Liquid crystal display device

Abstract

The utility model discloses a liquid crystal display device which comprises a backlight module, a quantum dot film, a light filtering liquid crystal box and a display liquid crystal box, and the quantum dot film, the light filtering liquid crystal box and the display liquid crystal box are sequentially arranged in a stacked mode in the light emitting direction of the backlight module. The filtering liquid crystal box is provided with a transmission area and a reflection area, the transmission area is used for transmitting blue light when a picture is displayed, and the reflection area is used for reflecting the blue light when the picture is displayed; the quantum dot film comprises a transparent area, a green quantum dot area and a red quantum dot area, the transparent area corresponds to the transmission area, and both the green quantum dot area and the red quantum dot area correspond to the reflection area. The quantum dot film can excite red light and green light with high color purity, the reflection area of the light filtering liquid crystal box can reflect blue light which is not utilized in the green quantum dot area and the red quantum dot area back for further utilization, and therefore the utilization rate of the backlight source is increased, the color purity of the red light and the color purity of the green light are improved, and therefore the backlight efficiency is improved. And high-color gamut display can be realized only by adopting a relatively thin color resistor in the display liquid crystal box.

Description

Technical Field

[0001] The utility model relates to the technical field of displays, in particular to a liquid crystal display device. Background Art

[0002] Liquid Crystal Display (LCD) has many advantages such as thin body, power saving, no radiation, etc., and has been widely used, such as LCD TV, mobile phone, personal digital assistant (PDA), digital camera, computer screen or notebook computer screen, etc., and it occupies a dominant position in the field of flat panel display.

[0003] The traditional liquid crystal display panel is composed of a color filter substrate (CF), a thin film transistor array substrate (TFT Array Substrate) and a liquid crystal layer (Liquid Crystal Layer) filled between the two substrates. The traditional liquid crystal display device achieves color display by using a color filter coated with red, green, blue and other color resistances to filter the monochromatic light (usually white light) provided by the backlight module. Usually, three sub-pixels with the same aperture ratio of red, green and blue are set to form a pixel. Due to the filtering property of the color resistance, red light, green light and blue light of different intensities can be obtained, and a color picture is presented by mixing the three primary colors of red, green and blue.

[0004] However, since the backlight module directly provides white light, it will also be mixed with other non-visible light, and the purity of the white light is low. Therefore, in order to improve the display color gamut of the liquid crystal display panel, the existing technology usually needs to set a thicker color resistance on the color filter to obtain higher purity red light, green light and blue light, but this will cause the color filter to have a lower transmittance and the backlight module to consume more power. Utility Model Content

[0005] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide a liquid crystal display device to solve the problems of thick color resistance and low color gamut and transmittance of the liquid crystal display panel in the prior art.

[0006] The purpose of the utility model is achieved through the following technical solutions:

[0007] The utility model provides a liquid crystal display device, comprising a backlight module and a quantum dot film, a filter liquid crystal box and a display liquid crystal box which are sequentially stacked and arranged in a light-emitting direction of the backlight module, wherein the display liquid crystal box is used to control the grayscale brightness of the display screen, and the backlight module is used to provide a blue light source;

[0008] The filter liquid crystal box comprises a first substrate, a second substrate arranged opposite to the first substrate, and a cholesteric liquid crystal layer located between the first substrate and the second substrate, wherein the cholesteric liquid crystal layer reflects blue light in a reflective state, and the filter liquid crystal box has a transmission area and a reflection area, wherein the transmission area is used to transmit blue light when displaying an image, and the reflection area is used to reflect blue light when displaying an image;

[0009] The quantum dot film includes a transparent area, a green quantum dot area and a red quantum dot area, the green quantum dot area is provided with green quantum dots and can excite green light, the red quantum dot area is provided with red quantum dots and can excite red light, the transparent area corresponds to the transmission area, and the green quantum dot area and the red quantum dot area both correspond to the reflection area;

[0010] When the liquid crystal display device is displaying an image, the cholesteric liquid crystal layers corresponding to the transmission areas are all in a transmission state, and the cholesteric liquid crystal layers corresponding to the reflection areas are all in a reflection state.

[0011] Furthermore, the alignment modes of the cholesteric liquid crystal layer corresponding to the transmission area are all transmission alignment, and the alignment modes of the cholesteric liquid crystal layer corresponding to the reflection area are all reflection alignment.

[0012] Furthermore, all the cholesteric liquid crystal layers are aligned in a reflective state, a common electrode is disposed on the first substrate, a first control electrode matching the common electrode is disposed on the second substrate, and the first control electrode corresponds to the transmission area.

[0013] Furthermore, a second control electrode cooperating with the common electrode is also disposed on the second substrate, and the second control electrode corresponds to the reflective area.

[0014] Furthermore, all the cholesteric liquid crystal layers are aligned in a transmission state, a common electrode is disposed on the first substrate, a second control electrode matching the common electrode is disposed on the second substrate, and the second control electrode corresponds to the reflective area.

[0015] Furthermore, a first control electrode cooperating with the common electrode is also disposed on the second substrate, and the first control electrode corresponds to the transmission area.

[0016] Furthermore, the planar shapes of the transparent area, the green quantum dot area and the red quantum dot area are parallel strip structures;

[0017] Alternatively, the planar shapes of the transparent area, the green quantum dot area and the red quantum dot area are block structures, and multiple transparent areas, multiple green quantum dot areas and multiple red quantum dot areas are distributed in an array, and in any two adjacent columns and any two adjacent rows, the arrangements of the transparent areas, the green quantum dot areas and the red quantum dot areas are staggered.

