US20200333663A1 - Reflective liquid crystal display panel, display device, and control method thereof - Google Patents

Abstract

A reflective liquid crystal display panel comprises: a first substrate, a second substrate, and a liquid crystal layer disposed therebetween; a layer of first electrode disposed between the first substrate and the liquid crystal layer; a layer of second electrode disposed between the second substrate and the liquid crystal layer and comprising a first sub-electrode and a second sub-electrode; a reflective structure disposed between the first substrate and the layer of first electrode; a first light-shielding layer disposed between the second substrate and the layer of second electrode, the first light-shielding layer having a plurality of openings including a light extraction opening; and a light extraction structure disposed on the second substrate in correspondence with the light-extraction opening, and configured to extract light from the second substrate and pass the extracted light through the light-extraction opening and the liquid crystal layer to the reflective structure.

Description

CROSS-REFERENCE TO THE RELATED APPLICATION
• The present application claims priority to Chinese Application No. 201910304573.6, filed on Apr. 16, 2019, of which the entirety is incorporated therein by reference.
TECHNICAL FIELD
• The present disclosure relates to the field of display technologies, and in particular, to a reflective liquid crystal display panel, a display device, and a control method thereof.
BACKGROUND
• The liquid crystal display is a display device which is currently used on a large scale, and has a series of advantages such as high color gamut, light weight, and fast response time, and has mature technologies in theoretical research and practical processes. In indoor scenes, the brightness of the display is sufficient to meet the needs of viewing; in an outdoor environment, due to the greater brightness of ambient light, the display is often required to have higher brightness.
• In view of the above situation, a reflective liquid crystal display panel has been developed, which realizes display by using ambient light itself, which can effectively avoid the situation that the brightness of the reflective liquid crystal display panel is insufficient due to excessive ambient light brightness; and the front light source is used in ambient light brightness. In the low case, the backlight is used for display.
• However, in the related art, the reflective liquid crystal display panel has poor contrast and the display effect is not satisfactory. Moreover, the reflective liquid crystal display panel is thick, which is not conducive to thin and light design.
SUMMARY
• According to an aspect of the present disclosure, there is provided a reflective liquid crystal display panel comprising: a first substrate; a second substrate disposed opposite to the first substrate; a liquid crystal layer disposed between the first substrate and the second substrate; a layer of first electrode disposed on a side of the first substrate facing the second substrate and between the first substrate and the liquid crystal layer; a layer of second electrode disposed on a side of the second substrate facing the first substrate and between the second substrate and the liquid crystal layer, the layer of second electrode comprising a first sub-electrode and a second sub-electrode disposed independently of each other; a reflective structure disposed between the first substrate and the layer of first electrode; a first light-shielding layer disposed on the second substrate and between the second substrate and the layer of second electrode, the first light-shielding layer having a plurality of openings including a light extraction opening; and a light extraction structure disposed on the second substrate in correspondence with the light-extraction opening and between the second substrate and the layer of second electrode, and configured to extract light from the second substrate and pass the extracted light through the light-extraction opening and the liquid crystal layer to the reflective structure.
• In some embodiments, the plurality of openings including a light exit opening spaced apart from the light extraction opening, and configured to emit therethrough the light which is reflected back by the reflective structure, the reflective liquid crystal display panel further comprising: a first filter structure disposed at the light exit opening; a second light-shielding layer disposed on a side of the second substrate facing away from the first substrate, and disposed opposite to the light extraction structure.
• In some embodiments, the light incident to the reflective structure is reflected through the liquid crystal layer to any one of: the light exit opening and/or the first light-shielding layer.
• In some embodiments, the second light-shielding layer is configured such that an orthogonal projection of the second light-shielding layer on the second substrate covers an orthogonal projection of the light extraction structure on the second substrate.
• In some embodiments, an area of the orthogonal projection of the second light-shielding layer is larger than an area of the orthogonal projection of the light extraction structure. In some embodiments, the reflective liquid crystal display panel further comprises: a first filter structure disposed at the light exit opening; a second light-shielding layer disposed on a side of the second substrate facing away from the first substrate, and disposed corresponding to the light extraction structure.
• In some embodiments, the light incident to the reflective structure is reflected through the liquid crystal layer to the light exit opening and/or the first light-shielding layer.
• In some embodiments, the second light-shielding layer is disposed in alignment with the light extraction structure.
• In some embodiments, an area of the second light-shielding layer is larger than an area of the light extraction structure.
• In some embodiments, the reflective liquid crystal display panel further comprises: a first planarization layer disposed between the first substrate and the first electrode, wherein the reflective structure is disposed in the first planarization layer.
• In some embodiments, the second substrate comprises: a glass substrate; a first low-refraction layer attached to a side of the glass substrate facing the first substrate, and separating the first light-shielding layer from the glass substrate, the first low-refraction layer has a refractive index of 1.25 or less; and a second low-refraction layer attached to a side of the glass substrate facing away from the first substrate, and separating the second light-shielding layer from the glass substrate, the second low-refraction layer has a refractive index of 1.25 or less.
• In some embodiments, the reflective liquid crystal display panel further comprises: a cover layer disposed on a side of the second low-refraction layer facing away from the glass substrate.
• In some embodiments, the first light-shielding layer further defines an ambient-light passage opening, and the ambient-light passage opening is spaced apart from the light extraction opening and the light exit opening, and the ambient-light passage opening is disposed corresponding to the reflective structure.
• In some embodiments, the reflective liquid crystal display panel further comprises: a polarization structure disposed at the ambient-light passage opening; a second filter structure disposed at the ambient-light passage opening and on a side of the polarization structure facing away from the liquid crystal layer; and a third electrode disposed between the first light-shielding layer and the second electrode.
• In some embodiments, the reflective liquid crystal display panel further comprises: a second planarization layer isolating the third electrode from the second electrode.
• In some embodiments, a direction of a light transmission axis of the polarization structure is at an angle of 45° with a direction of a long axis of liquid crystal molecules of the liquid crystal layer, and a thickness d of the liquid crystal layer satisfies: Δn*d=λ/4+m*λ, where Δn is refractive index difference for the liquid crystal layer, and Δn=ne−no, where no is ordinary light refractive index of the liquid crystal layer, ne is extraordinary light refractive index of the liquid crystal layer, λ is wavelength of the light incident on the liquid crystal layer, and m is a natural number.
• In some embodiments, the ambient-light passage opening is disposed between the light extraction opening and the light exit opening.
• In some embodiments, the reflective liquid crystal display panel further comprises: a light source for emitting light to the second substrate.
• According to another aspect of the present disclosure, there is provided a display device comprising: a reflective liquid crystal display panel according to any of the embodiments of the present disclosure, and a driving circuit electrically connected to the reflective liquid crystal display panel for providing respective signals to the first electrode and the second electrode to drive the reflective liquid crystal display panel.
• According to a further aspect of the present disclosure, there is provided a method for controlling display device, wherein the display device is a display device according to any of the embodiments of the present disclosure, wherein the reflective liquid crystal display panel further comprises a light source for emitting light to the second substrate, the method comprising: in a first mode of operation: turning on the light source, applying, with the driving circuit, electrical signals respectively to the first electrode, the first sub-electrode, and the second sub-electrode, so that light incident to the second substrate by the light source is extracted out by the light extraction structure, and incident onto the reflective structure through the liquid crystal layer, and reflected to the light exit opening and/or the first light-shielding layer by the reflective structure.
• In some embodiments, the first light-shielding layer further defines an ambient-light passage opening, and the ambient-light passage opening is provided apart from the light extraction opening and the light exit opening and in correspondence with the reflective structure, wherein the reflective liquid crystal display panel further comprises: a polarization structure disposed at the ambient-light passage opening; a second filter structure disposed at the ambient-light passage opening and on a side of the polarization structure facing away from the liquid crystal layer; and a third electrode disposed between the first light-shielding layer and the second electrode, the method further comprising: in the second operation mode: turning off the light source, applying, with the driving circuit, electrical signals respectively to the first electrode, the first sub-electrode, the second sub-electrode, and the third electrode such that ambient light is incident through the ambient-light passage opening onto the liquid crystal layer, and reflected by the reflective structure to the liquid crystal layer, and is emitted through the ambient-light passage opening.
