CN106707624A - Display element, backlight source and display device - Google Patents

Abstract

The invention provides a display device, a backlight source, and a display device, which belong to the field of display technology and can solve the problems of relatively low light efficiency and high backlight power consumption caused by the use of an absorbing color film in an existing TFT-LCD. The display device of the present invention includes a collimated light source and a diffractive optical element, which uses the diffractive optical element to present a pixel pattern on a side away from the collimated light source. When the display device is used in a display device, the display panel of the display device does not need to be provided with a color filter, which is equivalent to increasing the light efficiency of the backlight source to 100%, thus greatly reducing the power consumption of the backlight source. The display device of the present invention is applicable to various display devices.

Description

A display device, a backlight source, and a display device

technical field

The invention belongs to the field of display technology, and in particular relates to a display device, a backlight source and a display device.

Background technique

A traditional thin film transistor liquid crystal display (TFT-LCD, Thin Film Transistor Liquid Crystal Display,) includes an array substrate and a color filter substrate opposite to the array substrate, and liquid crystals filled between the array substrate and the color filter substrate; The working principle is: the electric field between the common electrode set on the color filter substrate and the pixel electrode on the array substrate drives the liquid crystal to rotate, and the intensity of the electric field is adjusted through the voltage change, thereby controlling the twist angle of the liquid crystal material, and then controlling the liquid crystal area. The amount of light transmitted, and finally an image is obtained.

The inventors have found that there are at least the following problems in the prior art: traditional TFT-LCDs use absorbing color filters to produce different colors, the theoretical maximum value of the luminous efficiency ratio is 33%, the luminous efficiency is relatively low, and the power consumption of the backlight is relatively high accordingly .

Contents of the invention

The present invention aims at the problems of relatively low light efficiency and high backlight power consumption caused by the use of an absorption type color film in the existing TFT-LCD, and provides a display device, a backlight source and a display device.

The technical solution adopted to solve the technical problems of the present invention is:

A display device, comprising a collimated light source and a diffractive optical element arranged above the light-emitting surface of the collimated light source, wherein the diffractive optical element can shape the collimated light emitted by the collimated light source so that the The collimated light presents a pixel pattern on a side away from the collimated light source.

Among them, the diffractive optical elements (Diffractive Optical Elements, DOE) in the present invention are based on the diffraction theory of light waves, using computer-aided design, and using modern micro-nano processing technology to prepare step-shaped or optical elements on the surface of substrates or traditional optical devices. The continuous relief structure forms a type of diffractive optical element with pure phase and extremely high diffraction efficiency.

This type of diffractive optical element can also be formed by holographic exposure of the photopolymer film layer to control the refractive index distribution in the film layer to form a refractive index modulated diffractive optical element.

Preferably, the direction perpendicular to the light-emitting surface is the first direction, and the included angle between the propagation direction of the collimated light and the first direction is ±10°.

Wherein, the collimated light source in the present invention means that the light emitted by the light source is parallel light, and the divergence angle of the parallel light is less than 20°.

Preferably, the collimated light source includes a plurality of parallel-connected lasers arranged in an array, and the lasers include a first primary color laser, a second primary color laser, and a third primary color laser. The LED chip needs to be packaged with a collimating lens.

Preferably, the collimated light source includes an auxiliary light collimating component and an LED light source disposed on one side of the auxiliary light collimating component, and the auxiliary light collimating component is used to transform the light emitted by the LED light source into The first primary color collimated light, the second primary color collimated light, and the third primary color collimated light directed at the diffractive optical element.

Preferably, the diffractive optical element includes a plurality of steps, and in the direction perpendicular to the light-emitting surface, the height of the steps ranges from 50 nanometers to 5 microns, and in the direction parallel to the light-emitting surface, the The width of the step ranges from 50 nanometers to 3 microns, and the height and width of the steps are generally inconsistent.

For the diffractive optical element based on the refractive index modulation of the photopolymer film layer, the refractive index modulation range of the photopolymer is 0.005-0.5 (common materials ~ 0.02), and the thickness of the film layer is 300 nanometers to 5 mm. The specific thickness depends on the specific thickness. The design (Δn*d required in the design) and the chosen material are determined. Generally, you can choose (but not limited to) (n _max -n _min )*h _grating [or n _average *h _grating , or (n _average -1)*h _grating ]=λ, λ/2, λ/3, λ/ 4. λ/6 or λ/8, etc. The size of the smallest unit of refractive index modulation is 50 nanometers to 3 micrometers.

