Double-sided reflective display device and driving method

Abstract

The invention discloses a double-face reflection type display device and a driving method. The double-face reflection type display device comprises a dye liquid crystal box and a bistable liquid crystal box which are arranged in a mutually stacked mode. The dye liquid crystal box comprises a first opposite substrate, a first array substrate and a dye liquid crystal layer, and Bragg reflection layers corresponding to at least two of blue sub-pixels, green sub-pixels and red sub-pixels are arranged on the first array substrate. A first filter layer corresponding to the green sub-pixel and / or the red sub-pixel is arranged on the first opposite substrate; the bistable liquid crystal box comprises a second opposite substrate, a second array substrate and a bistable liquid crystal layer, the bistable liquid crystal layer comprises bistable liquid crystal molecules and color dye molecules mixed with the bistable liquid crystal molecules, and the bistable liquid crystal molecules reflect light rays with the same color as the color dye molecules in the reflection state. Therefore, double-sided color display can be realized only by adopting two liquid crystal boxes, color display is realized, and the thickness is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of displays, and particularly to a dual-sided reflective display device and a driving method thereof. Background Art

[0002] Display panels have the advantages of being thin, light, durable, and energy-saving and environment-friendly with low power consumption. However, they need to be used with a backlight, 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 that require a backlight. Therefore, in an outdoor environment with strong sunlight, the information on the electronic paper can still be clearly seen without the problem of viewing angles. Moreover, due to their advantages such as power saving, high reflectivity, and contrast ratio, electronic paper displays are now widely used in e-readers (such as e-books, e-newspapers) or other electronic components (such as price tags).

[0003] Existing electronic paper displays usually adopt E-Ink microcapsule technology (microcapsule electronic ink technology), SiPix microcup technology (microcup electrophoretic display technology), Bridgestone electronic liquid powder technology, bistable liquid crystal display (Cholesteric Liquid Crystal Display, CLCD) technology, microelectromechanical systems (MEMS) technology, or electrowetting technology. However, the existing electronic paper display technology is not as mature as liquid crystal display technology, with low mass production efficiency and relatively high manufacturing costs. Moreover, existing electronic paper displays can only achieve black-and-white or single-color displays.

[0004] In the existing dual-sided reflective display device using bistable liquid crystals, due to the requirements of the pitch of bistable liquid crystals, bistable liquid crystals with one pitch can only reflect one color and transmit light of other colors. Therefore, most of the dual-sided reflective display devices with a single layer of bistable liquid crystals are displayed in the form of yellow background with black characters, or black background with yellow characters, black background with red characters, or red background with black characters, etc., and cannot achieve white background display like a book, which greatly limits their product applications; moreover, the color of the light reflected by bistable liquid crystals is poor, affecting the display effect. If white display or color display needs to be achieved, the dual-sided reflective display device needs to use three layers of bistable liquid crystal cells to reflect red / green / blue light respectively to achieve white display and color display. However, the three-layer bistable liquid crystal cell not only has a larger cell thickness and higher power consumption, but also has a complex process and high cost. If dual-sided reflective display needs to be achieved, the structure of the dual-sided reflective display device will be more complex and the thickness will be thicker. Summary of the Invention

[0005] In order to overcome the disadvantages and deficiencies existing in the prior art, the purpose of the present invention is to provide a double-sided reflective display device and a driving method, so as to solve the problems that in the prior art, an electronic paper display can only achieve a single color or the thickness of a full-color display box is relatively thick.

[0006] The purpose of the present invention is achieved by the following technical solutions: The present invention provides a double-sided reflective display device, including a dye liquid crystal cell and a bistable liquid crystal cell which are stacked on each other. The dye liquid crystal cell is close to the first surface of the double-sided reflective display device, and the bistable liquid crystal cell is close to the second surface of the double-sided reflective display device; The dye liquid crystal cell includes a first counter substrate, a first array substrate disposed opposite to the first counter substrate, and a dye liquid crystal layer located between the first counter substrate and the first array substrate. The dye liquid crystal cell has a plurality of first pixel units distributed in an array. Among the plurality of first pixel units, there are blue sub-pixels, green sub-pixels, and red sub-pixels. A first pixel electrode and a Bragg reflection layer are provided on the first array substrate. At least two of the blue sub-pixels, the green sub-pixels, and the red sub-pixels correspond to the Bragg reflection layer. A first filter layer corresponding to the green sub-pixel and / or the red sub-pixel is provided on the first counter substrate. A first common electrode is provided on the first counter substrate to cooperate with the first pixel electrode; The bistable liquid crystal cell includes a second counter substrate, a second array substrate disposed opposite to the second counter substrate, and a bistable liquid crystal layer located between the second counter substrate and the second array substrate. The bistable liquid crystal layer includes bistable liquid crystal molecules and color dye molecules mixed with the bistable liquid crystal molecules. The bistable liquid crystal molecules reflect light of the same color as the color dye molecules in the reflective state. The bistable liquid crystal cell has a plurality of second pixel units distributed in an array. Among the plurality of second pixel units, there are a first sub-pixel corresponding to the blue sub-pixel, a second sub-pixel corresponding to the green sub-pixel, and a third sub-pixel corresponding to the red sub-pixel. A second pixel electrode is provided on the second array substrate. A second common electrode is provided on the second counter substrate to cooperate with the second pixel electrode.

[0007] Further, a second filter layer corresponding to two of the first sub-pixel, the second sub-pixel, and the third sub-pixel is provided on the second array substrate.

[0008] Further, the bistable liquid crystal molecules reflect red light in the reflective state, and the color dye molecules are red dye molecules; The Bragg reflection layer includes a long-pass filter and a short-pass filter. The blue sub-pixel corresponds to the long-pass filter, and the green sub-pixel corresponds to the short-pass filter. The long-pass filter can transmit red and green light and reflect blue light, and the short-pass filter can transmit blue light and reflect red and green light; The first filter layer includes a green filter layer corresponding to the green sub-pixel, and the second filter layer includes a blue filter layer corresponding to the first sub-pixel and a green filter layer corresponding to the second sub-pixel.

[0009] Further, the bistable liquid crystal molecules reflect blue light in the reflective state, and the color dye molecules are blue dye molecules; The Bragg reflection layer includes a short-pass filter. Both the green sub-pixel and the red sub-pixel correspond to the short-pass filter. The short-pass filter can transmit blue light and reflect red and green light; The first filter layer includes a green filter layer corresponding to the green sub-pixel and a red filter layer corresponding to the red sub-pixel, and the second filter layer includes a green filter layer corresponding to the second sub-pixel and a red filter layer corresponding to the third sub-pixel.

[0010] Further, the bistable liquid crystal molecules reflect green light in the reflective state, and the color dye molecules are green dye molecules; The Bragg reflection layer includes a long-pass filter and a short-pass filter. The blue sub-pixel corresponds to the long-pass filter, and the red sub-pixel corresponds to the short-pass filter. The long-pass filter can transmit red and green light and reflect blue light, and the short-pass filter can transmit blue light and reflect red and green light; The first filter layer includes a red filter layer corresponding to the red sub-pixel, and the second filter layer includes a blue filter layer corresponding to the first sub-pixel and a red filter layer corresponding to the third sub-pixel.

