Transmission and reflection switchable display device

Abstract

The invention discloses a display device capable of being switched between transmission and reflection. The display device comprises an OLED display panel and a liquid crystal display panel arranged on the light emitting side of the OLED display panel. The liquid crystal display panel comprises a second substrate, a liquid crystal layer and a first substrate which are sequentially arranged, a linear polarizer and a quarter-wave plate are arranged on the first substrate, the quarter-wave plate is located on the side, facing the liquid crystal layer, of the linear polarizer, and the light-transmitting axis of the linear polarizer and the fast and slow axis of the quarter-wave plate form an angle of 45 degrees. In the transmission mode, liquid crystal molecules in the whole liquid crystal layer are controlled to be in a standing posture, the OLED display panel is opened and displays a picture, light rays emitted by the OLED display panel can penetrate through the liquid crystal display panel, ambient light reflected by the OLED display panel can be absorbed by the linear polaroid, and therefore the situation that the contrast ratio of transmission display is reduced by the ambient light reflected by the OLED display panel is avoided; and in the reflection mode, the OLED display panel is closed, so that the liquid crystal display panel can display pictures by using the ambient light reflected by the OLED display panel.

Description

Technical Field

[0001] The present invention relates to the technical field of displays, and in particular to a display device capable of switching between transmission and reflection. Background Art

[0002] With the development of the information age, the application of display screens has become increasingly broad and diversified, and various technical display screens have also flourished. Self-luminous displays are the next generation of displays after LCD (liquid crystal display). They have the advantages of good picture quality, small size, light weight, low driving voltage, low power consumption, no radiation and relatively low manufacturing cost. Their development and application are becoming more and more extensive. Self-luminous displays include OLED (Organic Light-Emitting Diode) displays and Micro LED (micro light-emitting diode) displays.

[0003] OLED displays use voltage to drive organic light-emitting materials to emit light, whether in bright or dark environments, which results in higher power consumption. Moreover, when natural light from the outside shines on the OLED screen, it will be reflected back by the metal cathode after passing through the encapsulation layer. The reflected light from the cathode will also reduce the display contrast and affect the display. Summary of the invention

[0004] In order to overcome the shortcomings and deficiencies in the prior art, an object of the present invention is to provide a display device with switchable transmission and reflection to solve the problems of high display power consumption and low contrast in brighter environments of OLED displays in the prior art.

[0005] The purpose of the present invention is achieved through the following technical solutions: The present invention provides a display device capable of switching between transmission and reflection, comprising an OLED display panel and a liquid crystal display panel arranged on a light-emitting side of the OLED display panel; The liquid crystal display panel comprises a first substrate, a second substrate arranged opposite to the first substrate, and a liquid crystal layer located between the first substrate and the second substrate, the first substrate is located on a side of the liquid crystal layer away from the OLED display panel, the second substrate is located on a side of the liquid crystal layer facing the OLED display panel, a linear polarizer and a quarter wave plate are provided on the first substrate, the quarter wave plate is located on a side of the linear polarizer facing the liquid crystal layer, a light transmission axis of the linear polarizer and a fast-slow axis of the quarter wave plate form an angle of 45 degrees, a control electrode is provided on the second substrate, and a common electrode matched with the control electrode is provided on the first substrate or the second substrate; The OLED display panel includes a substrate, and an anode, a light-emitting layer, and a cathode sequentially arranged on the substrate, wherein the anode and the cathode are used to control the light-emitting state of the light-emitting layer; In the transmission mode, the liquid crystal molecules in the entire liquid crystal layer are in a standing position, the ambient light reflected by the cathode is absorbed by the linear polarizer, the OLED display panel is turned on and displays the image, and the light emitted by the OLED display panel can pass through the liquid crystal display panel; in the reflection mode, the OLED display panel is turned off, the liquid crystal molecules in the liquid crystal layer in the dark state area are in a standing position, the ambient light reflected by the cathode in the dark state area is absorbed by the linear polarizer, the liquid crystal molecules in the liquid crystal layer in the bright state area are in a lying position and have a phase delay of λ / 4, and the ambient light reflected by the cathode in the bright state area can be emitted from the linear polarizer.

[0006] Furthermore, the display device includes a diffuse reflection structure, and the diffuse reflection structure is arranged on the light emitting side of the OLED display panel.