• The additional aspects and advantages of the present application will be set forth in part in or obviously obtained in part from the descriptions which follow, or known through practicing the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
• The above and/or additional aspects and advantages of the present disclosure will become apparent and readily understood from the descriptions of the embodiments in association with the drawings as below.
• FIG. 1 is a schematic diagram of a single sub-pixel of a reflective liquid crystal display panel according to an embodiment of the present disclosure, wherein the reflective liquid crystal display panel is in a first operation mode and exhibits a bright state display, and the broken lines indicate light propagation;
• FIG. 2 is a schematic diagram of a single sub-pixel of a transparent display panel shown inFIG. 1, wherein the reflective liquid crystal display panel is in a first operation mode and exhibits a dark state display, and the broken lines indicate light propagation;
• FIG. 3 is a schematic diagram of a single sub-pixel of the transparent display panel shown inFIG. 1, wherein the reflective liquid crystal display panel is in a second operation mode and exhibits a bright state display, and broken lines indicate light propagation;
• FIG. 4 is a schematic diagram of a single sub-pixel of the transparent display panel shown inFIG. 1, wherein the reflective liquid crystal display panel is in a second operation mode and exhibits a dark state display, and broken lines indicate light propagation;
• FIG. 5 is a schematic view of a first light-shielding layer shown inFIG. 1;
• FIG. 6 is a flow chart showing a control method of a display device according to an embodiment of the present disclosure; and
• FIG. 7 is a flow chart showing a control method of a display device according to another embodiment of the present disclosure.
DETAILED DESCRIPTION
• The embodiments of the present disclosure are described in detail below, and the examples of the embodiments are illustrated in the drawings in which the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are intended to be illustrative of the present disclosure only, and are not for limiting the scope of the present disclosure.
• A reflective liquidcrystal display panel100 according to an embodiment of the present disclosure will be described below with reference toFIGS. 1-5.
• As shown inFIG. 1, the reflective liquidcrystal display panel100 according to the embodiment of the present disclosure may comprise afirst substrate1, asecond substrate2, afirst electrode3, asecond electrode4, aliquid crystal layer5, areflective structure6, and alight extraction structure7, a first light-shielding layer8, afirst filter structure13, and a second light-shielding layer9.
• Thefirst substrate1 and thesecond substrate2 may each be formed substantially as a plate-like structure. Thesecond substrate2 is disposed opposite to thefirst substrate1. Thefirst electrode3 is disposed on a side of thefirst substrate1 facing thesecond substrate2. Thesecond electrode4 is disposed on a side of thesecond substrate2 facing thefirst substrate1, and thesecond electrode4 is disposed between thesecond substrate2 and thefirst electrode3. Thesecond electrode4 may comprise asub-electrode41 and asecond sub-electrode42.
• Theliquid crystal layer5 is disposed between thefirst electrode3 and thesecond electrode4. When an electric field is applied between thefirst electrode3 and thesecond electrode4, the liquid crystal molecules in theliquid crystal layer5 can be deflected by the electric field. When the light passes through theliquid crystal layer5, the direction of propagation of the light is changed. Alignment layers may be respectively provided on both sides of theliquid crystal layer5, so that the upper surface and the lower surface of theliquid crystal layer5 may be oriented in parallel.
• Thereflective structure6 may be disposed between thefirst substrate1 and thefirst electrode3, for reflecting the light incident on thereflective structure6. Thelight extraction structure7 may be disposed between thesecond substrate2 and thesecond electrode4, and the light-harvesting structure7 is configured to cause the light, which is totally reflected in thesecond substrate2, to pass through theliquid crystal layer5 to thereflective structure6. That is, thelight extraction structure7 can extract or take out the light, which is totally reflected in thesecond substrate2, at a predetermined angle, and the light that is taken passes through theliquid crystal layer5 to thereflective structure6 to be reflected by thereflective structure6, and the taken light can be used for displaying.
• The first light-shielding layer8 is disposed between thesecond substrate2 and thesecond electrode4. The first light-shielding layer8 may define alight extraction opening81 and alight exit opening82 which are spaced at a distance. Thelight extraction structure7 may be disposed in area corresponding to thelight extraction opening81. Thelight extraction portion81 may be disposed corresponding to thelight extraction structure7. The light extracted from thesecond substrate2 by thelight extraction structure7 can be incident into theliquid crystal layer5 through thelight extraction opening81, pass through theliquid crystal layer5, and reflected by thereflective structure6 back to theliquid crystal layer5, and finally the light passes through theliquid crystal layer5 to thelight exit opening82. Thefirst filter structure13 is disposed at thelight exit opening82. Thefirst filter structure13 can cover thelight exit opening82, so that the light that is directed toward thelight exit opening82 can be emitted through thefirst filter structure13 to enter the environment. Thus, color display of the reflective liquidcrystal display panel100 can be achieved.
• In some embodiment, thelight extraction structure7 may be disposed in an area corresponding to thelight extraction opening81, which may comprise, and is not limited to, such a case where thelight extraction structure7 is disposed in thelight extraction opening81. For example, the light-harvesting structure7 may be disposed outside thelight extraction opening81. In other words, thelight extraction structure7 may be disposed in a same layer as or in a different layer from, the first light-shielding layer8, as long as thelight extraction structure7 is positioned corresponding to thelight extraction opening81 so that the light taken out from thesecond substrate2 by thelight extraction structure7 can pass thelight extraction opening81 and be incident on theliquid crystal layer5.
• The second light-shielding layer9 is disposed on a side of thesecond substrate2 facing away from thefirst substrate1. The second light-shielding layer9 can be disposed corresponding to thelight extraction structure7. Since the light that is totally reflected in thesecond substrate2 is taken out by thelight extraction structure7 at a predetermined angle so that incident angle of a part of the light in thesecond substrate2 is changed so that the part of the light will not be totally reflected in thesecond substrate2, thus the part of the light may be emitted from a side of thesecond substrate2 facing away from thefirst substrate1. The second light-shielding layer9 is disposed corresponding to the light-harvesting structure7, so that the second light-shielding layer9 can block that part of the light, and that part of the light can be prevented from entering into the environment which otherwise would reduce the CR value of the reflective liquidcrystal display panel100 and deteriorate the contrast of the reflective liquidcrystal display panel100. Thereby, the contrast of the reflective liquidcrystal display panel100 can be improved, the display effect of the reflective liquidcrystal display panel100 can be improved, and user's experience can be improved.
• In some embodiments, the second light-shielding layer9 is disposed corresponding to the light-harvesting structure7. It can be understood that the second light-shielding layer9 can block the light leakage caused by thesecond substrate2 during the light extraction by thelight extraction structure7. There is no special limitation on the relative position between the second light-shielding layer9 and thelight extraction structure7. For example, in the direction from thefirst substrate1 toward the second substrate2 (for example, the up-and-down direction inFIG. 1), the second light-shielding layer9 can be positioned in alignment with thelight structure7, or not directly in alignment with thelight structure7.
• In a conventional technology, a part of the light emitted by a front light source is emitted from a side of a light guide plate to realize display, and another part is directly irradiated to the environment and to user's eyes. The light guide plate emits light on the entire surface, and the light that is directly emitted to the environment cannot be blocked. As compared with the conventional technology, in the light-emitting liquid crystal display panel of the present application, the light that would otherwise be directly irradiated into the environment, that is, the light that would otherwise be directly emitted to user's eyes can be effectively block, thereby the contrast of the reflective liquid crystal display panel can be effectively improved. Moreover, the reflective liquid crystal display panel of the present application has a simple structure. In some embodiments, it is not needed to provide a polarizing plate structure, and the thickness and weight of the reflective liquid crystal display panel can be reduced.
• In addition, thelight extraction structure7 may be a light extraction grating. Of course, thelight extraction structure7 is not limited thereto, and other light extraction devices/structures may be used as long as the propagation state of the light transmitted through total reflection in thesecond substrate2 can be changed so that the light totally reflected inside thesecond substrate2 can be emitted from thesecond substrate2.
• When the reflective liquidcrystal display panel100 is in operation, electrical signals may be respectively applied to thefirst electrode3 and thesecond electrode4 so that theliquid crystal layer5 is driven or not driven, and the liquid crystal molecules in theliquid crystal layer5 are deflected or not deflected, and the light taken out by thelight extraction structure7 is angularly deflected or not angularly deflected in theliquid crystal layer5, thus the direction of light propagation can be controlled. Theliquid crystal layer5 can be divided into a plurality of independently controlled liquid crystal cells. When different electric fields are applied to the liquid crystal molecules of different regions, in the case that the liquid crystal molecules have different deflection angles, the refractive indices thereof are different, and the light propagation directions are different. In such a way, the light taken out by thelight extraction structure7 can be reflected by thereflection structure6 to the first light-shielding layer8 and/or the firstlight filter structure13, to achieve a display with different gray-scales (such as 0 to 255 levels of gray-scales display).