[0018] Furthermore, the areas of the transparent region, the green quantum dot region and the red quantum dot region are all the same.

[0019] Furthermore, the display liquid crystal box is provided with a plurality of pixel units distributed in an array, the plurality of pixel units having blue sub-pixels, green sub-pixels and red sub-pixels, the transparent area corresponds to the blue sub-pixels, the green quantum dot area corresponds to the green sub-pixels, and the red quantum dot area corresponds to the red sub-pixels.

[0020] Furthermore, a diffusion sheet is provided between the display liquid crystal box and the filter liquid crystal box, and the diffusion sheet is used for uniformly mixing the colors of the light emitted from the filter liquid crystal box.

[0021] The beneficial effect of the utility model is that by adopting a blue backlight source, and matching it with a quantum dot film and a filter liquid crystal box, the quantum dot film can excite red light and green light with relatively high purity, and the reflective area of ​​the filter liquid crystal box can reflect the unused blue light in the green quantum dot area and the red quantum dot area back for further utilization, thereby improving the utilization rate of the backlight source and improving the color purity of the red light and the green light. Therefore, only a thinner color resistance needs to be used in the display liquid crystal box to achieve high color gamut display and improve the light transmittance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the liquid crystal display device in the initial state in the first embodiment of the present utility model;

[0023] Figure 2 It is a schematic diagram of the planar structure of the array substrate in the first embodiment of the utility model;

[0024] Figure 3 It is a schematic diagram of the planar structure of the color film substrate in the first embodiment of the utility model;

[0025] Figure 4 This is one of the planar structural schematic diagrams of the filter liquid crystal box in the first embodiment of the utility model;

[0026] Figure 5 This is one of the schematic diagrams of the planar structure of the quantum dot film in the first embodiment of the utility model;

[0027] Figure 6This is the second schematic diagram of the planar structure of the filter liquid crystal box in the first embodiment of the utility model;

[0028] Figure 7 This is the second schematic diagram of the planar structure of the quantum dot film in the first embodiment of the utility model;

[0029] Figure 8 It is a schematic diagram of the structure of the liquid crystal display device in the first embodiment of the utility model when displaying a picture;

[0030] Fig. 9 This is a schematic diagram of the optical path analysis of the liquid crystal display device in the first embodiment of the present utility model when displaying a picture;

[0031] Fig.10 is a schematic structural diagram of the liquid crystal display device in the initial state in the second embodiment of the present utility model;

[0032] Fig.11 It is a schematic structural diagram of the liquid crystal display device in the initial state in the third embodiment of the present utility model;

[0033] Fig.12 This is a schematic diagram of the principle of the three-state transformation of the cholesteric liquid crystal in the third embodiment of the present utility model;

[0034] Fig.13 This is a schematic diagram of the driving signal for the three-state transformation of the cholesteric liquid crystal in the third embodiment of the present utility model;

[0035] Fig.14 It is a schematic diagram of the structure of the liquid crystal display device in the third embodiment of the present utility model when displaying a picture;

[0036] Fig.15 This is a schematic diagram of the structure of a liquid crystal display device when displaying a picture in another implementation mode of the third embodiment of the utility model;

[0037] Fig.16 It is a schematic structural diagram of the liquid crystal display device in the fourth embodiment of the present utility model in the initial state;

[0038] Fig.17 It is a schematic diagram of the structure of the liquid crystal display device in the fourth embodiment of the present utility model when displaying a picture;

[0039] Fig.18 It is a structural schematic diagram of a liquid crystal display device when displaying a picture in another implementation manner of the fourth embodiment of the utility model. DETAILED DESCRIPTION

[0040] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the present invention, the specific implementation, structure, features and effects of the liquid crystal display device proposed by the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments:

[0041] [Example 1]

[0042] Figure 1 It is a schematic structural diagram of the liquid crystal display device in the first embodiment of the present utility model in the initial state. Figure 2 It is a schematic diagram of the planar structure of the array substrate in the first embodiment of the present utility model. Figure 3 It is a schematic diagram of the planar structure of the color film substrate in the first embodiment of the utility model. Figure 4 This is one of the planar structural schematic diagrams of the filter liquid crystal box in the first embodiment of the utility model. Figure 5 This is one of the schematic diagrams of the planar structure of the quantum dot film in the first embodiment of the present utility model. Figure 6 This is the second schematic diagram of the planar structure of the filter liquid crystal box in the first embodiment of the utility model. Figure 7 This is the second schematic diagram of the planar structure of the quantum dot film in the first embodiment of the present utility model.

[0043] like Figures 1 to 7 As shown, a liquid crystal display device provided by the first embodiment of the utility model includes a backlight module 40 and a quantum dot film 30, a filter liquid crystal box 20 and a display liquid crystal box 10 which are stacked in sequence toward the light emitting direction of the backlight module 40, that is, the backlight module 40, the quantum dot film 30, the filter liquid crystal box 20 and the display liquid crystal box 10 are stacked in sequence toward the external environment. Among them, the display liquid crystal box 10 is used to control the grayscale brightness of the display screen, and the backlight module 40 is used to provide a blue light source. The backlight module 40 can use a blue LED lamp as a light source to emit blue light. The quantum dot film 30 can be bonded to the side of the backlight module 40 facing the filter liquid crystal box 20, so as to be combined with the backlight module 40 into an integrated structure; of course, the quantum dot film 30 can be bonded to the side of the filter liquid crystal box 20 facing the backlight module 40, so as to be combined with the filter liquid crystal box 20 into an integrated structure.