The present invention also provides a backlight source, including the above-mentioned display device.

Preferably, the backlight source further includes a backplane, and the laser is welded on the backplane.

The present invention also provides a display device, including the above display device.

Preferably, the display device includes a display panel and a backlight, wherein the diffractive optical element is arranged inside or outside the display panel, and the backlight is the collimated light source.

Preferably, the display panel includes a first substrate and a second substrate oppositely arranged, wherein the first substrate is close to the backlight, and the diffractive optical element is formed by photolithography or nanoimprinting or photopolymerization The object film layer is formed on the side of the first substrate or the second substrate that is close to or away from the collimated light source through holographic exposure.

The display device of the present invention includes a collimated light source and a diffractive optical element, which uses the diffractive optical element to present a pixel pattern on a side away from the collimated light source. When the display device is used in a display device, the display panel of the display device does not need to be provided with a color filter, which is equivalent to increasing the light efficiency of the backlight source to 100%, thus greatly reducing the power consumption of the backlight source. The display device of the present invention is applicable to various display devices.

Description of drawings

FIG. 1 is a schematic structural view of a display device according to Embodiment 1 of the present invention;

2-8 are schematic structural views of a display device according to Embodiment 2 of the present invention;

9-10 are schematic structural views of the backlight source of Embodiment 3 of the present invention;

11-17 are schematic structural views of a display device according to Embodiment 4 of the present invention;

18-19 are structural schematic diagrams of a diffractive optical element according to Embodiment 2 of the present invention;

Wherein, reference signs are: 1. Diffractive optical element; 2. Collimated light source; 21. Laser; 22. Auxiliary light collimating component; 23. LED light source; 24. Diaphragm; 3. Pixel pattern; 4. Backlight ; 41. Backplane; 5. Display panel; 51. First substrate; 52. Second substrate; 53. Liquid crystal.

detailed description

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1:

This embodiment provides a display device, as shown in FIG. 1 , including a collimated light source 2 and a diffractive optical element 1 arranged above the light-emitting surface of the collimated light source 2, wherein the diffractive optical element 1 can The collimated light emitted by the collimated light source 2 is shaped so that the collimated light presents a pixel pattern 3 on a side away from the collimated light source 2 .

In the display device of this embodiment, a diffractive optical element 1 is used to present a pixel pattern 3 on a side away from the collimated light source 2 . When the display device is used in a display device, the display panel of the display device does not need to be provided with a color filter, which is equivalent to increasing the light efficiency of the backlight source to 100%, thus greatly reducing the power consumption of the backlight source. The display device of the present invention is applicable to various display devices.

Example 2:

This embodiment provides a display device, as shown in FIG. 2 , including a collimated light source 2 and a diffractive optical element 1 arranged above the light-emitting surface of the collimated light source 2. The diffractive optical element 1 can The collimated light emitted by the collimated light source 2 is shaped so that the collimated light presents a pixel pattern 3 on a side away from the collimated light source 2 . Taking the direction perpendicular to the light-emitting surface as the first direction, the included angle between the propagation direction of the collimated light and the first direction is ±10°.

That is to say, the light emitted by the collimated light source 2 in this embodiment is parallel light, and the divergence angle of the parallel light is less than 20°. Preferably, the divergence angle of the parallel light is less than 10°. More preferably, the divergence angle of the parallel light is less than 10°. The angle is less than 5°. Wherein, the smaller the divergence angle of the parallel light is, the more favorable it is to accurately present the pixel pattern 3 . It can be seen from the schematic diagram in FIG. 2 that one collimated light source 2 can be correspondingly transformed into a pattern of multiple pixels, so the pixel resolution is relatively high.

As an optional implementation in this embodiment, the collimated light source 2 adopts multiple parallel-connected lasers 21 arranged in an array, and the lasers 21 include a first primary color laser, a second primary color laser, and a third primary color laser.