• For example, the electric field between thefirst electrode3 and thesecond electrode4 is controlled such that the light taken out of thesecond substrate2 by thelight extraction structure7 passes through theliquid crystal layer5, and is reflected by thereflective structure6 to be totally irradiated on to thefirst filter structure13, thus a Level 255 bright-state display is achieved (as shown inFIG. 1). In another example, the electric field between thefirst electrode3 and thesecond electrode4 is controlled so that the light taken out from thesecond substrate2 by thelight extraction structure7 passes through theliquid crystal layer5, and is reflected by thereflective structure6 to be totally irradiated onto the first light-shielding layer8, thus a Level 0 dark state display is achieved (as shown inFIG. 2). In a further example, the electric field between thefirst electrode3 and thesecond electrode4 is controlled so that the light extracted from thesecond substrate2 by thelight structure7 passes through theliquid crystal layer5 and is reflected by thereflective structure6 to be irradiated onto thefirst filter structure13 and the first light-shielding layer8, to realize an intermediate gray scale display. When the reflective liquidcrystal display panel100 performs an intermediate gray scale display, the angle deflection of the light in theliquid crystal layer5 can be controlled by controlling the electric signals applied to thefirst electrode3 and thesecond electrode4, thereby controlling the area of thefirst filter structure13 irradiated by the light extracted by thelight extraction structure7 to be increased or decreased so as to display with a plurality of gray scales.
• It should be noted that, in the “thesecond electrode4 comprises thefirst sub-electrode41 and the second sub-electrode42 which are disposed independently of each other”, “independent of each other” may be construed as thefirst sub-electrode41 and the second sub-electrode42 are spaced apart, and thefirst sub-electrode41 and the second sub-electrode42 are independently loaded, and voltage loaded to thefirst sub-electrode41 and the voltage loaded to the second sub-electrode42 may be the same or different. The number of the first sub-electrodes41 and the number of the second sub-electrodes41 may be specifically set according to actual applications. For a single sub-pixel, thefirst sub-electrode41 and the second sub-electrode42 may be alternately arranged in a left-right direction. The first sub-electrode41 or the second sub-electrode42 may be shared between adjacent two sub-pixels.
• In the reflective liquidcrystal display panel100 according to the embodiment of the present disclosure, thelight extraction opening81 and thelight exit opening82 are spaced, and the second light-shielding layer6 is disposed corresponding to thelight extraction structure7 so that the light leakage of thesecond substrate2 can be blocked by the second light-shielding layer9 without influence on the reflective liquidcrystal display panel100 emitting light. Thereby, the contrast of the reflective liquidcrystal display panel100 can be improved, the display performance of the reflective liquidcrystal display panel100 can be improved. Further, the structure of the reflective liquidcrystal display panel100 is simple, which is advantageous for realizing the slim and light design of the reflective liquidcrystal display panel100. In some embodiments, it is not needed to provide a polarizing plate structure, which is further advantageous for realizing the slim and light design of the reflective liquidcrystal display panel100.
• The first light-shielding layer8 and the second light-shielding layer9 may each be a black matrix (BM), and thefirst filter structure13 may be a filter, such as a color filter (CF). When thefirst filter structure13 is a color filter, thefirst filter structure13 needs to match with the light-take structure7.
• When thelight extraction structure7 is a light extraction grating, due to the diversity of the light extraction grating structures, one type of light extraction grating can take out light in a specific wavelength range, and another type of light extraction grating can take out all visible light.
• When the light extraction grating can take out light in a specific wavelength range, the light extraction grating can take out the monochromatic light that is totally reflected and propagated in thesecond substrate2. For example, the light extraction grating may include a first light extraction grating, a second light extraction grating, and a third light extraction grating; and the first light extraction grating may take out a first monochromatic light totally reflected in thesecond substrate2, the second light extraction grating may take out a second monochromatic light totally reflected in thesecond substrate2, and the third light extraction grating may take out a third monochromatic light totally reflected in thesecond substrate2. The first monochromatic light, the second monochromatic light and the third monochromatic light can be mixed into white light. As an example, the first monochromatic light is red light, the second monochromatic light is green light, and the third monochromatic light is blue light. For a red sub-pixel, the light extraction grating can take out the red light total reflected in thesecond substrate2, and the red light after passing through thefirst filter structure13 can still be emitted as red light. For a green sub-pixel, the light extraction grating can take out the green light totally reflected in thesecond substrate2, and the green light after passing through thefirst filter structure13 can still be emitted as green light. For a blue sub-pixel, the light extraction grating can take out the blue light that is totally reflected in thesecond substrate2, and the blue light after passing through thefirst filter structure13 can still be emitted as blue light.
• For another example, in the examples ofFIG. 1 andFIG. 2, for each sub-pixel, the light extraction grating may take out the blue light totally reflected in thesecond substrate2. In such a case, for the red sub-pixel, thefirst filter structure13 may be a quantum dot color filter (i.e., QDCF) to convert the blue light extracted by the light extraction grating into red light. For the green sub-pixel, thefirst filter structure13 may also be a quantum dot color filter to convert the blue light extracted by the light extraction grating into green light. For the blue sub-pixel, thefirst filter structure13 retains the blue light extracted by the extraction grating as blue light to emit. Therefore, the structures of the light extraction gratings of the plurality of sub-pixels can be the same, and thefirst filter structure13 is simplified, so that thefirst filter structure13 does not need to be divided into a plurality of filter units to respectively select light waves of different colors, thereby facilitating the manufacturing of the reflective liquidcrystal display panel100.
• The quantum dot color filter can turn the light into divergent light, thereby further satisfying the requirement of multiple viewing angles and colorization of the reflective liquidcrystal display panel100.
• Further, the reflective liquidcrystal display panel100 may further comprise alight source17 that can be positioned to be attached to a side of thesecond substrate2, for example, the left side of thesecond substrate2 as shown inFIG. 1. Thelight source17 is configured to inject light into thesecond substrate2. The light can be totally reflected and propagated in thesecond substrate2. Thelight extraction structure7 takes out the light totally reflected in thesecond substrate2 for display. Thus, the reflective liquidcrystal display panel100 can realize a backlight display, for example, realizes a backlight display with the side-injected light, and does not require the user to provide an additional light source. The use convenience of the reflective liquidcrystal display panel100 can be improved.
• In some embodiments, thelight source17 can be integrally disposed within thesecond substrate2, for example, near the side end faces of thesecond substrate2. Therefore, the reflective liquidcrystal display panel100 of the present application can integrate the light source, which is positioned in front in the conventional technology, into thesecond substrate2, further simplifying the structure of the reflective liquidcrystal display panel100, and making the reflective liquidcrystal display panel100 thin and light and portable.
• It is to be understood that in some embodiments, the reflective liquidcrystal display panel100 does not include thelight source17 as described above. In such a case, the user may use other light sources, such as a flashlight, to inject light into thesecond substrate2, and the reflective liquidcrystal display panel100 may also realize a backlight display with the side-entered light.
• The light from thelight source17 and incident onto thesecond substrate2 may be polarized collimated light, and the deflecting direction of the light may be parallel or coplanar with the long axis direction of the liquid crystal molecules. When the light from thelight source17 and incident on thesecond substrate2 is polarized collimated light, a polarizing plate may be disposed on the light incident side of thesecond substrate2 to convert the light emitted from thelight source17 into polarized light, and an optical device such as a coupling lampshade or the like may be disposed on the light incident side of thesecond substrate2 so that the light emitted from thelight source17 is collimated into thesecond substrate2; the present disclosure shall not be limited thereto.
• In some embodiments of the present disclosure, the second light-shielding layer9 is disposed in alignment with thelight extraction structure7. For example, in the examples ofFIG. 1 toFIG. 4, the second light-shielding layer9 and thelight extraction structure7 are disposed facing each other in an up-and-down direction, which facilitates the design of the reflective liquidcrystal display panel100, facilitates the simplification calculations in the design of the reflective liquidcrystal display panel100, and reduces design costs.
• When thelight extraction structure7 is a light extraction grating, the incident angle of the incident light of thesecond substrate2 and the grating period can be designed such that a part of the light emitted from a side surface of thesecond substrate2 facing away from thefirst substrate1 through thelight extraction structure7 may be emitted perpendicular to thesecond substrate2; and in such a case, may face each other the light emitted as above can be blocked by aligning the second light-shielding layer9 with thelight extraction structure7.
• It should be noted that “the second light-shielding layer9 and thelight extraction structure7 are disposed facing each other in the up-and-down direction” may be construed as that the center of the second light-shielding layer9 and the center of thelight extraction structure7 are disposed facing each other in the up-and-down direction.
