TWI467276B - Reflective display device and method of fabricating the same - Google Patents

Description

Reflective display panel and preparation method thereof

The invention relates to a reflective display panel and a preparation method thereof, in particular to a color reflective display panel using the interference principle and the use of the polymer dispersed liquid crystal and a preparation method thereof.

The range of applications for displays is quite wide, such as home televisions, car televisions, industrial displays, outdoor billboards, and the like. The types of displays can be classified into liquid crystal displays, cathode ray tubes (CRTs), light emitting diodes (LEDs), field emission displays (FEDs), and interferometric modulation (IMOD). Among them, the interferometric modulation display is one of reflective color displays, which has the advantages of low power consumption, moderate reading quality, and lightness and thinness. As shown in FIG. 1 , it is a conventional interference modulation display. An upper substrate 11 and a lower substrate 12, the upper substrate 11 includes a color filter (not shown) to achieve a color effect, and the upper substrate 11 has a plurality of sub-pixel regions sub-P _R (red), sub-P _G (green) corresponds to each color of the color filter. The lower substrate 12 includes movable reflective layers 14R, 14G corresponding to the electrodes 16R, 16G of the upper substrate 11, respectively, and the upper substrate 11 and the lower substrate 12 are supported by a post 13 with a pitch. When the voltage is applied to the red sub-pixel area sub-P _R , the movable reflective layer 14R is brought into contact with the electrode 16R due to the electrostatic attraction up, so that the red sub-pixel is black (ie, the light L cannot be reflected). . When this voltage is removed, the movable reflective layer 14R will return to the lower position, and the light L can be reflected to make the pixels appear red. The other green sub-pixel has no voltage, so the light can be reflected, making the green sub-pixel appear green.

However, such an interferometric modulation display has a low energy consumption effect, but the mechanical movement of the movable reflective layer causes poor stability, reduced service life, and a small viewing angle (only about 70°). . In addition, since each sub-pixel can only present a single brightness, it is necessary to use a majority of sub-pixels (for example, 16 sub-pixels) to create a gray scale effect, thus making the production steps and driving methods very complicated. Therefore, there is still a need to develop a new reflective substrate structure in the field, which can achieve the advantages of low energy consumption, lightness, high stability, long service life, and the commercial requirements of simple process and low production cost.

Accordingly, the present invention provides a reflective display panel comprising: a first substrate having a substrate layer on a surface thereof, the substrate layer having a plurality of pixel regions, each of the pixel layers having a pixel region Two or more sub-pixel grooves, wherein the sub-pixel grooves in the same pixel region have different depths, and a bottom surface of the sub-pixel groove of the base layer is provided with a light-reflecting conductive layer; a second substrate a conductive layer and a light semi-reflective layer are disposed on the surface, and a polymer-dispersed liquid crystal (PDLC) is disposed on the conductive layer of the second substrate and the base layer of the first substrate Between, and in the groove of each sub-pixel.

The reflective display panel of the present invention is a reflective display panel with an innovative structure, so that it can have low energy consumption (no backlight, no moving reflective layer as a switch), light and thin, high stability, long service life, and reduced The number of polarizers and filters used is low, the cost is large, and the viewing angle is large (up to about 80° or more).

The reflective display panel of the present invention is a color reflective display panel. The reflective display panel of the present invention can still display various colors without using a color filter.

The main principle of the reflective display panel of the present invention is to use interference technology to control the optical path difference between incident and reflection, to obtain different colors of light, and to use the polymer dispersed liquid crystal (PDLC) as the brightness switch control, and to achieve contrast. Good, high chroma effect. The reflective display panel of the present invention can produce light of different colors without using a color polarizer. In addition, the mechanically movable movable reflective layer is replaced by a polymer-dispersed liquid crystal, thereby improving stability and reliability. Moreover, the reduction in the number of use of the polarizer and the filter can reduce the production cost and meet the environmental requirements.

In the present invention, the optical path difference ΔL can be calculated according to the following formula (and refer to FIG. 2):

ΔL=2ndcosθ ₃ =mλ

Here, λ is incident light, n is a refractive index, d is a thickness of a polymer dispersed liquid crystal layer, and θ ₃ is a refractive angle at which light is incident on the polymer dispersed liquid crystal layer.

