CN110426871A - A kind of backlight adjustment structure and display device - Google Patents

Abstract

The invention discloses a kind of backlight adjustment structure and display devices, and thicker to improve size existing for the anti-peeping display device of the prior art, shared model is easy to obscure with anti-peeping mode, and the problem that pixel density when display is lower.The backlight adjustment structure, comprising: waveguide plate, the light guide plate include the first opposite side incidence surface, second side incidence surface, and a surface of connection first side incidence surface and second side incidence surface；First light source, the first light source are located at first side incidence surface of the waveguide plate；Second light source, the second light source are located at second side incidence surface of the waveguide plate；Multiple groups gradual change optical grating construction, the gradual change optical grating construction is located at the surface of the waveguide plate, and is being directed toward on the direction of the second light source by the first light source, and the screen periods in gradual change optical grating construction described in every group are sequentially reduced.

Description

A backlight adjustment structure and display device

technical field

The invention relates to the field of peep-proof display, in particular to a backlight adjustment structure and a display device.

Background technique

With the advancement of technology, displays have become the main terminal for disseminating information. At present, information security is getting more and more attention in some important fields. In order to prevent personal and national information from being peeped by criminals, more and more anti-peeping technologies are applied to displays.

Anti-peeping display devices in the prior art usually use resin lenses with a certain thickness arranged in the display device to realize different display functions, among which, a resin lens with a short focal length is used to realize a shared display mode, and a resin lens with a long focal length is used to realize Anti-peeping display mode, but the anti-peeping display device with this structure has the following problems:

1. The structure is complex, the overall device size is thick, and a liquid crystal cell device and a resin lens layer are required;

2. When the positions of the long-focus resin lens and the short-focus resin lens are fixed, in the corresponding display mode, it is required that the light can be accurately irradiated to the corresponding resin lens, and the transmitted light cannot be a very narrow Beam beams (it is necessary to ensure that the shared mode beam path does not coincide with the anti-peeping beam path), will cause the sharing mode and the anti-peeping mode to be easily confused; The distance between the light positions will also be very large, and it is impossible to be exactly the position of the light-taking port of the corresponding pixel, so the sharing mode and the anti-peeping mode are also very easy to confuse;

3. The display pixel density (Pixels Per Inch, PPI) is low, and only 1/2 of the pixels are available for shared display or anti-peep display, which substantially reduces the display PPI and loses the display effect.

Contents of the invention

The embodiment of the present invention provides a backlight adjustment structure and a display device to improve the anti-peeping display device in the prior art, which is relatively thick in size, easy to confuse the sharing mode and the anti-peeping mode, and the problem of low pixel density during display. .

A backlight adjustment structure provided by an embodiment of the present invention includes:

A waveguide plate, the light guide plate includes a first side incident light surface, a second side light incident surface, and a surface connecting the first side light incident surface and the second side light incident surface;

a first light source, the first light source is located on the first side light incident surface of the waveguide plate;

a second light source, the second light source is located on the second light-incident surface of the waveguide plate;

Multiple groups of graded grating structures, the graded grating structures are located on the surface of the waveguide plate, and in the direction from the first light source to the second light source, the grating period in each group of the graded grating structures Decrease in turn; multiple groups of the gradient grating structure are configured to converge the light exiting through the waveguide plate when only the first light source enters the light, and when only the second light source enters the light, The light emitted by the waveguide plate diverges.

In a possible implementation manner, multiple groups of the progressive grating structures are configured to converge the light emitted through the waveguide plate at different positions when only the first light source receives light.

In a possible implementation manner, the grating structures in any two groups of the graded grating structures are the same.

In a possible implementation manner, the smaller the variation range of the grating period in the graded grating structure is, the farther the converged position point is from the surface.

In a possible implementation manner, the gradient grating structure is configured to converge the light emitted through the waveguide plate to the same point when only the first light source receives light.

In a possible implementation manner, in the direction from the first light source to the second light source, for any adjacent two groups of the gradient grating structures, the gradient grating structures close to the first light source The minimum grating period of the structure is greater than the maximum grating period of the graded grating structure far away from the first light source.