• It can be understood that the second light-shielding layer9 and thelight extraction structure7 can also be disposed not in alignment with each other, that is, the center of the second light-shielding layer9 and the center of thelight extraction structure7 are not disposed not in alignment with each other.
• In some embodiments of the present disclosure, the area of the second light-shielding layer9 is larger than the area of thelight extraction structure7, and thus the light-shielding area of the second light-shielding layer9 is larger than the light extraction area of thelight extraction structure7, and the projection area of the second light-shielding layer9 on thesecond substrate2 is larger than the projection area of thelight extraction structure7 on thesecond substrate2; in other words, in the example ofFIGS. 1-4, the projection area of the second light-shielding layer9 is greater than that of thelight extraction structure7 in the up-and-down direction. Therefore, the second light-shielding layer9 can effectively and completely block the part of the light emitted from the surface of a side thesecond substrate2 facing away from thefirst substrate1 due to thelight extraction structure7, thereby ensuring the light-shielding of the second light-shielding layer9, and ensuring the contrast enhancement effect of the reflective liquidcrystal display panel100.
• In further embodiments of the present disclosure, as shown inFIG. 1 toFIG. 4, the reflective liquidcrystal display panel100 may further comprise afirst planarization layer10. Thefirst planarization layer10 may be disposed between thefirst substrate1 and thefirst electrode3, and thefirst planarization layer10 may enclose thereflective structure6, thereby facilitating the planarization of thefirst electrode3, avoiding thefirst electrode3 from breakage due to the surface on which thefirst electrode3 is provided is not flat due to the arrangement of thereflective structure6, protecting thefirst electrode3, enhancing the reliability of thefirst electrode3 in use. In some embodiments, thefirst electrode3 may be formed as a planar electrode.
• It should be noted that “thefirst planarization layer10 encloses thereflective structure6” can be construed that thereflective structure6 is embedded in thefirst planarization layer10, which may include that thefirst planarization layer10 completely wraps around thereflective structure6 and that thefirst planarization layer10 does not completely wrap thereflective structure6. For example, in the examples ofFIGS. 1-4, thefirst planarization layer10 completely encloses thereflective structure6, and both the upper surface and the lower surface of thereflective structure6 are covered by thefirst planarization layer10. For another example, thereflective structure6 can be not completely enclosed by thefirst planarization layer10 may, wherein the upper and/or lower surface of thereflective structure6 can be not covered by thefirst planarization layer10 and is flush with the corresponding surface of thefirst planarization layer10.
• In some optional embodiments of the present disclosure, thesecond substrate2 comprises aglass substrate21, a first low-refraction layer22, and a second low-refraction layer23. The first low-refraction layer22 is attached to a side of thefirst substrate1 facing the glass substrate21 (for example, the upper side thereof as shown inFIG. 1), and the first low-refraction layer22 separates the first light-shielding layer8 from theglass substrate21. The second low-refraction layer23 is attached to a side of thesubstrate1 facing away from the glass substrate21 (for example, the lower side thereof as shown inFIG. 1), and the second low-refraction layer23 separates the second light-shielding layer9 from theglass substrate21. In such a way, the structure of thesecond substrate2 can be made simple and easy to be implemented, and the total reflection of light in thesecond substrate2 can be effectively ensured.
• In some embodiments, the refractive indices of the first low-refraction layer22 and the second low-refraction layer23 can be both smaller than the refractive index of theglass substrate21. In a specific example, the refractive index of the first low-refraction layer22 is 1.25 or less, and the refractive index of the second low-refraction layer23 is 1.25 or less, so that the critical angle of total reflection occurring in thesecond substrate2 is small, thereby reducing the requirements on the incident angle of the incident light for thesecond substrate2 and facilitate the setting of the incident light.
• Of course, thesecond substrate2 can also be formed with other structures, and thus is not limited thereto, as long as the light can be totally reflected and propagated in thesecond substrate2.
• Further, as shown inFIG. 1 toFIG. 4, the reflective liquidcrystal display panel100 may further comprise acover layer11 disposed on a side of the second low-refraction layer23 facing away from theglass substrate21. Thecover layer11 may cover a side of the second low-refraction layer23 facing away from theglass substrate21, so that thecover layer11 can protect the second low-refraction layer23, avoiding wear of the second low-refraction layer23, and prolonging the life of the reflective liquidcrystal display panel100.
• An anti-reflection film layer can be formed on thecover layer11 by optical coating to prevent contrast deterioration due to ambient light reflection, thereby further ensuring the contrast of the reflective liquidcrystal display panel100. In many applications nowadays, such as mobile phones, it is necessary to provide a touch component on the outer side of the display screen, which needs to be protected by a cover glass (i.e., protection glass). Thecover layer11 of the present application can be used as the protection layer in the mobile phone application; the present disclosure is not limited thereto.
• In some embodiments of the present disclosure, as shown inFIG. 3 toFIG. 5, the first light-shielding layer8 may further define an ambient-light passage opening83, and the ambient-light passage opening83 is spaced apart from thelight extraction opening81 and thelight exit opening82. The ambient-light passage opening83 may be disposed corresponding to thereflective structure6, and the ambient light incident from the ambient-light passage opening83 into theliquid crystal layer5 can be reflected by thereflective structure6 to be redirected toward the ambient-light passage opening83, so that the reflective liquidcrystal display panel100 can perform display with the ambient light.
• The reflective liquidcrystal display panel100 may further comprise apolarization structure12, asecond filter structure14, and athird electrode15. Thepolarization structure12 can function to transmit a single kind of polarized light. Thepolarization structure12 can be disposed at theambient light passage83. Thepolarization structure12 can cover the ambient-light passage opening83. Thesecond filter structure14 may be also disposed at the ambient-light passage opening83, and thesecond filter structure14 may be located on a side of thepolarization structure12 facing away from theliquid crystal layer5. Thesecond filter structure14 may cover the ambient light passage opening83 such that the light emitted from the environment to the ambientlight passage opening83 may pass through thesecond filter structure14 and thepolarization structure12 in sequence. Thethird electrode15 can be disposed between the first light-shielding layer8 and thesecond electrode4, and thethird electrode15 may be spaced apart from thesecond electrode4. Thereby, the signals loaded to thefirst electrode3, thesecond electrode4, and thethird electrode15 can be separately controlled, so that the reflective liquidcrystal display panel100 can realize display using ambient light in the case where the ambient light is strong.
• For example, when the ambient light is strong, when the reflective liquidcrystal display panel100 is in operation, electrical signals are applied to thefirst electrode3, thesecond electrode4, and thethird electrode15, respectively, so that the ambient light passing through the first ambient-light passage opening83 and through thesecond filter structure14 and thepolarization structure12 and incident on theliquid crystal layer5 is reflected by thereflective structure6 and again directed to the ambient-light passage opening83. By controlling the electrical signals to thefirst electrode3, thesecond electrode4 and thethird electrode15, the amount of light that is again directed to the ambientlight passage opening83 and passes through thepolarization structure12 can be different, thus the reflective liquidcrystal display panel100 can realize display with different gray scales using the ambient light.
• In some embodiments, thepolarization structure12 may be, but is not limited to, a metal wire grid or a wire-grid polarizer (WGP).
• Further, as shown inFIG. 1 toFIG. 4, the reflective liquidcrystal display panel100 may further comprise asecond planarization layer16 which isolates thethird electrode15 from thesecond electrode4 to avoid signal interference between thesecond electrode4 and thethird electrodes15, thereby ensuring stable and reliable operation of the reflective liquidcrystal display panel100. In some embodiments, thesecond planarization layer16 can be made of an insulating material to further effectively avoid signal interference between thesecond electrode4 and thethird electrode15.
• For example, in the examples ofFIGS. 1-4, thefirst sub-electrode41 and the second sub-electrode42 are spaced apart, and thefirst sub-electrode41 and the second sub-electrode42 may each be formed as a strip electrode, and thethird electrode15 can be formed as a planar electrode. In such a case, the providing of thesecond planarization layer16 can help thethird electrode15 to be planar, avoiding thethird electrode15 from being broken due to the unevenness of the surface, on which thethird electrode15 is disposed, resulted from the structure and distribution of thefirst sub-electrode41 and thesecond sub-electrode42, thereby protecting thethird electrode15, and further improving the use reliability of the reflective liquidcrystal display panel100.
• Further, thesecond planarization layer16 may be an insulating member to further effectively avoid signal interference between thesecond electrode4 and thethird electrode15.