[0011] Further, a metal reflection layer corresponding to two of the first sub-pixel, the second sub-pixel, and the third sub-pixel is provided on the first array substrate. The metal reflection layer is disposed on the side of the Bragg reflection layer facing the bistable liquid crystal cell, and the second array substrate is in a transparent state in the regions corresponding to the first sub-pixel, the second sub-pixel, and the third sub-pixel.

[0012] Further, the bistable liquid crystal molecules reflect red light in the reflective state, and the color dye molecules are red dye molecules; The Bragg reflection layer includes a long-pass filter and a short-pass filter. The blue sub-pixel corresponds to the long-pass filter, and the green sub-pixel corresponds to the short-pass filter. The long-pass filter can transmit red and green light and reflect blue light, and the short-pass filter can transmit blue light and reflect red and green light; The first filter layer includes a blue filter layer corresponding to the blue sub-pixel and a green filter layer corresponding to the green sub-pixel, and the metal reflection layer corresponds to the first sub-pixel and the second sub-pixel.

[0013] Further, the bistable liquid crystal molecules reflect blue light in the reflective state, and the color dye molecules are blue dye molecules; The Bragg reflection layer includes a short-pass filter. Both the green sub-pixel and the red sub-pixel correspond to the short-pass filter. The short-pass filter can transmit blue light and reflect red and green light; The first filter layer includes a green filter layer corresponding to the green sub-pixel and a red filter layer corresponding to the red sub-pixel, and the metal reflection layer corresponds to the second sub-pixel and the third sub-pixel.

[0014] Further, the bistable liquid crystal molecules reflect green light in the reflective state, and the color dye molecules are green dye molecules; The Bragg reflection layer includes a long-pass filter and a short-pass filter. The blue sub-pixel corresponds to the long-pass filter, and the red sub-pixel corresponds to the short-pass filter. The long-pass filter can transmit red and green light and reflect blue light, and the short-pass filter can transmit blue light and reflect red and green light; The first filter layer includes a blue filter layer corresponding to the blue sub-pixel and a red filter layer corresponding to the red sub-pixel, and the metal reflection layer corresponds to the first sub-pixel and the third sub-pixel.

[0015] This application also provides a driving method for a double-sided reflective display device for driving the double-sided reflective display device as described above. The driving method includes: During double-sided display, control both the dye liquid crystal cell and the bistable liquid crystal cell to be turned on. The dye liquid crystal cell displays a color picture towards the first side, and the bistable liquid crystal cell displays a color picture towards the second side.

[0016] The beneficial effects of the present invention are as follows: By providing a Bragg reflection layer corresponding to at least two of the blue sub-pixels, green sub-pixels, and red sub-pixels on the first array substrate of the dye liquid crystal cell, and providing a first filter layer corresponding to the green sub-pixels and / or red sub-pixels on the first counter substrate, and combining with a bistable liquid crystal cell using bistable liquid crystal molecules and color dye molecules, the dual-sided reflective display device can achieve full-color reflective display on one side of the dye liquid crystal cell, and can achieve color reflective display on the side of the bistable liquid crystal cell. It not only realizes dual-sided color display, but also reduces the thickness. Brief Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of the dual-sided reflective display device in the initial state in Embodiment 1 of the present invention.

[0018] Figure 2 It is a schematic plan view of the first array substrate in Embodiment 1 of the present invention.

[0019] Figure 3 It is a schematic plan view of the second array substrate in Embodiment 1 of the present invention.

[0020] Figure 4 It is a transmittance curve diagram of different light rays by the long-pass filter and the short-pass filter in Embodiment 1 of the present invention.

[0021] Figure 5 It is a reflectance curve diagram of different incident angle light rays by the short-pass filter in Embodiment 1 of the present invention.

[0022] Figure 6 It is a reflectance curve diagram of different incident angle light rays by the long-pass filter in Embodiment 1 of the present invention.

[0023] Figure 7 It is a schematic diagram of the principle of the transformation of three states of the bistable liquid crystal in Embodiment 1 of the present invention.

[0024] Figure 8 It is a schematic diagram of the driving signal of the transformation of three states of the bistable liquid crystal in Embodiment 1 of the present invention.

[0025] Figure 9 It is one of the schematic structural diagrams of the dual-sided reflective display device in the black state in Embodiment 1 of the present invention.

[0026] Figure 10 It is another schematic structural diagram of the dual-sided reflective display device in the black state in Embodiment 1 of the present invention.

[0027] Figure 11 It is one of the schematic structural diagrams of the dual-sided reflective display device in the dual-sided full-color display state in Embodiment 1 of the present invention.

[0028] Figure 12 It is the second schematic structural diagram of the double-sided reflective display device in double-sided full-color display in Embodiment 1 of the present invention.

[0029] Figure 13 It is the schematic structural diagram of the double-sided reflective display device in the initial state in Embodiment 2 of the present invention.

[0030] Figure 14 It is the schematic structural diagram of the double-sided reflective display device in double-sided full-color display in Embodiment 2 of the present invention.

[0031] Figure 15 It is the schematic structural diagram of the double-sided reflective display device in the initial state in Embodiment 3 of the present invention.

[0032] Figure 16 It is the schematic structural diagram of the double-sided reflective display device in double-sided full-color display in Embodiment 3 of the present invention.

[0033] Figure 17 It is the schematic structural diagram of the double-sided reflective display device in the initial state in Embodiment 4 of the present invention.

[0034] Figure 18 It is the schematic structural diagram of the double-sided reflective display device in double-sided full-color display in Embodiment 4 of the present invention.

[0035] Figure 19 It is the schematic structural diagram of the double-sided reflective display device in the initial state in Embodiment 5 of the present invention.

[0036] Figure 20 It is the schematic plan view of the first array substrate in Embodiment 5 of the present invention.

[0037] Figure 21 It is the schematic structural diagram of the double-sided reflective display device in double-sided color display in Embodiment 5 of the present invention. Detailed Embodiments

[0038] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific embodiments, structures, features, and effects of the double-sided reflective display device and the driving method according to the present invention as follows: [Embodiment 1] Figure 1 It is the schematic structural diagram of the double-sided reflective display device in the initial state in Embodiment 1 of the present invention. Figure 2 It is the schematic plan view of the first array substrate in Embodiment 1 of the present invention. Figure 3 It is the schematic plan view of the second array substrate in Embodiment 1 of the present invention.

[0039] As Figures 1 to 3As shown in the figure, a double-sided reflective display device provided by Embodiment 1 of the present invention includes a dye liquid crystal cell 10 and a bistable liquid crystal cell 20 which are stacked on each other. The dye liquid crystal cell 10 is close to the first surface of the double-sided reflective display device, and the bistable liquid crystal cell 20 is close to the second surface of the double-sided reflective display device. For example, the first surface is the upper side of the double-sided reflective display device, and the second surface is the lower side of the double-sided reflective display device.