[0044] The filter liquid crystal box 20 includes a first substrate 21, a second substrate 22 disposed opposite to the first substrate 21, and a cholesteric liquid crystal layer 23 located between the first substrate 21 and the second substrate 22. The cholesteric liquid crystal layer 23 reflects blue light in a reflective state. Figure 1 , Figure 4 and Figure 6 As shown, the filter liquid crystal box 20 has a transmission area 201 and a reflection area 202. The transmission area 201 is used to transmit blue light when displaying an image, and the reflection area 202 is used to reflect blue light when displaying an image. When the liquid crystal display device is displaying an image, the cholesteric liquid crystal layer 23 corresponding to the transmission area 201 is in a transmission state, so that the transmission area 201 can transmit the blue light emitted by the backlight source, and the cholesteric liquid crystal layer 23 corresponding to the reflection area 202 is in a reflection state, so that the unused blue light in the green quantum dot area 302 and the red quantum dot area 303 can be reflected, thereby improving the utilization rate of the backlight source.

[0045] Among them, the cholesteric liquid crystal in the cholesteric liquid crystal layer 23 has three stable textures: P state (Planar, planar texture state, reflection state), FC state (Focal Conic, focal conic state, fog state) and H state (transparent state). In the P state, the reflection spectrum of the cholesteric liquid crystal is in the visible spectrum, and the cholesteric liquid crystal reflects bright colored light. The specific reflected color can be set according to the pitch of the cholesteric liquid crystal; in the FC state, the cholesteric liquid crystal no longer reflects the above colored light, and the light can be scattered and passed through the cholesteric liquid crystal; in the H state, the cholesteric liquid crystal no longer reflects the above colored light, and the light can directly pass through the cholesteric liquid crystal, and it does not have a scattering effect on the light. The P state and the FC state do not require voltage to maintain, that is, the P state and the FC state are stable states. Under the action of a certain electric field, these three states can be converted to each other, and the cholesteric liquid crystal layer 23 can also be initially aligned into the focal conic state (transmission state) and the reflection state by means of alignment. Among them, the arrangement direction of cholesteric liquid crystal is different, the reflected visible light spectrum is different, and the remaining spectrum is transmitted. The reflection spectrum band (Δλ) of cholesteric liquid crystal is proportional to the helical pitch (Po) and birefringence (Δn=ne-no) of cholesteric liquid crystal, and the formula is: Δλ=PoΔn. Therefore, cholesteric liquid crystals with different helical pitches can reflect light of different colors in the reflection state. In this embodiment, the helical pitch of cholesteric liquid crystal in the cholesteric liquid crystal layer 23 is 190-340nm, so that blue light can be reflected in the reflection state.

[0046] The quantum dot film 30 includes a transparent area 301, a green quantum dot area 302 and a red quantum dot area 303. The quantum dot film 30 is transparent in the transparent area 301. The green quantum dot area 302 is provided with green quantum dots and can excite green light. The red quantum dot area 303 is provided with red quantum dots and can excite red light. The transparent area 301 corresponds to the transmission area 201, that is, the projection of the transparent area 301 on the filter liquid crystal box 20 coincides with the transmission area 201, so that the blue light emitted by the backlight source can be transmitted; the green quantum dot area 302 and the red quantum dot area 303 both correspond to the reflection area 202, that is, the projection of the green quantum dot area 302 and the red quantum dot area 303 on the filter liquid crystal box 20 coincides with the reflection area 202, so that the cholesteric liquid crystal layer 23 in the reflective state can play a certain filtering role on the green light excited by the green quantum dot area 302 and the red light excited by the red quantum dot area 303, so as to improve the purity of the green light and the red light.

[0047] The size of red quantum dots is 3nm to 3.5nm; the size of green quantum dots is 2nm to 3nm. In other words, the sizes of red quantum dots and green quantum dots are different. By utilizing the size effect and Stokes spectrum shift effect of quantum dots, red quantum dots can absorb light emitted by the light source with a greater energy than red light and convert it into monochromatic red light and emit it, and the color of red light will become purer; green quantum dots can absorb light emitted by the light source with a greater energy than green light and convert it into monochromatic green light and emit it, and the color of green light will become purer.

[0048] Among them, quantum dots (QDs) are usually nanoparticles composed of II-Vl or III-V elements, with a size smaller than or close to the exciton Bohr radius (generally no more than 10nm in diameter), and have obvious quantum effects. It is generally considered to be a quasi-zero-dimensional material, a semiconductor nanostructure that binds conduction band electrons, valence band holes and excitons in three spatial directions.

[0049] When the particle size of nanomaterials drops to a certain value (generally below 10nm), the electron energy levels near the metal Fermi level change from quasi-continuous to discrete levels, and the energy gap between the discontinuous highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels of nano-semiconductor particles becomes wider, causing the absorption and fluorescence peaks to blue shift. This phenomenon is called the quantum size effect.