When m is a positive integer, constructive interference (constructive interference) can be obtained; and when m is a half integer (for example, 3/2, 5/2, 7/2, 9/2, etc.), destructiveness can be obtained. Interference (destructive interference).

Since the polymer-dispersed liquid crystal (PDLC) used in the reflective display panel of the present invention has a refractive index larger than that of air, the incident angle of the light incident is changed in a smaller range than that of air. It can be known from the formula of the optical path difference that reducing the influence range of the incident angle can reduce the chromatic aberration and effectively improve the viewing angle.

Since the reflective display panel of the present invention uses a polymer dispersed liquid crystal, a gray scale effect can be produced. In the prior art, an interferometric modulation display must use a plurality of sub-pixels (for example, one pixel needs to contain sixteen sub-pixels) to generate gray scales, but the present invention does not need to use a plurality of sub-pixels to generate gray scales. Therefore, the reflective display panel of the present invention does meet the commercial requirements of simple process and low production cost, and has great industrial utilization value.

In the reflective display panel of the present invention, the conductive layer on the surface of the second substrate is preferably disposed opposite to the base layer of the surface of the first substrate, and the conductive layer and the base layer are preferably located on the second substrate. Between the first substrates.

In the reflective display panel of the present invention, the number of the sub-pixel grooves of each of the pixel regions may preferably be three. For example, each pixel region contains a red (R) sub-pixel, a green (G) sub-pixel, and a blue (B) sub-pixel.

In the reflective display panel of the present invention, the depth D of the sub-pixel groove and the refraction angle θ _{3 of the} light incident on the polymer dispersed liquid crystal layer, and the wavelength λ of the light reflected by the sub-pixel are preferably satisfied. [Formula 1]:

[Formula 1] 2Dcosθ ₃ =mλ/n

Wherein m is an integer of 1 or more (for example, m = 1, 2, 3, 4, ..., etc.), and n is a refractive index of a polymer dispersed liquid crystal (for example, about 1.524). Among them, cos θ _{3 is} close to the value 1 and is preferable, and constructive interference can be obtained. For example, when the red pixel is predetermined to be designed, since the red wavelength is 600 nm to 700 nm, the depth D3 of the red sub-pixel groove may be about 196.85 nm to 229.66 nm, or about 393.7 nm to 459.32 nm, or about 590.55 nm. Between -688.98nm, etc.; when the green pixel is predetermined to be designed, since the green wavelength is 510nm-540nm, the depth D2 of the green sub-pixel groove may be about 167.32nm-177.17nm, or about 334.65nm-354.33nm. Or about 501.97nm-531.50nm, etc.; when the blue pixel is predetermined to be designed, since the blue wavelength is 455nm-480nm, the depth D1 of the blue sub-pixel groove may be about 149.28nm-157.48nm Or, between about 298.56 nm and 314.96 nm, or between about 447.83 nm and 472.44 nm, and so on.

In the reflective display panel of the present invention, the substrate layer and the first substrate preferably further comprise a light absorbing layer.

In the reflective display panel of the present invention, the conductive layer is preferably disposed between the second substrate and the light semi-reflective layer.

In the reflective display panel of the present invention, the material of the base layer is preferably a polymer material. For example, a low-viscosity photocurable resin after curing, a resin-type black photoresist, a light gap photoresist, other photoresist, a polymer gel, a PDMS, and a SU-8 photoresist.

In the reflective display panel of the present invention, the polymer dispersed liquid crystal (PDLC) preferably comprises: a high molecular polymer, and a liquid crystal. In addition, the polymer dispersed liquid crystal may further include a dyeing agent, and the material of the dyeing agent is not particularly limited, and the filtering effect can be achieved.

In the reflective display panel of the present invention, the surface of the second substrate is preferably further provided with an optical film layer. For example, an optical film such as a polarizer, a filter, or an antireflection film.

The invention further provides a method for preparing a reflective display panel, comprising the steps of:

(A) providing a first substrate;

(B) forming a base layer on the surface of the first substrate, the base layer having a plurality of pixel regions, each of the pixel regions having two or more sub-pixel grooves, wherein the same pixel The depth of the sub-pixel grooves in the zone is different;

(C) forming a light-reflective conductive layer on a bottom surface of the sub-pixel grooves of the base layer;

(D) filling a liquid crystal photosensitive composition in the sub-pixel grooves;

(E) combining the first substrate with a second substrate having a conductive layer and a light semi-reflective layer on the surface, and arranging the base layer, the liquid crystal photosensitive composition, the conductive layer, and the light semi-reflective layer Between the first substrate and the second substrate;

Wherein, after the step (E), or between the step (D) and the step (E), a step (F) is further included: exposure causes the liquid crystal photosensitive composition to cure to form a polymer dispersion. liquid crystal.

