CN106527008B - A kind of display device and display device - Google Patents

Abstract

The embodiment of the invention provides a kind of display device and display devices, are related to field of display technology, and reflection type cholesteric liquid crystal display part can be improved to the reflectivity of corresponding color light in ambient light, optimize its display effect.The display device includes as the first substrate for showing side, the cholesteric crystal layer of the second substrate and setting being oppositely arranged with the first substrate between the first substrate and the second substrate；Aforementioned display device part further includes that photoluminescent layers of the cholesteric crystal layer far from the first substrate side are arranged in；Wherein, the light with first wave length in the cholesteric crystal layer reflection ambient light；The light that the photoluminescent layers are inspired by the ambient light has color corresponding with the first wave length.

Description

Display device and display device

technical field

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

Background technique

Cholesteric liquid crystal (CLC for short) molecules have two zero-field stable textures, namely the focal conic texture (abbreviated as fc state) that can transmit external light and the planar texture that can reflect external light. structure (abbreviated as p-state). Among them, the focal conic texture is formed by applying a certain voltage to the CLC, and the texture can still exist stably after the voltage is removed. The CLC in the fc state has a scattering effect on external light, and depending on the device structure, for The scattering effect of light is also different in detail. The p state can be obtained without applying a voltage, and the wavelength λ of the reflected light is related to the pitch p of the CLC molecule and the average refractive index n of the CLC, namely: λ=n×p; from this formula, the p value of the CLC can be obtained The larger the λ, the larger the λ of the reflected light, so as long as the pitch is adjusted, the CLC can reflect a specific color of light.

As shown in FIG. 1 , a reflective liquid crystal display device with CLC is generally composed of an upper substrate, an upper electrode, a cholesteric liquid crystal layer, a lower electrode, and a lower substrate arranged up and down. When no voltage is applied, the CLC molecules are in a state of planar texture, which can reflect external light of a certain wavelength according to the size of the pitch and the average refractive index; when the voltage V ₁ is applied, the CLC molecules are in a state of focal conic texture, which has a scattering effect on the external light , the device has a white mist effect, that is, different display effects can be achieved by adjusting the loading voltage, no additional backlight module is required, the structure is relatively simple, and can be widely used in hospitals, stations, exhibition halls, entertainment venues, monitoring and command centers and other occasions.

However, due to the large half-peak width of the reflection spectrum of CLC and the limited thickness of the liquid crystal layer (cell gap) in reflective liquid crystal display devices, the reflectivity of CLC to external light is low, and it is difficult to meet people's needs for display effects.

Contents of the invention

In view of this, in order to solve the problems of the prior art, the embodiment of the present invention provides a display device and a display device, which can improve the reflectivity of the reflective cholesteric liquid crystal display device to the corresponding color light in the external light, and optimize its display effect .

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

On the one hand, an embodiment of the present invention provides a display device, which includes a first substrate as a display side, a second substrate disposed opposite to the first substrate, and a substrate disposed between the first substrate and the A cholesteric liquid crystal layer between the second substrates; the display device also includes a photoluminescent layer disposed on a side of the cholesteric liquid crystal layer away from the first substrate; wherein the cholesteric liquid crystal The layer reflects light with a first wavelength in the external light; the light excited by the photoluminescence layer by the external light has a color corresponding to the first wavelength.

Optionally, the photoluminescent layer is made of photoluminescent quantum dot material.

Optionally, the first wavelength is within a wavelength range of light excited by the photoluminescent layer by the external light. Optionally, the display device further includes a first electrode and a second electrode disposed on both sides of the cholesteric liquid crystal layer and respectively close to the first substrate and the second substrate.

Preferably, the first substrate is made of a transparent material, the first electrode is made of a transparent electrode; the photoluminescence layer is disposed between the cholesteric liquid crystal layer and the second electrode.

Preferably, the first substrate is made of transparent material, the first electrode and the second electrode are made of transparent electrodes; the photoluminescent layer is arranged between the second electrode and the second substrate between.

Preferably, both the first substrate and the second substrate are made of transparent materials, and the first electrode and the second electrode are both made of transparent electrodes; the photoluminescent layer is arranged on the second substrate away from the side of the second electrode.