In a possible implementation manner, the surface is a light exit surface of the waveguide plate.

In a possible implementation manner, the surface is the surface of the waveguide plate opposite to the light-emitting surface, and the surface of the gradient grating structure facing away from the waveguide plate is also covered with a reflective layer.

An embodiment of the present invention also provides a display device, including the backlight adjustment structure provided by the embodiment of the invention, and also includes an opposite substrate opposite to the backlight adjustment structure, and a display device located between the backlight adjustment structure and the The liquid crystal layer between the opposing substrates.

In a possible implementation manner, the display device includes a plurality of pixel units; the gradient grating structure corresponds to the pixel units one by one; or, a group of the gradient grating structures corresponds to a plurality of the pixel units.

The beneficial effects of the present invention are as follows:

The backlight adjustment structure provided by the embodiment of the present invention includes: multiple groups of graded grating structures located on one surface of the waveguide plate, and for the multiple groups of graded grating structures, in the direction from the first light source to the second light source, each group The grating period in the graded grating structure decreases sequentially, and then when only the first light source receives light, multiple groups of graded grating structures can converge the light emitted through the waveguide plate, and when only the second light source receives light , can diverge the light emitted by the waveguide plate, compared with the anti-peeping display device in the prior art, since there is no need to set resin lens layers with different focal lengths, the thickness of the anti-peeping display device can be thinned, and, because there is no The shared or anti-peeping display mode needs to be realized through resin lenses with different focal lengths in different positions, thereby avoiding the anti-peeping display device in the prior art. The problem of confusion is easy to occur. In addition, in the same display mode, the gradient grating structure at each position can be focused or diffused, thereby avoiding the problem of low pixel density during display in the anti-peeping display device of the prior art. .

Description of drawings

FIG. 1 is a schematic structural diagram of a backlight adjustment structure provided by an embodiment of the present invention;

Fig. 2 is a schematic diagram of an enlarged structure of a gradient grating structure in Fig. 1;

FIG. 3 is a schematic structural diagram of a backlight adjustment structure with a medium anti-peeping display effect provided by an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a backlight adjustment structure with a strong anti-peeping display effect provided by an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a backlight adjustment structure provided with a reflective layer according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a display device provided by an embodiment of the present invention;

Fig. 7 is a schematic diagram of a weak anti-peeping display device provided by an embodiment of the present invention when it is anti-peeping;

Fig. 8 is a schematic diagram of a weak anti-peeping display device provided by an embodiment of the present invention when sharing a display;

Fig. 9 is a schematic diagram of the anti-peeping display device provided by the embodiment of the present invention when it is anti-peeping;

FIG. 10 is a schematic diagram of a privacy-preventing display device provided by an embodiment of the present invention during sharing;

Fig. 11 is a schematic diagram of a strong anti-peeping display device provided by an embodiment of the present invention when it is anti-peeping;

Fig. 12 is a schematic diagram of a strong privacy display device provided by an embodiment of the present invention when sharing a display;

Fig. 13 is a schematic diagram of the diffraction principle of the graded grating structure provided by the embodiment of the present invention;

Fig. 14 is a schematic diagram of the diffraction principle of the gradient grating structure provided by the embodiment of the present invention when converging;

Fig. 15 is a schematic diagram of the diffraction principle of the gradient grating structure provided by the embodiment of the present invention when it diverges;

Fig. 16 is a schematic diagram of the relationship between the design parameters of the graded grating structure and the diffraction angle provided by the embodiment of the present invention;

Fig. 17 is a schematic diagram of the optical simulation effect of multiple gradient grating structures when converging according to an embodiment of the present invention;

FIG. 18 is a schematic diagram of a light simulation effect of a gradient grating structure converging according to an embodiment of the present invention;

FIG. 19 is a schematic diagram of light simulation effects of a plurality of gradient grating structures during emission provided by an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the specific implementation of the fingerprint reader provided by the embodiment of the present invention, its manufacturing method and display device will be described in detail below with reference to the accompanying drawings.