[0007] Furthermore, the diffuse reflection structure is arranged on a side of the second substrate facing the liquid crystal layer; Alternatively, the diffuse reflection structure is arranged on a side of the second substrate away from the liquid crystal layer; Alternatively, the diffuse reflection structure is arranged on a side of the OLED display panel facing the liquid crystal display panel.

[0008] Furthermore, the diffuse reflection structure has a plurality of protruding structures, or the diffuse reflection structure is a PDLC liquid crystal cell or a PNLC liquid crystal cell.

[0009] Furthermore, the second substrate is provided with a plurality of scan lines, a plurality of data lines and a plurality of thin film transistors, the scan lines and the data lines are insulated from each other and cross-defined to form a plurality of first pixel units distributed in a matrix, the control electrode includes pixel electrodes corresponding to the first pixel units one by one, and the pixel electrodes are electrically connected to the scan lines and the data lines adjacent to the thin film transistors through the thin film transistors.

[0010] Furthermore, the display device has a pattern area and a background area, and the control electrode includes a first electrode and a second electrode that are insulated from each other, the first electrode corresponds to the pattern area, and the second electrode corresponds to the background area.

[0011] Furthermore, a black matrix and a color resist layer are provided on the first substrate, the black matrix is ​​used to separate the multiple color resist layers from each other, the liquid crystal display panel has a first pixel unit corresponding to the color resist layer, and a second pixel unit corresponding to the OLED display panel, and the first pixel unit corresponds to the second pixel unit one by one.

[0012] Furthermore, the common electrode matched with the control electrode is provided on the first substrate, the liquid crystal molecules in the liquid crystal layer are aligned parallel to the first substrate and the second substrate, the alignment direction of the liquid crystal molecules close to the first substrate is perpendicular to the alignment direction of the liquid crystal molecules close to the second substrate, and the liquid crystal layer has a phase delay of λ / 4 in an initial state; Alternatively, the common electrode that cooperates with the control electrode is provided on the first substrate, and the liquid crystal molecules in the liquid crystal layer are aligned perpendicular to the first substrate and the second substrate. When the liquid crystal molecules are in a lying posture, the long axis of the liquid crystal molecules is 45° with the transmission axis of the linear polarizer. At this time, the liquid crystal layer has a phase delay of λ / 4.

[0013] Furthermore, the liquid crystal layer includes liquid crystal molecules and nanoparticles mixed with each other, the refractive index of the nanoparticles is different from the refractive index of the liquid crystal molecules, and the nanoparticles and the liquid crystal molecules cooperate with each other and can reflect and scatter light.

[0014] Furthermore, the refractive index of the nanoparticles differs from the refractive index of the liquid crystal molecules by more than 0.1; And / or, the nanoparticles are spherical or strip-shaped; And / or, the diameter of the nanoparticles is 5nm~500nm; And / or, the nanoparticles are white or transparent.

[0015] The beneficial effect of the present invention is that: by arranging a liquid crystal display panel on the light-emitting side of an OLED display panel, and providing a linear polarizer and a quarter-wave plate that cooperate with each other on the liquid crystal display panel, in the transmission mode, the liquid crystal molecules in the entire liquid crystal layer are controlled to be in a standing posture, the OLED display panel is turned on and displays the picture, so that the light emitted by the OLED display panel can pass through the liquid crystal display panel, and the ambient light reflected by the OLED display panel is absorbed by the linear polarizer, thereby avoiding the ambient light reflected by the OLED display panel from reducing the contrast of the transmission display; in the reflection mode, the OLED display panel is turned off, and the liquid crystal display panel displays normally, so that the liquid crystal display panel can use the ambient light reflected by the OLED display panel to display the picture, so as to reduce the power consumption of the display. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the display device in the initial state in the first embodiment of the present invention.

[0017] Figure 2 It is a schematic diagram of the planar structure of the second substrate in the first embodiment of the present invention.

[0018] Figure 3 1 is a schematic diagram of the structure of the display device in the first embodiment of the present invention when in the bright state of the reflective mode.

[0019] Figure 4 It is a schematic diagram of the optical path principle of the display device in the first embodiment of the present invention when it is in the bright state of the reflective mode.

[0020] Figure 5 1 is a schematic diagram of the structure of the display device in the first embodiment of the present invention in the dark state of the reflective mode.

[0021] Figure 6 It is a schematic diagram of the optical path principle of the display device in the first embodiment of the present invention when it is in the dark state of the reflective mode.