[0040] The dye liquid crystal cell 10 includes a first counter substrate 11, a first array substrate 12 disposed opposite to the first counter substrate 11, and a dye liquid crystal layer 13 located between the first counter substrate 11 and the first array substrate 12. The first counter substrate 11 is close to the first surface of the dye liquid crystal cell 10, and the first array substrate 12 is close to the second surface of the dye liquid crystal cell 10. The dye liquid crystal cell 10 has a plurality of first pixel units P1 distributed in an array. Among the plurality of first pixel units P1, there are a blue sub-pixel P11, a green sub-pixel P12, and a red sub-pixel P13. A first pixel electrode 121 and a Bragg reflection layer are provided on the first array substrate 12, and at least two of the blue sub-pixel P11, the green sub-pixel P12, and the red sub-pixel P13 correspond to the Bragg reflection layer. A first filter layer is provided on the first counter substrate 11, and the green sub-pixel P12 and / or the red sub-pixel P13 correspond to the first filter layer. A first common electrode 111 is provided on the first counter substrate 11 to cooperate with the first pixel electrode 121. The first common electrode 111 is a planar electrode that entirely covers the first counter substrate 11, and the first pixel electrode 121 is a block electrode corresponding to the first pixel unit P1 one by one.

[0041] The dye liquid crystal layer 13 includes liquid crystal molecules 131 and dye molecules 132 that are mixed with each other, that is, the dye liquid crystal layer 13 is doped with dye molecules 132. The dye molecules 132 are, for example, black dye molecules. The liquid crystal molecules 131 in the dye liquid crystal layer 13 are positive liquid crystal molecules (liquid crystal molecules with positive dielectric anisotropy), such as Figure 1As shown, in the initial state, the liquid crystal molecules 131 and the dye molecules 132 are aligned parallel to the first counter substrate 11 and the first array substrate 12. The alignment directions of the dye liquid crystal layer 13 on the side close to the first counter substrate 11 and the side close to the first array substrate 12 are perpendicular to each other. That is, the liquid crystal molecules 131 and the dye molecules 132 in the dye liquid crystal layer 13 are in a state of being twisted by 90° from bottom to top to form a TN display mode. Among them, the light absorption ability of the long axis of the dye molecule 132 is greater than that of the short axis. The dye molecule 132 has the characteristic that the ability to absorb light by the long axis is strong and the ability to absorb light by the short axis is very weak. Therefore, it is possible to control the grayscale brightness without additionally setting polarizers on both sides of the liquid crystal cell. Since the liquid crystal molecules 131 and the dye molecules 132 in the dye liquid crystal layer 13 are in a state of being twisted by 90° from bottom to top, the liquid crystal cell in this embodiment is in a closed state, that is, a dark state, in the initial state.

[0042] As Figure 2 shown, a plurality of first scan lines 101, a plurality of first data lines 102, and a plurality of first thin film transistors 103 are provided on the first array substrate 12. The first array substrate 12 is provided with a first pixel electrode 121 and a first thin film transistor 103 in the area corresponding to each first pixel unit P1. 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. Among them, 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 on the same layer and electrically connected. The first gate and the first active layer are separated by an insulating layer. The first source is electrically connected to the first data line 102, and the first drain is electrically connected to the first pixel electrode 121 through a contact hole.

[0043] Furthermore, a first black matrix 112 is also provided on the first counter substrate 11. The first black matrix 112 is used to separate the plurality of first pixel units P1 from each other, thereby avoiding the problems of light leakage or color mixing between the plurality of first pixel units P1. In this embodiment, the first counter substrate 11 is in a fully transparent state (that is, light can completely pass through the first counter substrate 11, and basically does not reflect or absorb light) in the areas of the blue sub-pixel P11 and the red sub-pixel P13. The areas of the blue sub-pixel P11 and the red sub-pixel P13 on the first counter substrate 11 are covered by a planarization layer (OC material).

[0044] The bistable liquid crystal cell 20 includes a second counter substrate 21, a second array substrate 22 disposed opposite to the second counter substrate 21, and a bistable liquid crystal layer 23 located between the second counter substrate 21 and the second array substrate 22. The second counter substrate 21 is close to the first surface of the bistable liquid crystal cell 20, and the second array substrate 22 is close to the second surface of the bistable liquid crystal cell 20, that is, the second counter substrate 21 and the first array substrate 12 are bonded to each other. The bistable liquid crystal layer 23 includes bistable liquid crystal molecules 231 and color dye molecules 232 mixed with the bistable liquid crystal molecules 231. The color dye molecules 232 rotate synchronously with the bistable liquid crystal molecules 231. The bistable liquid crystal molecules 231 reflect light of the same color as the color dye molecules 232 in the reflective state. The bistable liquid crystal cell 20 has a plurality of second pixel units P2 arranged in an array. The second pixel units P2 correspond to the first pixel units P1 one by one. Among the plurality of second pixel units P2, there are a first sub-pixel P21 corresponding to the blue sub-pixel P11, a second sub-pixel P22 corresponding to the green sub-pixel P12, and a third sub-pixel P23 corresponding to the red sub-pixel P13. A second pixel electrode 221 is provided on the second array substrate 22, and the second pixel electrode 221 corresponds to the second pixel unit P2 one by one. A second common electrode 211 cooperating with the second pixel electrode 221 is provided on the second counter substrate 21. The second pixel electrode 221 is a block-shaped electrode corresponding to the second pixel unit P2, and the second common electrode 211 is a planar electrode covering the entire second counter substrate 21.

[0045] As Figure 3 shown, a plurality of second scan lines 201, a plurality of second data lines 202, and a plurality of second thin film transistors 203 are provided on the second array substrate 22. The second array substrate 22 is provided with a second pixel electrode 221 and a second thin film transistor 203 in the area corresponding to each second pixel unit P2. 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. Among them, 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 separated by an insulating layer. The second source is electrically connected to the second data line 202, and the second drain is electrically connected to the second pixel electrode 221 through a contact hole.

[0046] In this embodiment, a second filter layer corresponding to two of the first sub-pixel P21, the second sub-pixel P22, and the third sub-pixel P23 is provided on the second array substrate 22. Among them, the first filter layer and the second filter layer can be a filter gap layer or a color resist material layer for filtering light.

[0047] In this embodiment, the bistable liquid crystal molecules 231 (with a pitch of 290 - 580 μm) reflect red light in the reflective state, and the color dye molecules 232 are red dye molecules. The Bragg reflection layer includes a long-pass filter 141 and a short-pass filter 142. The blue sub-pixel P11 corresponds to the long-pass filter 141, and the green sub-pixel P12 corresponds to the short-pass filter 142. The long-pass filter 141 can transmit red and green light and reflect blue light, and the short-pass filter 142 can transmit blue light and reflect red and green light. The first filter layer includes a green filter layer corresponding to the green sub-pixel P12. The first counter substrate 11 is in a transparent state in the regions corresponding to the blue sub-pixel P11 and the red sub-pixel P13. That is, the blue sub-pixel P11 can reflect blue light through the long-pass filter 141, the green sub-pixel P12 reflects green light through the short-pass filter 142 and the green filter layer, and the red sub-pixel P13 reflects red light through the bistable liquid crystal molecules 231 and the red dye molecules, so that the dye liquid crystal cell 10 can achieve full-color reflective display towards the first surface.