[0050] The quantum size effect has caused a huge change in the photoelectric properties of semiconductor quantum dots. When the size of semiconductor quantum dot particles is smaller than the Bohr radius of the exciton, the quantum size effect changes the energy level structure of the semiconductor material, transforming it from a continuous energy band structure to a discrete energy level structure with molecular characteristics. By utilizing this phenomenon, semiconductor quantum dots of different particle sizes can be prepared in the same reaction to generate light emission of different frequencies, so that a variety of luminescent colors can be easily controlled.

[0051] The energy of photons absorbed by a solid (absorption) will be greater than that of photons radiated (luminescence). Therefore, the luminescence spectrum will shift toward a lower energy direction (redshift) compared to the absorption spectrum. The difference in the energies of the two photons is called the Stokes Shift.

[0052] Since quantum dots have a narrow emission spectrum and high luminous efficiency, and have quantum size effect and Stokes spectrum shift effect, the corresponding quantum dots in the sub-pixels of each color can absorb light emitted by the backlight source whose energy is greater than the color energy of the sub-pixel unit, and efficiently convert the absorbed light into monochromatic light of the sub-pixel unit color and emit it, making the color corresponding to the sub-pixel of that color purer and more saturated, and can improve the transmittance of the backlight source.

[0053] In this embodiment, the alignment modes of the cholesteric liquid crystal layer 23 corresponding to the transmission area 201 are all in the transmission state (foggy state, transparent state), and the alignment modes of the cholesteric liquid crystal layer 23 corresponding to the reflection area 202 are all in the reflection state, so that the filter liquid crystal box 20 does not need to set a control electrode to drive the state of the cholesteric liquid crystal.

[0054] like Figure 3 As shown, the display liquid crystal box 10 is provided with a plurality of pixel units P distributed in an array, wherein the plurality of pixel units P include blue sub-pixels P1, green sub-pixels P2 and red sub-pixels P3, and a column of blue sub-pixels P1, a column of green sub-pixels P2 and a column of red sub-pixels P3 are periodically arranged in the row direction.

[0055] In this embodiment, Figure 5 As shown, the transparent area 301 corresponds to the blue sub-pixel P1, the green quantum dot area 302 corresponds to the green sub-pixel P2, and the red quantum dot area 303 corresponds to the red sub-pixel P3, thereby further improving the display color gamut of the picture. The planar shape of the transparent area 301, the green quantum dot area 302 and the red quantum dot area 303 is a strip structure parallel to each other. The transparent area 301, the green quantum dot area 302 and the red quantum dot area 303 extend along the column direction, and a transparent area 301, a green quantum dot area 302 and a red quantum dot area 303 are periodically arranged in the row direction. Figure 4 As shown, the transparent area 301 corresponds to the transmission area 201, and the green quantum dot area 302 and the red quantum dot area 303 both correspond to the reflection area 202, that is, the planar shapes of the transmission area 201 and the reflection area 202 are parallel to each other and extend along the column direction, and a transmission area 201 and a reflection area 202 are periodically arranged in the row direction. Of course, in other embodiments, the transparent area 301, the green quantum dot area 302, and the red quantum dot area 303 can also adopt other corresponding relationships with the pixel unit P.

[0056] In another embodiment, if Figure 7 As shown, the planar shape of the transparent area 301, the green quantum dot area 302 and the red quantum dot area 303 is a block structure, and multiple transparent areas 301, multiple green quantum dot areas 302 and multiple red quantum dot areas 303 are distributed in an array. In any two adjacent columns and any two adjacent rows, the arrangement of the transparent area 301, the green quantum dot area 302 and the red quantum dot area 303 is staggered, that is, the transparent area 301, the green quantum dot area 302 and the red quantum dot area 303 are distributed in a manner similar to a mosaic, so that the blue light, green light and red light passing through the light filtering liquid crystal box 20 can be mixed more evenly to form white light with higher color purity, thereby improving the display color gamut of the product. Figure 6As shown, the transparent area 301 corresponds to the transmission area 201, and the green quantum dot area 302 and the red quantum dot area 303 both correspond to the reflection area 202, that is, the planar shape of the transmission area 201 and the reflection area 202 is a block structure, and multiple transmission areas 201 and multiple reflection areas 202 are distributed in an array. The transmission areas 201 correspond to the transparent areas 301 one by one, and one reflection area 202 corresponds to one green quantum dot area 302 and one red quantum dot area 303.

[0057] Furthermore, the areas of the transparent region 301, the green quantum dot region 302 and the red quantum dot region 303 are all the same. Therefore, the area of ​​the reflective region 202 is twice the area of ​​the transmissive region 201, so that the amount of blue light, green light and red light passing through the light-filtering liquid crystal box 20 is the same, so as to facilitate mixing to form white light with higher color purity, thereby improving the display color gamut of the product.

[0058] like Figure 1 As shown, the display liquid crystal box 10 includes a color filter substrate 11, an array substrate 12 disposed opposite to the color filter substrate 11, and a liquid crystal layer 13 located between the color filter substrate 11 and the array substrate 12. The liquid crystal layer 13 uses positive liquid crystal molecules, that is, liquid crystal molecules with positive dielectric anisotropy. Figure 1 As shown, in the initial state, the positive liquid crystal molecules in the liquid crystal layer 13 are aligned parallel to the color filter substrate 11 and the array substrate 12, and the alignment directions of the positive liquid crystal molecules close to the color filter substrate 11 and the positive liquid crystal molecules close to the array substrate 12 are parallel or anti-parallel to each other. Of course, in other embodiments, the positive liquid crystal molecules in the liquid crystal layer 13 are aligned parallel to the color filter substrate 11 and the array substrate 12, and the alignment directions of the positive liquid crystal molecules close to the color filter substrate 11 and the positive liquid crystal molecules close to the array substrate 12 can also be perpendicular to each other, that is, the positive liquid crystal molecules in the liquid crystal layer 13 are twisted 90° to form a TN display mode. Alternatively, the liquid crystal layer 13 can also use negative liquid crystal molecules, and the negative liquid crystal molecules in the liquid crystal layer 13 can be aligned perpendicular to the color filter substrate 11 and the array substrate 12, that is, similar to the alignment mode of the VA display mode.