Specifically, the laser 21 can use semiconductor laser chip particles, and its material can be selected from In-Ga-N, Al-Ga-N, In-Ga-As, Al-Ga-As, In-P, In-Ga-As -P, CdS, ZnS, etc., the structure of which can be selected from homojunction, single heterojunction, double heterojunction, quantum well, etc. The power of the laser 21 is between 10μW-900mW, and the first primary color laser, the second primary color laser, and the third primary color laser are respectively blue (B) laser, green (G) laser, and red (R) laser in Fig. 2 to Fig. 5 As an example, the lasers 21 of R, G, and B can be arranged alternately, and the order is not limited, as shown in Fig. Cluster distribution, but not limited to these two distribution methods. The connection mode of the R, G, and B lasers 21 can be collinear parallel connection of different colors as shown in FIG. 3 and FIG. 5 , or can be collinear parallel connection of the same color as shown in FIG. 4 and FIG. 6 . It can be understood that the laser 21 can also be in R, G, B, W modes.

In particular, the above-mentioned lasers can also be replaced by LED light sources of corresponding colors. In this case, a corresponding collimating lens needs to be packaged on the LED light source.

That is, as another optional implementation in this embodiment, the collimated light source 2 includes an auxiliary light collimating component 22 and an LED light source 23 arranged on one side of the auxiliary light collimating component 22, and the auxiliary light The collimating component 22 is used to transform the light emitted by the LED light source 23 into collimated light of the first primary color, collimated light of the second primary color and collimated light of the third primary color directed to the diffractive optical element 1 .

In this embodiment, the LED light source 23 is LED or OLED, (the light output side of the LED or OLED can choose to use a collimating lens, or the LED light source 23 can be a laser), and it is used in conjunction with the auxiliary light collimating component 22 to emit collimated light Referring to FIG. 7 and FIG. 8 , the auxiliary light collimation component 22 is an optical waveguide. Specifically, the shared optical waveguide shown in FIG. 7 can be selected, or the divided optical waveguide shown in FIG. 8 can be selected. The optical waveguide can be a single-mode waveguide or a multi-mode waveguide. The single-mode waveguide has a higher degree of light collimation, but the overall light efficiency is low; the multi-mode optical waveguide has a lower light collimation degree, but the overall The light effect is high. The period of the optical coupling grating of the optical waveguide satisfies the following conditions:

where N is the equivalent refractive index of the selected waveguide mode, λ is the vacuum wavelength, and P is the grating period.

Preferably, the diffractive optical element 1 includes a plurality of steps, and the height of the steps ranges from 50 nanometers to 5 microns in the direction perpendicular to the light-emitting surface, and in the direction parallel to the light-emitting surface , the width of the step ranges from 50 nanometers to 3 microns, and the height and width of the steps are generally inconsistent.

For the diffractive optical element based on the refractive index modulation of the photopolymer film layer, the refractive index modulation range of the photopolymer is 0.005-0.5 (common materials ~ 0.02), and the thickness of the film layer is 300 nanometers to 5 mm. The specific thickness depends on the specific thickness. The design (Δn*d required in the design) and the chosen material are determined. Generally, you can choose (but not limited to) (n _max -n _min )*h _grating [or n _average *h _grating , or (n _average -1)*h _grating ]=λ, λ/2, λ/3, λ/ 4. λ/6 or λ/8, etc. The size of the smallest unit of refractive index modulation is 50 nanometers to 3 micrometers.

Wherein, in this embodiment, by controlling the phase distribution on the DOE, the shaping of the incident light is realized to output the pixel pattern 3 . Specifically, on the one hand, as shown in Figure 18, it can be realized by controlling the height of the steps. At this time, the size and height of the step units are tens of nanometers to tens of microns; on the other hand, as shown in Figure 19, through different The duty cycle is realized. At this time, the step heights are the same, ranging from tens of nanometers to several microns. In addition, it can also be realized by adjusting the refractive index distribution in the film layer. The smallest unit size of the refractive index modulation is 50 nanometers-3 Micron, through FDTD, FEM, RCWA, FMM and other optical simulation algorithms, combined with genetic algorithm, Fourier annealing algorithm and other numerical optimization algorithms, adjust and iterate to obtain the corresponding pixel pattern3.

Example 3:

This embodiment provides a backlight source 4, which includes the display device of the above embodiment.

Preferably, the backlight source 4 further includes a backplane 41 .

As an optional implementation in this embodiment, as shown in FIG. 9, the display device is prepared on the membrane 24 through a photolithography process, a nanoimprint process, or a photopolymer holographic exposure process. When used, it will have The film 24 of the display device is attached to the back plate 41 of the backlight 4 .

As another optional implementation in this embodiment, as shown in FIG. 10 , the collimated light source 2 adopts a plurality of parallel-connected lasers 21 arranged in an array, and the lasers 21 are welded on the back plate 41 .