[0022] Figure 7 1 is a schematic diagram of the structure of the display device in the first embodiment of the present invention when in the bright state of the transmission mode.

[0023] Figure 8 Schematic diagram of the optical path principle of the display device in the first embodiment of the present invention when in the bright state of the transmission mode.

[0024] Fig. 9 This is one of the structural schematic diagrams of the display device in the initial state in the second embodiment of the present invention.

[0025] Fig.10 This is the second structural schematic diagram of the display device in the initial state in the second embodiment of the present invention.

[0026] Fig.11 It is a schematic diagram of the structure of the display device in the third embodiment of the present invention in the dark state of the reflective mode.

[0027] Fig.12 It is a schematic diagram of the structure of the display device in the third embodiment of the present invention when in the bright state of the reflective mode.

[0028] Fig.13 It is a schematic diagram of the structure of the display device in the initial state in the fourth embodiment of the present invention.

[0029] Fig.14 This is one of the planar structural schematic diagrams of the display device in the fourth embodiment of the present invention.

[0030] Fig.15 This is one of the planar structural schematic diagrams of the control electrode in the fourth embodiment of the present invention.

[0031] Fig.16 This is the second schematic diagram of the planar structure of the display device in the fourth embodiment of the present invention.

[0032] Fig.17 This is the second schematic diagram of the planar structure of the control electrode in the fourth embodiment of the present invention.

[0033] Fig.18 It is a schematic diagram of the structure of the display device in the fourth embodiment of the present invention when the screen is in the off-screen display state.

[0034] Fig.19 It is a schematic diagram of the structure of the display device in the initial state in the fifth embodiment of the present invention.

[0035] Fig. 20 It is a schematic diagram of the planar structure of the first substrate in Embodiment 5 of the present invention.

[0036] Fig.21 It is a schematic diagram of the planar structure of the OLED display panel in the fifth embodiment of the present invention.

[0037] Fig. 22 It is a schematic diagram of the structure of the display device in the initial state in the sixth embodiment of the present invention.

[0038] Fig.23 It is a schematic diagram of the structure of spherical nanoparticles and liquid crystal molecules in Example 6 of the present invention.

[0039] Fig.24 It is a schematic diagram of the structure of strip-shaped nanoparticles and liquid crystal molecules in Example 6 of the present invention. DETAILED DESCRIPTION

[0040] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation manner, structure, features and effects of the display device with switchable transmission and reflection according to the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments: [Example 1] Figure 1 It is a schematic diagram of the structure of the display device in the initial state in the first embodiment of the present invention. Figure 2 It is a schematic diagram of the planar structure of the second substrate in the first embodiment of the present invention.

[0041] like Figure 1 and Figure 2 As shown, a display device capable of switching between transmission and reflection is provided in the first embodiment of the present invention, comprising an OLED display panel 20 and a liquid crystal display panel 10 disposed on the light-emitting side of the OLED display panel 20. The OLED display panel 20 is used to control the display of the image in the transmission mode, and the liquid crystal display panel 10 is used to control whether the light reflected by the OLED display panel 20 can be emitted from the liquid crystal display panel 10.

[0042] The OLED display panel 20 includes a substrate 21 and an anode 22, a light-emitting layer 23 and a cathode 24 sequentially arranged on the substrate 21. The light-emitting layer 23 is located between the anode 22 and the cathode 24. The anode 22 and the cathode 24 are used to control the light-emitting state of the light-emitting layer 23. The corresponding light-emitting layer 23 is controlled to emit light by applying corresponding electrical signals to the anode 22 and the cathode 24. Among them, the anode 22 may include an indium tin oxide (Indium Tin Oxide, referred to as ITO) wiring layer, a silver (Ag) reflection layer and an ITO electrode layer sequentially arranged on the substrate 21. Among them, the ITO wiring layer and the ITO electrode layer may also be replaced by an indium zinc oxide (Indium Zinc Oxide, referred to as IZO) wiring layer and an IZO electrode layer. The cathode 24 may be made of materials such as silver, silver-magnesium (Mg) alloy, molybdenum (Mo), and aluminum (Al). It is understandable that the anode 22, the light-emitting layer 23 and the cathode 24 are not a whole-surface structure, but have a patterned structure corresponding to the pixels. For a more detailed introduction to the OLED display panel 20, please refer to the prior art, which will not be repeated here.