[0048] The second filter layer includes a blue filter layer corresponding to the first sub-pixel P21 and a green filter layer corresponding to the second sub-pixel P22. The second array substrate 22 is in a transparent state in the region corresponding to the third sub-pixel P23. That is, the first sub-pixel P21 reflects blue light through the blue filter layer and the long-pass filter 141, the second sub-pixel P22 reflects green light through the short-pass filter 142 and the green filter layer, and the third sub-pixel P23 reflects red light through the bistable liquid crystal molecules 231 and the red dye molecules, so that the bistable liquid crystal cell 20 can achieve full-color reflective display towards the second surface. Among them, the first filter layer includes a green light gap layer 113g corresponding to the green sub-pixel P12, or the first filter layer includes a green color resist layer 223g corresponding to the green sub-pixel P12. The second filter layer includes a blue color resist layer 223b corresponding to the first sub-pixel P21 and a green color resist layer 223g corresponding to the second sub-pixel P22, or the second filter layer includes a blue light gap layer 113b ( Figure 19 ) corresponding to the first sub-pixel P21 and a green light gap layer 113g corresponding to the second sub-pixel P22. The green light gap layer 113g has multiple slits with a width of 500 - 570 nm. The green light gap layer 113g can transmit green light and absorb red and blue light; the blue light gap layer 113b has multiple slits with a width of 420 - 470 nm. The blue light gap layer 113b can transmit blue light and absorb red and green light.

[0049] Further, a second black matrix 222 is further disposed on the second array substrate 22. The second black matrix 222 is used to space apart a plurality of second pixel units P2 from each other, thereby avoiding light leakage or color mixing problems between the plurality of second pixel units P2. In this embodiment, the second array substrate 22 is in a fully transparent state in the region of the third sub-pixel P23 (i.e., light can completely pass through the second array substrate 22, and basically does not reflect or absorb light), and the region of the second array substrate 22 in the third sub-pixel P23 is covered by a planarization layer (OC material).

[0050] Among them, the short-pass filter 141 (Short-pass filter, SPF) and the long-pass filter 142 (Long-pass filter, LPF) both belong to the distributed Bragg reflector (DBR). The short-pass filter 142 can transmit blue light with a wavelength below 490 nm and reflect red and green light with a wavelength between 500 and 680 nm. The long-pass filter 141 can transmit red and green light with a wavelength between 500 and 680 nm and reflect blue light with a wavelength below 490 nm. The distributed Bragg reflector (DBR) is a reflector used in a waveguide. The long-pass filter 141 and the short-pass filter 142 use SiO₂ (silicon dioxide) and TiO₂ (titanium dioxide) as alternating materials, and two different band-pass DBRs are achieved by adjusting the thickness and logarithm of the film layer. When light passes through different media, it will be reflected at the interface, and the magnitude of the reflectivity is related to the refractive index between the media. Therefore, if we stack different refractive index thin films alternately and periodically, when light passes through these different refractive index thin films, due to the phase angle change of the light reflected from each layer, constructive interference occurs, and then they combine with each other to obtain strong reflected light. If the number of multi-film layers becomes very large and the difference between the refractive indices n1, n2, n3... of the thin films becomes very small, the light is like traveling in the same medium, and the reflection coefficient becomes very small. Due to the multiple interference of light, the interference effect is very obvious, so the selection of wavelength becomes very sensitive. When using a situation similar to a grating, such a periodic structure is called a distributed Bragg reflector.

[0051] Figure 4 is the transmittance curve graph of the long-pass filter and the short-pass filter for different lights in the first embodiment of the present invention. As Figure 4 shown, in the figure, the curves R, G, and B respectively represent the wavelengths of red, green, and blue lights, and the curves L and S respectively represent the transmittances of the long-pass filter 141 and the short-pass filter 142 for lights with different wavelengths. From Figure 4It can be seen that the long-pass filter 141 has a good transmission effect on blue light with a wavelength below 490 nm, and the transmittance can reach more than 95%; the short-pass filter 142 has a good transmission effect on red and green light with a wavelength of 500 - 680 nm, and the transmittance can reach more than 95%.

[0052] Figure 5 It is the reflectivity curve diagram of the short-pass filter for light with different incident angles in the first embodiment of the present invention. Figure 6 It is the reflectivity curve diagram of the long-pass filter for light with different incident angles in the first embodiment of the present invention, as Figure 5 and Figure 6 shown. Among them, the curves S1, S2, S3, and S4 respectively represent the reflectivities of the short-pass filter 142 for white light with incident angles of 0°, 20°, 40°, and 60°, and the curves L1, L2, L3, and L4 respectively represent the reflectivities of the long-pass filter 141 for white light with incident angles of 0°, 20°, 40°, and 60°. From Figure 5 and Figure 6 it can be seen that when the incident light angle is less than 40°, the short-pass filter 142 has a reflectivity as high as 98% for red and green light with a wavelength of 490 - 700 nm, which helps to reflect and utilize red and green light. At the same time, the long-pass filter 141 also has a reflectivity of 94% for blue light with a wavelength of 400 - 500 nm, reducing the blue light emission rate and improving the reflection and utilization of blue light.

[0053] Among them, the bistable liquid crystal molecules 231 have three stable textures: the P state (Planar, planar texture state, reflection state), the FC state (Focal Conic, focal cone state, fog state), and the H state (transparent state). In the P state, the reflection spectrum of the bistable liquid crystal molecules 231 is in the non-visible spectral band, and the bistable liquid crystal molecules 231 reflect non-visible light. The specific light they reflect can be set according to the pitch of the bistable liquid crystal molecules 231, and the reflected wavelength satisfies the condition of λ = n * P (λ is the wavelength, P is the pitch, and n is the refractive index). When in the FC state, the bistable liquid crystal molecules 231 no longer reflect the above light, and the light can be scattered and transmitted through the bistable liquid crystal molecules 231. When in the H state, the bistable liquid crystal molecules 231 also no longer reflect the above light, and the light can be directly transmitted through the bistable liquid crystal molecules 231 without scattering the light. Under the action of a certain electric field, these three states can be converted into each other.