A backlight adjustment structure provided by an embodiment of the present invention is shown in FIG. 1 and FIG. 2 , wherein FIG. 2 is a schematic diagram of an enlarged structure of a group of gradient grating structures in FIG. 1 , and the backlight adjustment structure includes:

The waveguide plate 1, the light guide plate 1 includes an opposite first side light incident surface 11, a second side light incident surface 12, and a surface 10 connecting the first side light incident surface 11 and the second side light incident surface 12;

The first light source 21, the first light source 21 is located on the first side light incident surface 11 of the waveguide plate 1;

The second light source 22, the second light source 22 is located on the second light incident surface 12 of the waveguide plate; the second light source 22 and the first light source 21 can be specifically collimated light sources, incident into the waveguide plate 1 at a specific incident angle, so that the light incident into the waveguide plate 1 is transmitted by total reflection;

Multiple groups of graded grating structures 3, the graded grating structure 3 is located on the surface 10 of the waveguide plate 1, and in the direction from the first light source 11 to the second light source 12 (as indicated by the arrow AB in Figure 1), each group of graded grating The grating period in the structure 3 decreases successively. For example, as shown in FIG. The distance between 31 and another adjacent slit 31 is a grating period P of the progressive grating structure, and then the grating structure includes a plurality of grating periods, such as, along the direction indicated by the arrow AB, the grating period P included in the progressive grating structure 3 They are P1, P2, P3...Pn in sequence, wherein, P1>P2>P3>...Pn; multiple sets of gradient grating structures 3 are configured so that when only the first light source 21 receives light, the light emitted through the waveguide plate 1 Convergence is performed, and when only the second light source 22 receives light, the light emitted from the waveguide plate 1 is diverged.

The backlight adjustment structure provided by the embodiment of the present invention includes: multiple groups of graded grating structures 3 located on the first surface 10 of the waveguide plate 1, the multiple groups of graded grating structures 3, in the direction from the first light source 21 to the second light source 22, The grating periods in each group of graded grating structures 3 decrease sequentially, and then when only the first light source 21 enters the light, multiple groups of graded grating structures 3 can converge the light exiting through the waveguide plate 1, while only the second light source 21 When the light source 22 receives light, it can diverge the light emitted by the waveguide plate 1. Compared with the anti-peeping display device in the prior art, since there is no need to set resin lens layers with different focal lengths, the thickness of the anti-peeping display device can be thinned. thickness, and because it is not necessary to realize the sharing or anti-peeping display mode through resin lenses with different focal lengths in different positions, it can avoid the anti-peeping display device in the prior art, which is caused by the inaccurate correspondence between the light and the corresponding focal length of the resin lens The sharing and anti-peeping display modes are prone to confusion. In addition, in the same display mode, the gradient grating structure at each position can be focused or diffused, thereby avoiding the display confusion that exists in the anti-peeping display device in the prior art. The problem with smaller pixel densities.

In specific implementation, the control of light can be realized by adjusting the structures of multiple sets of gradient gratings. Specifically, as shown in FIG. 1 , multiple groups of progressive grating structures 3 are configured to converge the light emitted through the waveguide plate 1 to different positions when only the first light source 21 receives light. In the embodiment of the present invention, multiple groups of grating structures 3 converge the light emitted from the waveguide plate 1 at different positions. Directly above the grating structure 3 , different graded grating structures 3 converge the light exiting through the waveguide plate 1 directly above the different graded grating structures 3 .

In specific implementation, when multiple groups of graded grating structures 3 converge the light exiting through the waveguide plate 1 at different points, the grating structures in any two groups of graded grating structures 3 are the same, that is, the structures of multiple groups of graded grating structures 3 They are all the same, the heights of the converging points of the light emitted from each position are the same, and the converging effect is the same, so as to realize the uniformity control of the display effect of each position in one mode.

