CN205281086U - Back light module and liquid crystal display device - Google Patents

Abstract

The application discloses back light module and liquid crystal display device for realize more frivolous LCD, and can improve LCD's light efficiency, reduction consumption and product cost. The utility model provides backlight unit includes: the backlight is in with the setting diffraction grating on the backlight, wherein, the diffraction grating sculpture is in on the backlight, each monochromatic luminescence unit in the backlight corresponds the last N kind grating pattern of diffraction grating, N is for being greater than 1 natural number.

Description

A kind of backlight module and liquid-crystal display

Technical field

The application relates to display technology field, particularly relates to a kind of backlight module and liquid-crystal display.

Background technology

Along with the develop rapidly of display art, people are more and more higher to the requirement of display device. Frivolous, energy-conservation, picture is fine and smooth, to reduce costs be the developing goal of display device all the time. The stepped construction of backlight module, TFT substrate, lower polaroid, color membrane substrates and upper polarizer limits the thickness of conventional liquid crystal part, it is very difficult to accomplish more frivolous. In addition, the use of colored filter is the loss luminous energy of 60% at least, can only rely on and improve the brightness requirement that backlight illumination meets real device, and this adds power consumption undoubtedly.

Practical novel content

The embodiment of the present application provides a kind of backlight module and liquid-crystal display, and in order to realize more frivolous liquid-crystal display, and the light that can improve liquid-crystal display is imitated, reduced power consumption and product cost.

A kind of backlight module that the embodiment of the present application provides, comprising:

Backlight and be arranged on the diffraction grating on described backlight;

Wherein, described diffraction grating is etched on described backlight, the N kind grating pattern on the corresponding described diffraction grating of the monochromatic luminous unit of each in described backlight, N be greater than 1 natural number.

A kind of backlight module that the embodiment of the present application provides, comprise: backlight, be arranged on the diffraction grating on described backlight, wherein, described diffraction grating is etched on described backlight, the N kind grating pattern on the corresponding described diffraction grating of the monochromatic luminous unit of each in described backlight, N be greater than 1 natural number, therefore, liquid-crystal display can be made to omit lower polaroid and color membrane substrates, it is achieved that more frivolous liquid-crystal display, it is to increase the light effect of liquid-crystal display, reduction power consumption; And owing to the effect of the diffraction grating set up is the light direction adjusting light, it is possible to reduce the density of backlight array, therefore while carrying specular removal, can reduce costs.

Goodly, described backlight is direct-light-type backlight.

Goodly, the light that the monochromatic luminous unit of each in described backlight sends is collimation light.

Goodly, described backlight comprises the monochromatic luminous unit sending red, green, blue three kinds monochrome collimation light.

Goodly, described diffraction grating is sine phase grating or blazed grating.

Goodly, when described diffraction grating is sine phase grating, if its angle of inclination is ��_G, grating constant is ��, and grating length is L, and thickness is d, and so its complex amplitude projection coefficient is:

$t\left(r_q\right)=\[\underset{q=-\mathrm{\∞}}{\overset{\mathrm{\∞}}{\Σ}}{J}_q\left(v\right)\exp \left(i2{\mathrm{\πqur}}_q\right)\]\·rect\left(\frac{r_q}{L}\right)$

Wherein, q represents the order of diffration time of diffraction grating; J_qRepresent q rank first kind Bessel's function; U=1/ ��, represents the spatial frequency of grating; r_q=(��_q,��_q,��_q) represent emergent light direction cosine; The intensity of emergent light is modulated by v=2 �� �� nd/ ��, and �� n is grating refractive index, and �� is wavelength.

Goodly, when described diffraction grating is sine phase grating, if the direction cosine of the incident light of this sine phase grating are (��, ��, ��), then the outgoing direction of the emergent light of this sine phase grating is (��_q,��_q,��_q), and meet following relation:

$\left\{\begin{array}{c}{\mathrm{\α}}_q=\mathrm{\α}+q\frac{\mathrm{\λ}}{\mathrm{\Λ}}cos{\mathrm{\θ}}_G\\ {\mathrm{\β}}_q=\mathrm{\β}+q\frac{\mathrm{\λ}}{\mathrm{\Λ}}{\mathrm{sin\θ}}_G\\ {\mathrm{\γ}}_q={(1-{\mathrm{\α}}_q^2-{\mathrm{\β}}_q^2)}^{1/2}\end{array}\right..$

Goodly, exist between the various grating patterns on described diffraction grating that the monochromatic luminous unit of each in described backlight is corresponding and preset angle so that the incident light that corresponding monochromatic luminous unit sends is N number of angle outgoing.