[0043] The liquid crystal display panel 10 includes a first substrate 11, a second substrate 12 disposed opposite to the first substrate 11, and a liquid crystal layer 13 located between the first substrate 11 and the second substrate 12. The first substrate 11 is located on the side of the liquid crystal layer 13 away from the OLED display panel 20, and the second substrate 12 is located on the side of the liquid crystal layer 13 facing the OLED display panel 20. In this embodiment, the liquid crystal molecules 131 in the liquid crystal layer 13 are positive liquid crystal molecules, that is, liquid crystal molecules with positive dielectric anisotropy. The liquid crystal molecules 131 are aligned parallel to the first substrate 11 and the second substrate 12, and the alignment direction of the liquid crystal molecules 131 on the side close to the first substrate 11 is perpendicular to the alignment direction on the side close to the second substrate 12. The liquid crystal molecules 131 are twisted 90° or 270° from the side close to the first substrate 11 toward the second substrate 12 to realize the TN display mode. The liquid crystal layer 13 has a phase delay of λ / 4 in the initial state, so that the reflective liquid crystal display device is in a bright state in the initial state to realize the normally white mode in the reflective mode.

[0044] A linear polarizer 141 and a quarter wave plate 142 are provided on the first substrate 11. The quarter wave plate 142 is located on the side of the linear polarizer 141 facing the liquid crystal layer 13. The light transmission axis of the linear polarizer 141 and the fast and slow axes of the quarter wave plate 142 (the fast axis and the slow axis of the quarter wave plate 142 are perpendicular to each other) are 45°. For example, the light transmission axis of the linear polarizer 141 is 0°, the fast axis of the quarter wave plate 142 is 45°, and the slow axis of the quarter wave plate 142 is -45°.

[0045] In this embodiment, a control electrode 121 is provided on the second substrate 12, and a common electrode 112 matched with the control electrode 121 is provided on the first substrate 11. The control electrode 121 includes a pixel electrode corresponding to the first pixel unit P1 one by one, and the common electrode 112 is a planar electrode covering the entire surface of the first substrate 11. The pixel electrode is used to apply a grayscale voltage, thereby forming a vertical electric field with the common electrode 112 to control the liquid crystal molecules 131 to deflect horizontally in the vertical direction. Of course, in other embodiments, the common electrode 112 can also be provided on the second substrate 12 to form a fringe field switching mode (Fringe Field Switching, FFS) or an in-plane switching mode (In-Plane Switching, IPS).

[0046] like Figure 2 As shown, the second substrate 12 is provided with a plurality of scan lines 1 and a plurality of data lines 2 on the side facing the liquid crystal layer 13. The plurality of scan lines 1 and the plurality of data lines 2 are insulated from each other and cross-defined to form a plurality of first pixel units P1. A pixel electrode and a thin film transistor 3 are provided in each first pixel unit P1. The pixel electrode 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 through a contact hole.

[0047] In this embodiment, a black matrix 111 and a transparent area are provided on the first substrate 11. The black matrix 111 is used to separate the plurality of transparent areas from each other. The liquid crystal display panel 10 has a first pixel unit P1 corresponding to the transparent area, so that a black and white image display is realized in the reflective mode. Figure 1 As shown, the OLED display panel 20 has a second pixel unit P2 corresponding to the light-emitting layer 23, wherein the first pixel unit P1 can correspond one-to-one with the second pixel unit P2. Of course, each first pixel unit P1 can also correspond to multiple second pixel units P2, or multiple first pixel units P1 correspond to one second pixel unit P2.

[0048] Furthermore, the display device includes a diffuse reflection structure 122, which is disposed on the light-emitting side of the OLED display panel 20. The diffuse reflection structure 122 scatters ambient light, thereby achieving a diffuse reflection effect in the reflection mode to enhance the display effect. In this embodiment, the diffuse reflection structure 122 is disposed on the side of the second substrate 12 facing the liquid crystal layer 13, and the diffuse reflection structure 122 has a plurality of protruding structures, similar to a frosted structure. The diffuse reflection structure 122 can be made of OC material and nano-imprinted on the side of the second substrate 12 facing the liquid crystal layer 13.

[0049] The first substrate 11, the second substrate 12 and the base 21 may be made of glass, acrylic acid, polycarbonate, etc. The control electrode 121 and the common electrode 112 may be made of indium tin oxide (ITO) or indium zinc oxide (IZO), etc.

