Dual-sided display device and driving method

Abstract

This invention discloses a dual-sided display device and driving method. The dual-sided display device includes a first liquid crystal cell, a backlight module, and a second liquid crystal cell stacked sequentially. The backlight module includes a side-lit light source and a light guide structure. The light guide structure includes a first light guide plate, a second light guide plate, and a third light guide plate stacked sequentially. By providing a first reflective layer between the first and second light guide plates, and a second reflective layer between the second and third light guide plates, and by staggering the projections of the first and second reflective layers onto the second light guide plate and jointly covering the second light guide plate, the utilization rate of light can be improved, and interference between the displayed images of the first and second liquid crystal cells can be avoided. Furthermore, the second light guide plate has a light-transmitting gap at the adjacent boundary between the first and second reflective layers, which makes the light intensity on both sides of the backlight module more uniform, ensuring consistent brightness of the images displayed on both sides.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a double-sided display device and its driving method. Background Technology

[0002] Liquid crystal displays (LCDs) have advantages such as good image quality, small size, light weight, low driving voltage, low power consumption, no radiation, and relatively low manufacturing cost, and are widely used in electronic devices such as laptops, mobile phones, e-readers, and LCD TVs.

[0003] An existing display device includes a first thin film transistor array substrate (TFT array substrate), a color filter substrate (CF substrate), and liquid crystal molecules filled between the first thin film transistor array substrate and the color filter substrate. When the display device is in operation, driving voltages are applied to the first thin film transistor array substrate and the color filter substrate respectively to control the rotation direction of the liquid crystal molecules between the two substrates, so as to refract the backlight provided by the backlight module of the display device and thus display the image.

[0004] However, existing display devices can only achieve single-sided display, meaning the image can only be displayed on one side of the device. In some scenarios, however, it is necessary for both sides of the display device to be able to display the image. Currently, most display devices use two displays arranged back-to-back, with each display responsible for displaying content on one side. Each display requires its own backlight module to provide a backlight source. This setup not only increases the thickness of the display device, resulting in poor aesthetics, but also increases power consumption. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the prior art, the present invention aims to provide a double-sided display device and driving method to solve the problems of excessive thickness and high power consumption of the double-sided display device in the prior art.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] The present invention provides a dual-sided display device, comprising a first liquid crystal cell, a backlight module and a second liquid crystal cell stacked on top of each other, wherein the backlight module is disposed between the first liquid crystal cell and the second liquid crystal cell and is used to provide a light source for the first liquid crystal cell and the second liquid crystal cell;

[0008] The backlight module includes a light guide structure and a side-lit light source disposed on the side of the light guide structure. The light guide structure includes a first light guide plate, a second light guide plate, and a third light guide plate stacked sequentially on each other. A first reflective layer is provided between the first light guide plate and the second light guide plate. The surfaces of the first light guide plate and the second light guide plate near the first reflective layer are provided with first dots, which are located in the corresponding area of ​​the first reflective layer. A second reflective layer is provided between the second light guide plate and the third light guide plate. The surfaces of the second light guide plate and the third light guide plate near the second reflective layer are provided with second dots, which are located in the corresponding area of ​​the second reflective layer. The projections of the first reflective layer and the second reflective layer on the second light guide plate are staggered and together cover the second light guide plate. The second light guide plate has a light-transmitting gap at the adjacent boundary between the first reflective layer and the second reflective layer.

[0009] Furthermore, the projection of the first reflective layer onto the second light guide plate covers one half of the second light guide plate, and the projection of the second reflective layer onto the second light guide plate covers at least the other half of the second light guide plate.

[0010] Furthermore, the first reflective layer includes a plurality of first reflective areas, and a first light-transmitting gap is provided between any two adjacent first reflective areas. The second reflective layer includes a plurality of second reflective areas, and a second light-transmitting gap is provided between any two adjacent second reflective areas. The first reflective areas correspond to the second light-transmitting gaps, and the second reflective areas correspond to the first light-transmitting gaps.

[0011] Furthermore, the first reflective area, the first light-transmitting gap, the second reflective area, and the second light-transmitting gap are all parallel strip structures;

[0012] Alternatively, the first reflective area, the first light-transmitting gap, the second reflective area, and the second light-transmitting gap may all be block structures.

[0013] Furthermore, the projections of the first reflective layer and the second reflective layer onto the second light guide plate are completely offset or partially overlapped.

[0014] This application also provides a dual-sided display device, including a first liquid crystal cell, a backlight module and a second liquid crystal cell stacked on top of each other, wherein the backlight module is disposed between the first liquid crystal cell and the second liquid crystal cell and is used to provide a light source for the first liquid crystal cell and the second liquid crystal cell.

[0015] The backlight module includes a lamp panel and an electrochromic structure layer. The electrochromic structure layer has multiple color-changing areas distributed in an array, and each color-changing area can switch between a transparent state and an opaque state individually.

[0016] The electrochromic structure layer includes a first electrochromic structure layer disposed on the side of the lamp panel facing the first liquid crystal cell and a second electrochromic structure layer disposed on the side of the lamp panel facing the second liquid crystal cell. The color-changing area includes a first color-changing area in the first electrochromic structure layer and a second color-changing area in the second electrochromic structure layer. The first color-changing area and the second color-changing area correspond one-to-one. At least one of the first color-changing area and the corresponding second color-changing area is in a non-transparent state at the same time.

[0017] The dual-sided display device has a plurality of sub-pixels arranged in an array. The sub-pixels include a first sub-pixel in the first liquid crystal cell and a second sub-pixel in the second liquid crystal cell. The first sub-pixel and the second sub-pixel correspond one-to-one. Two adjacent color-changing areas form a light-controlling area. Each light-controlling area corresponds to at least one area of ​​the sub-pixel.

[0018] Furthermore, the electrochromic structure layer includes a first substrate, a second substrate, and an electrochromic material layer located between the first substrate and the second substrate. A first electrode is provided on the first substrate, and a second electrode cooperating with the first electrode is provided on the second substrate. The first electrode and / or the second electrode includes a plurality of independently controlled electrode blocks, each electrode block corresponding to a color-changing area. The first electrode and the second electrode are used to control the electrochromic material layer to switch between a transparent state and an opaque state.

[0019] Furthermore, the light panel is provided with a plurality of LED lights arranged in an array, each of which is independently controlled to be on or off, and each LED light corresponds one-to-one with the color-changing area;

[0020] The light panel uses a blue or purple light source, and the backlight module includes two white quantum dot films, which are respectively disposed on both sides of the light panel.

[0021] This application also provides a driving method for a double-sided display device, used to drive the double-sided display device as described above, the driving method comprising:

[0022] In one of the light control areas, when at least one first sub-pixel is in a bright state and at least one second sub-pixel is in a bright state, one of the two first color-changing areas in the light control area is controlled to be in a transparent state, and one of the two second color-changing areas in the light control area is controlled to be in a transparent state, and one of the first color-changing areas and the corresponding second color-changing areas is in a non-transparent state;

[0023] In one of the light control areas, when at least one first sub-pixel is in a bright state and all the second sub-pixels are in a dark state, the two first color-changing areas in the light control area are controlled to be in a transparent state, and the two second color-changing areas in the light control area are controlled to be in a non-transparent state.

[0024] In one of the light control areas, when all the first sub-pixels are in a dark state and at least one second sub-pixel is in a bright state, the two first color-changing areas in the light control area are controlled to be in a non-transparent state, and the two second color-changing areas in the light control area are controlled to be in a transparent state.

[0025] In one of the light control areas, when all the first sub-pixels and all the second sub-pixels are in a dark state, the two first color-changing areas in the light control area are controlled to be in a non-transparent state, and the two second color-changing areas in the light control area are controlled to be in a non-transparent state.

