Reflective display device and driving method

Abstract

The application discloses a reflective display device and a driving method. The reflective display device comprises a first liquid crystal box and a second liquid crystal box, and has a first color pixel unit, a second color pixel unit and a third color pixel unit. A color film substrate of the first liquid crystal box is transparent in a region corresponding to the first color pixel unit, is provided with a second color color resistance layer in a region corresponding to the second color pixel unit, and is provided with a third color color resistance layer in a region corresponding to the third color pixel unit. One of first cholesteric liquid crystal molecules of the first liquid crystal box and second cholesteric liquid crystal molecules of the second liquid crystal box reflects first color light when in a reflective state, and the other reflects complementary color light of the first color light when in the reflective state. The filtering wavelength of the second color color resistance layer and the filtering wavelength of the third color color resistance layer both partially overlap with the wavelength of the complementary color light. Thus, the reflective display device can realize color display by adopting double liquid crystal boxes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of display technology, in particular to a reflective display device and a driving method. BACKGROUND

[0002] Display panels have the advantages of thinness, durability, low power consumption, and compliance with energy conservation and environmental protection, but need to be used with a backlight source, resulting in a thick module and high cost. Electronic paper displays (reflective displays) have become a type of display that meets the needs of the public. Electronic paper displays can use external light sources to display images, unlike liquid crystal displays, which require a backlight source. Therefore, in an outdoor environment with strong sunlight, information on electronic paper can still be clearly seen without the problem of viewing angle. Electronic paper displays have now been widely used in electronic readers (such as electronic books and electronic newspapers) or other electronic components (such as price tags) due to their advantages of power saving, high reflectivity, and contrast ratio.

[0003] Existing electronic paper displays usually adopt E-Ink microcapsule technology (microcapsule electronic ink technology), SiPix microcup technology (microcup type electrophoretic display technology), Bridgestone electronic liquid powder technology, cholesteric liquid crystal display (CLCD) technology, micro-electro-mechanical systems (MEMS) technology, or electrowetting technology. However, existing electronic paper display technologies are not very mature compared to liquid crystal display technologies, have low mass production efficiency, and have relatively high manufacturing costs. Moreover, existing electronic paper displays cannot achieve color display.

[0004] In the prior art, a reflective display device using cholesteric liquid crystals can only reflect one color and transmit light of other colors due to the requirement of the pitch of the cholesteric liquid crystals. Therefore, the reflective display device with a single layer of cholesteric liquid crystals is mostly used to display in the form of yellow background and black characters or black background and yellow characters, black background and red characters, or red background and black characters, and cannot achieve black background and white characters or white background and black characters like a book, which greatly limits the application of the product. Moreover, the color of the reflected light of the cholesteric liquid crystals is poor, which affects the display effect. Figure 1 is a schematic view of a structure of a reflective display device using three layers of cholesteric liquid crystal cells in the prior art, as shown in Figure 1 If white display or color display is required, the reflective display device needs to use three layers of cholesteric liquid crystal cells to reflect red, green, and blue light, respectively, so as to achieve white display and color display. However, the three layers of cholesteric liquid crystal cells not only have a large cell thickness, but also have a high cost. SUMMARY

[0005] In order to overcome the shortcomings and deficiencies existing in the prior art, the present application aims to provide a reflective display device and a driving method to solve the problem of poor reflection color of the single-layer cholesteric liquid crystal reflective display device in the prior art.

[0006] The object of the present application is achieved by the following technical solutions:

[0007] The present application provides a reflective display device, comprising a first liquid crystal cell and a second liquid crystal cell stacked on the light-entering side of the first liquid crystal cell, the reflective display device having a plurality of pixel units arranged in an array, the plurality of pixel units having first color pixel units, second color pixel units and third color pixel units.

[0008] The first liquid crystal cell comprises a color filter substrate, a first array substrate arranged opposite to the color filter substrate, and a first liquid crystal layer between the color filter substrate and the first array substrate, the color filter substrate being located on the side of the first liquid crystal cell away from the second liquid crystal cell, the first liquid crystal layer comprising first cholesteric liquid crystal molecules, the first cholesteric liquid crystal molecules reflecting light of the same color in a reflective state, the color filter substrate having a transparent state in the region corresponding to the first color pixel units, a second color color resistance layer in the region corresponding to the second color pixel units, and a third color color resistance layer in the region corresponding to the third color pixel units, the first array substrate having first pixel electrodes corresponding to the pixel units, and the color filter substrate having first common electrodes corresponding to the first pixel electrodes;

[0009] The second liquid crystal cell comprises an opposite substrate, a second array substrate arranged opposite to the opposite substrate, and a second liquid crystal layer between the opposite substrate and the second array substrate, the second liquid crystal layer comprising second cholesteric liquid crystal molecules, the second cholesteric liquid crystal molecules reflecting light of the same color in a reflective state, the second array substrate having second pixel electrodes corresponding to the pixel units, and the opposite substrate having second common electrodes corresponding to the second pixel electrodes;

[0010] One of the first cholesteric liquid crystal molecules and the second cholesteric liquid crystal molecules reflects first color light in a reflective state, and the other reflects complementary color light of the first color light in a reflective state, the filtering wavelength of the second color color resistance layer and the filtering wavelength of the third color color resistance layer both partially overlapping with the wavelength of the complementary color light.

[0011] Further, the first liquid crystal layer comprises first dye liquid crystal molecules mixed with the first cholesteric liquid crystal molecules, the first dye liquid crystal molecules being of the same color as the first cholesteric liquid crystal molecules and rotating synchronously with the first cholesteric liquid crystal molecules.

[0012] Further, the second liquid crystal layer comprises second dye liquid crystal molecules intermixed with the second cholesteric liquid crystal molecules, the second dye liquid crystal molecules are of the same color as the second cholesteric liquid crystal molecules and rotate synchronously with the second cholesteric liquid crystal molecules.

[0013] Further, the first color, the second color and the third color are each one of red, green and blue.

[0014] Further, the first cholesteric liquid crystal molecules each reflect first color light when in the reflective state, and the second cholesteric liquid crystal molecules each reflect fourth color light when in the reflective state; or, the first cholesteric liquid crystal molecules each reflect fourth color light when in the reflective state, and the second cholesteric liquid crystal molecules each reflect first color light when in the reflective state.

[0015] The first color and the fourth color are complementary colors.

[0016] Further, the reflective display device comprises a light-absorbing layer arranged on the entire surface, the light-absorbing layer is arranged on a side of the second liquid crystal cell away from the first liquid crystal cell and is used to absorb light passing through the first liquid crystal cell and the second liquid crystal cell.

[0017] Further, the color filter substrate is provided with a black matrix, the black matrix is used to separate the plurality of pixel units from each other.

[0018] The application also provides a driving method of a reflective display device, for driving the reflective display device as described above, the first cholesteric liquid crystal molecules each reflect fourth color light when in the reflective state, the second cholesteric liquid crystal molecules each reflect first color light when in the reflective state, the first color and the fourth color are complementary colors, and the driving method comprises:

[0019] When the first color pixel unit is in the bright state, the second cholesteric liquid crystal molecules in the corresponding region of the first color pixel unit are controlled to be in the reflective state, and the first cholesteric liquid crystal molecules in the corresponding region of the first color pixel unit are controlled to be in the transparent state or the fog state, at this time, the second liquid crystal layer in the corresponding region of the first color pixel unit reflects first color light; when the first color pixel unit is in the dark state, the first cholesteric liquid crystal molecules and the second cholesteric liquid crystal molecules in the corresponding region of the first color pixel unit are controlled to be in the transparent state or the fog state, at this time, light directly passes through the first liquid crystal layer and the second liquid crystal layer.