[0050] Figure 3 1 is a schematic diagram of the structure of the display device in the first embodiment of the present invention when in the bright state of the reflective mode. Figure 4 Schematic diagram of the optical path principle of the display device in the first embodiment of the present invention when in the bright state of the reflective mode. Figure 3 As shown, in the bright state of the reflective mode, the OLED display panel 20 is turned off, no voltage is applied to the pixel electrodes in the bright state area, and the liquid crystal molecules 131 in the liquid crystal layer 13 maintain the initial flat and twisted state. At this time, the liquid crystal layer 13 has a phase delay of λ / 4, and the ambient light reflected by the cathode 24 in the bright state area can be emitted from the linear polarizer 141. Figure 4 As shown, the ambient light I passes through the linear polarizer 141 and becomes linear polarized light (e.g., 0°), the linear polarized light passes through the quarter wave plate 142 and becomes circular polarized light (e.g., left-handed), the circular polarized light passes through the liquid crystal layer 13 and becomes linear polarized light (e.g., 0°), and the polarization direction of the linear polarized light remains unchanged after being reflected by the cathode 24; the reflected light passes through the liquid crystal layer 13 and becomes circular polarized light (e.g., left-handed), the circular polarized light passes through the quarter wave plate 142 and becomes linear polarized light (e.g., 0°), and then is emitted from the linear polarizer 141 to realize the bright state of the reflection mode.

[0051] Figure 5 1 is a schematic diagram of the structure of the display device in the first embodiment of the present invention in the dark state of the reflective mode. Figure 6 Schematic diagram of the optical path principle of the display device in the dark state of the reflective mode in the first embodiment of the present invention. Figure 5 As shown, in the dark state of the reflective mode, the LED display panel 20 is turned off, a common voltage is applied to the common electrode 112, a dark voltage (for example, 5V) is applied to the pixel electrode in the dark state area, and a strong vertical electric field ( Figure 5 In E1), the liquid crystal molecules 131 in the liquid crystal layer 13 are deflected in the vertical direction and are perpendicular to the first substrate 11 and the second substrate 12. At this time, the liquid crystal molecules 131 in the dark state area are all in a standing posture and have no phase delay, and the ambient light reflected by the cathode 24 in the dark state area is absorbed by the linear polarizer 141. Figure 6As shown, the ambient light I passes through the linear polarizer 141 and becomes linear polarized light (for example, 0°), the linear polarized light passes through the quarter wave plate 142 and becomes circular polarized light (for example, left-handed), the circular polarized light passes through the liquid crystal layer 13 and is still circular polarized light (for example, left-handed), the circular polarized light is reflected by the cathode 24 and the rotation direction is opposite (becomes right-handed); the reflected light passes through the liquid crystal layer 13 and is still circular polarized light (for example, right-handed), the circular polarized light passes through the quarter wave plate 142 and becomes linear polarized light (for example, 90°), and then is absorbed by the linear polarizer 141 to realize the dark state of the reflective mode.

[0052] Figure 7 1 is a schematic diagram of the structure of the display device in the first embodiment of the present invention when in the bright state of the transmission mode. Figure 8 Schematic diagram of the optical path principle of the display device in the first embodiment of the present invention when in the bright state of the transmission mode. Figure 7 As shown, in the transmission mode, the OLED display panel 20 is turned on and displays the picture, and the picture displayed in the transmission mode is controlled by the OLED display panel 20. A common voltage is applied to the common electrode 112, and a dark voltage (for example, 5V) is applied to all pixel electrodes, and a strong vertical electric field ( Figure 7 In FIG. E1 , the liquid crystal molecules 131 in the liquid crystal layer 13 are deflected in the vertical direction and are perpendicular to the first substrate 11 and the second substrate 12. At this time, all the liquid crystal molecules 131 are in a standing posture and have no phase delay. The ambient light reflected by the cathode 24 is absorbed by the linear polarizer 141, but the light emitted by the OLED display panel 20 can pass through the liquid crystal display panel 10. Figure 6 As shown, for ambient light, ambient light I passes through the linear polarizer 141 and becomes linear polarized light (e.g., 0°), and the linear polarized light passes through the quarter wave plate 142 and becomes circular polarized light (e.g., left-handed), and the circular polarized light passes through the liquid crystal layer 13 and remains circular polarized light (e.g., left-handed), and the circular polarized light is reflected by the cathode 24 and has the opposite rotation direction (becomes right-handed); the reflected light passes through the liquid crystal layer 13 and remains circular polarized light (e.g., right-handed), and the circular polarized light passes through the quarter wave plate 142 and becomes linear polarized light (e.g., 90°), and is then absorbed by the linear polarizer 141. Figure 8 As shown, for the light (backlight) emitted by the OLED display panel 20, the backlight passes through the liquid crystal layer 13 and the quarter wave plate 142 in sequence without being changed, and then passes through the linear polarizer 141 to become linear polarized light (for example, 0°) and is emitted from the linear polarizer 141. Thus, the light emitted by the OLED display panel 20 can pass through the liquid crystal display panel 10, and the displayed picture is controlled by the OLED display panel 20 in the transmission mode, and the ambient light reflected by the OLED display panel 20 is absorbed by the linear polarizer 141, so as to avoid the ambient light reflected by the OLED display panel 20 reducing the contrast of the transmission display.