[0026] Furthermore, the light panel is provided with multiple LEDs arranged in an array, each LED being independently controlled to be on or off. Each LED corresponds one-to-one with a color-changing area, and the driving method includes:

[0027] When at least one of the first color-changing area and the corresponding second color-changing area is transparent, the corresponding LED light is turned on; when both the first color-changing area and the corresponding second color-changing area are opaque, the corresponding LED light is turned off.

[0028] The beneficial effects of this invention are as follows: By providing a first reflective layer between the first light guide plate and the second light guide plate, and a second reflective layer between the second light guide plate and the third light guide plate, and by having the projections of the first reflective layer and the second reflective layer on the second light guide plate staggered and jointly covering the second light guide plate, the utilization rate of light can be improved, and interference between the display images of the first liquid crystal cell and the second liquid crystal cell can be avoided. Moreover, the second light guide plate has a light-transmitting gap at the adjacent boundary of the first reflective layer and the second reflective layer, allowing light from one side of the first light guide plate to enter the third light guide plate through the light-transmitting gap of the second light guide plate, and light from one side of the third light guide plate to enter the first light guide plate through the light-transmitting gap of the second light guide plate, thereby increasing the light mixing effect and making the light intensity on both sides of the backlight module more uniform, ensuring consistent brightness of the double-sided display. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the double-sided display device in the initial state according to Embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the light guide structure in Embodiment 1 of the present invention;

[0031] Figure 3 This is a schematic diagram of the planar structure of the first reflective layer in Embodiment 1 of the present invention;

[0032] Figure 4 This is a schematic diagram of the planar structure of the second reflective layer in Embodiment 1 of the present invention;

[0033] Figure 5 This is a schematic diagram of the planar structure of the first array substrate in Embodiment 1 of the present invention;

[0034] Figure 6 This is a schematic diagram of the planar structure of the first color filter substrate in Embodiment 1 of the present invention;

[0035] Figure 7 This is a schematic diagram of the planar structure of the second array substrate in Embodiment 1 of the present invention;

[0036] Figure 8 This is a schematic diagram of the planar structure of the second color filter substrate in Embodiment 1 of the present invention;

[0037] Figure 9 This is a schematic diagram of the double-sided display device in the bright state according to Embodiment 1 of the present invention;

[0038] Figure 10 This is a schematic diagram of the optical path of one side of the light source in the light guide structure of Embodiment 1 of the present invention;

[0039] Figure 11 This is a schematic diagram of the optical path of the light source on the other side of the light guide structure in Embodiment 1 of the present invention;

[0040] Figure 12 This is a schematic diagram of the structure of the double-sided display device in the initial state in Embodiment 2 of the present invention;

[0041] Figure 13 This is a schematic diagram of the light guide structure in Embodiment 2 of the present invention;

[0042] Figure 14 This is a schematic diagram of the planar structure of the first reflective layer in Embodiment 2 of the present invention;

[0043] Figure 15 This is a schematic diagram of the planar structure of the second reflective layer in Embodiment 2 of the present invention;

[0044] Figure 16This is a schematic diagram of the planar structure of the first reflective layer in Embodiment 3 of the present invention;

[0045] Figure 17 This is a schematic diagram of the planar structure of the second reflective layer in Embodiment 3 of the present invention;

[0046] Figure 18 This is a schematic diagram of the structure of the double-sided display device in the initial state in Embodiment 4 of the present invention;

[0047] Figure 19 This is a schematic diagram of the electrochromic structure layer in the non-transparent state in Embodiment 4 of the present invention;

[0048] Figure 20 This is a schematic diagram of the electrochromic structure layer in the transparent state in Embodiment 4 of the present invention;

[0049] Figure 21 This is one of the schematic diagrams of the electrochromic structure layer of the double-sided display device in the bright state in Embodiment 4 of the present invention;

[0050] Figure 22 This is the second schematic diagram of the electrochromic structure layer of the double-sided display device in the bright state in Embodiment 4 of the present invention. Detailed Implementation

[0051] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of the double-sided display device and driving method proposed according to the present invention:

[0052] [Example 1]

[0053] Figure 1 This is a schematic diagram of the structure of the double-sided display device in the initial state in Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of the light guide structure in Embodiment 1 of the present invention. Figure 3 This is a schematic diagram of the planar structure of the first reflective layer in Embodiment 1 of the present invention. Figure 4 This is a schematic diagram of the planar structure of the second reflective layer in Embodiment 1 of the present invention.

[0054] like Figures 1 to 4 As shown, a dual-sided display device provided in Embodiment 1 of the present invention includes a first liquid crystal cell 10, a backlight module 40, and a second liquid crystal cell 20 stacked on top of each other. The backlight module 40 is disposed between the first liquid crystal cell 10 and the second liquid crystal cell 20. The backlight module 40 emits light from both sides and is used to provide a light source for the first liquid crystal cell 10 and the second liquid crystal cell 20. The first liquid crystal cell 10 is used to control the display of the image on the first side, and the second liquid crystal cell 20 is used to control the display of the image on the second side.

[0055] The backlight module 40 includes a light guide structure 42 and a side-lit light source 41 disposed on the side of the light guide structure 42. For example... Figure 2 As shown, the light guide structure 42 includes a first light guide plate 421, a second light guide plate 422, and a third light guide plate 423 stacked sequentially on top of each other. A first reflective layer 424 is provided between the first light guide plate 421 and the second light guide plate 422. The surfaces of the first light guide plate 421 and the second light guide plate 422 near the first reflective layer 424 are provided with first dots 426a. The first dots 426a are located in the corresponding areas of the first reflective layer 424. That is, the surface of the first light guide plate 421 facing the first reflective layer 424 is provided with first dots 426a, and the surface of the second light guide plate 422 facing the first reflective layer 424 is provided with first dots 426a. The projections of the first dots 426a on the first light guide plate 421 and the second light guide plate 422 onto the second light guide plate 422 are all located in the corresponding areas of the first reflective layer 424. A second reflective layer 425 is provided between the second light guide plate 422 and the third light guide plate 423. Second dots 426b are provided on the surfaces of both the second light guide plate 422 and the third light guide plate 423 near the second reflective layer 425. The second dots 426b are located within the corresponding areas of the second reflective layer 425; that is, the second dots 426b are provided on the surface of the second light guide plate 422 facing the second reflective layer 425, and the second dots 426b are provided on the surface of the third light guide plate 423 facing the second reflective layer 425. The projections of the second dots 426b on the second light guide plate 422 and the third light guide plate 423 onto the second light guide plate 422 are all located within the corresponding areas of the second reflective layer 425. A coating process can be used to coat the surfaces of the corresponding areas of the first light guide plate 421, the second light guide plate 422, and the third light guide plate 423 with a reflective material (e.g., aluminum or silver), thereby forming the first reflective layer 424 and the second reflective layer 425.

[0056] The projections of the first reflective layer 424 and the second reflective layer 425 onto the second light guide plate 422 are staggered and together cover the second light guide plate 422. That is, the projections of the first reflective layer 424 and the second reflective layer 425 onto the second light guide plate 422 will not completely overlap, and the sum of their projection areas is greater than or equal to the area of ​​the second light guide plate 422. This improves light utilization and prevents vertical light from passing through the backlight module 40, thus avoiding interference between the displayed images of the first liquid crystal cell 10 and the second liquid crystal cell 20. The second light guide plate 422 has a light-transmitting gap 422a at the adjacent boundary of the first reflective layer 424 and the second reflective layer 425. Since the second light guide plate 422 has a certain thickness, and the first reflective layer 424 and the second reflective layer 425 are located on opposite surfaces of the second light guide plate 422 and are staggered, a light-transmitting gap 422a is formed at the adjacent boundary of the first reflective layer 424 and the second reflective layer 425. In addition, due to the use of a side-lit light source 41, light from one side of the first light guide plate 421 can enter the third light guide plate 423 through the light-transmitting gap 422a of the second light guide plate 422, and light from one side of the third light guide plate 423 can also enter the first light guide plate 421 through the light-transmitting gap 422a of the second light guide plate 422, thereby increasing the light mixing effect and making the light intensity on both sides of the backlight module 40 more uniform, ensuring consistent brightness of the double-sided display. Moreover, when one of the first liquid crystal cell 10 and the second liquid crystal cell 20 is used for display, the light source can be utilized to the maximum extent, avoiding waste of light source and improving the utilization rate of light source.