[0020] When the second color pixel unit is in the bright state, the first cholesteric liquid crystal molecules in the corresponding region of the second color pixel unit are controlled to be in the reflective state, and the second cholesteric liquid crystal molecules in the corresponding region of the second color pixel unit are controlled to be in the transparent state, the haze state or the reflective state, at this time, the first liquid crystal layer in the corresponding region of the second color pixel unit reflects the second color light; when the second color pixel unit is in the dark state, the first cholesteric liquid crystal molecules in the corresponding region of the second color pixel unit are controlled to be in the transparent state or the haze state, and the second cholesteric liquid crystal molecules in the corresponding region of the second color pixel unit are controlled to be in the transparent state, the haze state or the reflective state, at this time, the light directly passes through the first liquid crystal layer and the second liquid crystal layer.

[0021] When the third color pixel unit is in the bright state, the first cholesteric liquid crystal molecules in the corresponding region of the third color pixel unit are controlled to be in the reflective state, and the second cholesteric liquid crystal molecules in the corresponding region of the third color pixel unit are controlled to be in the transparent state, the haze state or the reflective state, at this time, the first liquid crystal layer in the corresponding region of the third color pixel unit reflects the third color light; when the third color pixel unit is in the dark state, the first cholesteric liquid crystal molecules in the corresponding region of the third color pixel unit are controlled to be in the transparent state or the haze state, and the second cholesteric liquid crystal molecules in the corresponding region of the third color pixel unit are controlled to be in the transparent state, the haze state or the reflective state, at this time, the light directly passes through the first liquid crystal layer and the second liquid crystal layer.

[0022] The application also provides a driving method of a reflective display device, for driving the reflective display device as described above, the first cholesteric liquid crystal molecules reflect first color light when in the reflective state, the second cholesteric liquid crystal molecules reflect fourth color light when in the reflective state, the first color and the fourth color are complementary colors, and the driving method comprises:

[0023] When the first color pixel unit is in the bright state, the first cholesteric liquid crystal molecules in the corresponding region of the first color pixel unit are controlled to be in the reflective state, and the second cholesteric liquid crystal molecules in the corresponding region of the first color pixel unit are controlled to be in the transparent state or the haze state, at this time, the first liquid crystal layer in the corresponding region of the first color pixel unit reflects the first color light; when the first color pixel unit is in the dark state, the first cholesteric liquid crystal molecules and the second cholesteric liquid crystal molecules in the corresponding region of the first color pixel unit are controlled to be in the transparent state or the haze state, at this time, the light directly passes through the first liquid crystal layer and the second liquid crystal layer.

[0024] When the second color pixel unit is in the bright state, the second cholesteric liquid crystal molecules in the corresponding region of the second color pixel unit are controlled to be in the reflective state, and the first cholesteric liquid crystal molecules in the corresponding region of the second color pixel unit are controlled to be in the transparent state, the haze state or the reflective state, at this time, the second liquid crystal layer in the corresponding region of the second color pixel unit reflects the second color light; when the second color pixel unit is in the dark state, the second cholesteric liquid crystal molecules in the corresponding region of the second color pixel unit are controlled to be in the transparent state or the haze state, and the first cholesteric liquid crystal molecules in the corresponding region of the second color pixel unit are controlled to be in the transparent state, the haze state or the reflective state, at this time, the light directly passes through the first liquid crystal layer and the second liquid crystal layer.

[0025] When the third color pixel unit is in the bright state, the second cholesteric liquid crystal molecules in the corresponding region of the third color pixel unit are controlled to be in the reflective state, and the first cholesteric liquid crystal molecules in the corresponding region of the third color pixel unit are controlled to be in the transparent state, the haze state or the reflective state, at this time, the second liquid crystal layer in the corresponding region of the third color pixel unit reflects the third color light; when the third color pixel unit is in the dark state, the second cholesteric liquid crystal molecules in the corresponding region of the third color pixel unit are controlled to be in the transparent state or the haze state, and the first cholesteric liquid crystal molecules in the corresponding region of the third color pixel unit are controlled to be in the transparent state, the haze state or the reflective state, at this time, the light directly passes through the first liquid crystal layer and the second liquid crystal layer.

[0026] Further, the driving method comprises:

[0027] When the reflective display device displays the first color, all the first color pixel units are controlled to be in the bright state, and all the second color pixel units and the third color pixel units are controlled to be in the dark state;

[0028] When the reflective display device displays the second color, all the first color pixel units and the third color pixel units are controlled to be in the dark state, and all the second color pixel units are controlled to be in the bright state;

[0029] When the reflective display device displays the third color, all the first color pixel units and the second color pixel units are controlled to be in the dark state, and all the third color pixel units are controlled to be in the bright state;

[0030] When the reflective display device displays a color picture, all the first color pixel units, the second color pixel units and the third color pixel units display corresponding brightness respectively.

[0031] The present application has the advantages that: by arranging the first liquid crystal box and the second liquid crystal box in the reflective display device, the color film substrate of the first liquid crystal box is transparent in the region corresponding to the first color pixel unit, is provided with the second color color resistance layer in the region corresponding to the second color pixel unit, and is provided with the third color color resistance layer in the region corresponding to the third color pixel unit, and one of the first cholesteric liquid crystal molecules of the first liquid crystal box and the second cholesteric liquid crystal molecules of the second liquid crystal box reflects the first color light in the reflective state, and the other reflects the complementary color light of the first color light in the reflective state, the filtering wavelength of the second color resistance layer and the filtering wavelength of the third color resistance layer are partially overlapped with the wavelength of the complementary color light, so that the reflective display device can realize color display by adopting the double liquid crystal boxes, the color is more rich, and the box thickness is smaller. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 FIG. 1 is a structural schematic diagram of a reflective display device adopting a three-layer cholesteric liquid crystal box in the prior art.

[0033] Figure 2 FIG. 2 is a structural schematic diagram of the reflective display device in the initial state in the embodiment one of the present application.

[0034] Figure 3 FIG. 3 is a pixel arrangement structural schematic diagram of the reflective display device in the embodiment one of the present application.

[0035] Figure 4 FIG. 4 is a planar structural schematic diagram of the first array substrate in the embodiment one of the present application.

[0036] Figure 5 FIG. 5 is a planar structural schematic diagram of the second array substrate in the embodiment one of the present application.

[0037] Figure 6 FIG. 6 is a principle schematic diagram of the three-state transformation of the cholesteric liquid crystal in the embodiment one of the present application.

[0038] Figure 7 FIG. 7 is a driving signal schematic diagram of the three-state transformation of the cholesteric liquid crystal in the embodiment one of the present application.

[0039] Figure 8 FIG. 8 is one of the structural schematic diagrams of the reflective display device in the embodiment one of the present application when displaying the pure red picture.

[0040] Figure 9 FIG. 9 is the second structural schematic diagram of the reflective display device in the embodiment one of the present application when displaying the pure red picture.

[0041] Figure 10 FIG. 10 is the third structural schematic diagram of the reflective display device in the embodiment one of the present application when displaying the pure red picture.

[0042] Figure 11is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a pure green picture.

[0043] Figure 12 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a pure green picture.

[0044] Figure 13 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a pure green picture.

[0045] Figure 14 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a pure blue picture.

[0046] Figure 15 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a pure blue picture.

[0047] Figure 16 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a pure blue picture.

[0048] Figure 17 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a pure black picture.

[0049] Figure 18 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a pure black picture.

[0050] Figure 19 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a pure black picture.

[0051] Figure 20 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a color picture.

[0052] Figure 21 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a color picture.

[0053] Figure 22 is a structural schematic view of the reflective display device in the embodiment one of the present application when displaying a color picture.

[0054] Figure 23 is a structural schematic view of the reflective display device in the embodiment two of the present application when in an initial state.

[0055] Figure 24 is a structural schematic view of the reflective display device in the embodiment three of the present application when in an initial state.

[0056] Figure 25 is a structural schematic diagram of the reflective display device in the initial state in Embodiment Three of the present application.