The reflective display panel produced by the invention is a reflective display panel with an innovative structure, so that it can have low energy consumption (no backlight, no moving reflective layer as a switch), light and thin, high stability, long use It has the advantages of long life, reduced number of used polarizers and filters, low cost, and large viewing angle (up to about 80°).

The reflective display panel of the present invention has a simple preparation method, and the reflective display panel of the present invention has a simple structure and does not require the use of a color polarizer. Therefore, the preparation method is simple, rapid, and low in cost.

Since the reflective display panel of the present invention uses a polymer dispersed liquid crystal, a gray scale effect can be produced. In the prior art, an interferometric modulation display must use a plurality of sub-pixels (for example, one pixel needs to contain sixteen sub-pixels) to generate gray scales, but the present invention does not need to use a plurality of sub-pixels to generate gray scales. Therefore, the reflective display panel of the present invention does meet the commercial requirements of simple process and low production cost, and has great industrial utilization value.

In the method for preparing a reflective display panel of the present invention, the substrate layer in the step (B) is preferably formed by: (B1) forming a precursor layer on the surface of the first substrate; (B2) The precursor layer is formed into a shape having a sub-pixel groove by nanoimprinting; (B3) curing the precursor layer to form the base layer (which can be achieved by, for example, heat curing or photocuring).

In the method for preparing the reflective display panel of the present invention, the material of the precursor layer in the step (B1) is preferably a polymer material. For example, low-viscosity photocurable resin, resin-type black photoresist, optical gap photoresist, other photoresist, polymer gel polymer gel, PDMS, SU-8 photoresist.

In the method for preparing a reflective display panel of the present invention, the liquid crystal photosensitive composition in the step (D) preferably comprises: a photosensitive compound, a dye, and a liquid crystal. Moreover, the liquid crystal photosensitive composition preferably further comprises a dyeing agent, and the material of the dyeing agent is not particularly limited, and the filtering effect can be achieved.

In the preparation method of the reflective display panel of the present invention, the ratio of the photosensitive compound, the dye, and the liquid crystal may preferably be: (photosensitive compound: dye: liquid crystal) = (5 to 90 parts by weight: 0.1 to 10 parts by weight) : 10 to 95 parts by weight).

In the method for fabricating the reflective display panel of the present invention, in the step (E), the conductive layer is preferably disposed between the second substrate and the light semi-reflective layer.

In the method for preparing a reflective display panel of the present invention, in the step (B), the depth D of the sub-pixel groove and the refraction angle θ _{3 of the} light incident on the polymer dispersed liquid crystal layer, and a predetermined sub-pixel reflection The wavelength λ of the emitted light preferably satisfies [Equation 1]:

[Formula 1] 2Dcosθ ₃ =mλ/n

Wherein m is an integer of 1 or more (for example, m = 1, 2, 3, 4, ..., etc.), and n is a refractive index of a polymer dispersed liquid crystal (for example, about 1.524). Among them, cos θ _{3 is} close to the value 1 and is preferable, and constructive interference can be obtained. For example, when the red pixel is predetermined to be designed, since the red wavelength is 600 nm to 700 nm, the depth D3 of the red sub-pixel groove may be about 196.85 nm to 229.66 nm, or about 393.7 nm to 459.32 nm, or about 590.55 nm. Between -688.98nm, etc.; when the green pixel is predetermined to be designed, since the green wavelength is 510nm-540nm, the depth D2 of the green sub-pixel groove may be about 167.32nm-177.17nm, or about 334.65nm-354.33nm. Or about 501.97nm-531.50nm, etc.; when the blue pixel is predetermined to be designed, since the blue wavelength is 455nm-480nm, the depth D1 of the blue sub-pixel groove may be about 149.28nm-157.48nm Or, between about 298.56 nm and 314.96 nm, or between about 447.83 nm and 472.44 nm, and so on.

In the preparation method of the reflective display panel of the present invention, between the step (A) and the step (B), it is preferable to further comprise a step (A1) of forming a light absorbing layer on the surface of the first substrate.