[0053] [Example 2] Fig. 9 This is one of the structural schematic diagrams of the display device in the initial state in the second embodiment of the present invention. Fig.10 FIG. 2 is a second structural diagram of the display device in the initial state in the second embodiment of the present invention. Fig. 9 and Fig.10 The display device with switchable transmission and reflection provided by the second embodiment of the present invention is similar to the display device of the first embodiment ( Figures 1 to 8 ) are substantially the same, except that, in this embodiment: like Fig. 9 As shown, the diffuse reflection structure 122 is disposed on a side of the second substrate 12 away from the liquid crystal layer 13. Alternatively, as Fig.10 As shown, the diffuse reflection structure 122 is disposed on the side of the OLED display panel 20 facing the liquid crystal display panel 10. That is, the diffuse reflection structure 122 is disposed between the liquid crystal display panel 10 and the OLED display panel 20, thereby avoiding the influence of the protruding structure of the diffuse reflection structure 122 on the alignment of the liquid crystal layer 13, which causes the liquid crystal alignment to be chaotic and produces a problem of poor Domain. Of course, in other embodiments, the diffuse reflection structure 122 is also a PDLC (polymer dispersed liquid crystal) liquid crystal box or a PNLC (Polymer Network Liquid Crystal) liquid crystal box. The PDLC liquid crystal box and the PNLC liquid crystal box have a scattering effect on light when in a foggy state, and can also achieve a diffuse reflection effect in a reflective mode to enhance the display effect.

[0054] 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.

[0055] [Example 3] Fig.11 It is a schematic diagram of the structure of the display device in the third embodiment of the present invention in the dark state of the reflective mode. Fig.12 Schematic diagram of the structure of the display device in the third embodiment of the present invention in the bright state of the reflective mode. Fig.11 and Fig.12 As shown, the display device with switchable transmission and reflection provided in the third embodiment of the present invention is different from the display device in the first embodiment ( Figures 1 to 9 )、Example 2 ( Fig. 9 and Fig.10 ) are substantially the same, except that, in this embodiment: like Fig.11As shown, a common electrode 112 matching the control electrode 121 is provided on the first substrate 11, and the liquid crystal molecules 131 in the liquid crystal layer 13 are aligned perpendicular to the first substrate 11 and the second substrate 12. When the liquid crystal molecules 131 are in a flat posture, the long axis of the liquid crystal molecules 131 is 45° with the light transmission axis of the linear polarizer 141. At this time, the liquid crystal layer 13 has a phase delay of λ / 4. Further, the liquid crystal molecules 131 use negative liquid crystal molecules, that is, liquid crystal molecules with negative dielectric anisotropy. The liquid crystal molecules 131 are aligned perpendicular to the first substrate 11 and the second substrate 12 to realize the VA display mode. When the liquid crystal molecules 131 are in a flat posture, the long axis of the liquid crystal molecules 131 is 45° with the light transmission axis of the linear polarizer 141. At this time, the liquid crystal layer 13 has a phase delay of λ / 4. Among them, the pre-tilt angle of the liquid crystal molecules 131 can be 80~90°, so as to deflect toward the flat posture and orient the deflection direction of the liquid crystal molecules 131. In this embodiment, the liquid crystal molecules 131 are aligned perpendicularly to the first substrate 11 and the second substrate 12, so that the liquid crystal display panel 10 can prevent the OLED display panel 20 from reflecting ambient light in the initial state. In the transmission display mode, there is no need to apply a driving voltage to the control electrode 121, thereby saving power consumption.