[0059] A color resist layer 112 and a black matrix (BM) 111 separating the color resist layer 112 are provided on the color filter substrate 11 on the side facing the liquid crystal layer 13. The color resist layer 112 includes, for example, three color resist materials of blue (B), green (G), and red (R), which respectively form a blue sub-pixel P1, a green sub-pixel P2, and a red sub-pixel P3. The black matrix 111 is located between the blue sub-pixel P1, the green sub-pixel P2, and the red sub-pixel P3, so that adjacent pixel units P are separated from each other by the black matrix 111.

[0060] like Figure 2As shown, the array substrate 12 is formed into a plurality of pixel units P by a plurality of scan lines 1 and a plurality of data lines 2 which are insulated and crossed from each other on the side facing the liquid crystal layer 13. The black matrix 111 corresponds to the scan lines 1 and the data lines 2 up and down. A pixel electrode 122 and a thin film transistor 3 are provided in each pixel unit P. The pixel electrode 122 is electrically connected to the data line 2 adjacent to the thin film transistor 3 through the thin film transistor 3. The thin film transistor 3 includes a gate, an active layer, a drain and a source. The gate is located in the same layer as the scan line 1 and is electrically connected. The gate is separated from the active layer by an insulating layer. The source is electrically connected to the data line 2. The drain is electrically connected to the pixel electrode 122 through a contact hole.

[0061] In this embodiment, a common electrode 121 is further provided on the side of the array substrate 12 facing the liquid crystal layer 13. The common electrode 121 and the pixel electrode 122 are located in different layers and are insulated and isolated by an insulating layer. The common electrode 121 can be located above or below the pixel electrode 122 ( Figure 1 As shown in the figure, the common electrode 121 is located below the pixel electrode 122). Preferably, the common electrode 121 is a planar electrode arranged on the entire surface, and the pixel electrode 122 is a slit electrode having a plurality of electrode strips in each pixel unit P to form a fringe field switching mode (Fringe Field Switching, FFS). Of course, in other embodiments, the pixel electrode 122 and the common electrode 121 are located on the same layer, but the two are insulated and isolated from each other. The pixel electrode 122 and the common electrode 121 can each include a plurality of electrode strips, and the electrode strips of the pixel electrode 122 and the electrode strips of the common electrode 121 are alternately arranged to form an in-plane switching mode (In-Plane Switching, IPS). Alternatively, the array substrate 12 is provided with a pixel electrode 122 on the side facing the liquid crystal layer 13, and the color film substrate 11 is provided with a common electrode 121 on the side facing the liquid crystal layer 13 to form a TN mode or a VA mode. As for other introductions to the TN mode and the VA mode, please refer to the prior art and will not be repeated here.

[0062] A first polarizer 113 is disposed on the color filter substrate 11 , and a second polarizer 123 is disposed on the array substrate 12 . The light transmission axis of the first polarizer 113 and the light transmission axis of the second polarizer 123 are perpendicular to each other.

[0063] The color filter substrate 11, the array substrate 12, the first substrate 21 and the second substrate 22 may be made of glass, acrylic, polycarbonate, etc. The common electrode 121 and the pixel electrode 122 may be made of transparent conductive materials such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0064] Figure 8 Schematic diagram of the structure of the liquid crystal display device in the first embodiment of the present utility model when displaying a picture. Figure 8As shown, when the liquid crystal display device is displaying a picture, the cholesteric liquid crystal layer 23 corresponding to the transmission area 201 is controlled to be in a transmission state, and the cholesteric liquid crystal layer 23 corresponding to the reflection area 202 is controlled to be in a reflection state, a common voltage is applied to the common electrode 121, and a corresponding grayscale voltage of 0-255 is applied to the pixel electrode 122, so that the corresponding pixel unit P presents different brightness to display different pictures. Among them, since the alignment modes of the cholesteric liquid crystal layer 23 corresponding to the transmission area 201 in the present application are all in a transmission state (fog state, transparent state) alignment, and the alignment modes of the cholesteric liquid crystal layer 23 corresponding to the reflection area 202 are all in a reflection state alignment, therefore, the filter liquid crystal box 20 does not need to be controlled by an electrical signal, saving driving power consumption.