[0054] Figure 7 It is the schematic diagram of the principle of the transformation of the three states of the bistable liquid crystal in the present invention. Figure 8 It is the schematic diagram of the drive signal for the transformation of the three states of the bistable liquid crystal in the present invention. As Figure 7 and Figure 8As shown, a common voltage Vcom is applied to the first common electrode 111, and a first driving voltage V1 is continuously applied to the first pixel electrode 121. There is a voltage difference (about 30V) between the common voltage Vcom and the first driving voltage V1. A strong vertical electric field will be formed between the first common electrode 111 and the first pixel electrode 121, and the bistable liquid crystal molecules 231 will rotate and stop in the H state (transparent state). A common voltage Vcom is applied to the first common electrode 111, and a second driving voltage V2 is applied to the first pixel electrode 121. There is a voltage difference (for example, 30V) between the second driving voltage V2 and the common voltage Vcom, and the second driving voltage V2 gradually becomes the same as the common voltage Vcom within the first preset time, that is, the second driving voltage V2 first has a large voltage difference from the common voltage Vcom and then slowly decreases to be the same as the common voltage Vcom. Therefore, a strong vertical electric field will first be formed between the first common electrode 111 and the first pixel electrode 121, and then the vertical electric field slowly disappears, causing the bistable liquid crystal in the bistable liquid crystal molecules 231 to rotate and stop in the FC state, which is a scattering state and has a light scattering effect. A common voltage Vcom is applied to the first common electrode 111, and a third driving voltage V3 is applied to the first pixel electrode 121. There is a voltage difference (for example, 30V) between the third driving voltage V3 and the common voltage Vcom, and the third driving voltage V3 directly becomes the same as the common voltage Vcom at the second preset time, and the second preset time is less than the first preset time, that is, the third driving voltage V3 first has a large voltage difference from the common voltage Vcom and then quickly decreases to be the same as the common voltage Vcom. Therefore, a strong vertical electric field will first be formed between the first common electrode 111 and the first pixel electrode 121, and then the vertical electric field quickly disappears, causing the bistable liquid crystal molecules 231 to rotate and stop in the P state, which is a reflective state. Among them, the common voltage Vcom is a DC common voltage signal of 0V, and the first driving voltage V1, the second driving voltage V2, and the third driving voltage V3 are all AC voltage signals that fluctuate up and down with the DC common voltage signal. The arrangement directions of the bistable liquid crystals are different, and the reflected visible light spectra are different, and the remaining spectra are transmitted. The P state and the FC state do not require voltage to maintain. The reflection spectral band (Δλ) of the bistable liquid crystal molecules is proportional to the pitch (Po) of the bistable liquid crystal molecules and the average refractive index (n = (ne + no) / 2), and the formula is: Δλ = nPo. Therefore, bistable liquid crystal molecules with different pitches can reflect light of different colors in the reflective state.

[0055] Among them, the first counter substrate 11, the first array substrate 12, the second counter substrate 21, and the second array substrate 22 can be made of transparent substrates such as glass, acrylic, and polycarbonate. The materials of the first common electrode 111, the first pixel electrode 121, the second common electrode 221, and the second pixel electrode 221 can be made of transparent electrodes such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0056] This embodiment also provides a driving method for a dual-sided reflective display device, which is used to drive the dual-sided reflective display device as described above. The driving method includes: During dual-sided display, control both the dye liquid crystal cell 10 and the bistable liquid crystal cell 20 to be turned on. The dye liquid crystal cell 10 displays a color picture towards the first side, and the bistable liquid crystal cell 20 displays a color picture towards the second side.

[0057] Specifically, Figure 9 is one of the schematic structural diagrams of the dual-sided reflective display device in the black state in Embodiment 1 of the present invention. Figure 10 is the second schematic structural diagram of the dual-sided reflective display device in the black state in Embodiment 1 of the present invention. As Figure 9 and Figure 10 shown, when both the first pixel unit P1 and the second pixel unit P2 are in the black state, no electrical signal or the same electrical signal is applied to both the first common electrode 111 and the first pixel electrode 121, so that basically no vertical electric field is formed between the first common electrode 111 and the first pixel electrode 121. The liquid crystal molecules 131 and dye molecules 132 in the dye liquid crystal layer 13 maintain their initial lying posture and are twisted from top to bottom, and light cannot pass through the dye liquid crystal layer 13 and is absorbed by the dye liquid crystal layer 13. And the bistable liquid crystal molecules 231 corresponding to the first sub-pixel P21 and the second sub-pixel P22 are in the reflective state, and the bistable liquid crystal molecules 231 corresponding to the third sub-pixel P23 are in the fog state ( Figure 9 ) or the transparent state ( Figure 10 ). The light of the first sub-pixel P21 and the second sub-pixel P22 is absorbed by the second filter layer and the color dye molecules 232 in the bistable liquid crystal layer 23, and the light of the third sub-pixel P23 is absorbed by the dye liquid crystal layer 13.

[0058] Figure 11 is one of the schematic structural diagrams of the dual-sided reflective display device in the dual-sided full-color display state in Embodiment 1 of the present invention. Figure 12 is the second schematic structural diagram of the dual-sided reflective display device in the dual-sided full-color display state in Embodiment 1 of the present invention. As Figure 11 and Figure 12 shown, when both the first pixel unit P1 and the second pixel unit P2 are in the bright state, a common voltage signal is applied to the first common electrode 111, and a corresponding gray-scale electrical signal is applied to the first pixel electrode 121, so that a vertical electric field is basically formed between the first common electrode 111 and the first pixel electrode 121. The liquid crystal molecules 131 and dye molecules 132 in the dye liquid crystal layer 13 are in the standing posture, and light can pass through the dye liquid crystal layer 13. And the bistable liquid crystal molecules 231 corresponding to the first sub-pixel P21 and the second sub-pixel P22 are in the fog state ( Figure 11 ) or the transparent state ( Figure 12) When the bistable liquid crystal molecules 231 corresponding to the third sub-pixel P23 are in the reflective state. Among them, the blue sub-pixel P11 can reflect blue light through the long-pass filter 141, the green sub-pixel P12 reflects green light through the short-pass filter 142 and the green filter layer, and the red sub-pixel P13 reflects red light through the bistable liquid crystal molecules 231 and red dye molecules, so that the dye liquid crystal cell 10 can achieve full-color reflective display towards the first side. The first sub-pixel P21 reflects blue light through the blue filter layer and the long-pass filter 141, the second sub-pixel P22 reflects green light through the short-pass filter 142 and the green filter layer, and the third sub-pixel P23 reflects red light through the bistable liquid crystal molecules 231 and red dye molecules, so that the bistable liquid crystal cell 20 can achieve full-color reflective display towards the second side.

[0059] [Embodiment 2] Figure 13 It is a schematic structural diagram of the double-sided reflective display device in the initial state in the second embodiment of the present invention. Figure 14 It is a schematic structural diagram of the double-sided reflective display device in the double-sided full-color display in the second embodiment of the present invention. As Figure 13 and Figure 14 shown, the double-sided reflective display device and the driving method provided in the second embodiment of the present invention are basically the same as those in the first embodiment ( Figures 1 to 12 ), and the difference lies in: In this embodiment, the bistable liquid crystal molecules 231 (pitch 190 - 340um) reflect blue light in the reflective state, and the color dye molecules 232 are blue dye molecules. The Bragg reflection layer includes a short-pass filter 142, and both the green sub-pixel P12 and the red sub-pixel P13 correspond to the short-pass filter 142. The short-pass filter 142 can transmit blue light and reflect red and green light. The first filter layer includes a green filter layer corresponding to the green sub-pixel P12 and a red filter layer corresponding to the red sub-pixel P13. The first counter substrate 11 is in a transparent state in the area corresponding to the blue sub-pixel P11, that is, the blue sub-pixel P11 can reflect blue light through the bistable liquid crystal molecules 231 and blue dye molecules, the green sub-pixel P12 reflects green light through the short-pass filter 142 and the green filter layer, and the red sub-pixel P13 reflects red light through the short-pass filter 142 and the red filter layer, so that the dye liquid crystal cell 10 can achieve full-color reflective display towards the first side.