Optionally, the display device further includes a light absorbing layer disposed on a side of the photoluminescent layer away from the cholesteric liquid crystal layer.

Preferably, the display device further includes a base substrate; the light absorbing layer is directly disposed on the base substrate.

On the other hand, an embodiment of the present invention further provides a display device, including the above-mentioned display device.

Based on this, in the above-mentioned display device provided by the embodiment of the present invention, a photoluminescent layer is provided on the side of the cholesteric liquid crystal layer away from the external light, and the light excited by the photoluminescent layer by the external light has the same energy as the cholesteric liquid crystal layer. The color corresponding to the reflected light. When no voltage is applied, the cholesteric liquid crystal layer reflects the left (or right) light with a wavelength in the external light, and the rest of the external light is irradiated downwards to the corresponding photoluminescent layer. Excite the latter to emit light of the same color, except that the left (or right) rotation light with a wavelength is reflected and cannot be emitted, and the rest of the red light radiated upwards can be transmitted. The photoluminescence layer, as a color enhancement layer, increases the reflectance of the above-mentioned display device to the light of the corresponding color in the external light, and optimizes its display effect.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic structural view of a cholesteric liquid crystal display device provided by the prior art;

FIG. 2 is a first structural schematic diagram of a display device provided by an embodiment of the present invention;

FIG. 3 is a schematic structural diagram II of a display device provided by an embodiment of the present invention;

FIG. 4 is a schematic structural diagram III of a display device provided by an embodiment of the present invention;

FIG. 5 is a fourth structural schematic diagram of a display device provided by an embodiment of the present invention.

Description of drawings:

01-display device; 100-base substrate; 10-first substrate; 11-first electrode; 20-second substrate; 21-second electrode; 30-cholesteric liquid crystal layer; 40-photoluminescent layer; 50 - light absorbing layer.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that, unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of the present invention have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in idealized or extremely formalized meanings, unless explicitly stated herein defined in this way.

For example, the words "comprising" or "comprising" and other similar words used in the patent application specification and claims of the present invention mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents. , without excluding other elements or objects. The orientation or positional relationship indicated by "above", "below" and other terms are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of explaining the simplified description of the technical solution of the present invention, rather than indicating or implying No device or element must have a specific orientation, be constructed, and operate in a specific orientation and therefore should not be construed as limiting the invention.

As shown in FIG. 2 to FIG. 4 , an embodiment of the present invention provides a display device, which includes a first substrate 10 as the display side, a second substrate 20 disposed opposite to the first substrate, and a substrate disposed on the first substrate. 10 and the cholesteric liquid crystal layer 30 between the second substrate 20; the display device also includes a photoluminescent layer 40 arranged on the side of the cholesteric liquid crystal layer 30 away from the first substrate 10; wherein the cholesteric liquid crystal The layer 30 reflects the light of the first wavelength (here and hereinafter both marked as λ ₁ ) in the external light; the light excited by the photoluminescent layer 40 by the external light has a color corresponding to the first wavelength λ ₁ .

It should be noted that the photoluminescent material constituting the photoluminescent layer 40 can make electrons jump from the valence band to the conduction band and leave holes on the valence band under the excitation of light with sufficient energy. The respective conduction band and valence band relax to reach the lowest unoccupied excited state and become a quasi-equilibrium state. The electrons and holes in the quasi-equilibrium state then recombine to emit light, that is, to form a spectrum diagram of the intensity or energy distribution of light of different wavelengths, so as to achieve the effect of being excited by light, and the way of emitting light is to radiate light in all directions.

The photoluminescent material may specifically be a photoluminescent quantum dot material, and the specific material may follow the existing technology, which is not limited in the embodiment of the present invention.

When no voltage is applied, the light reflected by the cholesteric liquid crystal molecules is polarized, that is, only the light with the same helical direction is reflected. For cholesteric liquid crystal molecules whose helical pitch and average refractive index are determined, if the CLC is a left-handed structure, only left-handed polarized light is reflected; on the contrary, if the CLC is a right-handed structure, only right-handed polarized light is reflected.