[0056] 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.

[0057] [Example 2] Fig.13 It is a schematic diagram of the structure of the display device in the initial state in the fourth embodiment of the present invention. Fig.14 This is one of the planar structural schematic diagrams of the display device in the fourth embodiment of the present invention. Fig.15 This is one of the planar structural schematic diagrams of the control electrode in the fourth embodiment of the present invention. Fig.16 This is the second schematic diagram of the planar structure of the display device in the fourth embodiment of the present invention. Fig.17 FIG. 2 is a second schematic diagram of the planar structure of the control electrode in the fourth embodiment of the present invention. Figures 13 to 17 As shown, the display device with switchable transmission and reflection provided by the second embodiment of the present invention is different from the display device of the first embodiment ( Figures 1 to 8 )、Example 2 ( Fig. 9 and Fig.10 )、Example 3 ( Fig.11 and Fig.12 ) are substantially the same, except that, in this embodiment: The display device has a pattern area 110 and a background area 120, and the control electrode 121 includes a first electrode 121a and a second electrode 121b that are insulated from each other. The first electrode 121a corresponds to the pattern area 110, and the second electrode 121b corresponds to the background area 120. Fig.14 and Fig.15 As shown, the pattern area 110 may be a logo pattern, such as a product logo; Fig.16 and Fig.17 As shown, the pattern area 110 can also be a clock pattern, so that the time is displayed using ambient light when the screen is off. Since the control electrode 121 in the present application includes a first electrode 121a corresponding to the pattern area 110 and a second electrode 121b corresponding to the background area 120, the control logic of the control electrode 121 is simpler, which can simplify the circuit design on the second substrate 12.

[0058] Fig.18 Schematic diagram of the structure of the display device in the fourth embodiment of the present invention when the screen is off display state. Fig.18 As shown, in the off-screen display state, the OLED display panel 20 is turned off, a common voltage is applied to the common electrode 112, no voltage is applied to the first electrode 121a, and the liquid crystal molecules 131 corresponding to the pattern area 110 maintain the initial flat and twisted state. At this time, the liquid crystal layer 13 has a phase delay of λ / 4, and the ambient light reflected by the cathode 24 in the pattern area 110 can be emitted from the linear polarizer 141, so that the pattern area 110 is in a bright state; a dark state voltage (for example, 5V) is applied to the second electrode 121b, and a strong vertical electric field is formed between the second electrode 121b and the common electrode 112, and the liquid crystal molecules 131 corresponding to the background area 120 are deflected in the vertical direction and perpendicular to the first substrate 11 and the second substrate 12. At this time, the liquid crystal molecules 131 in the background area 120 are all in a standing posture and have no phase delay, and the ambient light reflected by the cathode 24 in the background area 120 is absorbed by the linear polarizer 141, so that the pattern area 110 is in a dark state. Therefore, it is possible to display a bright pattern corresponding to the pattern area 110 when the screen is off. Of course, in other embodiments, when the screen is off, a dark voltage (eg, 5V) may be applied to the first electrode 121a, and no voltage may be applied to the second electrode 121b, thereby displaying a dark pattern corresponding to the pattern area 110 when the screen is off.

[0059] 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, Embodiment 2, and Embodiment 3, and will not be described in detail here.

[0060] [Example 5] Fig.19 It is a schematic diagram of the structure of the display device in the initial state in the fifth embodiment of the present invention. Fig. 20It is a schematic diagram of the planar structure of the first substrate in Embodiment 5 of the present invention. Fig.21 FIG. 1 is a schematic diagram of the planar structure of the OLED display panel in the fifth embodiment of the present invention. Figures 19 to 21 As shown, the display device with switchable transmission and reflection provided in the fifth embodiment of the present invention is different from the display device in the first embodiment ( Figures 1 to 8 )、Example 2 ( Fig. 9 and Fig.10 )、Example 3 ( Fig.11 and Fig.12 ), Embodiment 4 ( Figures 13 to 18 ) are substantially the same, except that, in this embodiment: like Figures 19 to 21 As shown, a black matrix 111 and a color resist layer 113 are provided on the first substrate 11. The black matrix 111 is used to separate the multiple color resist layers 113 from each other. The color resist layer 113 includes red, green and blue color resist materials, which correspond to red, green and blue pixels respectively, so that the display device can achieve full-color reflective display.