[0060] The second filter layer includes a green filter layer corresponding to the second sub-pixel P22 and a red filter layer corresponding to the third sub-pixel P23. The area on the second array substrate 22 corresponding to the first sub-pixel P21 is in a transparent state, that is, the first sub-pixel P21 reflects blue light through the bistable liquid crystal molecules 231 and blue dye molecules. The second sub-pixel P22 reflects green light through the short-pass filter 142 and the green filter layer. The third sub-pixel P23 reflects red light through the short-pass filter 142 and the red filter layer, so that the bistable liquid crystal cell 20 can achieve full-color reflective display towards the second side. Among them, the first filter layer includes a green light gap layer 113g corresponding to the green sub-pixel P12 and a red light gap layer 113r corresponding to the red sub-pixel P13. Alternatively, the first filter layer includes a green color resist layer 223g corresponding to the green sub-pixel P12 and a red color resist layer 223r corresponding to the red sub-pixel P13. The second filter layer includes a green color resist layer 223g corresponding to the second sub-pixel P22 and a red color resist layer 223r corresponding to the third sub-pixel P23. Alternatively, the second filter layer includes a green light gap layer 113g corresponding to the second sub-pixel P22 and a red light gap layer 113r corresponding to the third sub-pixel P23. The green light gap layer 113g has a plurality of slits with a width of 500-570 nm, and the green light gap layer 113g can transmit green light and absorb red and blue light. The red light gap layer 113r has a plurality of slits with a width of 630-780 nm, and the red light gap layer 113r can transmit red light and absorb blue and green light.

[0061] 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 will not be elaborated here.

[0062] [Embodiment 3] Figure 15 It is a schematic structural diagram of the double-sided reflective display device in the initial state in Embodiment 3 of the present invention. Figure 16 It is a schematic structural diagram of the double-sided reflective display device during double-sided full-color display in Embodiment 3 of the present invention. As Figure 15 and Figure 16 shown, the double-sided reflective display device and driving method provided in Embodiment 3 of the present invention are basically the same as those of the double-sided reflective display device and driving method in Embodiment 1 ( Figures 1 to 12 ), the difference is that: In this embodiment, the bistable liquid crystal molecules 231 (pitch: 230 - 490 μm) reflect green light in the reflective state, and the color dye molecules 232 are green dye molecules. The Bragg reflection layer includes a long-pass filter 141 and a short-pass filter 142. The blue sub-pixel P11 corresponds to the long-pass filter 141, and the red sub-pixel P13 corresponds to the short-pass filter 142. The long-pass filter 141 can transmit red and green light and reflect blue light, and the short-pass filter 142 can transmit blue light and reflect red and green light. The first filter layer includes a red filter layer corresponding to the red sub-pixel P13. The first counter substrate 11 is in a transparent state in the regions corresponding to the blue sub-pixel P11 and the green sub-pixel P12. That is, the blue sub-pixel P11 can reflect blue light through the long-pass filter 141, the green sub-pixel P12 reflects green light through the bistable liquid crystal molecules 231 and the green dye molecules, and the red sub-pixel P13 reflects red light through the short-pass filter 142 and the red filter layer, so that the dye liquid crystal cell 10 can achieve full-color reflective display towards the first surface.

[0063] The second filter layer includes a blue filter layer corresponding to the first sub-pixel P21 and a red filter layer corresponding to the third sub-pixel P23. The second array substrate 22 is in a transparent state in the region corresponding to the second sub-pixel P22. That is, the first sub-pixel P21 reflects blue light through the blue filter layer and the long-pass filter 141, the second sub-pixel P22 reflects green light through the bistable liquid crystal molecules 231 and the green dye molecules, and the third sub-pixel P23 reflects red light through the short-pass filter 142 and the red filter layer, so that the bistable liquid crystal cell 20 can achieve full-color reflective display towards the second surface. Among them, the first filter layer includes a red light gap layer 113r corresponding to the red sub-pixel P13, or the first filter layer includes a red color resist layer 223r corresponding to the red sub-pixel P13. The second filter layer includes a blue color resist layer 223b corresponding to the first sub-pixel P21 and a red color resist layer 223r corresponding to the third sub-pixel P23, or the second filter layer includes a blue light gap layer 113b corresponding to the first sub-pixel P21 and a red light gap layer 113r corresponding to the third sub-pixel P23. The red light gap layer 113r has multiple slits with a width of 630 - 780 nm, and the red light gap layer 113r can transmit red light and absorb blue and green light; the blue light gap layer 113b has multiple slits with a width of 420 - 470 nm, and the blue light gap layer 113b can transmit blue light and absorb red and green light.

[0064] 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 will not be elaborated here.

[0065] [Embodiment 4] Figure 17 It is a schematic structural diagram of the double-sided reflective display device in the initial state in Embodiment 4 of the present invention.Figure 18 This is a schematic structural diagram of the dual-sided reflective display device in the case of dual-sided full-color display in Embodiment 4 of the present invention. As Figure 17 and Figure 18 shown, the dual-sided reflective display device and the driving method provided in Embodiment 4 of the present invention are basically the same as those in Embodiment 1 ( Figures 1 to 12 ), Embodiment 2 ( Figures 13 to 14 ), and Embodiment 3 ( Figures 15 to 16 ). The differences are as follows: In this embodiment, the Bragg reflection layer includes a long-pass filter 141 and a short-pass filter 142. The blue sub-pixel P11 corresponds to the long-pass filter 141, and both the green sub-pixel P12 and the red sub-pixel P13 correspond to the short-pass filter 142. The first filter layer includes a green filter layer corresponding to the green sub-pixel P12 and a red filter layer corresponding to the red sub-pixel P13. The first counter substrate 11 is in a transparent state in the area corresponding to the blue sub-pixel P11. That is, the blue sub-pixel P11 can reflect blue light through the long-pass filter 141, the green sub-pixel P12 reflects green light through the short-pass filter 142 and the green filter layer, and the red sub-pixel P13 reflects red light through the short-pass filter 142 and the red filter layer. Thus, the dye liquid crystal cell 10 can achieve full-color reflection display towards the first surface. Thus, the picture displayed by the dye liquid crystal cell 10 towards the first surface and the picture displayed by the bistable liquid crystal cell 20 towards the second surface will not interfere with each other, and different or uncorrelated pictures can be displayed respectively.

[0066] Those skilled in the art should understand that the remaining structures and working principles of this embodiment are the same as those in Embodiment 1, Embodiment 2, and Embodiment 3, and will not be elaborated here.