In a specific implementation, the smaller the variation range of the grating period in the graded grating structure 3 is, the farther the convergent point is from the surface. In the embodiment of the present invention, by controlling the variation range of the grating period in the gradual grating structure 3, the control of the convergence position point can be realized, and the difference in the control position point will lead to different anti-peeping effect of the anti-peeping mode, that is , the farther the converging point is, the smaller the field of view of the light, the better the anti-peep effect, and the less likely it is for others to see. For example, as shown in Figures 1 and 3, in the backlight adjustment structure shown in Figure 1, the grating period variation range in each group of progressive grating structures 3, for example, changes from 5 to 1, that is, for example, each group of progressive gratings Structure 3 includes 5 grating periods, and the 5 grating periods of each group of progressive grating structures 3 are respectively P1=5, P2=4, P3=3, P4=2, P5=1; A backlight adjustment structure, wherein each group of gradient grating structures 3 also includes 5 grating periods, but the 5 grating periods of each group of gradient grating structures 3 are respectively P1=3, P2=2.75, P3=2.5, P4=2.25, P5=2, that is, the variation range of each group of progressive grating structures 3 in the backlight adjustment structure shown in FIG. 1 is 4, and the variation range of each group of gradual grating structures 3 shown in FIG. The variation range of the grating period of the backlight adjustment structure shown in Fig. 3 is greater than the variation range of the grating period shown in Fig. 3. The backlight structure shown in Fig. 1 is weak privacy protection, while the backlight structure shown in Fig. 3 is medium privacy protection, Fig. 3 Compared with the backlight adjustment structure shown in FIG. 1 , the anti-peeping display device made by the backlight adjustment structure shown in FIG. 1 is less likely to be seen by outsiders. It should be noted that the number and specific values of the grating periods of each group of progressive grating structures 3 above are only for the purpose of more clearly explaining the impact of different grating period variation ranges on the anti-peeping effect, and the present invention is not limited thereto. .

In a specific implementation, as shown in FIG. 4 , the graded grating structure 3 is configured to converge the light emitted by the waveguide plate 1 to the same point when only the first light source 21 receives light. In the embodiment of the present invention, the gradient grating structure 3 converges the grating emitted by the waveguide plate 1 at the same point, which can further enhance the anti-peeping effect, that is, the anti-peeping effect made of the backlight adjustment structure can be seen only at a certain position. The content displayed by the display device, but outside this position, the content displayed by the display device cannot be seen.

Specifically, for the case where the gradient grating structure 3 converges the light emitted through the waveguide plate at the same point, the gradient grating structure 3 can be set so that, in the direction from the first light source 21 to the second light source 22, for any For two adjacent groups of graded grating structures 3 , the minimum grating period of the graded grating structures 3 close to the first light source 21 is greater than the maximum grating period of the graded grating structures 3 far away from the first light source 21 . For example, the backlight adjustment structure includes three groups of gradient grating structures 3. In the direction from the first light source 21 to the second light source 22, the three groups of gradient grating structures 3 are respectively the first group of gradient grating structures, the second group of gradient grating structures, The third group of graded grating structures, wherein the grating period of the first group of graded grating structures is changed from 10 to 8, the grating period of the second group of grating structures is changed from 7 to 5, and the grating period of the third group of graded grating structures is changed from 4 to 2, that is, for the first group of graded grating structures and the second group of graded grating structures, the minimum grating period 8 of the first group of graded grating structures close to the first light source 21 is greater than that of the second group of graded grating structures far away from the first light source 21 The maximum grating period 7; for the second group of graded grating structures and the third group of graded grating structures, the minimum grating period 5 of the second group of graded grating structures close to the first light source 21 is greater than that of the third group of graded grating structures far away from the first light source The maximum grating period of 4. It should be noted that the number of graded grating structures 3 included in the backlight adjustment structure and the value of the grating period of each group of graded grating structures 3 above are only for more clearly illustrating the graded grating structure 3 of the embodiment of the present invention. The setting method is not limited in the present invention. In addition, in the present invention, the graded grating structure 3 can also be configured in other structural forms to converge the light rays exiting the waveguide plate 1 at the same point.