[0057] In this embodiment, the projections of the first reflective layer 424 and the second reflective layer 425 on the second light guide plate 422 are completely staggered, that is, the adjacent edges of the first reflective layer 424 and the second reflective layer 425 are aligned on the projections of the second light guide plate 422. This maximizes the light mixing effect while ensuring that the displayed images between the first liquid crystal cell 10 and the second liquid crystal cell 20 do not interfere with each other, making the light intensity on both sides of the backlight module 40 more uniform and ensuring consistent brightness of the images displayed on both sides. Of course, in other embodiments, the projections of the first reflective layer 424 and the second reflective layer 425 on the second light guide plate 422 may also partially overlap. The width of the overlapping area can be set according to the actual situation. For example, the width of the overlapping area is equal to half the thickness of the second light guide plate 422, thereby ensuring that the displayed images between the first liquid crystal cell 10 and the second liquid crystal cell 20 do not interfere with each other and also have a good light mixing effect.

[0058] Furthermore, the projection of the first reflective layer 424 onto the second light guide plate 422 covers half of the second light guide plate 422, and the projection of the second reflective layer 425 onto the second light guide plate 422 covers at least the other half of the second light guide plate 422. In this embodiment, as... Figure 3 and Figure 4As shown, the projection of the first reflective layer 424 onto the second light guide plate 422 covers half of the area of ​​the second light guide plate 422, and the projection of the second reflective layer 425 onto the second light guide plate 422 covers the other half of the area of ​​the second light guide plate 422. The sum of the projected areas of the first reflective layer 424 and the second reflective layer 425 onto the second light guide plate 422 is equal to the area of ​​the second light guide plate 422.

[0059] In this embodiment, since the projection of the first reflective layer 424 onto the second light guide plate 422 covers half of the second light guide plate 422, and the projection of the second reflective layer 425 onto the second light guide plate 422 covers the other half of the second light guide plate 422, the light-transmitting slit 422a at the adjacent boundary of the first reflective layer 424 and the second reflective layer 425 of the second light guide plate 422 is a strip structure. Therefore, in the direction perpendicular to the extension of the light-transmitting slit 422a, the side-lit light source 41 is disposed on opposite sides of the light guide structure 42. For example, the light-transmitting slit 422a extends in the vertical direction, and the side-lit light source 41 is disposed on the left and right sides of the light guide structure 42, thereby ensuring that the light entering the first light guide plate 421 and the third light guide plate 423 has a better mutual light mixing effect.

[0060] Figure 9 This is a schematic diagram of the double-sided display device in the bright state according to Embodiment 1 of the present invention. Figure 10 This is a schematic diagram of the optical path of one side of the light source in the light guide structure of Embodiment 1 of the present invention. Figure 11 This is a schematic diagram of the optical path of the light source on one side of the light guide structure in Embodiment 1 of the present invention. Figure 9 As shown, during display, the side-lit light sources 41 on both sides of the light guide structure 42 are turned on. The light emitted by the side-lit light sources 41 passes through the light guide structure 42 and is directed to the first liquid crystal cell 10 and the second liquid crystal cell 20 respectively, thereby providing a light source for the first liquid crystal cell 10 and the second liquid crystal cell 20. Figure 10 As shown, the light emitted from the side-lit light source 41 on the left side of the light guide structure 42 enters the first light guide plate 421, the second light guide plate 422, and the third light guide plate 423 from the left. Part of the light, when it hits the first dot 426a, is refracted and emitted towards the first liquid crystal cell 10 and the second liquid crystal cell 20; another part of the light, after multiple reflections, hits the second dot 426b and is then refracted towards the first liquid crystal cell 10 and the second liquid crystal cell 20; a portion of the light in the third light guide plate 423 also enters the first light guide plate 421 through the light-transmitting slit 422a of the second light guide plate 422, and is then refracted by the second dot 426b on the second light guide plate 422 towards the first liquid crystal cell 10. Figure 11As shown, the light emitted from the side-lit light source 41 on the right side of the light guide structure 42 enters the first light guide plate 421, the second light guide plate 422, and the third light guide plate 423 from the right. Part of the light, when it hits the second dot 426b, is refracted and emitted towards the first liquid crystal cell 10 and the second liquid crystal cell 20. Another part of the light, after multiple reflections, hits the first dot 426a and is then refracted towards the first liquid crystal cell 10 and the second liquid crystal cell 20. A portion of the light in the first light guide plate 421 also enters the third light guide plate 423 through the light-transmitting slit 422a of the second light guide plate 422, and is then refracted by the first dot 426a on the second light guide plate 422 towards the second liquid crystal cell 20. The light-transmitting slit 422a at the adjacent boundary of the first reflective layer 424 and the second reflective layer 425 in the second light guide plate 422 enhances the light mixing effect, making the light intensity on both sides of the backlight module 40 more uniform and ensuring consistent brightness of the double-sided display.

[0061] Furthermore, the backlight module 40 also includes two diffuser sheets 43, one on the side of the light guide structure 42 facing the first liquid crystal cell 10 and the other on the side of the light guide structure 42 facing the second liquid crystal cell 20. The diffuser sheets 43 are used to make the light from the light guide structure 42 directed towards the first liquid crystal cell 10 and the second liquid crystal cell 20 more uniform, thereby improving the display effect. Of course, in other embodiments, the backlight module 40 may also be provided with a prism sheet, so that the light is directed more perpendicularly towards the first liquid crystal cell 10 and the second liquid crystal cell 20.

[0062] like Figure 1 As shown, the first liquid crystal cell 10 has a plurality of first sub-pixels P1 arranged in an array, and the second liquid crystal cell 20 has a plurality of second sub-pixels P2 arranged in an array. Each first sub-pixel P1 and each second sub-pixel P2 has a red sub-pixel, a green sub-pixel, and a blue sub-pixel. The colors of the first sub-pixel P1 and its corresponding second sub-pixel P2 can be the same or different. Of course, in other embodiments, the first sub-pixels P1 in the first liquid crystal cell 10 and the second sub-pixels P2 in the second liquid crystal cell 20 may not have any corresponding relationship.

[0063] The first liquid crystal cell 10 includes a first color filter substrate 11, a first array substrate 12 disposed opposite to the first color filter substrate 11, and a first liquid crystal layer 13 located between the first color filter substrate 11 and the first array substrate 12. The first liquid crystal layer 13 uses positive liquid crystal molecules, that is, liquid crystal molecules with positive dielectric anisotropy. Figure 1As shown, in the initial state, the positive liquid crystal molecules in the first liquid crystal layer 13 are aligned parallel to the first color filter substrate 11 and the first array substrate 12. The alignment directions of the positive liquid crystal molecules near the first color filter substrate 11 and the positive liquid crystal molecules near the first array substrate 12 are parallel or antiparallel to each other. Of course, in other embodiments, the positive liquid crystal molecules in the first liquid crystal layer 13 are aligned parallel to the first color filter substrate 11 and the first array substrate 12. The alignment directions of the positive liquid crystal molecules near the first color filter substrate 11 and the positive liquid crystal molecules near the first array substrate 12 can also be perpendicular to each other, i.e., the positive liquid crystal molecules in the first liquid crystal layer 13 are twisted by 90° to form a TN display mode. Alternatively, the first liquid crystal layer 13 can also use negative liquid crystal molecules, which can be aligned perpendicular to the first color filter substrate 11 and the first array substrate 12, similar to the alignment method of the VA display mode.