In the method for fabricating the reflective display panel of the present invention, in the step (E), the conductive layer is preferably disposed between the second substrate and the light semi-reflective layer.

In the method for preparing a reflective display panel of the present invention, the material of the underlayer in the step (B) is preferably a polymer material, for example, a low-viscosity photocurable resin after curing, a resin-type black photoresist, Optical gap photoresist, other photoresist, polymer gel polymer gel, PDMS, SU-8 photoresist.

In the method for fabricating the reflective display panel of the present invention, the number of the sub-pixel grooves of each pixel region may preferably be three. For example, each pixel region contains a red (R) sub-pixel, a green (G) sub-pixel, and a blue (B) sub-pixel.

The embodiments of the present invention are described by way of specific examples, and those skilled in the art can readily appreciate the other advantages and advantages of the present invention. The present invention may be embodied or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention.

As shown in Fig. 3i, it is a preferred embodiment of the reflective display panel of the present invention. The reflective display panel 200 of the present invention comprises: a first substrate 20b having a cured polymer film layer 25' (base layer) disposed on the surface thereof, the cured polymer film layer 25' having a plurality of pixel regions P, each of the pixel regions 25' of the cured polymer film layer 25' has two or more sub-pixel grooves 3, wherein the depth D1 of the sub-pixel grooves 3 in the same pixel region P D2, D3 (as shown in FIG. 3f) are different, and the bottom surface of the sub-pixel groove 3 of the cured polymer film layer 25' is provided with a light-reflecting conductive layer 26, 26a, 26b, 26c; the second substrate 20a, a conductive film layer 21 and a light semi-reflective film layer 22 are disposed on the surface thereof; and cured polymer dispersed liquid crystals (PDLC) 30a, 30b, and 30c are disposed on the conductive film layer 21 of the second substrate 20a and the first A cured polymer film layer 25' of a substrate 20b is located in each of the sub-pixel grooves 3.

The manner in which the reflective display panel of the present invention is fabricated will be described in detail below.

[Examples]

In this embodiment, the order of making the upper substrate and the lower substrate is not particularly limited, and may be made one after the other or at the same time.

Fabrication of the upper substrate

First, as shown in FIG. 3a, a substrate 20a is provided, and a conductive film layer 21 is formed over the substrate 20a. Next, as shown in FIG. 3b, the conductive thin A light semi-reflective film layer 22 is formed over the film 21. Here, the substrate 20a may be a glass substrate, a plastic substrate, or a flexible substrate, and is not particularly limited.

Fabrication of the lower substrate

First, as shown in FIG. 3c, a substrate 20b is provided, and a light absorbing film layer 24 is formed over the substrate 20b. Here, the substrate 20b may be a glass substrate, a plastic substrate, or a flexible substrate, and is not particularly limited. The material of the light absorbing film layer 24 may be cadmium telluride (CdTe) or copper lanthanum gallium selenide (CIGS) or the like, but is not limited thereto. Next, as shown in FIG. 3d, a polymer film layer 25 (or a precursor layer) is formed over the light absorbing film layer 24. The material of the polymer film layer 25 may be polydimethylsiloxane (PDMS), SU-8 photoresist, low viscosity photocurable resin, resin type black photoresist, optical gap photoresist, other photoresist, It may be a polymer gel or the like, but is not limited thereto; the formation method may be a spray coating method, a flow coating method, a spin coating method, or a tape coating method.

Next, as shown in FIG. 3e, the polymer film layer 25 is imprinted and cured by thermosetting or ultraviolet light (UV) to form a cured polymer film layer 25' (or a base layer), and formed into different depths. The sub-pixel is groove 3. Here, the substrate 20b has a plurality of pixel regions (not shown), and each pixel region has three sub-pixels (ie, red sub-pixels sub-P _R , green sub-pixels sub-P _G , And blue sub-primitive sub-P _B ).