[0067] [Embodiment 5] Figure 19 This is a schematic structural diagram of the dual-sided reflective display device in the initial state in Embodiment 5 of the present invention. Figure 20 This is a schematic plan view of the first array substrate in Embodiment 5 of the present invention. Figure 21 This is a schematic structural diagram of the dual-sided reflective display device in the case of dual-sided color display in Embodiment 5 of the present invention. As Figure 19 and Figure 21 shown, the dual-sided reflective display device and the driving method provided in Embodiment 5 of the present invention are basically the same as those in Embodiment 1 ( Figures 1 to 12 ). The differences are as follows: In this embodiment, a metal reflection layer corresponding to two of the first sub-pixel P21, the second sub-pixel P22, and the third sub-pixel P23 is provided on the first array substrate 12. The metal reflection layer is disposed on the side of the Bragg reflection layer facing the bistable liquid crystal cell 20. The second array substrate 22 is in a transparent state in the regions corresponding to the first sub-pixel P21, the second sub-pixel P22, and the third sub-pixel P23. Optionally, the first pixel electrode 121 includes a reflective pixel electrode 121a and a transparent pixel electrode 121b. The reflective pixel electrode 121a is a metal reflection layer (for example, made of aluminum or silver), thereby reducing the cell thickness. That is, in this embodiment, by providing a metal reflection layer on the first array substrate 12 to replace the second filter layer on the second array substrate 22, the dual-sided reflective display device can achieve full-color reflective display on the first side and display white and single-color images on the second side.

[0068] In this embodiment, the bistable liquid crystal molecules 231 (pitch: 290 - 580 um) reflect red light in the reflective state, and the color dye molecules 232 are red dye molecules. The Bragg reflection layer includes a long-pass filter 141 and a short-pass filter 142. The blue sub-pixel P11 corresponds to the long-pass filter 141, and the green sub-pixel P12 corresponds to the short-pass filter 142. The long-pass filter 141 can transmit red and green light and reflect blue light, and the short-pass filter 142 can transmit blue light and reflect red and green light. The first filter layer includes a blue filter layer corresponding to the blue sub-pixel P11 and a green filter layer corresponding to the green sub-pixel P12. The first counter substrate 11 is in a transparent state in the region corresponding to the red sub-pixel P13. That is, the blue sub-pixel P11 can reflect blue light through the long-pass filter 141 and the blue filter layer, the green sub-pixel P12 reflects green light through the short-pass filter 142 and the green filter layer, and the red sub-pixel P13 reflects red light through the bistable liquid crystal molecules 231 and the red dye molecules, so that the dye liquid crystal cell 10 can achieve full-color reflective display facing the first side. The metal reflection layer corresponds to the first sub-pixel P21 and the second sub-pixel P22. That is, both the first sub-pixel P21 and the second sub-pixel P22 reflect white light through the metal reflection layer, and the third sub-pixel P23 reflects red light through the bistable liquid crystal molecules 231 and the red dye molecules, so that the bistable liquid crystal cell 20 can achieve a red-and-white image display facing the second side, such as red characters on a white background.

[0069] In one embodiment, the bistable liquid crystal molecules 231 (pitch: 190 - 340 μm) reflect blue light in the reflective state, and the color dye molecules 232 are blue dye molecules. The Bragg reflection layer includes a short-pass filter 142. The green sub-pixel P12 and the red sub-pixel P13 both correspond to the short-pass filter 142. The short-pass filter 142 can transmit blue light and reflect red and green light. The first filter layer includes a green filter layer corresponding to the green sub-pixel P12 and a red filter layer corresponding to the red sub-pixel P13. The first counter substrate 11 is in a transparent state in the area corresponding to the blue sub-pixel P11. That is, the blue sub-pixel P11 can reflect blue light through the bistable liquid crystal molecules 231 and the blue dye molecules. The green sub-pixel P12 reflects green light through the short-pass filter 142 and the green filter layer. The red sub-pixel P13 reflects red light through the short-pass filter 142 and the red filter layer. Thus, the dye liquid crystal cell 10 can achieve full-color reflective display toward the first surface. The metal reflection layer corresponds to the second sub-pixel P22 and the third sub-pixel P23. That is, the second sub-pixel P22 and the third sub-pixel P23 both reflect white light through the metal reflection layer. The first sub-pixel P21 reflects blue light through the bistable liquid crystal molecules 231 and the blue dye molecules. Thus, the bistable liquid crystal cell 20 can achieve blue and white picture display toward the second surface, such as white background with blue characters.

[0070] In one embodiment, the bistable liquid crystal molecules 231 (pitch: 230 - 490 μm) reflect green light in the reflective state, and the color dye molecules 232 are green dye molecules. The Bragg reflection layer includes a long-pass filter 141 and a short-pass filter 142. The blue sub-pixel P11 corresponds to the long-pass filter 141. The red sub-pixel P13 corresponds to the short-pass filter 142. The long-pass filter 141 can transmit red and green light and reflect blue light. The short-pass filter 142 can transmit blue light and reflect red and green light. The first filter layer includes a blue filter layer corresponding to the blue sub-pixel P11 and a red filter layer corresponding to the red sub-pixel P13. The first counter substrate 11 is in a transparent state in the area corresponding to the green sub-pixel P12. That is, the blue sub-pixel P11 can reflect blue light through the long-pass filter 141 and the blue filter layer. The green sub-pixel P12 reflects green light through the bistable liquid crystal molecules 231 and the green dye molecules. The red sub-pixel P13 reflects red light through the short-pass filter 142 and the red filter layer. Thus, the dye liquid crystal cell 10 can achieve full-color reflective display toward the first surface. The metal reflection layer corresponds to the first sub-pixel P21 and the third sub-pixel P23. That is, the first sub-pixel P21 and the third sub-pixel P23 both reflect white light through the metal reflection layer. The second sub-pixel P22 reflects green light through the bistable liquid crystal molecules 231 and the green dye molecules. Thus, the bistable liquid crystal cell 20 can achieve green and white picture display toward the second surface, such as white background with green characters.

[0071] Those skilled in the art should understand that the rest of the structure and working principle of this embodiment are the same as those of the first embodiment, and will not be elaborated here.

[0072] In this article, the orientation terms such as up, down, left, right, front, and back are defined based on the positions of the structures in the drawings and the positions relative to each other, only for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of these orientation terms should not limit the scope of protection claimed in this application. It should also be understood that the terms "first" and "second" used in this article are only for distinction in name and do not limit the quantity and order.