[0064] Figure 6 This is a schematic diagram of the planar structure of the first color filter substrate in Embodiment 1 of the present invention. Figure 6 As shown, a first color filter substrate 11 has a first color resist layer 112 and a first black matrix (BM) 111 separating the first color resist layer 112 on the side facing the first liquid crystal layer 13. The first color resist layer 112 includes, for example, red (R), green (G), and blue (B) color resist materials, which respectively form first sub-pixels P1 of red, green, and blue. The first black matrix 111 is located between the red, green, and blue first sub-pixels P1, so that adjacent first sub-pixels P1 are separated from each other by the first black matrix 111.

[0065] Figure 5 This is a schematic diagram of the planar structure of the first array substrate in Embodiment 1 of the present invention. Figure 5 As shown, on the side of the first array substrate 12 facing the first liquid crystal layer 13, multiple first scan lines 101 and multiple first data lines 102 are mutually insulated and intersecting to form multiple first sub-pixels P1. The first black matrix 111 corresponds vertically to the first scan lines 101 and the first data lines 102. Each first sub-pixel P1 is provided with a first pixel electrode 122 and a first thin-film transistor 103. The first pixel electrode 122 is electrically connected to 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 122 through a contact hole.

[0066] In this embodiment, a first common electrode 121 is further provided on the side of the first array substrate 12 facing the first liquid crystal layer 13. The first common electrode 121 and the first pixel electrode 122 are located on different layers and are insulated from each other by an insulating layer. The first common electrode 121 may be located above or below the first pixel electrode 122. Figure 1 The diagram shows the first common electrode 121 located below the first pixel electrode 122. Preferably, the first common electrode 121 is a planar electrode with its entire surface disposed, and the first pixel electrode 122 is a slit electrode with multiple electrode strips within each first sub-pixel P1 to form a fringe field switching (FFS) mode. Of course, in other embodiments, the first pixel electrode 122 and the first common electrode 121 are located on the same layer, but they are insulated from each other. Both the first pixel electrode 122 and the first common electrode 121 may include multiple electrode strips, and the electrode strips of the first pixel electrode 122 and the first common electrode 121 are arranged alternately to form an in-plane switching (IPS) mode. Alternatively, the first array substrate 12 has the first pixel electrode 122 on the side facing the first liquid crystal layer 13, and the first color filter substrate 11 has the first common electrode 121 on the side facing the first liquid crystal layer 13 to form a TN mode or a VA mode. For further descriptions of the TN mode and VA mode, please refer to the prior art, which will not be repeated here.

[0067] A first polarizer 31 is provided on the first color filter substrate 11, and a second polarizer 32 is provided on the first array substrate 12. The light transmission axis of the first polarizer 31 and the light transmission axis of the second polarizer 32 are perpendicular to each other.

[0068] The second liquid crystal cell 20 includes a second color filter substrate 21, a second array substrate 22 disposed opposite to the second color filter substrate 21, and a second liquid crystal layer 23 located between the second color filter substrate 21 and the second array substrate 22. The second liquid crystal layer 23 uses positive liquid crystal molecules, that is, liquid crystal molecules with positive dielectric anisotropy. For example... Figure 1As shown, in the initial state, the positive liquid crystal molecules in the second liquid crystal layer 23 are aligned parallel to the second color filter substrate 21 and the second array substrate 22. The alignment directions of the positive liquid crystal molecules near the second color filter substrate 21 and the positive liquid crystal molecules near the second array substrate 22 are parallel or antiparallel to each other. Of course, in other embodiments, the positive liquid crystal molecules in the second liquid crystal layer 23 are aligned parallel to the second color filter substrate 21 and the second array substrate 22. The alignment directions of the positive liquid crystal molecules near the second color filter substrate 21 and the positive liquid crystal molecules near the second array substrate 22 can also be perpendicular to each other, i.e., the positive liquid crystal molecules in the second liquid crystal layer 23 are twisted by 90° to form a TN display mode. Alternatively, the second liquid crystal layer 23 can also use negative liquid crystal molecules, which can be aligned perpendicular to the second color filter substrate 21 and the second array substrate 22, similar to the alignment method of the VA display mode.

[0069] Figure 8 This is a schematic diagram of the planar structure of the second color filter substrate in Embodiment 1 of the present invention. Figure 8 As shown, a second color filter substrate 21 has a second color resist layer 222 and a second black matrix (BM) 211 separating the second color resist layer 222 on the side facing the second liquid crystal layer 23. The second color resist layer 222 includes, for example, red (R), green (G), and blue (B) color resist materials, which respectively form second sub-pixels P2 of red, green, and blue. The second black matrix 211 is located between the red, green, and blue second sub-pixels P2, so that adjacent second sub-pixels P2 are separated from each other by the second black matrix 211. In this embodiment, the projection of the second black matrix 211 on the first liquid crystal cell 10 coincides with the first black matrix 111, and the projection of the second color resist layer 222 on the first liquid crystal cell 10 corresponds one-to-one with the first color resist layer 112.

[0070] Figure 7 This is a schematic diagram of the planar structure of the second array substrate in Embodiment 1 of the present invention. Figure 7As shown, on the side of the second array substrate 22 facing the second liquid crystal layer 23, multiple second scan lines 201 and multiple second data lines 202 are mutually insulated and intersecting to form multiple second sub-pixels P2. The second black matrix 211 corresponds vertically to the second scan lines 201 and the second data lines 202. Each second sub-pixel P2 is provided with a second pixel electrode 222 and a second thin-film transistor 203. The second pixel electrode 222 is electrically connected to 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 lines 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 222 through a contact hole. In this embodiment, the projection of the second scan line 201 on the first liquid crystal cell 10 coincides with the first scan line 101, and the projection of the second data line 202 on the first liquid crystal cell 10 coincides with the first data line 102.

[0071] In this embodiment, a second common electrode 221 is further provided on the side of the second array substrate 22 facing the second liquid crystal layer 23. The second common electrode 221 and the second pixel electrode 222 are located on different layers and are insulated from each other by an insulating layer. The second common electrode 221 may be located above or below the second pixel electrode 222. Figure 1 The diagram shows the second common electrode 221 located below the second pixel electrode 222. Preferably, the second common electrode 221 is a planar electrode with its entire surface disposed, and the second pixel electrode 222 is a slit electrode with multiple electrode strips within each second sub-pixel P2 to form a fringe field switching (FFS) mode. Of course, in other embodiments, the second pixel electrode 222 and the second common electrode 221 are located on the same layer, but they are insulated from each other. Both the second pixel electrode 222 and the second common electrode 221 may include multiple electrode strips, and the electrode strips of the second pixel electrode 222 and the second common electrode 221 are arranged alternately to form an in-plane switching (IPS) mode. Alternatively, the second array substrate 22 has the second pixel electrode 222 on the side facing the second liquid crystal layer 23, and the second color filter substrate 21 has the second common electrode 221 on the side facing the second liquid crystal layer 23 to form a TN mode or a VA mode. For further descriptions of the TN mode and VA mode, please refer to the prior art, which will not be repeated here.

[0072] The second color filter substrate 21 is provided with a third polarizer 33, and the second array substrate 22 is provided with a fourth polarizer 34. The transmission axis of the third polarizer 33 and the transmission axis of the fourth polarizer 34 are perpendicular to each other.