[0057] Figure 26 is a structural schematic diagram of the reflective display device in the initial state in Embodiment Three of the present application. DETAILED DESCRIPTION

[0058] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined purposes and effects, the specific embodiments, structures, features and effects of the reflective display device and the driving method according to the present application are described in detail as follows in combination with the drawings and the preferred embodiments:

[0059] [Embodiment One]

[0060] Figure 2 is a structural schematic diagram of the reflective display device in the initial state in Embodiment One of the present application. Figure 3 is a pixel arrangement structure schematic diagram of the reflective display device in Embodiment One of the present application. Figure 4 is a planar structure schematic diagram of the first array substrate in Embodiment One of the present application. Figure 5 is a planar structure schematic diagram of the second array substrate in Embodiment One of the present application.

[0061] As shown in Figures 2 to 5 Embodiment One of the present application provides a reflective display device, which includes a second liquid crystal cell 20 and a first liquid crystal cell 10 stacked on the light exit side of the second liquid crystal cell 20, i.e. the side of the first liquid crystal cell 10 closer to the external environment relative to the second liquid crystal cell 20. The reflective display device has a plurality of pixel units P arranged in an array, and the plurality of pixel units P have first color pixel units P1, second color pixel units P2 and third color pixel units P3, each of the first color pixel units P1, the second color pixel units P2 and the third color pixel units P3 being one of a red pixel unit (R), a green pixel unit (G) and a blue pixel unit (B).

[0062] The first liquid crystal cell 10 comprises a color filter substrate 11, a first array substrate 12 arranged opposite to the color filter substrate 11, and a first liquid crystal layer 13 between the color filter substrate 11 and the first array substrate 12. The color filter substrate 11 is located on the side of the first liquid crystal cell 10 away from the second liquid crystal cell 20, and the first array substrate 12 is located on the side of the first liquid crystal cell 10 close to the second liquid crystal cell 20. The first liquid crystal layer 13 comprises first cholesteric liquid crystal molecules 131, which reflect light of the same color in the reflective state. The color filter substrate 11 is transparent in the region corresponding to the first color pixel unit P1, is provided with a second color color resistance layer 113a in the region corresponding to the second color pixel unit P2, and is provided with a third color color resistance layer 113b in the region corresponding to the third color pixel unit P3. Specifically, for example, the color filter substrate 11 is provided with a transparent color resistance W in the region corresponding to the first color pixel unit P1, or is covered by a planar layer, is provided with a second color color resistance layer 113a in the region corresponding to the second color pixel unit P2, and is provided with a third color color resistance layer 113b in the region corresponding to the third color pixel unit P3. In other embodiments, the color filter substrate 11 can also not be provided with a transparent color resistance W in the region corresponding to the first color pixel unit P1, which is not limited herein.

[0063] Further, the first array substrate 12 is provided with a first pixel electrode 121, and each pixel unit P is provided with a first pixel electrode 121 corresponding thereto. The first pixel electrode 121 corresponds to the pixel unit P one by one, and the first pixel electrode 121 is a block electrode corresponding to the pixel unit P. The color filter substrate 11 is provided with a first common electrode 111 matched with the first pixel electrode 121, and the first common electrode 111 is a planar electrode covering the color filter substrate 11.

[0064] The second liquid crystal cell 20 comprises an opposed substrate 21, a second array substrate 22 arranged opposite to the opposed substrate 21, and a second liquid crystal layer 23 between the opposed substrate 21 and the second array substrate 22. The opposed substrate 21 is located on the side of the second liquid crystal cell 20 close to the first liquid crystal cell 10, and the second array substrate 22 is located on the side of the second liquid crystal cell 20 away from the first liquid crystal cell 10. Optionally, the opposed substrate 21 can share one substrate with the first array substrate 12, that is, the opposed substrate 21 is reused as the first array substrate 12, thereby reducing the film thickness. The second liquid crystal layer 23 comprises second cholesteric liquid crystal molecules 231, which reflect light of the same color in the reflective state. One of the first cholesteric liquid crystal molecules 131 and the second cholesteric liquid crystal molecules 231 reflects light of the first color in the reflective state, and the other reflects light of the complementary color of the first color in the reflective state. The filtering wavelength of the second color color resistance layer 113a and the filtering wavelength of the third color color resistance layer 113b both partially overlap with the wavelength of the complementary color light.

[0065] Further, the second array substrate 22 is provided with a second pixel electrode 221, and the second pixel electrode 221 is provided in each pixel unit P in a one-to-one correspondence with the pixel unit P. The second pixel electrode 221 is a block electrode corresponding to the pixel unit P, and the first pixel electrode 121 and the second pixel electrode 221 are in a one-to-one correspondence. The opposite substrate 21 is provided with a second common electrode 211 matched with the second pixel electrode 212, and the second common electrode 211 is a planar electrode covering the opposite substrate 21.

[0066] The cholesteric liquid crystal molecules (the first cholesteric liquid crystal molecules 131 and the second cholesteric liquid crystal molecules 231) have three stable textures, i.e., a P state (Planar, a planar texture state, a reflection state), an FC state (Focal Conic, a focal conic state, a fog state) and an H state (a transparent state). When in the P state, the cholesteric liquid crystal has a reflection spectrum in a visible spectrum, and the cholesteric liquid crystal reflects bright colored light, and the specific reflected color can be set according to the pitch of the cholesteric liquid crystal. When in the FC state, the cholesteric liquid crystal no longer reflects the colored light, and the light can be scattered and transmitted through the cholesteric liquid crystal. When in the H state, the cholesteric liquid crystal no longer reflects the colored light, and the light can directly transmit through the cholesteric liquid crystal, and the cholesteric liquid crystal has no scattering effect on the light. Under the action of a certain electric field, the three states can be converted into each other.

[0067] Figure 6 is a schematic diagram of the principle of the three state transformations of the cholesteric liquid crystal in the embodiment one of the application. Figure 7 is a schematic diagram of the driving signal of the three state transformations of the cholesteric liquid crystal in the embodiment one of the application.

[0068] In combination with Figure 2 , Figure 6 and Figure 7As shown, a common voltage signal Vcom is applied to the common electrode (the first common electrode 111 and the second common electrode 211), a first electric signal V1 is continuously applied to the pixel electrode (the first pixel electrode 121 and the second pixel electrode 221), and the common voltage signal Vcom has a voltage difference (about 20V) with the first electric signal V1, so that a strong vertical electric field is formed between the common electrode and the pixel electrode, the cholesteric liquid crystal molecules rotate and stop at the H state (transparent state). The common voltage signal Vcom is applied to the common electrode (the first common electrode 111 and the second common electrode 211), and the second electric signal V2 is applied to the pixel electrode (the first pixel electrode 121 and the second pixel electrode 221), the second electric signal V2 has a voltage difference (for example, 20V) with the common voltage signal Vcom, and the second electric signal V2 gradually becomes the same as the common voltage signal Vcom within a first preset time, that is, the second electric signal V2 first has a large voltage difference with the common voltage signal Vcom, and then slowly decreases and becomes the same as the common voltage signal Vcom; therefore, a strong vertical electric field is first formed between the common electrode and the pixel electrode, and then the vertical electric field slowly disappears, so that the cholesteric liquid crystal molecules rotate and stop at the FC state, which is a scattering state and has a scattering effect. The common voltage signal Vcom is applied to the common electrode (the first common electrode 111 and the second common electrode 211), and the third electric signal V3 is applied to the pixel electrode (the first pixel electrode 121 and the second pixel electrode 221), the third electric signal V3 has a voltage difference (for example, 30V) with the common voltage signal Vcom, and the third electric signal V3 directly becomes the same as the common voltage signal Vcom within a second preset time, the second preset time is less than the first preset time, that is, the third electric signal V3 first has a large voltage difference with the common voltage signal Vcom, and then quickly decreases and becomes the same as the common voltage signal Vcom; therefore, a strong vertical electric field is first formed between the common electrode and the pixel electrode, and then the vertical electric field quickly disappears, so that the cholesteric liquid crystal molecules rotate and stop at the P state, which is a reflection state. The arrangement direction of the cholesteric liquid crystal molecules is different, the reflected visible light spectrum is different, and the remaining spectrum is transmitted, and the P state and the FC state do not need voltage to be maintained. The reflection spectrum band (Δλ) of the cholesteric liquid crystal molecules is proportional to the screw moment (Po) and the average refractive index (n=(ne+no) / 2) of the cholesteric liquid crystal molecules, and the formula is: Δλ=nPo, therefore, cholesteric liquid crystal molecules with different pitches can reflect light of different colors in the reflection state.