• In some embodiments of the present disclosure, the direction of the light transmission axis of thepolarization structure12 is at an angle of 45° with the long-axis direction of the liquid crystal molecules of theliquid crystal layer5. The thickness d of theliquid crystal layer5 may be configured to satisfy: Δn*d=λ/4+m*λ, where Δn is the refractive index difference of theliquid crystal layer5, and Δn=ne−no, where no is the ordinary refractive index of theliquid crystal layer5, ne is the extraordinary refractive index of theliquid crystal layer5, and λ is the wavelength of the incident light of theliquid crystal layer5, m is a natural number. Thereby, with the thickness d of theliquid crystal layer5 appropriately designed, by controlling the electrical signals to thefirst electrode3, thesecond electrode4, and thethird electrode15, when theliquid crystal layer5 is not driven, the ambient light passing thesecond filter structure14 and thepolarization structure12 and incident on theliquid crystal layer5 is reflected by thereflective structure6 and blocked by thepolarization structure12, and thus the reflective liquidcrystal display panel100 can realize the L0 dark state display with the ambient light. At this time, the reflective liquidcrystal display panel100 can achieve a normally black display with ambient light. Further, by controlling the electrical signals to thefirst electrode3, thesecond electrode4, and thethird electrode15, when theliquid crystal layer5 is driven, the ambient light passing through thesecond filter structure14 and thepolarization structure12 and incident on theliquid crystal layer5 is reflected by thereflective structure6 and can be gradually emitted through thepolarization structure12 and thesecond filter structure14, thereby realizing the display with intermediate gray scale and the L255 bright state display.
• The display devices according to the embodiments of the second aspect of the present disclosure may comprises a driving circuit and a reflective liquidcrystal display panel100. The reflective liquidcrystal display panel100 is the reflective liquidcrystal display panel100 according to the embodiments of the first aspect of the present disclosure, and the driving circuit is electrically connected to the reflective liquidcrystal display panel100. The driving circuit can respectively apply electrical signals to thefirst electrode3, thefirst sub-electrode41 and the second sub-electrode42 such that the reflective liquidcrystal display panel100 can perform display with the backlight in the case that the ambient light brightness is low. In such a way, the contrast of the display device can be improved, and the display performance can be enhanced.
• According to the display device of the embodiments of the present disclosure, by using the reflective liquidcrystal display panel100 described above, the contrast of the display device can be improved, and the display performance of the display device can be improved.
• According to a third aspect of the present disclosure, control method of a display device is provided, and the display device can be the display device according to the embodiments of the second aspect of the present disclosure. The reflective liquidcrystal display panel100 may further comprises alight source17 for injecting light into thesecond substrate2. The light is totally reflected and propagated in thesecond substrate2.
• The display device has a first operation mode. In the first operation mode, thelight source17 is turned on, and the driving circuit applies electric signals to thefirst electrode3, thefirst sub-electrode41, and the second sub-electrode42 respectively, so that the light emitted by thelight source17 into thesecond substrate2 is taken out by thelight extraction structure7, passes through theliquid crystal layer5, and emits onto thereflective structure6, and is reflected by thereflective structure6 to thefirst filter structure13 and/or the first light-shielding layer8.
• Specifically, as shown inFIG. 6 andFIG. 7, when the display device operates, in the case that the ambient light brightness is low, the display device can operate in the first operation mode. When the display device is in the first operation mode, thelight source17 is turned on and emits light on thesecond substrate2, and the light is totally reflected and propagated in thesecond substrate2. The light-harvesting structure7 takes out the light totally reflected in thesecond substrate2 at a predetermined angle. The driving circuit apply respectively electric signals to thefirst electrode3, thefirst sub-electrode41, and thesecond sub-electrode42, so that the light taken out by thelight extraction structure7 passes through thelight extraction opening81, through theliquid crystal layer5, and is incident on thereflective structure6, and then is reflected by thereflective structure6 to thefirst filter structure13 and/or the first light-shielding layer8. That is, under the action of theliquid crystal layer5, thereflective structure6 can reflect all the light taken out by thelight extraction structure7 to the first light-shielding layer8, or thereflective structure6 can reflect all the light taken out by thelight extraction structure7 to thefirst filter structure13, or thereflective structure6 can reflect the light taken out by thelight extraction structure7 to the first light-shielding layer8 and thefirst filter structure13; thus the display device can perform display with different gray scales using the backlight.
• For example, in the examples ofFIGS. 1 and 2, when the display device operates, in the case that the display device is in the first mode of operation, thelight source17 is turned on and emits light to thesecond substrate2, and the light totally reflected in thesecond substrate2 is taken out by thelight extraction structure7 at a predetermined angle and is incident on theliquid crystal layer5. The driving circuit can respectively load thefirst electrode3, thefirst sub-electrode41, and the second sub-electrode42 with a Vcom signal, that is, the driving circuit loads thefirst electrode3 with Vcom signal, the driving circuit loads the first sub-electrode41 with the Vcom signal, and the driving circuit loads the second sub-electrode42 with the Vcom signal. At this time, the liquid crystal is not driven, the liquid crystal molecules in theliquid crystal layer5 are not deflected, and the direction of propagation of the light in theliquid crystal layer5 is not changed. After the light is reflected by thereflective structure6, all of the light is irradiated onto thefirst filter structure13 to realize the L255 display (as shown inFIG. 1). The driving circuit can load the Vcom signal to thefirst electrode3, load the Vcom signal to thefirst sub-electrode41, and load a Vop signal to thesecond sub-electrode42. At this time, the liquid crystal is driven, and the liquid crystal molecules in theliquid crystal layer5 are deflected. In such a case, theliquid crystal layer5 can be equivalent to an oblique prism, and the light is angularly deflected in theliquid crystal layer5, so that the light irradiation position is shifted and the light is completely irradiated onto the first light-shielding layer8 to realize the L0 dark state display (as shown inFIG. 2).
• In some embodiments, the driving signal Vcom can be 0 V, and the Vop signal can be the highest voltage signal. The driving circuit can load the Vcom signal to thefirst electrode3, the driving circuit applies the Vcom signal to thefirst sub-electrode41, and the driving circuit loads the second sub-electrode42 with a Vop′ signal. The Vop′ signal can be a signal having a level between the Vcom signal and the Vop signal. The Vop′ signal can have a varying voltage. The Vop′ signal changes to adjust the capability of theliquid crystal layer5 to deflect light, so that the area of thefirst filter structure13, which is illuminated by the light is increased or decreased to achieve display with different gray scales. As the voltage corresponding to the Vop′ signal is getting higher, the bottom angle of the equivalent oblique prism of theliquid crystal layer5 is larger, and the deflection ability of theliquid crystal layer5 is stronger, and the deviation of the final illumination position of the light relative to thefirst filter structure13 is the greater, thus a part of the light is irradiated on thefirst filter structure13 and the other part is irradiated on the first light-shielding layer8; as such, a display with intermediate gray scales is achieved, and the brightness is lower. When the voltage of the Vop′ signal is at the maximum, the driving signal becomes the Vop signal, and the light is all irradiated onto the first light-shielding layer8, so that the display device is switched to the dark state display and the brightness of the display device is the lowest at this time.
• According to the control method for display device according to the embodiments of the present disclosure, the driving manner of the display device is simplified, the contrast of the display device can be improved, and the display device has a good display performance.
• In some embodiments of the present disclosure, the first light-shielding layer8 of the reflective liquidcrystal display panel100 further defines an ambient-light passage opening83. The ambient-light passage opening83 may be spaced apart from thelight extraction opening81 and thelight exit opening82, and the ambient-light passage opening83 may be disposed corresponding to thereflective structure6. The reflective liquidcrystal display panel100 may further comprise apolarization structure12, asecond filter structure14, and athird electrode15. Thepolarization structure12 can be disposed at the ambient-light passage opening83. Thepolarization structure12 can cover the ambient-light passage opening83. Thesecond filter structure14 may also be disposed at the ambient-light passage opening83, and thesecond filter structure14 may be located on a side of thepolarization structure12 facing away from theliquid crystal layer5. Thesecond filter structure14 may cover the ambient light passage opening83 such that light directed from the environment to theambient light passage83 can pass through thesecond filter structure14 and thepolarization structure12 in sequence. Thethird electrode15 may be disposed between the first light-shielding layer8 and thesecond electrode4, and thethird electrode15 may be spaced apart from thesecond electrode4. In such a case, the display device may further have a second operation mode.
• Further, as shown inFIG. 1 toFIG. 4, the reflective liquidcrystal display panel100 may further comprise asecond planarization layer16 that isolates thethird electrode15 from thesecond electrode4 to avoid signal interference between thesecond electrode4 and the threeelectrodes15, thereby ensuring operation stability of the display device in the first mode of operation and meanwhile not affecting the second mode of operation of the display device.
• In a specific example, the direction of the light transmission axis of thepolarization structure12 is at an angle of 45° with respect to the long-axis direction of the liquid crystal molecules of theliquid crystal layer5. And the thickness d of theliquid crystal layer5 may satisfy following equation: Δn*d=λ/4+m*λ, wherein Δn is the refractive index difference of theliquid crystal layer5, and Δn=ne−no, where no is the ordinary refractive index of theliquid crystal layer5, and ne is the extraordinary refractive index of theliquid crystal layer5, λ is the wavelength of the light incident on theliquid crystal layer5, and m is a natural number. Thereby, by appropriately designing the thickness d of theliquid crystal layer5, the display device can perform display with different gray scales with use of the ambient light in the second operation mode.