[0073] Furthermore, the first color filter substrate 11 is disposed on the side of the first array substrate 12 away from the backlight module 40, and the second color filter substrate 21 is disposed on the side of the second array substrate 22 away from the backlight module 40. That is, both the first color filter substrate 11 and the second color filter substrate 21 are disposed close to the external environment, thereby avoiding metal reflection on the first array substrate 12 and the second array substrate 22.

[0074] The first color filter substrate 11, the first array substrate 12, the second color filter substrate 21, and the second array substrate 22 can be made of materials such as glass, acrylic, and polycarbonate. The first common electrode 121, the first pixel electrode 122, the second common electrode 221, and the second pixel electrode 222 can be made of transparent conductive materials such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0075] This embodiment also provides a driving method for a dual-sided display device, used to drive the dual-sided display device as described above, the driving method comprising:

[0076] like Figure 9 As shown, the first LCD cell 10, the backlight module 40, and the second LCD cell 20 are opened.

[0077] A common voltage is applied to the first common electrode 121, and a corresponding grayscale voltage is applied to the first pixel electrode 122. A voltage difference is formed between the first common electrode 121 and the first pixel electrode 122, generating a horizontal electric field. Figure 9 The E1 in the first liquid crystal layer 13 causes the positive liquid crystal molecules in the first liquid crystal layer 13 to deflect in the horizontal direction, thereby controlling the light transmittance and realizing grayscale control. The grayscale voltage includes grayscale voltages from 0 to 255 levels. When different grayscale voltages are applied to the first pixel electrode 122, the corresponding first sub-pixel P1 exhibits different brightness, thereby displaying the corresponding image on the first side of the double-sided display device.

[0078] A common voltage is applied to the second common electrode 221, and a corresponding grayscale voltage is applied to the second pixel electrode 222. A voltage difference is formed between the second common electrode 221 and the second pixel electrode 222, generating a horizontal electric field. Figure 9 The E2 in the second liquid crystal layer 23 causes the positive liquid crystal molecules in the second liquid crystal layer 23 to deflect in the horizontal direction, thereby controlling the light transmittance and achieving grayscale control. The grayscale voltage includes grayscale voltages from 0 to 255 levels. When different grayscale voltages are applied to the second pixel electrode 222, the corresponding second sub-pixel P2 exhibits different brightness, thereby displaying the corresponding image on the second side of the double-sided display device to achieve double-sided display.

[0079] [Example 2]

[0080] Figure 12 This is a schematic diagram of the structure of the double-sided display device in the initial state in Embodiment 2 of the present invention. Figure 13 This is a schematic diagram of the light guide structure in Embodiment 2 of the present invention. Figure 14 This is a schematic diagram of the planar structure of the first reflective layer in Embodiment 2 of the present invention. Figure 15 This is a schematic diagram of the planar structure of the second reflective layer in Embodiment 2 of the present invention. Figures 12 to 15 As shown, the double-sided display device provided in Embodiment 2 of the present invention is similar to that in Embodiment 1. Figures 1 to 11 The double-sided display devices in this embodiment are basically the same, except that in this embodiment:

[0081] The first reflective layer 424 includes multiple first reflective areas 424a, and a first light-transmitting gap 424b is provided between any two adjacent first reflective areas 424a. The second reflective layer 425 includes multiple second reflective areas 425a, and a second light-transmitting gap 425b is provided between any two adjacent second reflective areas 425a. The first reflective areas 424a correspond to the second light-transmitting gaps 425b, and vice versa. This increases the number of light-transmitting gaps 422a, further enhancing the light mixing effect and making the light intensity on both sides of the backlight module 40 more uniform, ensuring consistent brightness on both sides of the display.

[0082] like Figure 14 and Figure 15 As shown, the first reflective area 424a, the first light-transmitting gap 424b, the second reflective area 425a, and the second light-transmitting gap 425b are all parallel strip structures. Side-lit light sources 41 are positioned on opposite sides of the light guide structure 42 in a direction perpendicular to the extension of the light-transmitting gap 422a. For example, the light-transmitting gap 422a extends vertically, and the side-lit light sources 41 are positioned on the left and right sides of the light guide structure 42, thereby ensuring that the light entering the first light guide plate 421 and the third light guide plate 423 has a better mutual light mixing effect.

[0083] 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 repeated here.

[0084] [Example 3]

[0085] Figure 16 This is a schematic diagram of the planar structure of the first reflective layer in Embodiment 3 of the present invention. Figure 17 This is a schematic diagram of the planar structure of the second reflective layer in Embodiment 3 of the present invention. Figure 16 and Figure 17 As shown, the double-sided display device provided in Embodiment 2 of the present invention is similar to that in Embodiment 1. Figures 1 to 11 Example 2 Figures 12 to 15The double-sided display devices in this embodiment are basically the same, except that in this embodiment:

[0086] The first reflective layer 424 includes multiple first reflective areas 424a, and a first light-transmitting gap 424b is provided between any two adjacent first reflective areas 424a. The second reflective layer 425 includes multiple second reflective areas 425a, and a second light-transmitting gap 425b is provided between any two adjacent second reflective areas 425a. The first reflective areas 424a correspond to the second light-transmitting gaps 425b, and vice versa. This increases the number of light-transmitting gaps 422a, further enhancing the light mixing effect and making the light intensity on both sides of the backlight module 40 more uniform, ensuring consistent brightness on both sides of the display.

[0087] like Figure 16 and Figure 17 As shown, the first reflective area 424a, the first light-transmitting gap 424b, the second reflective area 425a, and the second light-transmitting gap 425b are all block-shaped structures. For example, the first reflective area 424a, the first light-transmitting gap 424b, the second reflective area 425a, and the second light-transmitting gap 425b are all rectangular (square) structures of the same size, such as a mosaic structure. This allows for a greater number of light-transmitting gaps 422a and a more uniform distribution of the light-transmitting gaps 422a on the second light guide plate 422, further enhancing the light mixing effect and making the light intensity on both sides of the backlight module 40 more uniform, ensuring consistent brightness of the double-sided display.

[0088] 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.

[0089] [Example 4]

[0090] Figure 18 This is a schematic diagram of the structure of the double-sided display device in the initial state in Embodiment 4 of the present invention. Figure 19 This is a schematic diagram of the electrochromic structure layer in the non-transparent state in Embodiment 4 of the present invention. Figure 20 This is a schematic diagram of the electrochromic structure layer in the transparent state in Embodiment 4 of the present invention.

[0091] like Figures 18 to 20 As shown, a double-sided display device provided in Embodiment 4 of the present invention includes a first liquid crystal cell 10, a backlight module 40 and a second liquid crystal cell 20 stacked on top of each other. The backlight module 40 is disposed between the first liquid crystal cell 10 and the second liquid crystal cell 20 and is used to provide a light source for the first liquid crystal cell 10 and the second liquid crystal cell 20. The first liquid crystal cell 10 is used to control the display of the image on the first side and the second liquid crystal cell 20 is used to control the display of the image on the second side.

[0092] The backlight module 40 includes a lamp panel 44 and an electrochromic structure layer. The electrochromic structure layer has multiple color-changing areas arranged in an array, and each color-changing area can switch independently between a transparent state and an opaque state. Figure 19 and Figure 20 As shown, the electrochromic structure layer includes a first substrate 45a, a second substrate 45c, and an electrochromic material layer 45b located between the first substrate 45a and the second substrate 45c. A first electrode 45d is provided on the first substrate 45a, and a second electrode 45e cooperating with the first electrode 45d is provided on the second substrate 45c. The second electrode 45e includes multiple independently controlled electrode blocks, each corresponding to a color-changing area. The first electrode 45d and the second electrode 45e are used to control the electrochromic material layer 45b to switch between a transparent state and an opaque state. Of course, in other embodiments, the first electrode 45d may include multiple independently controlled electrode blocks, or both the first electrode 45d and the second electrode 45e may include multiple independently controlled electrode blocks.