Wherein, when the backlight 4 is used in conjunction with the display panel 5, in the embodiment in which the diaphragm 24 is attached to the back plate 41 of the backlight 4, the alignment accuracy of the DOE and the pixel array of the display panel 5 is slightly lower. . However, the DOE and the pixel array of the display panel 5 in the embodiment in which the laser 21 is directly welded to the backplane 41 have higher alignment accuracy.

Example 4:

This embodiment provides a display device, as shown in FIG. 11 , including the display device of the above-mentioned embodiment.

Preferably, the display device includes a display panel 5 and a backlight 4 , wherein the diffractive optical element 1 is disposed inside or outside the display panel 5 , and the backlight 4 is the collimated light source 2 .

Preferably, the display panel 5 includes a first substrate 51 and a second substrate 52 oppositely arranged, and a liquid crystal 53 is disposed between the first substrate 51 and the second substrate 52, wherein, as shown in FIGS. 12 to 14 , Close to the backlight 4 is the first substrate 51, and the diffractive optical element 1 is formed on the side of the first substrate 51 or the second substrate 52 that is close to or far from the collimated light source 2 by photolithography or nanoimprinting. superior.

The shape of the pixel pattern 3 that can be presented by the display device of this embodiment can be square, rectangular, circular, ellipse, triangular, etc. The arrangement of pixels may be R, G, B or any arrangement of R, G, B, W. Specifically, the arrangement of pixels may be as shown in FIG. 15 to FIG. 17 , but is not limited thereto. It can be understood that in the display panel of the display device in the present invention, the collimated light source and the diffractive optical element are used together to play the role of the color filter, so it is equivalent to increasing the light efficiency of the backlight source to 100%, which can greatly reduce the backlight effect. In terms of power consumption, in actual use, in order to make the light color more brilliant, it is also feasible to add a color filter.

Obviously, many changes can be made to the specific implementation of the above-mentioned embodiments; for example, the arrangement form of the collimated light source can be adjusted as required, and its connection method can be selected according to specific product requirements.

Example 5:

This embodiment provides a display device, which is similar to the display device in the above embodiments, which may be: liquid crystal display panels, electronic paper, mobile phones, tablet computers, televisions, monitors, notebook computers, digital photo frames, Any product or component with a display function, such as a navigator.

It can be understood that, the above embodiments are only exemplary embodiments adopted for illustrating the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (10)

1. a kind of display device, it is characterised in that including collimated light source and spreading out above the exiting surface of the collimated light source Optical element is penetrated, wherein, the collimation light shaping that the diffraction optical element can send the collimated light source, so that the collimation Light is presented pattern of pixels in the one side away from the collimated light source.

2. display device according to claim 1, it is characterised in that perpendicular to the direction of the exiting surface be first party To the direction of propagation of the collimated light and the angle of first direction are 0-30 °.

3. display device according to claim 1, it is characterised in that the collimated light source include multiple array arrangements and Join the laser of connection, the laser includes the first primary colors laser, the second primary colors laser, third primary color laser.

4. display device according to claim 1, it is characterised in that the collimated light source include fill-in light collimating components and Located at the LED light source of the fill-in light collimating components side, the fill-in light collimating components are used for send the LED light source Light is changed into the first primary colors collimated light, the second primary colors collimated light, the third primary color collimated light of diffraction optical element described in directive.

5. display device according to claim 1, it is characterised in that the diffraction optical element includes multiple steps, On the direction of the exiting surface, the size range of the step is 10 nanometers -90 microns.

6. a kind of backlight, it is characterised in that including the display device described in claim any one of 1-5.

7. backlight according to claim 6, it is characterised in that the display device is the display described in claim 3 Device, the backlight also includes backboard, and the laser is welded on the backboard.

8. a kind of display device, it is characterised in that including the display device described in claim any one of 1-5.

9. display device according to claim 8, it is characterised in that the display device includes display panel and backlight Source, wherein, located at the display panel either internally or externally, the backlight is the collimated light to the diffraction optical element Source.

10. display device according to claim 9, it is characterised in that the display panel includes be oppositely arranged first Substrate and second substrate, wherein, near the backlight is first substrate, and the diffraction optical element passes through photoetching or nanometer Impressing or photo-induced polymer holographic exposure technology are formed at the first substrate or second substrate is close to or away from the standard In the one side in direct light source.