• The second operational mode of the display device will be further described below with reference toFIGS. 3 to 5 and 7.
• In the second mode of operation: thelight source17 is turned off, and the driving circuit applies electrical signals to thefirst electrode3, thefirst sub-electrode41, thesecond sub-electrode42, and thethird electrode15, respectively, so that ambient light passes through the ambient-light passage opening83 and is incident into theliquid crystal layer5, and is reflected by thereflective structure6 to theliquid crystal layer5, and is emitted from the ambient-light passage opening83.
• Specifically, when the display device operates, in the case that the ambient light brightness is high, the display device can operate in the second operation mode. When the display device is in the second operation mode, thelight source17 can be turned off, and the ambient light passes through the ambient-light passage opening83, and through thesecond filter structure14 and thepolarization structure12; and the driving circuit applies electric signals to thefirst electrode3, thefirst sub-electrode41, thesecond sub-electrode42 and thethird electrode15, respectively, so that the amount of the ambient light reflected by thereflective structure6 and passing through the ambientlight passage opening83 can be adjusted, thus the display device can realize display with different gray scales using the ambient light.
• For example, in the examples ofFIGS. 3 and 4, when the display device operates, in the case that the display device is in the second mode of operation, thelight source17 is turned off, and the ambient light passing through the ambient-light passage opening83 passes through thesecond filter structure14 and thepolarization structure12 sequentially. Thepolarization structure12 converts the ambient light into polarized light toward theliquid crystal layer5. The driving circuit can respectively load Vcom signals to thefirst electrode3, thefirst sub-electrode41, thesecond sub-electrode42 and thethird electrode15, that is, the driving circuit applies a Vcom signal to thefirst electrode3, a Vcom signal to thefirst sub-electrode41, a Vcom signal to thesecond sub-electrode42, and a Vcom signal to thethird electrode15. In such case, theliquid crystal layer5 is not driven, the liquid crystal molecules in theliquid crystal layer5 are not deflected, and the polarized light is not angularly deflected in theliquid crystal layer5. The thickness of theliquid crystal layer5 may be configured such that the polarized light after being reflected by thereflective structure6 cannot be emitted through thepolarizing structure12, realizing L0 dark state display (as shown inFIG. 4). The driving circuit can load the Vcom signal to thefirst electrode3, a Vop signal to thefirst sub-electrode41, the Vop signal to thesecond sub-electrode42, the Vop signal to thethird electrode15. At this time, the vertical electric field formed by thefirst electrode3, thesecond electrode4 and thethird electrode15 can drive the liquid crystal to be deflected, so that the liquid crystal molecules are erected on the whole surface, and the polarized light is reflected by thereflective structure6 and sequentially passes through thepolarizing structure12 and thesecond filter structure14 to realize the L255 bright state display (as shown inFIG. 3).
• In some embodiments, the driving signal Vcom may be 0V, and the Vop signal may be a signal with highest voltage. The driving circuit may respectively apply the Vop′ signal to thefirst electrode3, thefirst sub-electrode41, thesecond sub-electrode42 and thethird electrode15, the Vop′ signal is a signal between the Vcom signal and the Vop signal. The Vop′ signal can have a varying voltage. And the Vop′ signal changes to adjust the transmission amount of the polarized light passing through the polarization structure12 (or, the intensity of the outgoing light), thereby achieving display with different gray scales. The brightness is higher as the Vop′ signal is increased. When the Vop′ signal voltage is maximized, the driving signal becomes the Vop signal, and the amount of the polarized light passing through thepolarizing structure12 is maximized, so that the display device switches to the bright state display. At this time, the display device has the highest brightness.
• In some embodiments, the ambientlight passage opening83 can be disposed in alignment with the reflectingstructure6, so that ambient light incident into theliquid crystal layer5 through the ambientlight passage opening83 can be vertically incident on the reflectingstructure6 and vertically reflected by the reflectingstructure6 to ambientlight passage opening83, thus the design of the reflective liquidcrystal display panel100 is simplified.
• Other configurations and operations of display devices in accordance with embodiments of the present disclosure can be known by those of ordinary skills in the art from present disclosure, and thus will be omitted from being described in detail herein.
• A reflective liquidcrystal display panel100, a display device, and a control method thereof according to some embodiments of the present disclosure will be described in detail below with reference toFIGS. 1 to 5 andFIG. 7 with a detail example. It is to be understood that the following descriptions are only illustrative and not restrictive.
• As shown inFIG. 1 toFIG. 5, the reflective liquidcrystal display panel100 may comprise afirst substrate1, asecond substrate2, afirst electrode3, asecond electrode4, aliquid crystal layer5, areflective structure6, alight extraction structure7, and a first a light-shielding layer8, afirst filter structure13, a second light-shielding layer9, afirst planarization layer10, acover layer11, apolarization structure12, asecond filter structure14, athird electrode15, asecond planarization layer16, and alight source17. Thefirst electrode3, thefirst sub-electrode41, thesecond sub-electrode42 and thethird electrode15 can all be made of transparent conductive material such as Indium Tin Oxide (ITO), but shall not be limited thereto.
• Thefirst substrate1 and thesecond substrate2 may each be formed substantially in a plate-like structure, and thesecond substrate2 is disposed opposite to thefirst substrate1. Thefirst substrate1 may be a glass plate. Thesecond substrate2 may comprise aglass substrate21, a first low-refraction layer22 and a second low-refraction layer23. The first low-refraction layer22 is attached to a side of theglass substrate21 facing thefirst substrate1, and the second low-refraction layer23 is attached to a side of theglass substrate21 facing away from thefirst substrate1. Thecover layer11 is disposed on a side of the second low-refraction layer23 facing away from theglass substrate21. Thecover layer11 may cover the surface of the side of the second low-refraction layer23 facing away from theglass substrate21. In some implementations, the refractive index of the first low-refraction layer22 and the second low-refraction layer23 are both equal to or less than1.25. The first low-refraction layer22 and the second low-refraction layer23 may both be made of insulating material, that is, the first low-refraction layer22 and the second low-refraction layer23 may have insulating properties.
• Thefirst electrode3 is formed as a planar electrode, and thefirst electrode3 is disposed between thefirst substrate1 and the first low-refraction layer22. Thesecond electrode4 is disposed between the first low-refraction layer22 and thefirst electrode3.
• Thesecond electrode4 comprises afirst sub-electrode41 and twosecond sub-electrodes42. Thefirst sub-electrode41 and the twosecond sub-electrodes42 are disposed independently of each other. In the up and down direction, the upper and/or lower surfaces of thefirst sub-electrode41 and the twosecond sub-electrodes42 are arranged in alignment, respectively. In the left-right direction, thefirst sub-electrode41 is disposed between the twosecond sub-electrodes42, and the orthographic projections of the adjacentfirst sub-electrodes41 and the second sub-electrodes42 on thesecond substrate2 are spaced apart. Thefirst sub-electrode41 and the second sub-electrode42 can be strip electrodes extending in a direction perpendicular to the plane of the paper, respectively.
• Theliquid crystal layer5 is disposed between thefirst electrode3 and thesecond electrode4. Thereflective structure6 is disposed between thefirst substrate1 and thefirst electrode3. Thereflective structure6 may be disposed on a surface of a side of thefirst substrate1 facing the second substrate. Thereflective structure6 is used to reflect the light incident thereon.
• Thelight source17 is provided on the left side of thesecond substrate2 to inject light into theglass substrate21, and the light is totally reflected and propagated in theglass substrate21. Thelight extraction structure7 is disposed between thesecond substrate2 and thesecond electrode4, and thelight extraction structure7 is configured to take out the light totally reflected in thesecond substrate2 to pass through theliquid crystal layer5 to thereflective structure6, and the light taken out can be used for display. In some embodiments, thelight extraction structure7 may be a light extraction grating. In such a case, the light extraction grating may be formed on the upper surface of theglass substrate21.
• The first light-shielding layer8 is disposed between thesecond substrate2 and thesecond electrode4. The first low-refraction layer22 separates theglass substrate21 from the first light-shielding layer8. The first light-shielding layer8 defines alight extraction opening81, alight exit opening82, and an ambient light passage opening83 which are spaced apart. Thelight extraction opening81 is disposed corresponding to thelight extraction structure7, so that the light taken out from thesecond substrate2 by thelight extraction structure7 is incident through thelight extraction opening81 into theliquid crystal layer5, passes through theliquid crystal layer5 and is reflected by thereflective structure6 to theliquid crystal layer5, and finally the light again passes through theliquid crystal layer5 to thelight exit opening82. Thefirst filter structure13 is disposed at thelight exit opening82. Thefirst filter structure13 can cover thelight exit82 such that the light directed to thelight exit82 can all exit through thefirst filter structure13 to enter the environment.
• It can be understood that the specific position and the area of thereflective structure6 can be determined according to the size and the angle of the light extraction of the light extraction grating so that the light taken out by the light extraction grating can pass through theliquid crystal layer5 and be irradiated onto thereflective structure6, and then be reflected by thereflective structure6 to the first light-shielding layer8 and/or thefirst filter structure13.