[0069] As Figure 4As shown, a first array substrate 12 is provided with multiple first scan lines 101 and multiple first data lines 102. The multiple first scan lines 101 and multiple first data lines 102 are mutually insulated and intersecting to form multiple pixel units P. Each pixel unit P is provided with a first thin-film transistor 103 and a first pixel electrode 121. The first pixel electrode 121 is electrically connected to the first scan line 101 and the first data line 102 adjacent to the first thin-film transistor 103 through the first thin-film transistor 103. The first thin-film transistor 103 includes a first gate, a first active layer, a first drain, and a first source. The first gate and the first scan line 101 are located on the same layer and are electrically connected. The first gate and the first active layer are isolated by an insulating layer. The first source is electrically connected to the first data line 102. The first drain is electrically connected to the first pixel electrode 121 through a contact hole.

[0070] like Figure 5 As shown, the second array substrate 22 is provided with multiple second scan lines 201 and multiple second data lines 202. The multiple second scan lines 201 and multiple second data lines 202 are mutually insulated and intersecting to form multiple pixel units P. The second array substrate 22 provides a second thin film transistor 203 and a second pixel electrode 221 in each pixel unit P. The second pixel electrode 221 is electrically connected to the second scan line 201 and the second data line 202 adjacent to the second thin film transistor 203 through the second thin film transistor 203. The second thin film transistor 203 includes a second gate, a second active layer, a second drain, and a second source. The second gate and the second scan line 201 are located on the same layer and are electrically connected. The second gate and the second active layer are isolated by an insulating layer. The second source is electrically connected to the second data line 202. The second drain is electrically connected to the second pixel electrode 221 through a contact hole.

[0071] Optionally, the projections of the first scan line 101 and the second scan line 201 on the second array substrate 22 overlap, the projections of the first data line 102 and the second data line 202 on the second array substrate 22 overlap, the projections of the first thin film transistor 103 and the second thin film transistor 203 on the second array substrate 22 overlap, and the projections of the first pixel electrode 121 and the second pixel electrode 221 on the second array substrate 22 overlap.

[0072] In this embodiment, the second liquid crystal layer 23 further comprises second dye liquid crystal molecules 232 mixed with the second cholesteric liquid crystal molecules 231, the second dye liquid crystal molecules 232 are of the same color as the second cholesteric liquid crystal molecules 231 and rotate synchronously with the second cholesteric liquid crystal molecules 231. The second dye liquid crystal molecules 232 are positive dye liquid crystal molecules, the positive dye liquid crystal molecules have a long axis and a short axis, the long axis has a stronger light absorption capacity than the short axis, and the positive dye liquid crystal molecules have the characteristics that the long axis has a strong light absorption capacity and the short axis has a weak light absorption capacity. The long axis absorbs part of the light, thereby presenting a color corresponding to the second dye liquid crystal molecules 232. For example, the second dye liquid crystal molecules 232 are purple dye liquid crystal molecules, the long axis of the purple dye liquid crystal molecules can absorb green waves and present purple; similarly, if they are red dye liquid crystal molecules, the long axis of the red dye liquid crystal molecules can absorb cyan waves and present red. Of course, the second dye liquid crystal molecules 232 can also use other single-color dye liquid crystal molecules, such as blue, green, yellow, etc.

[0073] In the embodiment, the first cholesteric liquid crystal molecules 131 reflect the fourth color light in the reflective state, and the second cholesteric liquid crystal molecules 231 reflect the first color light in the reflective state. The first color and the fourth color are complementary colors, i.e., the first color and the fourth color mixed together are white. The first color, the second color, and the third color are each one of red, green, and blue. In the embodiment, the first cholesteric liquid crystal molecules 131 are cyan cholesteric liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are red cholesteric liquid crystal molecules, the second dye liquid crystal molecules 232 are red dye liquid crystal molecules, the second color color resist layer 113a is a green color resist, and the third color color resist layer 113b is a blue color resist. Of course, in other embodiments, the first cholesteric liquid crystal molecules 131 are cyan cholesteric liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are red cholesteric liquid crystal molecules, the second dye liquid crystal molecules 232 are red dye liquid crystal molecules, the second color color resist layer 113a is a blue color resist, and the third color color resist layer 113b is a green color resist; or the first cholesteric liquid crystal molecules 131 are purple cholesteric liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are green cholesteric liquid crystal molecules, the second dye liquid crystal molecules 232 are green dye liquid crystal molecules, the second color color resist layer 113a is a red color resist, and the third color color resist layer 113b is a blue color resist; or the first cholesteric liquid crystal molecules 131 are purple cholesteric liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are green cholesteric liquid crystal molecules, the second dye liquid crystal molecules 232 are green dye liquid crystal molecules, the second color color resist layer 113a is a blue color resist, and the third color color resist layer 113b is a red color resist; or the first cholesteric liquid crystal molecules 131 are yellow cholesteric liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are blue cholesteric liquid crystal molecules, the second dye liquid crystal molecules 232 are blue dye liquid crystal molecules, the second color color resist layer 113a is a red color resist, and the third color color resist layer 113b is a green color resist; or the first cholesteric liquid crystal molecules 131 are yellow cholesteric liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are blue cholesteric liquid crystal molecules, the second dye liquid crystal molecules 232 are blue dye liquid crystal molecules, the second color color resist layer 113a is a green color resist, and the third color color resist layer 113b is a red color resist. This is not limited herein.

[0074] Further, the reflective display device comprises a light-absorbing layer 30 arranged on the whole surface, which is arranged on the side of the second liquid crystal cell 20 away from the first liquid crystal cell 10 and is used to absorb the light passing through the first liquid crystal cell 10 and the second liquid crystal cell 20, so that the reflective display device is darker in the black state, thereby improving the contrast. Optionally, the light-absorbing layer 30 is black ink, and the L value (representing the lightness and darkness) of the black ink is greater than 25 and the OD value (optical density) is greater than 4, so that the light-absorbing layer 30 has the characteristics of high blackness and good glossiness, and ensures that the black picture is darker. Of course, the light-absorbing layer 30 can be made of BM material. In the embodiment, the light-absorbing layer 30 is a planar structure covering the second array substrate 22, and the light-absorbing layer 30 is arranged on the side of the second array substrate 22 away from the second liquid crystal layer 23.

[0075] Further, the color filter substrate 11 is provided with a black matrix 112, which is used to separate the plurality of pixel units P from each other, so that the problem of color mixing between adjacent pixel units P can be avoided.