[0065] Fig. 9 Schematic diagram of the optical path analysis of the liquid crystal display device in the first embodiment of the present utility model when displaying a picture. Fig. 9 As shown, when the liquid crystal display device displays a picture, the backlight module 40 emits a blue light source, and the blue light can directly pass through the transparent area 301 and the transmission area 201 and be emitted from the filter liquid crystal box 20. The green quantum dot area 302 and the red quantum dot area 303 can respectively excite the blue light into green light and red light, and the green light and the red light can be emitted from the reflection area 202 of the filter liquid crystal box 20. The blue light not used by the green quantum dot area 302 and the red quantum dot area 303 will be reflected back by the cholesteric liquid crystal layer 23 in the reflection state in the reflection area 202 for repeated use. On the one hand, the color purity of the green light and the red light in the reflection area 202 can be improved, and on the other hand, the utilization rate of the backlight source can be improved to save power consumption. The blue light, green light and red light passing through the filter liquid crystal box 20 will mix to form white light with higher color purity, thereby improving the display color gamut of the product. Therefore, only a thinner color resist layer 112 needs to be provided on the color film substrate 11 to achieve a high color gamut display. The thinner color resist layer 112 can also improve the transmittance of light and further improve the utilization rate of light.

[0066] [Example 2]

[0067] Fig.10 Schematic diagram of the structure of the liquid crystal display device in the initial state in the second embodiment of the present utility model. Fig.10 As shown, the liquid crystal display device provided by the second embodiment of the present invention is different from that provided by the first embodiment ( Figures 1 to 9 ) are substantially the same, except that, in this embodiment:

[0068] A diffusion sheet 50 is provided between the display liquid crystal box 10 and the filter liquid crystal box 20. The diffusion sheet 50 can scatter the blue light, green light and red light passing through the filter liquid crystal box 20 to a certain extent, thereby uniformly mixing the blue light, green light and red light emitted by the filter liquid crystal box 20 to form white light with higher color purity and improve the display color gamut of the product.

[0069] It should be understood by those skilled in the art 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 described in detail here.

[0070] [Example 3]

[0071] Fig.11 It is a schematic structural diagram of the liquid crystal display device in the initial state in the third embodiment of the present utility model. Fig.12 It is a schematic diagram of the principle of the transformation of the three states of cholesteric liquid crystal in the third embodiment of the present utility model.

[0072] Fig.13 This is a schematic diagram of the driving signal for the three-state transformation of the cholesteric liquid crystal in the third embodiment of the present utility model.

[0073] Fig.14 Schematic diagram of the structure of the liquid crystal display device in the third embodiment of the present utility model when displaying a picture. Figures 11 to 14 As shown, the liquid crystal display device provided in the third embodiment of the present invention is different from that in the first embodiment ( Figures 1 to 9 )、Example 2 ( Fig.10 ) is basically the same as the liquid crystal display device in the embodiment, except that, in this embodiment: the cholesteric phase liquid crystal usually controls the arrangement state of the liquid crystal molecules by voltage, such as initially applying a large voltage, that is, a transparent state, and then quickly removing the voltage and slowly removing the voltage to form a planar texture state or a focal conic state. Among them, the transparent state needs to be powered for a long time, while the planar texture state and the focal conic state do not need to be continuously powered after they are formed.

[0074] like Fig.11 As shown, the alignment modes of all cholesteric liquid crystal layers 23 are all reflective alignment, that is, all cholesteric liquid crystal layers 23 are initially aligned in a reflective state. A common electrode 211 is provided on the first substrate 21, and a first control electrode 221 and a second control electrode 222 are provided on the second substrate 22 to cooperate with the common electrode 211. The first control electrode 221 corresponds to the transmission area 201, and the second control electrode 221 corresponds to the reflection area 202. The common electrode 211 is a planar electrode that covers the entire surface of the first substrate 21. Therefore, when the liquid crystal display device is displaying a picture, the cholesteric liquid crystal in the transmission area 201 can be controlled to be in a transmission state (foggy state, transparent state) by the first control electrode 221 and the common electrode 211. Since the cholesteric liquid crystal in the reflection area 202 may be disturbed by other electric fields for a long time and rotate to a certain extent, resulting in a decrease in the reflection effect of the cholesteric liquid crystal corresponding to the reflection area 202 on blue light, the second control electrode 221 and the common electrode 211 jointly drive the cholesteric liquid crystal corresponding to the reflection area 202 to remain in a reflective state to ensure that the cholesteric liquid crystal corresponding to the reflection area 202 has a better reflection effect on blue light.

[0075] like Fig.12 and Fig.13 As shown, a common voltage signal Vcom is applied to the common electrode 211, and a first electric signal V1 is continuously applied to the control electrodes (the first control electrode 221 and the second control electrode 222), and a voltage difference (for example, 16V) is formed between the common voltage signal Vcom and the first electric signal V1, and a strong vertical electric field is formed between the common electrode 211 and the control electrode, and the cholesteric liquid crystal in the cholesteric liquid crystal layer 13 rotates and stagnates in the H state (transparent state); a common voltage signal Vcom is applied to the common electrode 211, and a second electric signal V2 is applied to the control electrode, and a voltage difference (for example, 16V) is formed between the second electric signal V2 and the common voltage signal Vcom, and the second electric signal V2 gradually becomes the same as the common voltage signal Vcom within a first preset time, that is, the second electric signal V2 first has a large voltage difference with the common voltage signal Vcom, and then slowly decreases and becomes the same as the common voltage signal Vcom. Therefore, a strong vertical electric field is first formed between the common electrode 211 and the control electrode, and then the vertical electric field disappears slowly, so that the cholesteric liquid crystal in the cholesteric liquid crystal layer 13 rotates and stagnates in the FC state, which is a scattering state and has a light-scattering effect; a common voltage signal Vcom is applied to the common electrode 211, and a third electric signal V3 is applied to the control electrode. There is a voltage difference (for example, 16V) between the third electric signal V3 and the common voltage signal Vcom, and the third electric signal V3 directly becomes the same as the common voltage signal Vcom at the second preset time, and the second preset time is less than the first preset time, that is, the third electric signal V3 first has a large voltage difference with the common voltage signal Vcom, and then quickly decreases and becomes the same as the common voltage signal Vcom. Therefore, a strong vertical electric field is first formed between the common electrode 211 and the control electrode, and then the vertical electric field disappears quickly, so that the cholesteric liquid crystal in the cholesteric liquid crystal layer 13 rotates and stagnates in the P state, which is a reflection state.