• As shown inFIG. 3 toFIG. 5, the ambientlight passage opening83 and the reflectingstructure6 are disposed opposite to each other, and the ambient light incident from the ambient-light passage opening83 into theliquid crystal layer5 can be vertically incident on the reflectingstructure6 and vertically reflected by the reflectingstructure6 to the ambient-light passage opening83. Thepolarization structure12 and thesecond filter structure14 are both disposed at the ambient-light passage opening83, and both thepolarization structure12 and thesecond filter structure14 can cover the ambient-light passage opening83. Thethird electrode15 is formed as a planar electrode, and thethird electrode15 is disposed between the first light-shielding layer8 and thesecond electrode4. Thethird electrode15 and thesecond electrode4 are spaced apart from each other in the up and down direction with asecond planarization layer16 isolating thethird electrode15 from thesecond electrode4. A portion of thesecond planarization layer16 is filled between the adjacentfirst sub-electrode41 andsecond sub-electrode42.
• In some embodiments, the direction of the light transmission axis of thepolarization structure12 is at an angle of 45° with respect to the long-axis direction of the liquid crystal molecules of theliquid crystal layer5. The thickness d of theliquid crystal layer5 may be configured to satisfy the following equation: Δn*d=λ/4+m*λ, wherein Δn is a refractive index difference of theliquid crystal layer5 and Δn=ne−no, where no is the ordinary refractive index of theliquid crystal layer5, ne is the extraordinary refractive index of theliquid crystal layer5, λ is the wavelength of the light incident on theliquid crystal layer5, and m is a natural number. For example, if the orientation of the long axis of the liquid crystal molecules inFIG. 3 is along the direction perpendicular to the paper, the direction of the light transmission axis of thepolarization structure12 is configured to be at an angle of 45° with respect to the direction vertical to the paper plane.
• The second light-shielding layer9 is disposed on a side of thesecond substrate2 facing away from thefirst substrate1. The second low-refraction layer23 is disposed to separate theglass substrate21 from the second light-shielding layer9. The second light-shielding layer9 and thelight extraction structure7 is disposed in alignment with each other, and the area of the second light-shielding layer9 is larger than the area of thelight extraction structure7 to block light leakage from the side of thesecond substrate2 facing away from thefirst substrate1. Thefirst planarization layer10 is disposed between thefirst substrate1 and thefirst electrode3, and thefirst planarization layer10 encloses thereflective structure6.
• The reflective liquid crystal display panel according to the embodiments of the present disclosure can be compatible with different brightness environments to meet the display requirements in different brightness environments. According to the reflective liquid crystal display panel of the embodiments of the present disclosure, the contrast of the reflective liquid crystal display panel can be improved, and the display performance of the reflective liquid crystal display panel can be improved. Further, the structure of the reflective liquid crystal display panel is simplified, which is advantageous for implementing the thin and light design of the reflective liquid crystal display panel. In some embodiments, it is not needed to provide a polarizing plate structure, which is also advantageous for implementing the thin and light design of the reflective liquid crystal display panel.
• A display device according to an embodiment of the present disclosure may comprise the reflective liquidcrystal display panel100 and a driving circuit. The driving circuit is electrically connected to the reflective liquidcrystal display panel100. The driving circuit can apply electrical signals to thefirst electrode3, thefirst sub-electrode41, thesecond sub-electrode42, and thethird electrode15 respectively, so that thetransparent display panel100 can use the backlight to perform display when the ambient light brightness is low, and use the ambient light for display when the ambient light brightness is high. The contrast of the display device can be improved, and the display device can render excellent display performance.
• The display device may has a first operation mode and a second operation mode. As shown inFIGS. 1, 2 and 7, in the first operation mode, thelight source17 is turned onto emit light on thesecond substrate2, and the light totally reflected in thesecond substrate2 is taken out by thelight extraction structure7 at a predetermined angle and directed through thelight extraction opening81 to theliquid crystal layer5. The driving circuit can respectively load thefirst electrode3, thefirst sub-electrode41, thesecond sub-electrode42 and thethird electrode15 with the Vcom signals, that is, the driving circuit loads a Vcom signal to thefirst electrode3, loads a Vcom signal to thefirst sub-electrode41, loads a Vcom signal to thesecond sub-electrode42, and loads a Vcom signal to thethird electrode15. In such a case, the liquid crystal is not driven, the liquid crystal molecules in theliquid crystal layer5 are not deflected, the direction of propagation of the light in theliquid crystal layer5 is not changed, and the light is reflected by thereflective structure6 and then totally irradiated onto thefirst filter structure13, thus realizing the L255 bright state display (as shown inFIG. 1). The driving circuit may apply a Vop signal to thesecond sub-electrode42, and the signals loaded thefirst electrode3, thefirst sub-electrode41 and thethird electrode15 are not changed. In such a case, the liquid crystal is driven, the liquid crystal molecules in theliquid crystal layer5 are deflected. At this time, theliquid crystal layer5 can be equivalent to a symmetric oblique prism and the light is angularly deflected in theliquid crystal layer5, so that the light irradiation position is shifted to the right, and the light is completely irradiated to the first light-shielding layer8. Thus, the L0 dark state display is implemented (as shown inFIG. 2). The driving circuit may apply a Vop′ signal to thesecond sub-electrode42, and the signals loaded to thefirst electrode3, thefirst sub-electrode41 and thethird electrode15 are not changed. In such a case, the liquid crystal is driven, and the liquid crystal molecules in theliquid crystal layer5 are deflected. At this time, theliquid crystal layer5 can be equivalent to a symmetric oblique prism and the light is angularly deflected in theliquid crystal layer5, so that the light irradiation position is shifted to the right from thefirst filter structure13, and the light is respectively irradiated to thefirst filter structure13 and the first light-shielding layer8. Thus, an intermediate gray scale display is realized.
• As shown inFIG. 3,FIG. 4 andFIG. 7, in the second mode of operation, thelight source17 can be turned off, and the ambient light passes through the secondlight filter structure14 and thepolarization structure12 via the ambient-light passage opening83, and thepolarization structure12 converts the ambient light into polarized light and direct it to theliquid crystal layer5. The driving circuit applies a Vcom signal to thefirst electrode3, a Vcom signal to thefirst sub-electrode41, and a Vcom signal to thesecond sub-electrode42, and a Vcom signal to thethird electrode15. In such a case, the liquid crystal is not driven, the liquid crystal molecules in theliquid crystal layer5 are not deflected, and the polarized light is not angularly deflected in theliquid crystal layer5. The thickness of theliquid crystal layer5 can be configured such that the polarized light after being reflected by thereflective structure6 cannot be transmitted through thepolarization structure12, thus, a L0 dark state display is realized (as shown inFIG. 4). The driving circuit may apply the Vcom signal to thefirst electrode3, the Vop signal to thefirst sub-electrode41, the Vop signal to thesecond sub-electrode42, and the Vop signal to thethird electrode15. In such case, the vertical electric field formed by thefirst electrode3, thesecond electrode4, and thethird electrode15 can drive the liquid crystal to deflect, so that the liquid crystal molecules are erected on the whole surface, and the polarized light is reflected by thereflective structure6 and then sequentially passed through thepolarizing structure12 and thesecond filter structure14, thus a L255 bright state display is realized (as shown inFIG. 3). The driving circuit may apply the Vcom signal to thefirst electrode3, the Vop′ signal to thefirst sub-electrode41, the Vop′ signal to thesecond sub-electrode42, the Vop′ signal to thethird electrode15. In such a case, the polarized light is reflected by thereflective structure6 and sequentially passes through thepolarizing structure12 and thesecond filter structure14. When the deflection angle of the light is different, the transmission amount of the light through thepolarization structure12 is different. Thus, intermediate gray scale display is achieved.
• In some embodiments, the Vop′ signal is a changing signal between the Vcom signal and the Vop signal (excluding the Vcom signal and the Vop signal).
• According to the control method for display device of the embodiments of the present disclosure, the driving mode of the display device is simplified, good contrast can be obtained in both the first operation mode and the second operation mode, and the display device has a good display performance.
• In the description of the present disclosure, it is to be understood that the orientation or positional relationship indicated by the terms such as “center”, “upper”, “lower”, “left”, “right”, “vertical”, “horizontal”, etc. is based on the orientation or positional relationship shown in the drawings, and is merely for the convenience and simplifying of description of the present disclosure, and thus is not intended to indicate or imply that a device or component related necessarily only have the specified orientation or be constructed and operated in the specified orientation only, and therefore shall not be construed as limitations on the scope of the present disclosure. In the description of the present disclosure, “plurality” means two or more.
• In the description of the present specification, the description with reference to the terms “an embodiment”, “embodiments”, “illustrative embodiment(s)”, “example(s)”, “specific example(s)”, “some examples”, or the like is intended to indicate that particular feature(s), structure(s), material(s), characteristic(s), or the like described with reference to the term(s) is/are included in at least one embodiment or example of the present disclosure. In the present specification, the schematic representation of the above terms does not necessarily mean the same embodiment or example. Furthermore, particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.
• While the embodiments of the present disclosure have been shown and described, various changes, modifications, substitutions, or variations can be made by those skilled in the art to the embodiments without departing from the spirit and scope of the present disclosure, and thus the scope of the present disclosure is defined by the claims and their equivalents.