The depth D1, D2, D3 of the sub-pixel groove and the refraction angle θ _{3 of the} light incident on the polymer dispersed liquid crystal layer, and the wavelength λ of the light reflected by the sub-pixel are satisfied as follows: [Formula 1]: 1] 2Dcosθ ₃ =mλ/n

Wherein m is an integer of 1 or more (for example, m=1, 2, 3, 4, ..., etc.), n is a refractive index of a polymer dispersed liquid crystal (here, about 1.524), and cos θ _{3 is} close to a value of 1 Good, can get constructive interference. For example, when the red pixel is predetermined to be designed, since the red wavelength is 600 nm to 700 nm, the depth D3 of the red sub-pixel groove may be about 196.85 nm to 229.66 nm, or about 393.7 nm to 459.32 nm, or about 590.55 nm. Between -688.98nm, etc.; when the green pixel is predetermined to be designed, since the green wavelength is 510nm-540nm, the depth D2 of the green sub-pixel groove may be about 167.32nm-177.17nm, or about 334.65nm-354.33nm. Or about 501.97nm-531.50nm, etc.; when the blue pixel is predetermined to be designed, since the blue wavelength is 455nm-480nm, the depth D1 of the blue sub-pixel groove may be about 149.28nm-157.48nm Or between about 298.56 nm and 314.96 nm, or between about 447.83 nm and 472.44 nm.

In this embodiment, the depths D1, D2, and D3 of the sub-pixel grooves are 149.28 nm - 157.48 nm, 167.32 nm - 177.17 nm, and 196.85 nm - 229.66 nm, respectively.

Thereafter, as shown in Fig. 3f, a light-reflecting conductive layer 26, 26a, 26b, 26c is formed at the bottom of each sub-pixel groove 3. Here, the material of the light-reflecting conductive layer 26, 26a, 26b, 26c may be aluminum, gold, silver, copper, or a mixture thereof, and the method of forming the light-reflecting conductive layer 26, 26a, 26b, 26c may be sputtering or steaming. Plating, ion plating, etc., but is not limited thereto.

Next, as shown in Fig. 3g, a liquid crystal-containing photo-sensitive composition 23a, 23b, 23c is filled in each of the sub-pixel grooves 3. The formation method may be, for example, a spray coating method, a wire bar coating method, a flow coating method, or a tape coating method. The liquid crystal-containing photosensitive composition includes: 10 to 95% by weight of liquid crystal, 5 to 90% by weight of a photo-reactive compound, 0.1 to 10% by weight of a photoinitiator, and 0.1 to 10% by weight. The dyeing agent is based on the total weight of the liquid crystal-containing photosensitive composition. Further, the photopolymerizable compound may be a UV-curable optical adhesive (NOA65, Norland Optical Adhesive), an acrylic group-containing monomer, an epoxy group-containing monomer, or a mixture thereof. As shown in Fig. 3g, each sub-pixel groove 3 contains a liquid crystal 27 and a photopolymerizable compound 28, and the rest are not shown.

Further, the liquid crystal-containing photosensitive composition may further comprise: 0.1 to 30% by weight of an additive based on the total weight of the liquid crystal-containing photosensitive composition. Among them, the additive can be selected from the group consisting of a flat agent, a leveling agent, an adhesion promoter, an antifoaming agent, and a mixture thereof.

Next, as shown in Fig. 3h, the substrate 20a and the substrate 20b are combined, and the light semi-reflective film layer 22 on the surface of the substrate 20a is bonded to the surface of the polymer film layer 25' on which the surface of the substrate 20b is cured. Thereafter, as shown in FIG. 3i, the substrate 20a and the substrate 20b are exposed by using a light source, and the liquid crystal containing photosensitive composition 23a, 23b, 23c filled in the recess 3 is converted into a cured polymer dispersed liquid crystal. 30a, 30b, 30c, the reflective display panel 200 of the present embodiment is obtained. As shown in FIG. 3i, the cured polymer-dispersed liquid crystals 30a, 30b, and 30c comprise a liquid crystal 27 and a cured polymer 29.

In the present embodiment, the exposure and/or heating steps of converting the photosensitive composition 23a, 23b, 23c into the cured polymer dispersed liquid crystals 30a, 30b, 30c may be before or after the combination of the substrate 20a and the substrate 20b, as needed. get on.

As shown in FIG. 4a, it is a schematic diagram of a reflective display panel 200 of the present embodiment. When a voltage is applied to the reflective display panel 200, the light L enters the reflective display panel 200 from the substrate 20a, and light of different colors is obtained by interference and reflected from the surface of the substrate 20a. When no voltage is supplied, as shown in FIG. 4b, since the rotation angle of the liquid crystal molecules is changed, the light incident into the reflective display panel 200 cannot be reflected, and the pixels appear black. Therefore, the reflective display panel 200 of the present embodiment can be presented with different screens by voltage control.