Goodly, the arrangement mode of the N kind grating pattern on described diffraction grating that the monochromatic luminous unit of each in described backlight is corresponding is entirely not identical.

Goodly, the arrangement mode of the N kind grating pattern on described diffraction grating that the luminous unit of the adjacent single color in described backlight is corresponding is different.

A kind of liquid-crystal display that the embodiment of the present application provides, comprises described backlight module.

Goodly, described liquid-crystal display also comprises: is arranged on the light-diffusing films on described diffraction grating and is successively set on the thin film transistor TFT substrate on described light-diffusing films, liquid crystal layer and polaroid.

Goodly, described TFT substrate comprises twisted nematic (TwistedNematic, TN), the electrode structure of plane conversion (In-PlaneSwitching, IPS), vertical orientation (VerticalAlignment, VA) display format.

Accompanying drawing explanation

The structural representation of a kind of liquid-crystal display that Fig. 1 provides for the embodiment of the present application;

The structural representation of the backlight that Fig. 2 provides for the embodiment of the present application;

Four kinds of grating pattern schematic diagram of the part of one of corresponding backlight monochromatic luminous unit on the diffraction grating that Fig. 3 provides for the embodiment of the present application;

The emergent light schematic diagram in four kinds of directions is sent after the grating that the light that the monochromatic luminous unit of on the backlight that Fig. 4 provides for the embodiment of the present application one sends is corresponding on diffraction grating;

The overall grating pattern schematic diagram of the diffraction grating that the whole display area of the backlight that Fig. 5 provides for the embodiment of the present application is corresponding;

The schematic diagram of the emergent light of the different colours that the incident light of the different colours of the backlight that Fig. 6 provides for the embodiment of the present application is evenly propagated along all directions after diffraction grating and light-diffusing films;

The light that the monochromatic luminous unit of the different colours on the backlight that Fig. 7 provides for the embodiment of the present application sends, after diffraction grating effect, is that sub-pixel unit different in TFT substrate provides different colours backlight, thus realizes the schematic diagram of colored display.

Embodiment

The embodiment of the present application provides a kind of backlight module and liquid-crystal display, and in order to realize more frivolous liquid-crystal display, and the light that can improve liquid-crystal display is imitated, reduced power consumption and product cost.

A kind of backlight module that the embodiment of the present application provides, comprising: backlight, be arranged on the diffraction grating on described backlight; Wherein, described diffraction grating is etched on described backlight, the N kind grating pattern on the corresponding described diffraction grating of the monochromatic luminous unit of each in described backlight, N be greater than 1 natural number. Thus, it is possible to make the liquid-crystal display comprising this backlight module omit lower polaroid and color membrane substrates, it is achieved that more frivolous liquid-crystal display, it is to increase the light effect of liquid-crystal display, reduction power consumption; And owing to the effect of the diffraction grating set up is the light direction adjusting light, it is possible to reduce the density of backlight array, therefore while carrying specular removal, can reduce costs.

The liquid crystal display device of a kind of slimming that can improve backlight utilising efficiency that the embodiment of the present application provides, see Fig. 1, from bottom to up, it is made up of direct-light-type backlight 1, diffraction grating 2, light-diffusing films 3, thin film transistor (ThinFilmTransistor, TFT) substrate 4, liquid crystal layer 5, polaroid 6 successively.

Wherein, backlight 1 can be direct-light-type backlight, see Fig. 2, backlight 1 uses red (R) green (G) blue (B) monochrome collimation light, described direct-light-type backlight can remove the use of color membrane substrates from, thus improve light extraction efficiency, reduce power consumption, make display frame more fine and smooth true to nature. Diffraction grating 2 can reduce the density of backlight array, thus reduces costs. Light-diffusing films 3 makes backlight that backlight 1 sends along all directions uniform.

The liquid-crystal display that the embodiment of the present application provides, only a polaroid 6, it is possible to understand that be upper polarizer, therefore compared with prior art, without lower polaroid and color membrane substrates, therefore the thickness of the liquid-crystal display that the embodiment of the present application provides reduces greatly, more frivolous; Further, the transmittance of color membrane substrates only has about 30%, and the liquid-crystal display that the embodiment of the present application provides, without color membrane substrates, therefore, it is possible to carry specular removal, reduces power consumption.

Diffraction grating 2 in the liquid-crystal display that the embodiment of the present application provides, such as, can be sine phase grating, be etched on backlight 1. In backlight 1 structure, the part on the corresponding diffraction grating 2 of each monochromatic luminous unit comprises N kind grating pattern, N be greater than 1 natural number. The effect of diffraction grating 2 is the light direction of adjustment light, thus reduces the density of monochromatic array of light emitting cells on backlight 1, with cost-saving.