In specific implementation, as shown in Figures 1-4, the surface 10 is the light-emitting surface of the waveguide plate 1, that is, if the upper surface 13 of the waveguide plate 1 is the light-emitting surface, the gradient grating structure 3 can be arranged on the waveguide plate. upper surface13.

In specific implementation, as shown in FIG. 5, the surface 10 is the surface of the waveguide plate 1 opposite to the light-emitting surface 13, and the side of the gradient grating structure 3 facing away from the waveguide plate 1 is also covered with a reflective layer 15, that is, if the waveguide plate When the upper surface 13 of 1 is the light-emitting surface, the graded grating structure 3 can also be arranged on the lower surface 14 of the waveguide plate 1, and when the graded grating structure 3 is arranged on the lower surface 14 of the waveguide plate 1, the graded grating structure 3 is covered with a layer of reflective layer 15, that is, the gradient grating structure 3 provided by the backlight adjustment structure can also be a reflective gradient grating structure. Compared with setting the gradient grating structure on the waveguide plate 1 to emit light, the reflective gradient grating structure is selected The transmissive gradient grating structure on the surface has higher light efficiency, about 2 times.

Based on the same inventive concept, an embodiment of the present invention also provides a display device, as shown in FIG. The liquid crystal layer 5 between the structure and the opposite substrate.

In a specific implementation, the display device includes a plurality of pixel units; the gradient grating structure 3 corresponds to the pixel units one by one; or, a group of gradient grating structures corresponds to a plurality of pixel units.

In specific implementation, as shown in FIG. 6 , the display device may further include a first resin layer 61 covering the gradient grating structure 3 , a lower polarizer 91 located on the side of the waveguide plate 1 facing the liquid crystal layer 5 , and a lower polarizer 91 located on the side of the waveguide plate 1 facing the liquid crystal layer 5 . The lower driving electrode 81 facing the liquid crystal layer 5; The second resin layer 62 on the side of the layer 7 facing the liquid crystal layer 5, the upper driving electrode 82 on the side of the second resin layer 62 facing the liquid crystal layer 5, and the upper polarizer 92 on the side of the upper substrate 4 away from the liquid crystal layer 5 .

The first resin layer 61, on the one hand, can planarize the graded grating structure 3 on the surface of the waveguide plate 1 to protect the graded grating structure 3 for subsequent preparation of other structures such as driving film layers; on the other hand, the first The refractive index of the resin layer 61 is lower than that of the waveguide plate 1 , which can have a light-locking effect on the waveguide plate 1 , that is, the refractive index of the waveguide plate 1 is required to be higher than that of the upper and lower media.

Quantum dot color film layer 7, when the display device of the embodiment of the present invention realizes monochromatic display, the wavelength of the light emitted by the first light source 21 and the second light source 22 can be determined according to the monochromatic color to be displayed; when the display device When realizing color display, the first light source 21 and the second light source 22 are light sources emitting blue light, and cooperate with the quantum dot color film layer 7 to realize color display. Specifically, the material of the waveguide plate 1 may be a glass substrate, or polymethylmethacrylate (PMMA). The entire surface of the waveguide plate 1 is smooth and flat. Gradient grating structure 3 can be directly formed by etching slits on the surface of waveguide plate 1, or can be fabricated by patterning other film layers on the surface of waveguide plate 3, and the material of other film layers can be specifically silicon nitride SiN can also be a metal material.

The display device in the embodiment of the present invention includes the quantum dot color film layer 7, the second driving electrode 82, cooperates with the backlight adjustment structure, and the liquid crystal 5, and can realize grayscale display. Specifically, common TN, IPS, ADS, VA can be used. and other display methods are not limited here.