[0093] The electrochromic material layer 45b can be made of nickel oxide (NiO) or an electropolymer material. After an electrical reaction, it turns gray. The depth of the gray is adjusted by changing the voltage, thus altering the transmittance of the electrochromic material layer 45b and allowing switching between transparent and opaque states. The electrochromic material layer 45b consumes only a small amount of power during the color change process (the full driving voltage is only 0.5V–1.5V). No power is consumed after the color change is complete and the power is turned off, saving power consumption. Returning to the transparent state only requires applying a reverse voltage. Taking nickel oxide (NiO) as an example, the chemical formula for the reaction is: Of course, in other embodiments, the electrochromic material layer 45b may also use inorganic color-changing materials (such as tungsten trioxide and other metal oxides), polymer color-changing materials (such as violet), and polymer color-changing materials combined with ink, thereby achieving switching between the black state and the transparent state.

[0094] There are two electrochromic structural layers: a first electrochromic structural layer 451 disposed on the side of the lamp panel 44 facing the first liquid crystal cell 10, and a second electrochromic structural layer 452 disposed on the side of the lamp panel 44 facing the second liquid crystal cell 20. The color-changing areas include a first color-changing area in the first electrochromic structural layer 451 and a second color-changing area in the second electrochromic structural layer 452. The first and second color-changing areas correspond one-to-one, and at least one of the first and corresponding second color-changing areas must be in a non-transparent state at any given time. For example, when the first color-changing area is transparent, the corresponding second color-changing area must be non-transparent; when the second color-changing area is transparent, the corresponding first color-changing area must be non-transparent; or, both the first and corresponding second color-changing areas can be non-transparent. This prevents vertical light from passing through the backlight module 40, thus avoiding interference between the displayed images of the first and second liquid crystal cells 10 and 20.

[0095] The double-sided display device has multiple sub-pixels arranged in an array. The sub-pixels include a first sub-pixel P1 in the first liquid crystal cell 10 and a second sub-pixel P2 in the second liquid crystal cell 20, with a one-to-one correspondence between the first sub-pixel P1 and the second sub-pixel P2. Each of the multiple first sub-pixels P1 and the multiple second sub-pixels P2 contains red, green, and blue sub-pixels. The colors of the first sub-pixel P1 and its corresponding second sub-pixel P2 can be the same or different. Two adjacent color-changing areas form a light-controlling area. Each light-controlling area corresponds to at least one sub-pixel region; that is, one light-controlling area corresponds to two adjacent first color-changing areas and two adjacent second color-changing areas. Each light-controlling area corresponds to at least one first sub-pixel P1 and at least one second sub-pixel P2. For example, each light-controlling area may correspond to at least three sub-pixels, i.e., one pixel, consisting of red, green, and blue sub-pixels; or, each light-controlling area may correspond to at least six sub-pixels, i.e., two pixels, consisting of two groups of red, green, and blue sub-pixels. This allows for simultaneous local dimming of the first liquid crystal cell 10 and the second liquid crystal cell 20, thereby improving the contrast of the displayed images in the first liquid crystal cell 10 and the second liquid crystal cell 20.

[0096] In this embodiment, the lamp board 44 is provided with a plurality of LEDs 441 (e.g., Mini LEDs or Micro LEDs) arranged in an array. Each LED 441 is independently controlled to be on or off. Each LED 441 corresponds to a color-changing area, so that when the area is dimmed, the corresponding LED 441 can also achieve the corresponding on or off state, thereby saving power consumption of the backlight module 40. The lamp board 44 is made of a transparent material, such as glass. The LEDs 441 are disposed on both sides of the lamp board 44, and the LEDs 441 on each side of the lamp board 44 are spaced apart. Each LED 441 can provide a light source for the first liquid crystal cell 10 and / or the second liquid crystal cell 20.

[0097] Furthermore, the light panel 44 uses a blue or purple light source, meaning the LED light 441 uses a blue or purple LED. The backlight module 40 includes two white quantum dot films 46, which are respectively disposed on both sides of the light panel 44. The white quantum dot films 46 can excite the blue or purple light source into white light. Of course, in other embodiments, white LEDs can also be used, but white LEDs are more expensive.

[0098] Among them, the white quantum dot film 46 contains quantum dots (QDs), which are typically nanoparticles composed of group II-V1 or III-V elements. Their size is smaller than or close to the exciton Bohr radius (generally no more than 10 nm in diameter), exhibiting significant quantum effects. It is generally considered a quasi-zero-dimensional material, a semiconductor nanostructure in which conduction band electrons, valence band holes, and excitons are bound in three spatial directions. When the particle size of the nanomaterial decreases to a certain value (generally below 10 nm), the electronic energy levels near the metal Fermi level change from quasi-continuous to discrete. The band gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels of the nanoscale semiconductor particles widens, causing a blue shift in absorption and fluorescence peaks. This phenomenon is called the quantum size effect.

[0099] The quantum size effect dramatically alters the photoelectric properties of semiconductor quantum dots. When the size of semiconductor quantum dot particles is smaller than the Bohr radius of excitons, the resulting quantum size effect changes the energy level structure of the semiconductor material, transforming it from a continuous band structure into a discrete energy level structure with molecular characteristics. This phenomenon can be used to prepare semiconductor quantum dots of different sizes in the same reaction, producing light emission at different frequencies, thus allowing for convenient control of various emission colors.

[0100] When a solid absorbs a photon (absorption), the energy of the absorbed photon will be greater than that of the emitted photon (emission). Therefore, the emission spectrum will be shifted (redshift) towards a lower energy direction compared to the absorption spectrum. The difference in energy between the two photons is called the Stokes shift.

[0101] Because quantum dots have a narrow emission spectrum and high luminous efficiency, and possess quantum size effect and Stokes spectral shift effect, each color-corresponding quantum dot can absorb light with energy greater than that color emitted by the backlight, and efficiently convert the absorbed light into monochromatic light of that color and emit it, making the color purer, more saturated, and improving the transmittance of the backlight.

[0102] Furthermore, the backlight module 40 also includes two diffuser sheets 43, which are respectively disposed between the first electrochromic structure layer 451 and one of the white quantum dot films 46, and between the second electrochromic structure layer 452 and the other white quantum dot film 46. The diffuser sheets 43 are used to make the light from the light guide structure 42 directed towards the first liquid crystal cell 10 and the second liquid crystal cell 20 more uniform, thereby improving the display effect. The backlight module 40 may also be provided with two prism sheets 47, which are respectively disposed on the side of one of the white quantum dot films 46 facing the first liquid crystal cell 10 and the side of the other white quantum dot film 46 facing the second liquid crystal cell 20, thereby making the light more perpendicular to the first liquid crystal cell 10 and the second liquid crystal cell 20.