[0076] Fig.15 Schematic diagram of the structure of the liquid crystal display device when displaying a picture in another embodiment of the third embodiment of the utility model. Fig.15 As shown, a common electrode 211 is provided on the first substrate 21, and a first control electrode 221 matching the common electrode 211 is provided on the second substrate 22, and both the first control electrode 221 and the common electrode 211 correspond to the transmission area 201. That is, the first control electrode 221 and the common electrode 211 can be provided only in the transmission area 201, and the second control electrode 221 and the common electrode 211 do not need to be provided in the reflection area 202.

[0077] It should be understood by those skilled in the art that the rest of the structure and working principle of this embodiment are the same as those of Embodiment 1 and Embodiment 2, and will not be described in detail here.

[0078] [Example 4]

[0079] Fig.16 It is a schematic structural diagram of the liquid crystal display device in the fourth embodiment of the present utility model in the initial state. Fig.17 Schematic diagram of the structure of the liquid crystal display device in the fourth embodiment of the present utility model when displaying a picture. Fig.16 and Fig.17 As shown, the liquid crystal display device provided by the fourth embodiment of the present invention is different from that provided by the first embodiment ( Figures 1 to 9 )、Example 2 ( Fig.10 ) are substantially the same, except that, in this embodiment:

[0080] like Fig.16 As shown, the alignment modes of all cholesteric liquid crystal layers 23 are all transmissive alignment, that is, all cholesteric liquid crystal layers 23 are initially aligned in a transmissive state, such as a foggy state (FC state). A common electrode 211 is provided on the first substrate 21, and a first control electrode 221 and a second control electrode 222 are provided on the second substrate 22 to cooperate with the common electrode 211. The first control electrode 221 corresponds to the transmissive area 201, and the second control electrode 222 corresponds to the reflective area 202. The common electrode 211 is a planar electrode that covers the entire surface of the first substrate 21. Therefore, when the liquid crystal display device is displaying a picture, the cholesteric liquid crystal in the reflective area 202 can be controlled to be in a reflective state through the second control electrode 221 and the common electrode 211. Since the cholesteric liquid crystal in the transmission area 201 may be disturbed by other electric fields for a long time and rotate to a certain extent, resulting in a reduction in the transmission effect of the cholesteric liquid crystal corresponding to the transmission area 201 on blue light, the first control electrode 221 and the common electrode 211 can reset the cholesteric liquid crystal in the transmission area 201 to a transmission state to ensure that the cholesteric liquid crystal corresponding to the transmission area 201 has a better transmission effect on blue light.

[0081] refer to Fig.12 and Fig.13As shown, a common voltage signal Vcom is applied to the common electrode 211, and a first electric signal V1 is continuously applied to the control electrodes (the first control electrode 221 and the second control electrode 222). There is a voltage difference (e.g., 16V) between the common voltage signal Vcom and the first electric signal V1. A strong vertical electric field is formed between the common electrode 211 and the control electrodes, and the cholesteric liquid crystal in the cholesteric liquid crystal layer 13 rotates and stagnates in the H state (transparent state). A common voltage signal Vcom is applied to the common electrode 211, and a second electric signal V2 is applied to the control electrodes. There is a voltage difference (e.g., 16V) between the second electric signal V2 and the common voltage signal Vcom, and the second electric signal V2 gradually becomes the same as the common voltage signal Vcom within a first preset time, that is, the second electric signal V2 first has a large voltage difference with the common voltage signal Vcom, and then slowly decreases and becomes the same as the common voltage signal Vcom. Therefore, a strong vertical electric field is first formed between the common electrode 211 and the control electrode, and then the vertical electric field disappears slowly, so that the cholesteric liquid crystal in the cholesteric liquid crystal layer 13 rotates and stagnates in the FC state, which is a scattering state and has a light-scattering effect. A common voltage signal Vcom is applied to the common electrode 211, and a third electric signal V3 is applied to the control electrode. There is a voltage difference (for example, 16V) between the third electric signal V3 and the common voltage signal Vcom, and the third electric signal V3 directly becomes the same as the common voltage signal Vcom at the second preset time. The second preset time is less than the first preset time, that is, the third electric signal V3 first has a large voltage difference with the common voltage signal Vcom, and then quickly decreases and becomes the same as the common voltage signal Vcom. Therefore, a strong vertical electric field is first formed between the common electrode 211 and the control electrode, and then the vertical electric field disappears quickly, so that the cholesteric liquid crystal in the cholesteric liquid crystal layer 13 rotates and stagnates in the P state, which is a reflection state.