[0073] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications by using the technical content disclosed above within the scope of the technical solution of the present invention, which are equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A double-sided reflective display device, characterized in that, It includes a dye liquid crystal cell (10) and a bistable liquid crystal cell (20) which are stacked on each other. The dye liquid crystal cell (10) is close to the first surface of the bistable reflective display device, and the bistable liquid crystal cell (20) is close to the second surface of the bistable reflective display device; The dye liquid crystal cell (10) includes a first counter substrate (11), a first array substrate (12) disposed opposite to the first counter substrate (11), and a dye liquid crystal layer (13) located between the first counter substrate (11) and the first array substrate (12). The dye liquid crystal cell (10) has a plurality of first pixel units (P1) distributed in an array. Among the plurality of first pixel units (P1), there are a blue sub-pixel (P11), a green sub-pixel (P12), and a red sub-pixel (P13). A first pixel electrode (121) and a Bragg reflection layer are provided on the first array substrate (12). At least two of the blue sub-pixel (P11), the green sub-pixel (P12), and the red sub-pixel (P13) correspond to the Bragg reflection layer. A first filter layer corresponding to the green sub-pixel (P12) and / or the red sub-pixel (P13) is provided on the first counter substrate (11). A first common electrode (111) cooperating with the first pixel electrode (121) is provided on the first counter substrate (11); The bistable liquid crystal cell (20) includes a second counter substrate (21), a second array substrate (22) disposed opposite to the second counter substrate (21), and a bistable liquid crystal layer (23) located between the second counter substrate (21) and the second array substrate (22). The bistable liquid crystal layer (23) includes bistable liquid crystal molecules (231) and color dye molecules (232) mixed with the bistable liquid crystal molecules (231). The bistable liquid crystal molecules (231) reflect light of the same color as the color dye molecules (232) in the reflective state. The bistable liquid crystal cell (20) has a plurality of second pixel units (P2) distributed in an array. Among the plurality of second pixel units (P2), there are a first sub-pixel (P21) corresponding to the blue sub-pixel (P11), a second sub-pixel (P22) corresponding to the green sub-pixel (P12), and a third sub-pixel (P23) corresponding to the red sub-pixel (P13). A second pixel electrode (221) is provided on the second array substrate (22). A second common electrode (211) cooperating with the second pixel electrode (221) is provided on the second counter substrate (21).

2. The dual-sided reflective display device according to claim 1, wherein, A second filter layer corresponding to two of the first sub-pixel (P21), the second sub-pixel (P22), and the third sub-pixel (P23) is provided on the second array substrate (22).

3. The double-sided reflective display device according to claim 2, wherein, The bistable liquid crystal molecules (231) reflect red light in the reflective state, and the color dye molecules (232) are red dye molecules; The Bragg reflection layer includes a long-pass filter (141) and a short-pass filter (142). The blue sub-pixel (P11) corresponds to the long-pass filter (141), and the green sub-pixel (P12) corresponds to the short-pass filter (142). The long-pass filter (141) can transmit red and green light and reflect blue light, and the short-pass filter (142) can transmit blue light and reflect red and green light; The first filter layer includes a green filter layer corresponding to the green sub-pixel (P12), and the second filter layer includes a blue filter layer corresponding to the first sub-pixel (P21) and a green filter layer corresponding to the second sub-pixel (P22).

4. The dual-sided reflective display device according to claim 2, wherein The bistable liquid crystal molecules (231) reflect blue light in the reflective state, and the color dye molecules (232) are blue dye molecules; The Bragg reflection layer includes a short-pass filter (142). Both the green sub-pixel (P12) and the red sub-pixel (P13) correspond to the short-pass filter (142). The short-pass filter (142) can transmit blue light and reflect red and green light; The first filter layer includes a green filter layer corresponding to the green sub-pixel (P12) and a red filter layer corresponding to the red sub-pixel (P13), and the second filter layer includes a green filter layer corresponding to the second sub-pixel (P22) and a red filter layer corresponding to the third sub-pixel (P23).

5. The double-sided reflective display device according to claim 2, characterized in that, The bistable liquid crystal molecules (231) reflect green light in the reflective state, and the color dye molecules (232) are green dye molecules; The Bragg reflection layer includes a long-pass filter (141) and a short-pass filter (142). The blue sub-pixel (P11) corresponds to the long-pass filter (141), and the red sub-pixel (P13) corresponds to the short-pass filter (142). The long-pass filter (141) can transmit red and green light and reflect blue light, and the short-pass filter (142) can transmit blue light and reflect red and green light; The first filter layer includes a red filter layer corresponding to the red sub-pixel (P13), and the second filter layer includes a blue filter layer corresponding to the first sub-pixel (P21) and a red filter layer corresponding to the third sub-pixel (P23).

6. The dual-sided reflective display device according to claim 1, wherein, A metal reflection layer corresponding to two of the first sub-pixel (P21), the second sub-pixel (P22), and the third sub-pixel (P23) is provided on the first array substrate (12). The metal reflection layer is disposed on the side of the Bragg reflection layer facing the bistable liquid crystal cell (20). The second array substrate (22) is in a transparent state in the regions corresponding to the first sub-pixel (P21), the second sub-pixel (P22), and the third sub-pixel (P23).

7. The double-sided reflective display device according to claim 6, wherein, The bistable liquid crystal molecules (231) reflect red light in the reflective state, and the color dye molecules (232) are red dye molecules; The Bragg reflection layer includes a long-pass filter (141) and a short-pass filter (142). The blue sub-pixel (P11) corresponds to the long-pass filter (141), and the green sub-pixel (P12) corresponds to the short-pass filter (142). The long-pass filter (141) can transmit red and green light and reflect blue light, and the short-pass filter (142) can transmit blue light and reflect red and green light; The first filter layer includes a blue filter layer corresponding to the blue sub-pixel (P11) and a green filter layer corresponding to the green sub-pixel (P12). The metal reflection layer corresponds to the first sub-pixel (P21) and the second sub-pixel (P22).

8. The dual-sided reflective display device according to claim 6, wherein, The bistable liquid crystal molecules (231) reflect blue light in the reflective state, and the color dye molecules (232) are blue dye molecules; The Bragg reflection layer includes a short-pass filter (142). Both the green sub-pixel (P12) and the red sub-pixel (P13) correspond to the short-pass filter (142). The short-pass filter (142) can transmit blue light and reflect red and green light; The first filter layer includes a green filter layer corresponding to the green sub-pixel (P12) and a red filter layer corresponding to the red sub-pixel (P13). The metal reflection layer corresponds to the second sub-pixel (P22) and the third sub-pixel (P23).

9. The double-sided reflective display device according to claim 6, wherein The bistable liquid crystal molecules (231) reflect green light in the reflective state, and the color dye molecules (232) are green dye molecules; The Bragg reflection layer includes a long-pass filter (141) and a short-pass filter (142). The blue sub-pixel (P11) corresponds to the long-pass filter (141), and the red sub-pixel (P13) corresponds to the short-pass filter (142). The long-pass filter (141) can transmit red and green light and reflect blue light, and the short-pass filter (142) can transmit blue light and reflect red and green light; The first filter layer includes a blue filter layer corresponding to the blue sub-pixel (P11) and a red filter layer corresponding to the red sub-pixel (P13). The metal reflection layer corresponds to the first sub-pixel (P21) and the third sub-pixel (P23).

10. A driving method for a double-sided reflective display device, characterized in that, For driving the dual-sided reflective display device according to any one of claims 1-9, the driving method includes: During dual-sided display, controlling both the dye liquid crystal cell (10) and the bistable liquid crystal cell (20) to be turned on. The dye liquid crystal cell (10) displays a color picture towards the first side, and the bistable liquid crystal cell (20) displays a color picture towards the second side.

Images