[0076] The color filter substrate 11, the first array substrate 12, the opposing substrate 21 and the second array substrate 22 can be made of transparent substrates such as glass, acrylic and polycarbonate. The first common electrode 111, the first pixel electrode 121, the second common electrode 211 and the second pixel electrode 221 can be made of transparent electrodes such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0077] The application further provides a driving method of the reflective display device, which is used to drive the reflective display device as described above. The driving method comprises:

[0078] When the first color pixel unit P1 is in the bright state, the first cholesteric liquid crystal molecules 131 in the corresponding region of the first color pixel unit P1 are all in the vertical standing posture or all in the disordered inclined state, so that the first cholesteric liquid crystal molecules 131 in the corresponding region of the first color pixel unit P1 are all in the transparent state or the fog state, and the light can pass through the first liquid crystal layer 13; and the second cholesteric liquid crystal molecules 231 in the corresponding region of the first color pixel unit P1 are all in the lying posture, so that the second cholesteric liquid crystal molecules 231 in the corresponding region of the first color pixel unit P1 are all in the reflection state, at this time, the second liquid crystal layer 23 in the corresponding region of the first color pixel unit P1 reflects the first color light (red light), and the second dye liquid crystal molecules 232 can filter the reflected first color light, so that the color of the reflected light is purer. When the first color pixel unit P1 is in the dark state, the first cholesteric liquid crystal molecules 131 and the second cholesteric liquid crystal molecules 231 in the corresponding region of the first color pixel unit P1 are all in the vertical standing posture or all in the disordered inclined state, so that the first cholesteric liquid crystal molecules 131 and the second cholesteric liquid crystal molecules 231 in the corresponding region of the first color pixel unit P1 are all in the transparent state or the fog state, at this time, the light directly passes through the first liquid crystal layer 13 and the second liquid crystal layer 23, is absorbed by the light absorbing layer 30, and presents black or fog black.

[0079] When the second color pixel unit P2 is in the bright state, the first cholesteric liquid crystal molecules 131 in the region corresponding to the second color pixel unit P2 are all in the flat-lying state, so that the first cholesteric liquid crystal molecules 131 in the region corresponding to the second color pixel unit P2 are all in the reflective state. Since the filtering wavelength of the second color color resistance layer 113a partially overlaps with the wavelength of the complementary color light (i.e., the light reflected by the first liquid crystal layer 13 in the reflective state), the first liquid crystal layer 13 in the region corresponding to the second color pixel unit P2 can reflect part of the second color light (green light) at this time. In addition, the second cholesteric liquid crystal molecules 231 in the region corresponding to the second color pixel unit P2 are all in the transparent state, the haze state or the reflective state. Since the second liquid crystal layer 23 cannot reflect the second color light, the second cholesteric liquid crystal molecules 231 can be in any state. When the second color pixel unit P2 is in the dark state, the first cholesteric liquid crystal molecules 131 in the region corresponding to the second color pixel unit P2 are all in the vertical standing state or all in the disordered inclined state, so that the first cholesteric liquid crystal molecules 131 in the region corresponding to the second color pixel unit P2 are all in the transparent state or the haze state. In addition, the second cholesteric liquid crystal molecules 231 in the region corresponding to the second color pixel unit P2 are all in the transparent state, the haze state or the reflective state. Since the second liquid crystal layer 23 cannot reflect the second color light, the second cholesteric liquid crystal molecules 231 can be in any state. At this time, the light directly passes through the first liquid crystal layer 13 and the second liquid crystal layer 23, is absorbed by the light-absorbing layer 30, and presents black or haze black. Of course, when the second cholesteric liquid crystal molecules 231 are in the reflective state or the haze state, part of the second color light will also be absorbed by the second dye liquid crystal molecules 232 to improve the black state effect.

[0080] When the third color pixel unit P3 is in the bright state, the first cholesteric liquid crystal molecules 131 in the region corresponding to the third color pixel unit P3 are all in the flat lying state, so that the first cholesteric liquid crystal molecules 131 in the region corresponding to the third color pixel unit P3 are all in the reflective state. Since the filtering wavelength of the third color color resistance layer 113b partially overlaps with the wavelength of the complementary color light (i.e. the light reflected by the first liquid crystal layer 13 in the reflective state), at this time, the first liquid crystal layer 13 in the region corresponding to the third color pixel unit P3 can reflect part of the third color light (blue light). In addition, the second cholesteric liquid crystal molecules 231 in the region corresponding to the third color pixel unit P3 are all in the transparent state, the haze state or the reflective state. Since the second liquid crystal layer 23 cannot reflect the second color light, the second cholesteric liquid crystal molecules 231 can be in any state. When the third color pixel unit P3 is in the dark state, the first cholesteric liquid crystal molecules 131 in the region corresponding to the third color pixel unit P3 are all in the vertical standing state or all in the disordered inclined state, so that the first cholesteric liquid crystal molecules 131 in the region corresponding to the third color pixel unit P3 are all in the transparent state or the haze state. In addition, the second cholesteric liquid crystal molecules 231 in the region corresponding to the third color pixel unit P3 are all in the transparent state, the haze state or the reflective state. Since the second liquid crystal layer 23 cannot reflect the third color light, the second cholesteric liquid crystal molecules 231 can be in any state. At this time, the light directly passes through the first liquid crystal layer 13 and the second liquid crystal layer 23 and is absorbed by the light absorbing layer 30, presenting black or haze black. Of course, when the second cholesteric liquid crystal molecules 231 are in the reflective state or the haze state, part of the third color light will also be absorbed by the second dye liquid crystal molecules 232 to improve the black state effect.

[0081] Table 1 below is a state analysis table of the first color pixel unit P1, the second color pixel unit P2 and the third color pixel unit P3 in the bright / dark state corresponding to the first cholesteric liquid crystal molecules 131 and the second cholesteric liquid crystal molecules 231:

[0082]

[0083] Figure 8 is one of the structure schematic diagrams of the reflective display device in the display of a pure red picture in the embodiment one of the present application. Figure 9 is the second structure schematic diagram of the reflective display device in the display of a pure red picture in the embodiment one of the present application. Figure 10 is the third structure schematic diagram of the reflective display device in the display of a pure red picture in the embodiment one of the present application. As shown in Table 1 and Figures 8 to 10 shown, when the reflective display device displays the first color, all the first color pixel units P1 are controlled to be in the bright state and reflect the first color light (red light), and all the second color pixel units P2 and the third color pixel units P3 are controlled to be in the dark state.

[0084] Figure 11 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a pure green picture. Figure 12 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a pure green picture. Figure 13 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a pure green picture. As shown in Table One and Figures 11 to 13 as shown, when the reflective display device displays the second color, all the first color pixel units PI and the third color pixel units P3 are controlled to be in dark state, and all the second color pixel units P2 are controlled to be in bright state, and the second color light (green light) is reflected.

[0085] Figure 14 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a pure blue picture. Figure 15 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a pure blue picture. Figure 16 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a pure blue picture. As shown in Table One and Figures 14 to 16 as shown, when the reflective display device displays the third color, all the first color pixel units PI and the second color pixel units P2 are controlled to be in dark state, and all the third color pixel units P3 are controlled to be in bright state, and the third color light (blue light) is reflected.

[0086] Figure 17 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a pure black picture. Figure 18 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a pure black picture. Figure 19 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a pure black picture. As shown in Table One and Figures 17 to 19 as shown, when the reflective display device displays a pure black picture, all the first color pixel units PI, the second color pixel units P2 and the third color pixel units P3 are controlled to be in dark state.

[0087] Figure 20 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a color picture. Figure 21 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a color picture. Figure 22 is a structural schematic diagram of the reflective display device in Embodiment One of the present application when displaying a color picture. As shown in Table One and Figures 20 to 22As shown, when the reflective display device displays a color picture, the first color pixel unit P1, the second color pixel unit P2 and the third color pixel unit P3 are controlled to display corresponding brightness respectively, and through the principle of mixing red, green and blue light, light of various colors is formed, so as to realize color display.