In summary, the reflective display panel of the present invention is a reflective display panel with an innovative structure, so that it can have low energy consumption (no backlight, no moving reflective layer as a switch), light and thin, high stability, Long service life, reduced number of used polarizers and filters, low cost, large viewing angle (up to about 80° or more).

The reflective display panel of the present invention is a color reflective display panel. The reflective display panel of the present invention can still display various colors without using a color filter.

The main principle of the reflective display panel of the present invention is to use interference technology to control the optical path difference between incident and reflection, to obtain different colors of light, and to use a polymer-dispersed liquid crystal (PDLC) as a brightness switch. Control, and achieve better contrast, high chroma effect. The reflective display panel of the present invention can produce light of different colors without using a color polarizer. In addition, the mechanically movable movable reflective layer is replaced by a polymer-dispersed liquid crystal, thereby improving stability and reliability. Moreover, the reduction in the number of use of the polarizer and the filter can reduce the production cost and meet the environmental requirements.

In the present invention, the optical path difference ΔL can be calculated according to the following formula (and also refer to FIG. 2):

ΔL=2ndcosθ ₃ =mλ

Here, λ is incident light, n is a refractive index, d is a thickness of a polymer dispersed liquid crystal layer, and θ ₃ is a refractive angle at which light is incident on the polymer dispersed liquid crystal layer.

When m is a positive integer, constructive interference (constructive interference) can be obtained; and when m is a half integer (for example, 3/2, 5/2, 7/2, 9/2, etc.), destructiveness can be obtained. Interference (destructive interference).

Since the polymer-dispersed liquid crystal (PDLC) used in the reflective display panel of the present invention has a refractive index larger than that of air, the incident angle of the light incident is changed in a smaller range than that of air. It can be known from the formula of the optical path difference that reducing the influence range of the incident angle can reduce the chromatic aberration and effectively improve the viewing angle.

Since the reflective display panel of the present invention uses a polymer dispersed liquid crystal, a gray scale effect can be produced. In the prior art, an interferometric modulation display must use a plurality of sub-pixels (for example, one pixel needs to contain sixteen sub-pixels) to generate gray scales, but the present invention does not need to use a plurality of sub-pixels to generate gray scales. Therefore, the reflective display panel of the present invention does meet the commercial requirements of simple process and low production cost, and has great industrial utilization value.

The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

11. . . Upper substrate

12. . . Lower substrate

13. . . Separator

14R, 14G. . . Movable reflective layer

16R, 16G. . . electrode

sub-P _R , sub-P _G , sub-P _B . . . Subpixel

P. . . Graphic area

L. . . Light

200. . . Reflective display panel

20a, 20b. . . Substrate

twenty one. . . Conductive film layer

twenty two. . . Light semi-reflective coating

23a, 23b, 23c. . . Photosensitive composition

twenty four. . . Light absorbing layer

25. . . Polymer film

25'. . . Cured polymer film

26, 26a, 26b, 26c. . . Light reflective conductive layer

27. . . liquid crystal

28. . . Photopolymerizable compound

29. . . Cured polymer

3. . . Subpixel groove

30a, 30b, 30c. . . Cured polymer dispersed liquid crystal

D1, D2, D3. . . depth

Figure 1 is a conventional interference modulation display.

Figure 2 is a schematic diagram of the calculation of optical path difference in the present invention.

3a to 3i are flowcharts showing the fabrication of a reflective display panel in accordance with a preferred embodiment of the present invention.

4a and 4b are schematic views showing the operation of a reflective display panel in accordance with a preferred embodiment of the present invention.

sub-P _R , sub-P _G , sub-P _B . . . Subpixel

P. . . Graphic area

200. . . Reflective display panel

20a, 20b. . . Substrate

twenty one. . . Conductive film layer

twenty two. . . Light semi-reflective coating

twenty four. . . Light absorbing layer

25'. . . Cured polymer film

26, 26a, 26b, 26c. . . Light reflective conductive layer

27. . . liquid crystal

29. . . Cured polymer

3. . . Subpixel groove

30a, 30b, 30c. . . Cured polymer dispersed liquid crystal

Claims (17)