[0103] like Figure 18 As shown, the first liquid crystal cell 10 includes a first color filter substrate 11, a first array substrate 12 disposed opposite to the first color filter substrate 11, and a first liquid crystal layer 13 located between the first color filter substrate 11 and the first array substrate 12. The first liquid crystal layer 13 uses positive liquid crystal molecules, that is, liquid crystal molecules with positive dielectric anisotropy. Figure 18 As shown, in the initial state, the positive liquid crystal molecules in the first liquid crystal layer 13 are aligned parallel to the first color filter substrate 11 and the first array substrate 12. The alignment directions of the positive liquid crystal molecules near the first color filter substrate 11 and the positive liquid crystal molecules near the first array substrate 12 are parallel or antiparallel to each other. Of course, in other embodiments, the positive liquid crystal molecules in the first liquid crystal layer 13 are aligned parallel to the first color filter substrate 11 and the first array substrate 12. The alignment directions of the positive liquid crystal molecules near the first color filter substrate 11 and the positive liquid crystal molecules near the first array substrate 12 can also be perpendicular to each other, i.e., the positive liquid crystal molecules in the first liquid crystal layer 13 are twisted by 90° to form a TN display mode. Alternatively, the first liquid crystal layer 13 can also use negative liquid crystal molecules, which can be aligned perpendicular to the first color filter substrate 11 and the first array substrate 12, similar to the alignment method of the VA display mode.

[0104] refer to Figure 6 As shown, a first color filter substrate 11 has a first color resist layer 112 and a first black matrix (BM) 111 separating the first color resist layer 112 on the side facing the first liquid crystal layer 13. The first color resist layer 112 includes, for example, red (R), green (G), and blue (B) color resist materials, which respectively form first sub-pixels P1 of red, green, and blue. The first black matrix 111 is located between the red, green, and blue first sub-pixels P1, so that adjacent first sub-pixels P1 are separated from each other by the first black matrix 111.

[0105] refer to Figure 5As shown, on the side of the first array substrate 12 facing the first liquid crystal layer 13, multiple first scan lines 101 and multiple first data lines 102 are mutually insulated and intersecting to form multiple first sub-pixels P1. The first black matrix 111 corresponds vertically to the first scan lines 101 and the first data lines 102. Each first sub-pixel P1 is provided with a first pixel electrode 122 and a first thin-film transistor 103. The first pixel electrode 122 is electrically connected to 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 122 through a contact hole.

[0106] In this embodiment, a first common electrode 121 is further provided on the side of the first array substrate 12 facing the first liquid crystal layer 13. The first common electrode 121 and the first pixel electrode 122 are located on different layers and are insulated from each other by an insulating layer. The first common electrode 121 may be located above or below the first pixel electrode 122. Figure 18 The diagram shows the first common electrode 121 located below the first pixel electrode 122. Preferably, the first common electrode 121 is a planar electrode with its entire surface disposed, and the first pixel electrode 122 is a slit electrode with multiple electrode strips within each first sub-pixel P1 to form a fringe field switching (FFS) mode. Of course, in other embodiments, the first pixel electrode 122 and the first common electrode 121 are located on the same layer, but they are insulated from each other. Both the first pixel electrode 122 and the first common electrode 121 may include multiple electrode strips, and the electrode strips of the first pixel electrode 122 and the first common electrode 121 are arranged alternately to form an in-plane switching (IPS) mode. Alternatively, the first array substrate 12 has the first pixel electrode 122 on the side facing the first liquid crystal layer 13, and the first color filter substrate 11 has the first common electrode 121 on the side facing the first liquid crystal layer 13 to form a TN mode or a VA mode. For further descriptions of the TN mode and VA mode, please refer to the prior art, which will not be repeated here.

[0107] A first polarizer 31 is provided on the first color filter substrate 11, and a second polarizer 32 is provided on the first array substrate 12. The light transmission axis of the first polarizer 31 and the light transmission axis of the second polarizer 32 are perpendicular to each other.

[0108] The second liquid crystal cell 20 includes a second color filter substrate 21, a second array substrate 22 disposed opposite to the second color filter substrate 21, and a second liquid crystal layer 23 located between the second color filter substrate 21 and the second array substrate 22. The second liquid crystal layer 23 uses positive liquid crystal molecules, that is, liquid crystal molecules with positive dielectric anisotropy. For example... Figure 18 As shown, in the initial state, the positive liquid crystal molecules in the second liquid crystal layer 23 are aligned parallel to the second color filter substrate 21 and the second array substrate 22. The alignment directions of the positive liquid crystal molecules near the second color filter substrate 21 and the positive liquid crystal molecules near the second array substrate 22 are parallel or antiparallel to each other. Of course, in other embodiments, the positive liquid crystal molecules in the second liquid crystal layer 23 are aligned parallel to the second color filter substrate 21 and the second array substrate 22. The alignment directions of the positive liquid crystal molecules near the second color filter substrate 21 and the positive liquid crystal molecules near the second array substrate 22 can also be perpendicular to each other, i.e., the positive liquid crystal molecules in the second liquid crystal layer 23 are twisted by 90° to form a TN display mode. Alternatively, the second liquid crystal layer 23 can also use negative liquid crystal molecules, which can be aligned perpendicular to the second color filter substrate 21 and the second array substrate 22, similar to the alignment method of the VA display mode.

[0109] refer to Figure 8 As shown, a second color filter substrate 21 has a second color resist layer 222 and a second black matrix (BM) 211 separating the second color resist layer 222 on the side facing the second liquid crystal layer 23. The second color resist layer 222 includes, for example, red (R), green (G), and blue (B) color resist materials, which respectively form second sub-pixels P2 of red, green, and blue. The second black matrix 211 is located between the red, green, and blue second sub-pixels P2, so that adjacent second sub-pixels P2 are separated from each other by the second black matrix 211. In this embodiment, the projection of the second black matrix 211 on the first liquid crystal cell 10 coincides with the first black matrix 111, and the projection of the second color resist layer 222 on the first liquid crystal cell 10 corresponds one-to-one with the first color resist layer 112.

[0110] refer to Figure 7As shown, on the side of the second array substrate 22 facing the second liquid crystal layer 23, multiple second scan lines 201 and multiple second data lines 202 are mutually insulated and intersecting to form multiple second sub-pixels P2. The second black matrix 211 corresponds vertically to the second scan lines 201 and the second data lines 202. Each second sub-pixel P2 is provided with a second pixel electrode 222 and a second thin-film transistor 203. The second pixel electrode 222 is electrically connected to 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 222 through a contact hole. In this embodiment, the projection of the second scan line 201 on the first liquid crystal cell 10 coincides with the first scan line 101, and the projection of the second data line 202 on the first liquid crystal cell 10 coincides with the first data line 102.

[0111] In this embodiment, a second common electrode 221 is further provided on the side of the second array substrate 22 facing the second liquid crystal layer 23. The second common electrode 221 and the second pixel electrode 222 are located on different layers and are insulated from each other by an insulating layer. The second common electrode 221 may be located above or below the second pixel electrode 222. Figure 18 The diagram shows the second common electrode 221 located below the second pixel electrode 222. Preferably, the second common electrode 221 is a planar electrode with its entire surface disposed, and the second pixel electrode 222 is a slit electrode with multiple electrode strips within each second sub-pixel P2 to form a fringe field switching (FFS) mode. Of course, in other embodiments, the second pixel electrode 222 and the second common electrode 221 are located on the same layer, but they are insulated from each other. Both the second pixel electrode 222 and the second common electrode 221 may include multiple electrode strips, and the electrode strips of the second pixel electrode 222 and the second common electrode 221 are arranged alternately to form an in-plane switching (IPS) mode. Alternatively, the second array substrate 22 has the second pixel electrode 222 on the side facing the second liquid crystal layer 23, and the second color filter substrate 21 has the second common electrode 221 on the side facing the second liquid crystal layer 23 to form a TN mode or a VA mode. For further descriptions of the TN mode and VA mode, please refer to the prior art, which will not be repeated here.

[0112] The second color filter substrate 21 is provided with a third polarizer 33, and the second array substrate 22 is provided with a fourth polarizer 34. The transmission axis of the third polarizer 33 and the transmission axis of the fourth polarizer 34 are perpendicular to each other.