[0088] [Example Two]

[0089] Figure 23 is a structural schematic diagram of the reflective display device in the initial state in the second embodiment of the present application. As Figure 23 shown, the reflective display device and the driving method provided by the second embodiment of the present application are basically the same as the reflective display device and the driving method in the first embodiment of the present application, and the difference lies in that: Figures 2 to 22

[0090] In the present embodiment, the first liquid crystal layer 13 comprises first dye liquid crystal molecules 132 mixed with the first cholesteric liquid crystal molecules 131, and the first dye liquid crystal molecules 132 are of the same color as the first cholesteric liquid crystal molecules 131 and rotate synchronously with the first cholesteric liquid crystal molecules 131. The first dye liquid crystal molecules 132 are positive dye liquid crystal molecules, and the positive dye liquid crystal molecules have the characteristics that the light absorption capacity of the long axis is greater than that of the short axis, the long axis has strong light absorption capacity, and the short axis has weak light absorption capacity. The long axis absorbs part of the light, thereby presenting the color corresponding to the first dye liquid crystal molecules 132. For example, the first dye liquid crystal molecules 132 are purple dye liquid crystal molecules, the long axis of the purple dye liquid crystal molecules can absorb green wave band and present purple color; similarly, if the first dye liquid crystal molecules 132 are red dye liquid crystal molecules, the long axis of the red dye liquid crystal molecules can absorb cyan wave band and present red color. Of course, the first dye liquid crystal molecules 132 can also be other single-color dye liquid crystal molecules, such as blue, green, yellow, etc.

[0091] ​Further, the first cholesteric liquid crystal molecules 131 all reflect first color light in the reflective state, and the second cholesteric liquid crystal molecules 231 all reflect fourth color light in the reflective state, the first color and the fourth color being complementary colors. The first color, the second color, and the third color are each one of red, green, and blue. In this embodiment, the first cholesteric liquid crystal molecules 131 are red cholesteric liquid crystal molecules, the first dye liquid crystal molecules 132 are red dye liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are cyan cholesteric liquid crystal molecules, the second color color resist layer 113a is a green color resist, and the third color color resist layer 113b is a blue color resist. Of course, in other embodiments, the first cholesteric liquid crystal molecules 131 are red cholesteric liquid crystal molecules, the first dye liquid crystal molecules 132 are red dye liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are cyan cholesteric liquid crystal molecules, the second color color resist layer 113a is a blue color resist, and the third color color resist layer 113b is a green color resist; or the first cholesteric liquid crystal molecules 131 are green cholesteric liquid crystal molecules, the first dye liquid crystal molecules 132 are green dye liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are violet cholesteric liquid crystal molecules, the second color color resist layer 113a is a red color resist, and the third color color resist layer 113b is a blue color resist; or the first cholesteric liquid crystal molecules 131 are green cholesteric liquid crystal molecules, the first dye liquid crystal molecules 132 are green dye liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are violet cholesteric liquid crystal molecules, the second color color resist layer 113a is a blue color resist, and the third color color resist layer 113b is a red color resist; or the first cholesteric liquid crystal molecules 131 are blue cholesteric liquid crystal molecules, the first dye liquid crystal molecules 132 are blue dye liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are yellow cholesteric liquid crystal molecules, the second color color resist layer 113a is a red color resist, and the third color color resist layer 113b is a green color resist; or the first cholesteric liquid crystal molecules 131 are blue cholesteric liquid crystal molecules, the first dye liquid crystal molecules 132 are blue dye liquid crystal molecules, the second cholesteric liquid crystal molecules 231 are yellow cholesteric liquid crystal molecules, the second color color resist layer 113a is a green color resist, and the third color color resist layer 113b is a red color resist. This is not limited.

[0092] The application also provides a driving method of the reflective display device, for driving the reflective display device as described above. The driving method comprises:

[0093] When the first color pixel unit P1 is in the bright state, the first cholesteric liquid crystal molecules 131 in the region corresponding to the first color pixel unit P1 are all in a flat lying posture, so that the first cholesteric liquid crystal molecules 131 in the region corresponding to the first color pixel unit P1 are all in a reflective state. At this time, the first cholesteric liquid crystal molecules 131 in the region corresponding to the first color pixel unit P1 reflect first color light (red light), and the first dye liquid crystal molecules 132 can filter the reflected first color light, so that the color of the reflected light is purer. In addition, the second cholesteric liquid crystal molecules 231 in the region corresponding to the first color pixel unit P1 are all in a vertical standing posture or all in a disordered inclined state, so that the second cholesteric liquid crystal molecules 231 in the region corresponding to the first color pixel unit P1 are all in a transparent state or a haze state, and the remaining light can pass through the second liquid crystal layer 23. When the first color pixel unit P1 is in the dark state, the first cholesteric liquid crystal molecules 131 and the second cholesteric liquid crystal molecules 231 in the region corresponding to the first color pixel unit P1 are all in a vertical standing posture or all in a disordered inclined state, so that the first cholesteric liquid crystal molecules 131 and the second cholesteric liquid crystal molecules 231 in the region corresponding to the first color pixel unit P1 are all in a transparent state or a haze state. At this time, the light directly passes through the first liquid crystal layer 13 and the second liquid crystal layer 23, is absorbed by the light absorbing layer 30, and presents black or haze black.

[0094] When the second color pixel unit P2 is in the bright state, the second cholesteric liquid crystal molecules 231 in the region corresponding to the second color pixel unit P2 are all in a flat lying state, so that the second cholesteric liquid crystal molecules 231 in the region corresponding to the second color pixel unit P2 are all in a reflective state. Since the filtering wavelength of the second color color resistance layer 113a partially overlaps with the wavelength of the complementary color light (i.e., the light reflected by the second liquid crystal layer 23 in the reflective state), the second liquid crystal layer 23 in the region corresponding to the second color pixel unit P2 can reflect part of the second color light (green light) at this time. In addition, the first cholesteric liquid crystal molecules 131 in the region corresponding to the second color pixel unit P2 are all in a transparent state, a haze state, or a reflective state. Since the first liquid crystal layer 13 cannot reflect the second color light, the first cholesteric liquid crystal molecules 131 can be in any state. However, when the first cholesteric liquid crystal molecules 131 are in a reflective state or a haze state, part of the second color light will also be absorbed by the first dye liquid crystal molecules 132, resulting in a decrease in the utilization rate of light by the second color pixel unit P2. Therefore, the first cholesteric liquid crystal molecules 131 in the region corresponding to the second color pixel unit P2 are preferably in a transparent state. When the second color pixel unit P2 is in the dark state, the second cholesteric liquid crystal molecules 231 in the region corresponding to the second color pixel unit P2 are all in a vertical standing state or all in a disordered inclined state, so that the second cholesteric liquid crystal molecules 231 in the region corresponding to the second color pixel unit P2 are all in a transparent state or a haze state. In addition, the first cholesteric liquid crystal molecules 131 in the region corresponding to the second color pixel unit P2 are all in a transparent state, a haze state, or a reflective state. Since the first liquid crystal layer 13 cannot reflect the second color light, the first cholesteric liquid crystal molecules 131 can be in any state. At this time, the light directly passes through the first liquid crystal layer 13 and the second liquid crystal layer 23 and is absorbed by the light absorbing layer 30, appearing black or haze black. Of course, when the first cholesteric liquid crystal molecules 131 are in a reflective state or a haze state, part of the second color light will also be absorbed by the first dye liquid crystal molecules 132 to improve the black state effect.

[0095] When the third color pixel unit P3 is in the bright state, the second cholesteric liquid crystal molecules 231 in the region corresponding to the third color pixel unit P3 are all in the flat lying state, so that the second cholesteric liquid crystal molecules 231 in the region corresponding to the third color pixel unit P3 are all in the reflective state. Since the filter wavelength of the third color color resistance layer 113b partially overlaps with the wavelength of the complementary color light (i.e. the light reflected by the second liquid crystal layer 23 in the reflective state), at this time, the second liquid crystal layer 23 in the region corresponding to the third color pixel unit P3 can reflect part of the third color light (blue light). In addition, the first cholesteric liquid crystal molecules 131 in the region corresponding to the third color pixel unit P3 are all in the transparent state, the haze state or the reflective state. Since the first liquid crystal layer 13 cannot reflect the third color light, the first cholesteric liquid crystal molecules 131 can be in any state. However, when the first cholesteric liquid crystal molecules 131 are in the reflective state or the haze state, part of the third color light will also be absorbed by the first dye liquid crystal molecules 132, resulting in a decrease in the utilization rate of light by the third color pixel unit P3. Therefore, the first cholesteric liquid crystal molecules 131 in the region corresponding to the third color pixel unit P3 are preferably in the transparent state.