The display mode and display principle of the display device provided by the embodiment of the present invention will be further described below in conjunction with FIGS. 7-19 , as follows:

Three privacy display options

The first type is weak anti-peeping display. Figure 7 is a schematic structural diagram of a weak anti-peeping display device when anti-peeping, in which the first light source 21 is turned on, the second light source 22 is turned off, the light is incident from the first light source 21, and the gradient grating structure 3 Converge the light emitted by the waveguide plate; FIG. 8 is a schematic structural diagram of the weak privacy display device when sharing, in which the first light source 21 is turned off, the second light source 22 is turned on, and the light is incident by the second light source 22. Gradient grating The structure 3 emits the light emitted by the waveguide plate. When converging, the focus point height of the diffracted light beam with the variable-period gradient grating structure is low, and the light field angle is slightly larger.

The second type is the middle anti-peeping display. FIG. 9 is a schematic structural diagram of the middle anti-peeping display device when it is anti-peeping, in which the first light source 21 is turned on, the second light source 22 is turned off, and the light is incident from the first light source 21. Gradient grating structure 3 Converge the light emitted by the waveguide plate; FIG. 10 is a schematic structural diagram of the anti-peeping display device when shared, in which the first light source 21 is turned off, the second light source 22 is turned on, and the light is incident by the second light source 22. Gradient grating The structure 3 emits the light emitted by the waveguide plate. When converging, the focus point height of the diffracted light beam with the variable-period gradient grating structure is high, and the light field angle is small.

The third type is strong anti-peeping display. Figure 11 is a schematic structural diagram of a strong anti-peeping display device when it is anti-peeping, in which the first light source 21 is turned on, the second light source 22 is turned off, and the light is incident from the first light source 21. Gradient grating structure 3. Converge the light emitted by the waveguide plate; FIG. 12 is a schematic structural diagram of the strong anti-peeping display device when sharing, in which the first light source 21 is turned off, the second light source 22 is turned on, and the light is incident by the second light source 22. Gradient grating The structure 3 emits the light emitted by the waveguide plate. A variable-period gradient grating structure, a variable-period gradient grating structure corresponds to multiple pixels, and each focal point of the variable-period gradient grating structure points to the same position (that is, the structural parameters of each variable-period gradient grating structure are different), At this time, the display device can only be seen when the human glasses are at a fixed position, and has a strong anti-peeping display effect.

The design principle and simulation results of the micro-nano gradient grating structure 3 are as follows:

As shown in Figure 13, the incident light is transmitted from left to right at an angle θ1 from the waveguide plate 1, and the period of the variable-period gradient grating structure 3 gradually decreases from left to right (P1>P2>P3...>Pn), Specifically, the angle θ(2,n) of the light exiting through the gradient grating structure can be obtained by the following formula:

n1sinθ1–n2sinθ(2,n)=mλ/p(n);

θ(2,n)=atan{(w/2-[P1+P1+...+P(n-1)])/f};

Among them, w is the width of the variable period grating, P1, P2...Pn is the period of the variable period grating, f is the focal point height of the variable period grating, θ1 is the incident angle (the angle of the light transmitted in the waveguide), n1 is the refraction of the waveguide layer rate, n2 is the refractive index of the diffractive medium.

As shown in Figure 14 and Figure 15, when the light in the waveguide plate 1 is transmitted in the forward direction (from the first light source on the left to the second light source on the right), the gradient grating structure converges to pick up light; when the light in the waveguide plate reverses During transmission, the gradient grating structure scatters and picks up light. Provide specific embodiment below:

Assuming that the refractive index of the waveguide plate 1 is n1=1.52, the height of the focal point is f=30um, and the transmission angle of light in the waveguide plate θ1=65°, according to the above calculation formula, the convergence angle can be calculated from θ-～θ+ corresponding to the grating The cycle parameters of , as shown in Figure 16.

As shown in Figures 17-19, they are the simulation results obtained based on the above design methods. When the light in the waveguide plate 1 is forwardly transmitted, the gradient grating structure 3 above the waveguide plate 1 presents a converging light-taking mode (Fig. At this time, the gradient grating structure 3 above the waveguide plate 1 is grating-imaged in a scattering light-taking mode ( FIG. 19 ), and the display mode is shared at this time. The duty cycle of the gradient grating structure 3 with variable period and the light-taking effect of the gradient grating structure influenced by the period can be designed according to specific application scenarios or requirements for backlight uniformity.