The above-mentioned photoluminescent layer 40 is excited by external light and has a color corresponding to the _first wavelength λ1, which means that the light excited by the photoluminescent layer 40 is the same color as the light reflected by the cholesteric liquid crystal layer 30. , the specific principle is as follows:

Taking the liquid crystal molecules in the cholesteric liquid crystal layer 30 as a left-handed structure as an example, the helical pitch and the average refractive index of the cholesteric liquid crystal molecules can determine that the cholesteric liquid crystal layer 30 reflects the left _- handed light with a wavelength λ1 in the external light. The color _of the light corresponding to the wavelength λ1 is, for example, red light (here only red light is used as an example for illustration, and the embodiment of the present invention is not limited thereto), that is, the device displays red.

Since the photoluminescent material selected for use in the photoluminescent layer 40 is a material that is excited by external light and also emits red light, when the external light except the left _- handed light with wavelength λ1 is irradiated downward to the photoluminescent When on the layer 40, the photoluminescent layer 40 will radiate red light in all directions, and in the red light emitted, the wavelength λ ₁ and the left-handed light with the wavelength λ ₁ that is the same as the helical direction of the cholesteric liquid crystal molecules are directed downward. The reflection cannot be emitted, and the rest of the upwardly excited red light can be transmitted, thereby increasing the reflectivity of the above-mentioned display device to the red light in the external light and optimizing its display effect.

Here still take the color of the light corresponding to the wavelength λ1 as red light as _an example, the wavelength range of the red part in visible light is 620-780nm, that is, the light with a wavelength of 620nm and the light with a wavelength of 780nm seen by the human eye are both red, No further difference in wavelength could be discerned. Therefore, the above-mentioned display device provided by the embodiment of the present invention only needs to set the selected photoluminescent material to be excited by external light and also emit light _of the same color as the light corresponding to the wavelength λ1.

That is to say, the wavelength range of the light emitted by the photoluminescent material excited by external light only needs to be within the range of 620-780nm of red light, which may include the above-mentioned wavelength λ ₁ , or may not include the above-mentioned wavelength λ ₁ .

Based on this, in the above-mentioned display device provided by the embodiment of the present invention, a photoluminescent layer 40 is provided on the side of the cholesteric liquid crystal layer 30 away from external light. The color corresponding to the reflected light λ ₁ of the phase liquid crystal layer 30, when no voltage is applied, the cholesteric phase liquid crystal layer 30 reflects the left (or right) rotation light with the wavelength λ ₁ in the external light, and the remaining part in the external light is downward After irradiating the corresponding photoluminescent layer 40, the latter is excited to emit light _of the same color. Except that the left (or right) rotation light with wavelength λ1 is reflected and cannot be emitted, the rest of the upwardly radiated red light can be transmitted. The photoluminescent layer 40 serves as a color enhancement layer to increase the reflectance of the above-mentioned display device to the light of the corresponding color in the external light, and optimize its display effect. Further, the _first wavelength λ1 is within the wavelength range of the light excited by the photoluminescent layer 40 by external light, and it is further preferred that the wavelength of the light excited by the photoluminescent layer 40 by the external light is equal to the first wavelength λ ₁ , that is, right-handed (or left-handed) light with wavelength λ ₁ can be transmitted from it.

Further, referring to FIG. 2 to FIG. 4 , the display device further includes a first electrode 11 and a second electrode 21 disposed on both sides of the cholesteric liquid crystal layer 30 and close to the first substrate 10 and the second substrate 20 respectively.

Taking the first substrate 10 as the above-mentioned display device, that is, the above-mentioned display device reflects external light and emits from the side of the first substrate 10 as an example, the specific placement of the photoluminescent layer 40 may include but not limited to the following three methods.

method one

Referring to FIG. 2 , the first substrate 10 is made of a transparent material, the first electrode 11 is made of a transparent electrode; the photoluminescence layer 40 is disposed between the cholesteric liquid crystal layer 30 and the second electrode 21 .

way two

Referring to FIG. 3 , the first substrate 10 is made of transparent material, the first electrode 11 and the second electrode 21 are made of transparent electrodes; the photoluminescent layer 40 is disposed between the second electrode 21 and the second substrate 20 .

way three

4, the first substrate 10 and the second substrate 20 are made of transparent materials, the first electrode 11 and the second electrode 21 are made of transparent electrodes; the photoluminescent layer 40 is arranged on the second substrate 20 away from the second One side of the electrode 21.