[0113] Furthermore, the first color filter substrate 11 is disposed on the side of the first array substrate 12 away from the backlight module 40, and the second color filter substrate 21 is disposed on the side of the second array substrate 22 away from the backlight module 40. That is, both the first color filter substrate 11 and the second color filter substrate 21 are disposed close to the external environment, thereby avoiding metal reflection on the first array substrate 12 and the second array substrate 22.

[0114] The first color filter substrate 11, the first array substrate 12, the second color filter substrate 21, and the second array substrate 22 can be made of materials such as glass, acrylic, and polycarbonate. The first common electrode 121, the first pixel electrode 122, the second common electrode 221, the second pixel electrode 222, the first electrode 45d, and the second electrode 45e can be made of transparent conductive materials such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0115] This embodiment also provides a driving method for a dual-sided display device, used to drive the dual-sided display device as described above, the driving method comprising:

[0116] Figure 21 This is one of the schematic diagrams illustrating the principle of the electrochromic structure layer in the bright state of the double-sided display device in Embodiment 4 of the present invention. For example... Figure 21 As shown, in a light control area, when at least one first sub-pixel P1 and at least one second sub-pixel P2 are both in a bright state, one of the two first color-changing areas in the light control area is controlled to be transparent, and one of the two second color-changing areas in the light control area is controlled to be transparent, while one of the first color-changing areas and the corresponding second color-changing area is in a non-transparent state. For example, in a light control area, when at least one first sub-pixel P1 and at least one second sub-pixel P2 are both in a bright state, one first color-changing area on the right side of the corresponding light control area is controlled to be transparent, and one first color-changing area on the left side of the corresponding light control area is controlled to be non-transparent; and one second color-changing area on the left side of the corresponding light control area is controlled to be transparent, and one second color-changing area on the right side of the corresponding light control area is controlled to be non-transparent.

[0117] Figure 22 This is the second schematic diagram illustrating the principle structure of the electrochromic structure layer in the bright state of the double-sided display device in Embodiment 4 of the present invention. Figure 22 As shown, in a light-controlling area, when at least one first sub-pixel P1 is in a bright state and all second sub-pixels P2 are in a dark state, both first color-changing areas in the light-controlling area are in a transparent state, and both second color-changing areas in the light-controlling area are in a non-transparent state. Alternatively, in a light-controlling area, when all first sub-pixels P1 are in a dark state and at least one second sub-pixel P2 is in a bright state, both first color-changing areas in the light-controlling area are in a non-transparent state, and both second color-changing areas in the light-controlling area are in a transparent state.

[0118] like Figure 21 and Figure 22 As shown, in a light control area, when all first sub-pixels P1 and all second sub-pixels P2 are in a dark state, the two first color-changing areas in the light control area are controlled to be in a non-transparent state, and the two second color-changing areas in the light control area are controlled to be in a non-transparent state.

[0119] Since each light control area corresponds to at least one sub-pixel, meaning each light control area can correspond to multiple sub-pixels, if any first sub-pixel P1 in a light control area is in a bright state, it is necessary to control one of the two first color-changing areas in the light control area to be in a transparent state; similarly, if any second sub-pixel P2 is in a bright state, it is necessary to control one of the two second color-changing areas in the light control area to be in a transparent state.

[0120] In this embodiment, when at least one of the first color-changing area and the corresponding second color-changing area is transparent, the corresponding LED 441 is turned on; when both the first color-changing area and the corresponding second color-changing area are opaque, the corresponding LED 441 is turned off. Thus, during local dimming, the corresponding LED 441 can also achieve the corresponding on or off state, turning off the LED 441 whose two sides are both dark, thereby saving power consumption of the backlight module 40.

[0121] In the actual display of the image, a common voltage is applied to the first common electrode 121, and a corresponding grayscale voltage is applied to the first pixel electrode 122. A voltage difference is formed between the first common electrode 121 and the first pixel electrode 122, generating a horizontal electric field. This causes the positive liquid crystal molecules in the first liquid crystal layer 13 to deflect in the horizontal direction, thereby controlling the light transmittance and achieving grayscale control. The grayscale voltage includes 0 to 255 levels. When different grayscale voltages are applied to the first pixel electrode 122, the corresponding first sub-pixel P1 exhibits different brightness, thus displaying the corresponding image on the first side of the double-sided display device.

[0122] A common voltage is applied to the second common electrode 221, and a corresponding grayscale voltage is applied to the second pixel electrode 222. A voltage difference is formed between the second common electrode 221 and the second pixel electrode 222, generating a horizontal electric field. This causes the positive liquid crystal molecules in the second liquid crystal layer 23 to deflect in the horizontal direction, thereby controlling the light transmittance and achieving grayscale control. The grayscale voltage includes 0 to 255 levels. When different grayscale voltages are applied to the second pixel electrode 222, the corresponding second sub-pixel P2 exhibits different brightness, thus displaying the corresponding image on the second side of the dual-sided display device to achieve dual-sided display.

[0123] 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.

[0124] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content without departing from the scope of the technical solution of the present invention, which are equivalent embodiments with equivalent changes. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A double-sided display device, characterized in that, It includes a first liquid crystal cell (10), a backlight module (40) and a second liquid crystal cell (20) stacked on top of each other. The backlight module (40) is disposed between the first liquid crystal cell (10) and the second liquid crystal cell (20) and is used to provide a light source for the first liquid crystal cell (10) and the second liquid crystal cell (20). The backlight module (40) includes a light guide structure (42) and a side-lit light source (41) disposed on the side of the light guide structure (42). The light guide structure (42) includes a first light guide plate (421), a second light guide plate (422), and a third light guide plate (423) stacked sequentially on each other. A first reflective layer (424) is provided between the first light guide plate (421) and the second light guide plate (422). The surfaces of the first light guide plate (421) and the second light guide plate (422) near the first reflective layer (424) are provided with first dots (426a), and the first dots (426a) are located in the area corresponding to the first reflective layer (424). The second light guide plate (421)... 2) A second reflective layer (425) is provided between the second light guide plate (422) and the third light guide plate (423). The surfaces of the second light guide plate (422) and the third light guide plate (423) near the second reflective layer (425) are provided with second dots (426b). The second dots (426b) are located in the area corresponding to the second reflective layer (425). The projections of the first reflective layer (424) and the second reflective layer (425) on the second light guide plate (422) are staggered and together cover the second light guide plate (422). The second light guide plate (422) has a light-transmitting slit (422a) at the adjacent boundary of the first reflective layer (424) and the second reflective layer (425).

2. The double-sided display device according to claim 1, characterized in that, The projection of the first reflective layer (424) onto the second light guide plate (422) covers half of the second light guide plate (422), and the projection of the second reflective layer (425) onto the second light guide plate (422) covers at least the other half of the second light guide plate (422).

3. The double-sided display device according to claim 1, characterized in that, The first reflective layer (424) includes a plurality of first reflective areas (424a), and a first light-transmitting gap (424b) is provided between any two adjacent first reflective areas (424a). The second reflective layer (425) includes a plurality of second reflective areas (425a), and a second light-transmitting gap (425b) is provided between any two adjacent second reflective areas (425a). The first reflective areas (424a) correspond to the second light-transmitting gaps (425b), and the second reflective areas (425a) correspond to the first light-transmitting gaps (424b).

4. The double-sided display device according to claim 3, characterized in that, The first reflective area (424a), the first light-transmitting gap (424b), the second reflective area (425a), and the second light-transmitting gap (425b) are all parallel strip structures; Alternatively, the first reflective area (424a), the first light-transmitting gap (424b), the second reflective area (425a), and the second light-transmitting gap (425b) may all be block structures.

5. The double-sided display device according to any one of claims 1-4, characterized in that, The projections of the first reflective layer (424) and the second reflective layer (425) onto the second light guide plate (422) are completely offset or partially overlap.

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