The backlight adjustment structure provided by the embodiment of the present invention includes: multiple groups of graded grating structures located on one surface of the waveguide plate, and for the multiple groups of graded grating structures, in the direction from the first light source to the second light source, each group of graded grating structures The grating period decreases in turn, and then when only the first light source enters the light, the multi-set gradient grating structure can converge the light exiting the waveguide plate, and when only the second light source enters the light, the light passing through the waveguide plate can be converged. The emitted light diverges. Compared with the anti-peeping display device in the prior art, since there is no need to set resin lens layers with different focal lengths, the thickness of the anti-peeping display device can be thinned. The shared or anti-peeping display mode can be realized by the resin lens, which can avoid the problem of easy confusion between the sharing and anti-peeping display mode caused by the inaccurate correspondence between the light and the corresponding focal length of the resin lens of the anti-peeping display device in the prior art. In addition, in the same display mode, the gradient grating structure at each position can be focused or diffused, thereby avoiding the problem of low pixel density during display in the anti-peeping display device in the prior art.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (10)

1. a kind of backlight adjustment structure characterized by comprising

Waveguide plate, the light guide plate include that the first opposite side incidence surface, second side incidence surface, and connection first side enter One surface of smooth surface and second side incidence surface；

First light source, the first light source are located at first side incidence surface of the waveguide plate；

Second light source, the second light source are located at second side incidence surface of the waveguide plate；

Multiple groups gradual change optical grating construction, the gradual change optical grating construction are located at the surface of the waveguide plate, and by described first Light source is directed toward on the direction of the second light source, and the screen periods in gradual change optical grating construction described in every group are sequentially reduced；Multiple groups institute Gradual change optical grating construction is stated to be configured as converging the light being emitted through the waveguide plate when only the first light source enters light It is poly-, and when only the second light source enters light, the light that the waveguide plate is emitted is dissipated.

2. backlight adjustment structure as described in claim 1, which is characterized in that gradual change optical grating construction described in multiple groups is configured as When only the first light source enters light, the light being emitted through the waveguide plate is converged to different location points.

3. backlight adjustment structure as claimed in claim 2, which is characterized in that the light in gradual change optical grating construction described in any two groups Grid structure is identical.

4. backlight adjustment structure as claimed in claim 3, which is characterized in that screen periods in the gradual change optical grating construction Variation range is smaller, and the location point of convergence is remoter with a distance from the surface.

5. backlight adjustment structure as described in claim 1, which is characterized in that the gradual change optical grating construction is configured as in only institute When stating first light source and entering light, the light being emitted through the waveguide plate is converged at into same position point.

6. backlight adjustment structure as claimed in claim 5, which is characterized in that be directed toward second light by the first light source On the direction in source, for gradual change optical grating construction described in two groups of arbitrary neighborhood, close to the gradual change grating of the first light source The minimum screen periods of structure, greater than the maximum screen periods of the gradual change optical grating construction far from the first light source.

7. backlight adjustment structure as claimed in any one of claims 1 to 6, which is characterized in that the surface is the waveguide plate Light-emitting surface.

8. backlight adjustment structure as claimed in claim 7, which is characterized in that the surface be the waveguide plate with it is described go out The opposite face of smooth surface, the gradual change optical grating construction are also covered with reflecting layer away from the waveguide plate on one side.

9. a kind of display device, which is characterized in that including the described in any item backlight adjustment structures of such as claim 1-8, also wrap The opposite substrate opposite with the backlight adjustment structure is included, and between the backlight adjustment structure and the opposite substrate Liquid crystal layer.

10. display device as claimed in claim 9, which is characterized in that the display device includes multiple pixel units；It is described Gradual change optical grating construction and the pixel unit correspond；Alternatively, gradual change optical grating construction described in one group corresponds to multiple pixels Unit.