A reflective display panel comprising: a first substrate having a base layer on a surface thereof, the base layer having a plurality of pixel regions, each of the pixel layers having more than two sub-pixel recesses a groove, wherein the sub-pixel grooves in the same pixel region have different depths, and a bottom surface of the sub-pixel groove of the base layer is provided with a light-reflecting conductive layer; and a second substrate is provided with a conductive surface a layer and a light semi-reflective layer; and a polymer dispersed liquid crystal (PDLC) disposed between the conductive layer of the second substrate and the base layer of the first substrate, and located in each of the sub-pixel grooves Wherein the depth D of the sub-pixel groove and the refraction angle θ _{3 of the} light incident on the polymer dispersed liquid crystal layer, the refractive index n of the polymer dispersed liquid crystal, and the wavelength λ of the light reflected by the sub-pixel Satisfy [Equation 1]: [Equation 1] 2Dcos θ ₃ = mλ/n where m is an integer of 1 or more. The reflective display panel of claim 1, wherein the conductive layer on the surface of the second substrate is disposed opposite to the base layer of the first substrate surface, and the conductive layer and the base layer are located The second substrate is between the first substrate. The reflective display panel of claim 1, wherein the number of the sub-pixel grooves of each pixel region is three. The reflective display panel of claim 1, wherein the base layer and the first substrate further comprise a light absorbing layer. The reflective display panel of claim 1, wherein the conductive layer is disposed between the second substrate and the light semi-reflective layer. The reflective display panel of claim 1, wherein the material of the base layer is a polymer material. The reflective display panel of claim 1, wherein the polymer dispersed liquid crystal system comprises: a high molecular polymer, a dye, and a liquid crystal. The reflective display panel of claim 1, wherein the surface of the second substrate is further provided with an optical film layer. A method for preparing a reflective display panel, comprising the steps of: (A) providing a first substrate; (B) forming a base layer on a surface of the first substrate, the substrate layer having a plurality of pixel regions, each of The pixel region has two or more sub-pixel grooves, wherein the sub-pixel grooves in the same pixel region have different depths; (C) forming a light-reflecting conductive layer on the substrate layer a bottom surface of the pixel recess; (D) filling a liquid crystal photosensitive composition in the sub-pixel grooves; and (E) providing the first substrate and a surface with a conductive layer and a light semi-reflective layer The second substrate is combined, and the base layer, the liquid crystal photosensitive composition, the conductive layer, and the light semi-reflective layer are disposed between the first substrate and the second substrate; wherein, after the step (E) Or further comprising a step (F) between the step (D) and the step (E): exposing the liquid crystal photosensitive composition to cure to form a polymer dispersed liquid crystal, and in the step (B) , the depth D of the light incident on the sub-pixel groove to the polymer-dispersed liquid crystal layer, the angle of refraction θ _3, high Dispersed liquid crystal refractive index n, and the sub-pixel of a predetermined light wavelength λ of the reflected line satisfies [Formula 1]: [Formula 1] 2Dcosθ ₃ = mλ / n where, m is an integer of 1 or more. The method for preparing a reflective display panel according to claim 9, wherein the substrate layer in the step (B) is formed by: (B1) forming a precursor layer on the first substrate; (B2) the precursor layer is formed into a shape having a sub-pixel groove by nanoimprinting; (B3) curing the precursor layer to form the base layer. The method for preparing a reflective display panel according to claim 10, wherein the material of the precursor layer in the step (B1) is a polymer material. The method for preparing a reflective display panel according to claim 9, wherein the liquid crystal photosensitive composition in the step (D) comprises: a photosensitive compound, a dye, and a liquid crystal. The method for preparing a reflective display panel according to claim 12, wherein the ratio of the photosensitive compound, the dye, and the liquid crystal Line: (photosensitive compound: dye: liquid crystal) = (5 to 90 parts by weight: 0.1 to 10 parts by weight: 10 to 95 parts by weight). The method for preparing a reflective display panel according to claim 9, wherein in the step (E), the conductive layer is disposed between the second substrate and the light semi-reflective layer. The method for preparing a reflective display panel according to claim 9, wherein the step (A) and the step (B) further comprise a step (A1) of forming a light absorbing layer on the first The surface of the substrate. The method for preparing a reflective display panel according to claim 9, wherein the material of the base layer in the step (B) is a polymer material. The method for preparing a reflective display panel according to claim 9, wherein the number of the sub-pixel grooves of each pixel region is three.