In the above three modes, the transparent material adopted by the first substrate 10 or the first substrate 10 and the second substrate 20 can be, for example, glass, transparent resin materials such as PC (Polycarbonate, polycarbonate), PMMA (Polymethylmethacrylate, polymethylmethacrylate) Methyl acrylate), PES (Polyethersulfone resin, polyethersulfone resin) and other materials; the transparent electrodes used for the first electrode 11 or the first electrode 11 and the second electrode 21 can be, for example, ITO (Indium TinOxide, indium tin oxide), IZO (Indium Zinc Oxide, Indium Zinc Oxide), FTO (Fluorine-Doped Tin Oxide, Fluorine-Doped Tin Oxide) and other transparent conductive materials, specifically, the existing technology can be used, which is not limited in the embodiment of the present invention.

Further on the basis of the above, considering that the absorption and utilization rate of excitation light by photoluminescent materials (such as photoluminescent quantum dots) cannot reach 100%, in order to avoid the transmission of light of other colors not utilized by the photoluminescent layer 40 As shown in FIG. 5 , the above-mentioned display device further includes a light-absorbing layer 50 disposed on the side of the photoluminescent layer 40 away from the cholesteric liquid crystal layer 30 .

It should be noted that FIG. 5 only uses the position of the photoluminescent layer 40 shown in the third manner above as an example, and the light absorbing layer 50 only needs to be disposed on the side of the photoluminescent layer 40 away from the cholesteric liquid crystal layer 30 .

The material of the light-absorbing layer 50 can be, for example, black pigment, metal chromium, chromium oxide, etc., specifically, the material of the black matrix in the prior art can be used, which is not limited in the embodiment of the present invention.

Further, in order to facilitate the installation of the above-mentioned light-absorbing layer 50, as shown in FIG. on the base substrate 100.

Further on the basis of the above, an embodiment of the present invention also provides a display device, including the above display device. The display device may further include three types of display devices that respectively reflect red light, green light, and blue light. The arrangement of the three display devices can follow the existing technology, which is not limited in the embodiment of the present invention.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the present invention, and should cover all Within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (4)

1. A display device for a reflective cholesteric liquid crystal display device, the display device comprising a first substrate as a display side, a second substrate arranged opposite to the first substrate, and a second substrate arranged on the first substrate A cholesteric liquid crystal layer between the substrate and the second substrate; characterized in that, the display device further includes a photoluminescent layer disposed on a side of the cholesteric liquid crystal layer away from the first substrate; Wherein, the cholesteric liquid crystal layer reflects light having a first wavelength in the external light; the light excited by the photoluminescent layer by the external light has a color corresponding to the first wavelength; The display device further includes a first electrode and a second electrode disposed on both sides of the cholesteric liquid crystal layer, respectively close to the first substrate and the second substrate; The first substrate is made of a transparent material, the first electrode is made of a transparent electrode; the photoluminescent layer is arranged between the cholesteric liquid crystal layer and the second electrode; or, the first The substrate is made of transparent material, the first electrode and the second electrode are made of transparent electrodes; the photoluminescent layer is arranged between the second electrode and the second substrate; or, the first Both a substrate and the second substrate are made of transparent materials, and both the first electrode and the second electrode are made of transparent electrodes; the photoluminescence layer is arranged on the second substrate away from the second electrode side of The photoluminescent layer is mainly composed of photoluminescent quantum dot materials; The first wavelength is within the wavelength range of light excited by the photoluminescent layer by the external light. 2 . The display device according to claim 1 , further comprising a light absorbing layer disposed on a side of the photoluminescent layer away from the cholesteric liquid crystal layer. 3 . 3 . The display device according to claim 2 , further comprising a base substrate; the light absorbing layer is directly disposed on the base substrate. 4 . 4. A reflective cholesteric liquid crystal display device, characterized in that it comprises the display device according to any one of claims 1 to 3.