimation nature in the two-dimensional direction in the plane to the light that liquid crystal display panel provided, has further promoted the display quality of display.

In summary, the light guide device provided in the embodiments of the present invention is applied to a backlight module and a liquid crystal display, and can improve the collimation of light provided by the backlight module, increase the utilization rate of a light source, and improve the display quality of the display.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing is directed to embodiments of the present application and it is noted that numerous modifications and adaptations may be made by those skilled in the art without departing from the principles of the present application and are intended to be within the scope of the present application.

Claims

1. A light guide device for conducting diverging light emitted by a light source to form collimated parallel light, wherein the light guide device comprises a reflector, a light guide plate and a collimation plate arranged in sequence; wherein,

The light guide plate includes a first wedge-shaped plate and a second wedge-shaped plate, the inclined surfaces of the first wedge-shaped plate and the second wedge-shaped plate are disposed opposite to each other and have a first gap therebetween, the first wedge-shaped plate and the second wedge-shaped plate The included angle between the inclined plane and the straight plane in the wedge-shaped plate is not greater than 5°, the end faces with the larger thickness of the first wedge-shaped plate and the second wedge-shaped plate are respectively set as the light incident surface of the light guide plate, and the first The flat surface of a wedge-shaped plate is disposed toward the reflector, and the flat surface of the second wedge-shaped plate is disposed as the light-emitting surface of the light guide plate and disposed toward the collimating plate;

The collimating plate includes a first sawtooth plate and a second sawtooth plate, the first sawtooth plate and the second sawtooth plate respectively have a flat surface and a triangular sawtooth surface arranged oppositely, the first sawtooth plate and the The triangular sawtooth surfaces of the second sawtooth plate are meshed with each other and have a second gap therebetween, the flat surface of the first sawtooth plate is set as the light incident surface of the collimating plate, and the flat surface of the second sawtooth plate is set is the light-emitting surface of the collimating plate.

2 . The light guide device according to claim 1 , wherein the end face of the first wedge-shaped plate with a smaller thickness is provided with a first reflective film, and/or the second wedge-shaped plate with a smaller thickness. 3 . The end face is provided with a second reflective film.

3 . The light guide device according to claim 1 , wherein the first wedge-shaped plate and the second wedge-shaped plate in the light guide plate are integrally formed, and the end of the first wedge-shaped plate with the smaller thickness is the same as the one. 4 . The thicker end of the second wedge-shaped plate is integrated into one body, and the thicker end of the first wedge-shaped plate is integrated with the smaller thickness end of the second wedge-shaped plate.

4. The light guide device according to any one of claims 1 to 3, wherein the end face of the first wedge-shaped plate with a larger thickness is set as the light incident face of the light guide plate for receiving the light emitted by the light source. The light guide device further includes a reflection mechanism, the reflection mechanism is arranged adjacent to the end face of the second wedge-shaped plate with a larger thickness, and the reflection mechanism is used to reduce the thickness of the first wedge-shaped plate from the thickness of the first wedge-shaped plate. The light emitted from the small end face is reflected toward the thick end face of the second wedge-shaped plate.

5 . The light guide device according to claim 4 , wherein the light guide device further comprises a transmission lens, and the transmission lens is disposed on a side of the reflector away from the light guide plate, and the transmission lens The first end of the lens receives a part of the light emitted by the light source, the part of the light is transmitted through the transmission lens and then emitted from the second end of the transmission lens, and the reflection mechanism emits light from the second end of the transmission lens. The light is reflected toward the thicker end face of the second wedge-shaped plate.

6 . The light guide device according to claim 5 , wherein the reflection mechanism comprises a reflection surface, and the reflection surface comprises a first reflection slope and a second reflection slope that intersect to form an included angle, and the first reflection slope The inclined surface reflects the light emitted from the second end of the transmission lens toward the second reflecting inclined surface, and the second reflecting inclined surface has a thicker thickness of the light emitted from the first reflecting inclined surface toward the second wedge-shaped plate. Large end reflections.

7. A backlight module, characterized in that it comprises a first light guide mechanism and a light source mechanism arranged on the side of the first light guide mechanism, and the first light guide mechanism adopts the method according to any one of claims 1-6. The light guide device described.

8 . The backlight module according to claim 7 , wherein the light source mechanism comprises a light source and a second light guide mechanism, and the second light guide mechanism adopts the light guide according to any one of claims 1 to 6 . Light device, the second light guide mechanism conducts the divergent light emitted by the light source to form collimated parallel light in the first dimension, and the first light guide mechanism conducts the light emitted by the second light guide mechanism to form Collimated parallel light in the second dimension is emitted.

9. A liquid crystal display, comprising a liquid crystal panel and a backlight module, the liquid crystal panel and the backlight module are arranged oppositely, and the backlight module provides a display light source to the liquid crystal panel, so that the liquid crystal panel displays an image, characterized in that the backlight module It is the backlight module of claim 7 or 8.