[0096] Table II below is a state analysis table of the first color pixel unit P1, the second color pixel unit P2 and the third color pixel unit P3 in the bright / dark state corresponding to the first cholesteric liquid crystal molecules 131 and the second cholesteric liquid crystal molecules 231:

[0097]

[0098] Please refer to Table II above:

[0099] When the reflective display device displays the first color, all the first color pixel units P1 are controlled to be in the bright state and reflect the first color light (red light), and all the second color pixel units P2 and the third color pixel units P3 are controlled to be in the dark state.

[0100] When the reflective display device displays the second color, all the first color pixel units P1 and the third color pixel units P3 are controlled to be in the dark state, all the second color pixel units P2 are controlled to be in the bright state, and the second color light (green light) is reflected.

[0101] When the reflective display device displays the third color, all the first color pixel units P1 and the second color pixel units P2 are controlled to be in the dark state, all the third color pixel units P3 are controlled to be in the bright state, and the third color light (blue light) is reflected.

[0102] When the reflective display device displays a pure black picture, all the first color pixel units P1, the second color pixel units P2 and the third color pixel units P3 are controlled to be in the dark state.

[0103] When the reflective display device displays a color picture, all the first color pixel units P1, the second color pixel units P2 and the third color pixel units P3 are controlled to display corresponding brightness respectively, and various color lights are formed through the mutual color mixing principle of red, green and blue lights, so that color display is realized.

[0104] Those skilled in the art should understand that the remaining structure and working principle of the embodiment are the same as those of the first embodiment, and will not be described here.

[0105] [Embodiment Three]

[0106] The reflective display device and the driving method provided by the third embodiment of the present application are basically the same as those in the first embodiment ( Figures 2 to 22 ) and the second embodiment ( Figure 23 ), and the difference lies in that:

[0107] Figure 24 is one of the structural schematic diagrams of the reflective display device in the initial state in the third embodiment of the present application. As Figure 24As shown, in one embodiment, the first liquid crystal layer 13 includes first dye liquid crystal molecules 132 mixed with the first cholesteric liquid crystal molecules 131. The first dye liquid crystal molecules 132 are the same color as the first cholesteric liquid crystal molecules 131 and rotate synchronously with the first cholesteric liquid crystal molecules 131. Simultaneously, the second liquid crystal layer 23 also includes second dye liquid crystal molecules 232 mixed with the second cholesteric liquid crystal molecules 231. The second dye liquid crystal molecules 232 are the same color as the second cholesteric liquid crystal molecules 231 and rotate synchronously with the second cholesteric liquid crystal molecules 231. The first dye liquid crystal molecules 132 can filter the light reflected by the first cholesteric liquid crystal molecules 131, making the color of the reflected light purer. The second dye liquid crystal molecules 232 can also filter the light reflected by the second cholesteric liquid crystal molecules 231, making the color of the reflected light purer.

[0108] Figure 25 This is the second schematic diagram of the reflective display device in its initial state according to Embodiment 3 of the present invention. Figure 25 As shown, in one embodiment, the first cholesteric liquid crystal molecule 131 is a yellow cholesteric liquid crystal molecule, the first dye liquid crystal molecule 132 is a yellow dye liquid crystal molecule, the second cholesteric liquid crystal molecule 231 is a blue cholesteric liquid crystal molecule, the second dye liquid crystal molecule 232 is a blue dye liquid crystal molecule, the second color resist layer 113a is a red color resist, and the third color resist layer 113b is a green color resist.

[0109] Figure 26 This is the third schematic diagram of the reflective display device in its initial state according to Embodiment 3 of the present invention. Figure 26 As shown, in one embodiment, the first cholesteric liquid crystal molecule 131 is a purple cholesteric liquid crystal molecule, the first dye liquid crystal molecule 132 is a purple dye liquid crystal molecule, the second cholesteric liquid crystal molecule 231 is a green cholesteric liquid crystal molecule, the second dye liquid crystal molecule 232 is a green dye liquid crystal molecule, the second color resist layer 113a is a blue color resist, and the third color resist layer 113b is a red color resist.

[0110] Those skilled in the art should understand that the remaining structures and working principles of this embodiment are the same as those of Embodiment 1 and Embodiment 2, and will not be repeated here.

[0111] In this document, the directional terms such as up, down, left, right, front, and back are defined according to the position of the structures in the accompanying drawings and the relative positions of the structures, and are only used for clarity and convenience in expressing the technical solution. It should be understood that the use of these directional terms should not limit the scope of protection claimed in this application. It should also be understood that the terms "first" and "second," etc., used herein are only used for distinction in name and are not used to limit the number or order.

[0112] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make some changes or modifications to the above disclosed technical contents without departing from the technical solution of the present application, and the equivalent embodiments with equivalent changes are also included. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application are still within the protection scope of the technical solution of the present application.

Claims

1. A reflective display device, characterized by The reflective display device comprises a first liquid crystal cell (10) and a second liquid crystal cell (20) stacked on the light entering side of the first liquid crystal cell (10), and has a plurality of pixel units (P) arranged in an array, wherein the pixel units (P) include first color pixel units (P1), second color pixel units (P2) and third color pixel units (P3); The first liquid crystal cell (10) comprises a color filter substrate (11), a first array substrate (12) arranged opposite to the color filter substrate (11), and a first liquid crystal layer (13) between the color filter substrate (11) and the first array substrate (12), the color filter substrate (11) is located on the side of the first liquid crystal cell (10) away from the second liquid crystal cell (20), the first liquid crystal layer (13) comprises first cholesteric liquid crystal molecules (131), the first cholesteric liquid crystal molecules (131) reflect light of the same color in the reflective state, the color filter substrate (11) is transparent in the region corresponding to the first color pixel units (P1), is provided with a second color color resistance layer (113a) in the region corresponding to the second color pixel units (P2), and is provided with a third color color resistance layer (113b) in the region corresponding to the third color pixel units (P3), the first array substrate (12) is provided with first pixel electrodes (121) corresponding to the pixel units (P), and the color filter substrate (11) is provided with a first common electrode (111) matched with the first pixel electrodes (121); The second liquid crystal cell (20) comprises an opposed substrate (21), a second array substrate (22) arranged opposite to the opposed substrate (21), and a second liquid crystal layer (23) between the opposed substrate (21) and the second array substrate (22), the second liquid crystal layer (23) comprises second cholesteric liquid crystal molecules (231), the second cholesteric liquid crystal molecules (231) reflect light of the same color in the reflective state, the second array substrate (22) is provided with second pixel electrodes (221) corresponding to the pixel units (P), and the opposed substrate (21) is provided with a second common electrode (211) matched with the second pixel electrodes (221); One of the first cholesteric liquid crystal molecules (131) and the second cholesteric liquid crystal molecules (231) reflects first color light in the reflective state, and the other reflects complementary color light of the first color light in the reflective state, the filtering wavelength of the second color color resistance layer (113a) and the filtering wavelength of the third color color resistance layer (113b) both partially overlap with the wavelength of the complementary color light.

2. The reflective display device of claim 1, wherein The first liquid crystal layer (13) comprises first dye liquid crystal molecules (132) mixed with the first cholesteric liquid crystal molecules (131), the first dye liquid crystal molecules (132) are of the same color as the first cholesteric liquid crystal molecules (131) and rotate synchronously with the first cholesteric liquid crystal molecules (131).