Such as, it is described for N=4, as shown in Figure 3. Part on the corresponding diffraction grating 2 of the monochromatic luminous unit of each in backlight 1 structure comprises 4 kinds of grating patterns, and in a certain angle between the grating that 4 kinds of grating patterns are corresponding, angle is different. After the grating of the incident light of each monochromatic luminous unit of backlight 1 on diffraction grating 2, in four angle outgoing, as shown in Figure 4. The grating of diffraction grating 2 in whole display area of backlight 1 correspondence is arranged as shown in Figure 5, it should be noted that, Fig. 5 is only schematic diagram, also may there is difference in the grating angle between different pixels, namely the grating pattern that each pixel cell is corresponding can be the same or different, and specifically can regulate according to light direction. Below the effect principle of grating is described.

Effect principles and methods about diffraction grating is as follows:

Such as, diffraction grating is sine phase grating, if its angle of inclination is ��_G, grating constant is ��, and grating length is L, and thickness is d, so its complex amplitude projection coefficient t (r_q) for below shown in formula one:

$t\left(r_q\right)=\[\underset{q=-\mathrm{\∞}}{\overset{\mathrm{\∞}}{\Σ}}{J}_q\left(v\right)\exp \left(i2{\mathrm{\πqur}}_q\right)\]\·rect\left(\frac{r_q}{L}\right)$ Formula one

Wherein, q represents the order of diffration time of diffraction grating; J_qRepresent q rank first kind Bessel's function; U=1/ ��, represents the spatial frequency of grating; r_q=(��_q,��_q,��_q) represent emergent light direction cosine; The intensity of emergent light is modulated by v=2 �� �� nd/ ��, and �� n is grating refractive index, and �� is wavelength.

It thus is seen that sine phase grating can modulate the phase place of its incident light, such as direction cosine be the incident light of (��, ��, ��) after sine phase grating, its outgoing direction turns into (��_q,��_q,��_q), there is between them the relation shown in following formula two:

$\left\{\begin{array}{c}{\mathrm{\α}}_q=\mathrm{\α}+q\frac{\mathrm{\λ}}{\mathrm{\Λ}}cos{\mathrm{\θ}}_G\\ {\mathrm{\β}}_q=\mathrm{\β}+q\frac{\mathrm{\λ}}{\mathrm{\Λ}}{\mathrm{sin\θ}}_G\\ {\mathrm{\γ}}_q={(1-{\mathrm{\α}}_q^2-{\mathrm{\β}}_q^2)}^{1/2}\end{array}\right.$ Formula two

By formula two it will be seen that for sine phase grating, the shooting angle of light is relevant to incident angle of light, grating parameter and wavelength X. Other conditions are constant and only change grating slope angle, ��_GTime, the direction of light outgoing also changes thereupon, therefore there will be phenomenon as shown in Figure 4.

Light through grating outgoing can only be propagated along special angle, therefore, further, in order to expand visual range, the liquid-crystal display that the embodiment of the present application provides adds one layer of light-diffusing films 3, the light through diffraction grating 2 outgoing is evenly propagated, as shown in Figure 6 along all directions in each position.

R, G, B tri-wavelength of coloured light are different, reasonably adjust grating parameter, it can be made to form effect as shown in Figure 7, that is: the red single luminous unit on backlight is after diffraction grating effect, for the sub-pixel unit that four in TFT substrate are different provides red backlight; Blue single luminous unit on backlight, after diffraction grating effect, is the blue backlight of sub-pixel unit offer that four in TFT substrate are different; Green single luminous unit on backlight after diffraction grating effect, for four different sub-pixel unit in TFT substrate provide green backlight; Each sub-pixel unit non-overlapping copies, the sub-pixel unit of three different colours forms a complete pixel cell, to realize colored display. Backlight array in Fig. 7, the array that namely each monochromatic luminous unit on backlight is formed; Array of diffraction gratings in Fig. 7, the array that the grating that namely each monochromatic luminous unit is corresponding is formed; Tft array in Fig. 7, the array being namely made up of TFT.

It thus is seen that the structure design of the liquid-crystal display of the embodiment of the present application offer makes the resolving power of display device not rely on the density of backlight array, thus reduce the cost of direct-light-type backlight.