[0082] Fig.18 1 is a schematic diagram of the structure of a liquid crystal display device when displaying a picture in another embodiment of the fourth embodiment of the present utility model. Fig.18 As shown, a common electrode 211 is provided on the first substrate 21, and a second control electrode 222 matched with the common electrode 211 is provided on the second substrate 22, and the second control electrode 222 and the common electrode 211 both correspond to the reflective area 202. That is, the second control electrode 221 and the common electrode 211 may be provided only in the reflective area 202, and the first control electrode 221 and the common electrode 211 do not need to be provided in the transmissive area 201.

[0083] It should be understood by those skilled in the art that the rest of the structure and working principle of this embodiment are the same as those of Embodiment 1 and Embodiment 2, and will not be described in detail here.

[0084] In this document, the directional words such as up, down, left, right, front, and back are defined by the positions of the structures in the drawings and the positions of the structures relative to each other, just for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words 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 document are only used to distinguish names and are not used to limit quantity and order.

[0085] The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the profession can make some changes or modifications to the technical contents disclosed above without departing from the scope of the technical solution of the present invention, which are equivalent embodiments of equivalent changes. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A liquid crystal display device, characterized in that: It comprises a backlight module (40), and a quantum dot film (30), a filter liquid crystal box (20), and a display liquid crystal box (10) which are sequentially stacked and arranged in a light emitting direction of the backlight module (40), wherein the display liquid crystal box (10) is used to control the grayscale brightness of a display image, and the backlight module (40) is used to provide a blue light source; The light filtering liquid crystal box (20) comprises a first substrate (21), a second substrate (22) arranged opposite to the first substrate (21), and a cholesteric liquid crystal layer (23) located between the first substrate (21) and the second substrate (22); the cholesteric liquid crystal layer (23) reflects blue light in a reflective state; the light filtering liquid crystal box (20) has a transmission area (201) and a reflection area (202); the transmission area (201) is used to transmit blue light when displaying an image; and the reflection area (202) is used to reflect blue light when displaying an image; The quantum dot film (30) comprises a transparent area (301), a green quantum dot area (302) and a red quantum dot area (303); the green quantum dot area (302) is provided with green quantum dots and can excite green light; the red quantum dot area (303) is provided with red quantum dots and can excite red light; the transparent area (301) corresponds to the transmission area (201); and the green quantum dot area (302) and the red quantum dot area (303) both correspond to the reflection area (202); When the liquid crystal display device is displaying an image, the cholesteric liquid crystal layer (23) corresponding to the transmission area (201) is in a transmission state, and the cholesteric liquid crystal layer (23) corresponding to the reflection area (202) is in a reflection state.

2. The liquid crystal display device according to claim 1, wherein: The alignment modes of the cholesteric liquid crystal layer (23) corresponding to the transmission area (201) are all transmission state alignment, and the alignment modes of the cholesteric liquid crystal layer (23) corresponding to the reflection area (202) are all reflection state alignment.

3. The liquid crystal display device according to claim 1, wherein: The alignment mode of all the cholesteric liquid crystal layers (23) is reflective alignment, a common electrode (211) is provided on the first substrate (21), a first control electrode (221) matched with the common electrode (211) is provided on the second substrate (22), and the first control electrode (221) corresponds to the transmission area (201).

4. The liquid crystal display device according to claim 3, characterized in that: A second control electrode (222) matched with the common electrode (211) is also provided on the second substrate (22), and the second control electrode (222) corresponds to the reflective area (202).

5. The liquid crystal display device according to claim 1, characterized in that: The alignment mode of all the cholesteric liquid crystal layers (23) is a transmission state alignment, a common electrode (211) is provided on the first substrate (21), a second control electrode (222) matched with the common electrode (211) is provided on the second substrate (22), and the second control electrode (222) corresponds to the reflective area (202).

6. The liquid crystal display device according to claim 5, characterized in that: A first control electrode (221) matched with the common electrode (211) is also provided on the second substrate (22), and the first control electrode (221) corresponds to the transmission area (201).

7. The liquid crystal display device according to any one of claims 1 to 6, characterized in that: The planar shapes of the transparent area (301), the green quantum dot area (302) and the red quantum dot area (303) are parallel strip structures; Alternatively, the planar shapes of the transparent area (301), the green quantum dot area (302) and the red quantum dot area (303) are block structures, and a plurality of the transparent areas (301), a plurality of the green quantum dot areas (302) and a plurality of the red quantum dot areas (303) are distributed in an array, and in any two adjacent columns and any two adjacent rows, the arrangements of the transparent areas (301), the green quantum dot areas (302) and the red quantum dot areas (303) are staggered.

8. The liquid crystal display device according to any one of claims 1 to 6, characterized in that: The areas of the transparent region (301), the green quantum dot region (302) and the red quantum dot region (303) are all the same.

9. The liquid crystal display device according to any one of claims 1 to 6, characterized in that: The display liquid crystal box (10) is provided with a plurality of pixel units (P) distributed in an array, wherein the plurality of pixel units (P) include a blue sub-pixel (P1), a green sub-pixel (P2) and a red sub-pixel (P3), the transparent area (301) corresponds to the blue sub-pixel (P1), the green quantum dot area (302) corresponds to the green sub-pixel (P2), and the red quantum dot area (303) corresponds to the red sub-pixel (P3).

10. The liquid crystal display device according to any one of claims 1 to 6, characterized in that: A diffusion sheet (50) is provided between the display liquid crystal box (10) and the filter liquid crystal box (20), and the diffusion sheet (50) is used to evenly mix the colors of light emitted by the filter liquid crystal box (20).

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