3. A reflective display device according to claim 1 or 2, characterised in that The second liquid crystal layer (23) comprises second dye liquid crystal molecules (232) mixed with the second cholesteric liquid crystal molecules (231), the second dye liquid crystal molecules (232) are of the same color as the second cholesteric liquid crystal molecules (231) and rotate synchronously with the second cholesteric liquid crystal molecules (231).

4. The reflective display device of claim 1, wherein The first color, the second color and the third color are each one of red, green and blue.

5. The reflective display device of claim 1, wherein The first cholesteric liquid crystal molecules (131) reflect first color light rays in the reflective state, and the second cholesteric liquid crystal molecules (231) reflect fourth color light rays in the reflective state; or, the first cholesteric liquid crystal molecules (131) reflect fourth color light rays in the reflective state, and the second cholesteric liquid crystal molecules (231) reflect first color light rays in the reflective state. The first color and the fourth color are complementary colors.

6. The reflective display apparatus of claim 1, wherein The reflective display device comprises a light-absorbing layer (30) arranged on the entire surface, the light-absorbing layer (30) is arranged on the side of the second liquid crystal cell (20) away from the first liquid crystal cell (10) and is used for absorbing light rays passing through the first liquid crystal cell (10) and the second liquid crystal cell (20).

7. The reflective display device of claim 1, wherein The color filter substrate (11) is provided with a black matrix (112), and the black matrix (112) is used for spacing the plurality of pixel units (P) from each other.

8. A driving method of a reflective display device, characterized by, The reflective display device is driven by a driving method, the first cholesteric liquid crystal molecules (131) reflect fourth color light rays in the reflective state, the second cholesteric liquid crystal molecules (231) reflect first color light rays in the reflective state, the first color and the fourth color are complementary colors, and the driving method comprises: When the first color pixel unit (P1) is in the bright state, the second cholesteric liquid crystal molecules (231) in the corresponding region of the first color pixel unit (P1) are controlled to be in the reflective state, and the first cholesteric liquid crystal molecules (131) in the corresponding region of the first color pixel unit (P1) are controlled to be in the transparent state or the fog state, at this time, the second liquid crystal layer (23) in the corresponding region of the first color pixel unit (P1) reflects first color light rays; when the first color pixel unit (P1) is in the dark state, the first cholesteric liquid crystal molecules (131) and the second cholesteric liquid crystal molecules (231) in the corresponding region of the first color pixel unit (P1) are controlled to be in the transparent state or the fog state, at this time, light rays directly pass through the first liquid crystal layer (13) and the second liquid crystal layer (23). When the second color pixel unit (P2) is in the bright state, the first cholesteric liquid crystal molecules (131) in the corresponding region of the second color pixel unit (P2) are controlled to be in the reflective state, and the second cholesteric liquid crystal molecules (231) in the corresponding region of the second color pixel unit (P2) are controlled to be in the transparent state, the haze state or the reflective state, at this time, the first liquid crystal layer (13) in the corresponding region of the second color pixel unit (P2) reflects the second color light; when the second color pixel unit (P2) is in the dark state, the first cholesteric liquid crystal molecules (131) in the corresponding region of the second color pixel unit (P2) are controlled to be in the transparent state or the haze state, and the second cholesteric liquid crystal molecules (231) in the corresponding region of the second color pixel unit (P2) are controlled to be in the transparent state, the haze state or the reflective state, at this time, the light directly passes through the first liquid crystal layer (13) and the second liquid crystal layer (23); When the third color pixel unit (P3) is in the bright state, the first cholesteric liquid crystal molecules (131) in the corresponding region of the third color pixel unit (P3) are controlled to be in the reflective state, and the second cholesteric liquid crystal molecules (231) in the corresponding region of the third color pixel unit (P3) are controlled to be in the transparent state, the haze state or the reflective state, at this time, the first liquid crystal layer (13) in the corresponding region of the third color pixel unit (P3) reflects the third color light; when the third color pixel unit (P3) is in the dark state, the first cholesteric liquid crystal molecules (131) in the corresponding region of the third color pixel unit (P3) are controlled to be in the transparent state or the haze state, and the second cholesteric liquid crystal molecules (231) in the corresponding region of the third color pixel unit (P3) are controlled to be in the transparent state, the haze state or the reflective state, at this time, the light directly passes through the first liquid crystal layer (13) and the second liquid crystal layer (23).

9. A driving method of a reflective display device, characterized by, The driving method for driving the reflective display device as claimed in any one of claims 1-7, wherein the first cholesteric liquid crystal molecules (131) in the reflective state reflect the first color light, and the second cholesteric liquid crystal molecules (231) in the reflective state reflect the fourth color light, and the first color and the fourth color are complementary colors, the driving method comprising: When the first color pixel unit (P1) is in the bright state, the first cholesteric liquid crystal molecules (131) in the corresponding region of the first color pixel unit (P1) are controlled to be in the reflective state, and the second cholesteric liquid crystal molecules (231) in the corresponding region of the first color pixel unit (P1) are controlled to be in the transparent state or the haze state, at this time, the first liquid crystal layer (13) in the corresponding region of the first color pixel unit (P1) reflects the first color light; when the first color pixel unit (P1) is in the dark state, the first cholesteric liquid crystal molecules (131) and the second cholesteric liquid crystal molecules (231) in the corresponding region of the first color pixel unit (P1) are controlled to be in the transparent state or the haze state, at this time, the light directly passes through the first liquid crystal layer (13) and the second liquid crystal layer (23); When the second color pixel unit (P2) is in the bright state, the second cholesteric liquid crystal molecules (231) in the corresponding region of the second color pixel unit (P2) are controlled to be in the reflective state, and the first cholesteric liquid crystal molecules (131) in the corresponding region of the second color pixel unit (P2) are controlled to be in the transparent state, the haze state or the reflective state, at this time, the second liquid crystal layer (23) in the corresponding region of the second color pixel unit (P2) reflects the second color light; when the second color pixel unit (P2) is in the dark state, the second cholesteric liquid crystal molecules (231) in the corresponding region of the second color pixel unit (P2) are controlled to be in the transparent state or the haze state, and the first cholesteric liquid crystal molecules (131) in the corresponding region of the second color pixel unit (P2) are controlled to be in the transparent state, the haze state or the reflective state, at this time, the light directly passes through the first liquid crystal layer (13) and the second liquid crystal layer (23); When the third color pixel unit (P3) is in the bright state, the second cholesteric liquid crystal molecules (231) in the corresponding region of the third color pixel unit (P3) are controlled to be in the reflective state, and the first cholesteric liquid crystal molecules (131) in the corresponding region of the third color pixel unit (P3) are controlled to be in the transparent state, the haze state or the reflective state, at this time, the second liquid crystal layer (23) in the corresponding region of the third color pixel unit (P3) reflects the third color light; when the third color pixel unit (P3) is in the dark state, the second cholesteric liquid crystal molecules (231) in the corresponding region of the third color pixel unit (P3) are controlled to be in the transparent state or the haze state, and the first cholesteric liquid crystal molecules (131) in the corresponding region of the third color pixel unit (P3) are controlled to be in the transparent state, the haze state or the reflective state, at this time, the light directly passes through the first liquid crystal layer (13) and the second liquid crystal layer (23).

10. The driving method of the reflective display device according to claim 8 or 9, wherein The driving method comprises: When the reflective display device displays the first color, all the first color pixel units (P1) are controlled to be in the bright state, and all the second color pixel units (P2) and the third color pixel units (P3) are controlled to be in the dark state; When the reflective display device displays the second color, all the first color pixel units (P1) and the third color pixel units (P3) are controlled to be in the dark state, and all the second color pixel units (P2) are controlled to be in the bright state; When the reflective display device displays the third color, all the first color pixel units (P1) and the second color pixel units (P2) are controlled to be in the dark state, and all the third color pixel units (P3) are controlled to be in the bright state; When the reflective display device displays a color picture, all the first color pixel units (P1), the second color pixel units (P2) and the third color pixel units (P3) display corresponding brightness respectively.

Images