Claims (17)

What is claimed is:

1. A reflective liquid crystal display panel comprising:

a first substrate;

a second substrate disposed opposite to the first substrate;

a liquid crystal layer disposed between the first substrate and the second substrate;

a layer of a first electrode disposed on a side of the first substrate facing the second substrate and between the first substrate and the liquid crystal layer;

a layer of a second electrode disposed on a side of the second substrate facing the first substrate and between the second substrate and the liquid crystal layer, the layer of the second electrode comprising a first sub-electrode and a second sub-electrode disposed independently of each other;

a reflective structure disposed between the first substrate and the layer of the first electrode;

a first light-shielding layer disposed on the second substrate and between the second substrate and the layer of the second electrode, the first light-shielding layer having a plurality of openings including a light-extraction opening; and

a light extraction structure disposed on the second substrate in correspondence with the light-extraction opening and between the second substrate and the layer of the second electrode, and configured to extract light from the second substrate and pass the extracted light through the light-extraction opening and the liquid crystal layer to the reflective structure

2. The reflective liquid crystal display panel according toclaim 1,

wherein the plurality of openings including a light exit opening spaced apart from the light-extraction opening, and configured to emit therethrough the light which is reflected back by the reflective structure,

the reflective liquid crystal display panel further comprising:

a first filter structure disposed at the light exit opening;

a second light-shielding layer disposed on a side of the second substrate facing away from the first substrate, and disposed opposite to the light extraction structure.

3. The reflective liquid crystal display panel according toclaim 2, wherein the light incident to the reflective structure is reflected through the liquid crystal layer to any one of:

the light exit opening and/or the first light-shielding layer.

4. The reflective liquid crystal display panel according toclaim 2, wherein the second light-shielding layer is configured such that

an orthogonal projection of the second light-shielding layer on the second substrate covers an orthogonal projection of the light extraction structure on the second substrate.

5. The reflective liquid crystal display panel according toclaim 4, wherein an area of the orthogonal projection of the second light-shielding layer is larger than an area of the orthogonal projection of the light extraction structure.

6. The reflective liquid crystal display panel according toclaim 1, further comprising:

a first planarization layer disposed between the first substrate and the layer of the first electrode, wherein the reflective structure is disposed in the first planarization layer.

7. The reflective liquid crystal display panel according toclaim 1, wherein the second substrate comprises:

a glass substrate;

a first low-refraction layer attached to a side of the glass substrate facing the first substrate, and separating the first light-shielding layer from the glass substrate, the first low-refraction layer has a refractive index of 1.25 or less; and

a second low-refraction layer attached to a side of the glass substrate facing away from the first substrate, and separating a second light-shielding layer from the glass substrate, the second low-refraction layer has a refractive index of 1.25 or less.

8. The reflective liquid crystal display panel according toclaim 7, further comprising:

a cover layer disposed on a side of the second low-refraction layer facing away from the glass substrate.

9. The reflective liquid crystal display panel according toclaim 2, wherein the first light-shielding layer further defines an ambient-light passage opening, and the ambient-light passage opening is spaced apart from the light-extraction opening and the light exit opening, and the ambient-light passage opening is disposed corresponding to the reflective structure.

10. The reflective liquid crystal display panel according toclaim 9, further comprising:

a polarization structure disposed at the ambient-light passage opening;

a second filter structure disposed at the ambient-light passage opening and on a side of the polarization structure facing away from the liquid crystal layer; and

a layer of a third electrode disposed between the first light-shielding layer and the layer of the second electrode.

11. The reflective liquid crystal display panel according toclaim 10, further comprising:

a second planarization layer isolating the third electrode from the second electrode.

12. The reflective liquid crystal display panel according toclaim 10, wherein a direction of a light transmission axis of the polarization structure is at an angle of 45° with a direction of a long axis of liquid crystal molecules of the liquid crystal layer, and a thickness d of the liquid crystal layer satisfies: Δn*d=λ/4+m*λ, where Δn is refractive index difference for the liquid crystal layer, and Δn=ne−no, where no is ordinary light refractive index of the liquid crystal layer, ne is extraordinary light refractive index of the liquid crystal layer, λ is wavelength of the light incident on the liquid crystal layer, and m is a natural number.

13. The reflective liquid crystal display panel according toclaim 9, wherein the ambient-light passage opening is disposed between the light-extraction opening and the light exit opening.

14. The reflective liquid crystal display panel according toclaim 1, further comprising:

a light source for emitting light to the second substrate.

15. A display device comprising:

a reflective liquid crystal display panel according toclaim 2, and

a driving circuit electrically connected to the reflective liquid crystal display panel for providing respective signals to the first electrode and the second electrode to drive the reflective liquid crystal display panel.

16. A method for controlling display device,

wherein the display device is a display device according toclaim 15,

wherein the reflective liquid crystal display panel further comprises a light source for emitting light to the second substrate,

the method comprising:

in a first mode of operation:

turning on the light source,

applying, with the driving circuit, electrical signals respectively to the first electrode, the first sub-electrode, and the second sub-electrode, so that light incident to the second substrate by the light source is extracted out by the light extraction structure, and incident onto the reflective structure through the liquid crystal layer, and reflected to the light exit opening and/or the first light-shielding layer by the reflective structure.

17. The method according toclaim 16, wherein the first light-shielding layer further defines an ambient-light passage opening, and the ambient-light passage opening is provided apart from the light-extraction opening and the light exit opening and in correspondence with the reflective structure,

wherein the reflective liquid crystal display panel further comprises:

a polarization structure disposed at the ambient-light passage opening;

a second filter structure disposed at the ambient-light passage opening and on a side of the polarization structure facing away from the liquid crystal layer; and

a third electrode disposed between the first light-shielding layer and the second electrode,

the method further comprising:

in a second operation mode:

turning off the light source,

applying, with the driving circuit, electrical signals respectively to the first electrode, the first sub-electrode, the second sub-electrode, and the third electrode such that ambient light is incident through the ambient-light passage opening onto the liquid crystal layer, and reflected by the reflective structure to the liquid crystal layer, and is emitted through the ambient-light passage opening.

Images