It should be noted that, in the embodiment of the present application: the grating number that the monochromatic luminous unit of each on backlight is corresponding is not limit when meeting technological ability, for each monochromatic corresponding 4 grating of luminous unit in the embodiment of the present application, but it is not limited to this; The arrangement mode of each grating pattern that the monochromatic luminous unit of each on backlight is corresponding is not limit, and makes emergent light be N kind angle outgoing as long as N number of grating shape is at a certain angle and meets pixel composition structure; The electrode structure of TFT substrate is not limit, such as the electrode structure of TN, IPS, VA display format, and TFT substrate can be TFT glass substrate; Arrangement mode and the pixel rendering structure of the monochromatic luminous unit on backlight are not limit, Real, BV, Pentile mode.

In sum, the technical scheme that the embodiment of the present application provides, it is possible to obviously reduce the module thickness of liquid crystal display device, it is to increase the light extraction efficiency of backlight, and reduce device power consumption, product cost.

Obviously, the application can be carried out various change and modification and not depart from the spirit and scope of the application by the technician of this area. Like this, if these amendments of the application and modification belong within the scope of the application's claim and equivalent technologies thereof, then the application also is intended to comprise these change and modification.

Claims (13)

1. a backlight module, it is characterised in that, comprising:

Backlight and be arranged on the diffraction grating on described backlight;

Wherein, described diffraction grating is etched on described backlight, the N kind grating pattern on the corresponding described diffraction grating of the monochromatic luminous unit of each in described backlight, N be greater than 1 natural number.

2. backlight module according to claim 1, it is characterised in that, described backlight is direct-light-type backlight.

3. backlight module according to claim 2, it is characterised in that, the light that the monochromatic luminous unit of each in described backlight sends is collimation light.

4. backlight module according to claim 3, it is characterised in that, described backlight comprises the monochromatic luminous unit sending red, green, blue three kinds monochrome collimation light.

5. backlight module according to claim 1, it is characterised in that, described diffraction grating is sine phase grating or blazed grating.

6. backlight module according to claim 5, it is characterised in that, when described diffraction grating is sine phase grating, if its angle of inclination is ��_G, grating constant is ��, and grating length is L, and thickness is d, and so its complex amplitude projection coefficient is:

$t\left(r_q\right)=\[\underset{q=-\mathrm{\∞}}{\overset{\mathrm{\∞}}{\Σ}}{J}_q\left(v\right)\exp \left(i2{\mathrm{\πqur}}_q\right)\]\·rect\left(\frac{r_q}{L}\right)$

Wherein, q represents the order of diffration time of diffraction grating; J_qRepresent q rank first kind Bessel's function; U=1/ ��, represents the spatial frequency of grating; r_q=(��_q,��_q,��_q) represent emergent light direction cosine; The intensity of emergent light is modulated by v=2 �� �� nd/ ��, and �� n is grating refractive index, and �� is wavelength.

7. backlight module according to claim 6, it is characterised in that, when described diffraction grating is sine phase grating, if the direction cosine of the incident light of this sine phase grating are (��, ��, ��), then the outgoing direction of the emergent light of this sine phase grating is (��_q,��_q,��_q), and meet following relation:

$\left\{\begin{array}{c}{\mathrm{\α}}_q=\mathrm{\α}+q\frac{\mathrm{\λ}}{\mathrm{\Λ}}{\mathrm{cos\θ}}_G\\ {\mathrm{\β}}_q=\mathrm{\β}+q\frac{\mathrm{\λ}}{\mathrm{\Λ}}{\mathrm{sin\θ}}_G\\ {\mathrm{\γ}}_q={(1-{\mathrm{\α}}_q^2-{\mathrm{\β}}_q^2)}^{1/2}\end{array}\right..$

8. backlight module according to claim 1, it is characterized in that, exist between various grating patterns on the described diffraction grating that the monochromatic luminous unit of each in described backlight is corresponding and preset angle so that the incident light that corresponding monochromatic luminous unit sends is N number of angle outgoing.

9. backlight module according to claim 1, it is characterised in that, the arrangement mode of the N kind grating pattern on the described diffraction grating that the monochromatic luminous unit of each in described backlight is corresponding is entirely not identical.

10. backlight module according to claim 1, it is characterised in that, the arrangement mode of the N kind grating pattern on the described diffraction grating that the luminous unit of the adjacent single color in described backlight is corresponding is different.

11. 1 kinds of liquid-crystal displays, it is characterised in that, comprise the backlight module described in the arbitrary claim of claim 1��10.

12. liquid-crystal displays according to claim 11, it is characterised in that, also comprise: be arranged on the light-diffusing films on described diffraction grating and be successively set on the thin film transistor TFT substrate on described light-diffusing films, liquid crystal layer and polaroid.

13. liquid-crystal displays according to claim 12, it is characterised in that, described TFT substrate comprises the electrode structure of twisted nematic TN, plane conversion IPS, vertical orientation VA display format.