[0061] Furthermore, the liquid crystal display panel 10 has a first pixel unit P1 corresponding to the color resist layer 113, and the OLED display panel 20 has a second pixel unit P2 corresponding to the light emitting layer 23, and the first pixel unit P1 corresponds to the second pixel unit P2 one by one. Since the first substrate 11 in this embodiment is a color filter substrate, in order not to affect the display of the color picture of the OLED display panel 20, the first pixel unit P1 needs to correspond to the second pixel unit P2 one by one, and the colors of the first pixel unit P1 and the second pixel unit P2 also need to correspond, that is, the red first pixel unit P1 corresponds to the red second pixel unit P2, the green first pixel unit P1 corresponds to the green second pixel unit P2, and the blue first pixel unit P1 corresponds to the blue second pixel unit P2.

[0062] 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, Embodiment 2, Embodiment 3, and Embodiment 4, and will not be described in detail here.

[0063] [Example 6] Fig. 22 Schematic diagram of the structure of the display device in the initial state in the sixth embodiment of the present invention. Fig. 22 As shown, the display device with switchable transmission and reflection provided in the sixth embodiment of the present invention is different from the display device in the first embodiment ( Figures 1 to 8 )、Example 2 ( Fig. 9 and Fig.10 )、Example 3 ( Fig.11 and Fig.12 ), Embodiment 4 ( Figures 13 to 18 )、Example 5 ( Figure 22 to Figure 24) are substantially the same, except that, in this embodiment: The liquid crystal layer 13 includes liquid crystal molecules 131 and nanoparticles 132 that are mixed with each other. The refractive index of the nanoparticles 132 is different from that of the liquid crystal molecules 131. The nanoparticles 132 cooperate with the liquid crystal molecules 131 and can reflect and scatter light. Since the nanoparticles 132 and the liquid crystal molecules 131 can scatter light after cooperating with each other, the diffuse reflection structure 122 may not be provided in this embodiment, thereby making the thickness of the display device thinner. Moreover, the nanoparticles 132 and the liquid crystal molecules 131 can also reflect light after cooperating with each other, so that the utilization rate of ambient light in the reflection mode can be improved, and the contrast of the reflection display can be improved.

[0064] Among them, the proportion of nanoparticles 132 in the liquid crystal layer 13 is 45% to 65%, and the proportion is preferably 50%. The diameter of the nanoparticles 132 is 5nm to 500nm, and the nanoparticles 132 are white or transparent. The function of the nanoparticles 132 is to increase the reflection and scattering effect of the incident light, improve the overall reflectivity of the display device, and increase the viewing angle. The nanoparticles 132 can use inorganic or organic materials and are evenly dispersed in the liquid crystal layer 13 and exist stably. The refractive index of the nanoparticles 132 is different from the refractive index of the liquid crystal molecules 131. The difference between the refractive index of the nanoparticles 132 and the refractive index of the liquid crystal molecules 131 is preferably greater than 0.1, so as to increase the reflection and refractive index of the interface between the liquid crystal molecules 131 and the nanoparticles 132. Of course, in actual use, the specific material of the nanoparticles 132 can be selected according to actual needs, as long as the material meets the requirements of different refractive indexes from the liquid crystal molecules 131, a diameter of 5nm to 500nm, and white or transparent.

[0065] Fig.23 It is a schematic diagram of the structure of spherical nanoparticles and liquid crystal molecules in Example 6 of the present invention. Fig.24 Schematic diagram of the structure of strip-shaped nanoparticles and liquid crystal molecules in Example 6 of the present invention. Fig.23 As shown, the nanoparticles 132 may be spherical in structure with a diameter of 5 nm to 500 nm. The nanoparticles 132 may be organic macromolecules and combined with the liquid crystal molecules 131 to be uniformly dispersed. Of course, the nanoparticles 132 may also be inorganic nanoparticles, such as SiOx particles. Fig.24 As shown, the nanoparticles 132 may also be in a strip-shaped structure, such as carbon nanotubes, glass fibers, etc., and are uniformly mixed with the liquid crystal molecules 131. The diameter of the nanoparticles 132 is 5nm-20nm, and the length is 5nm-500nm.

[0066] It should be understood by those skilled in the art that the remaining structures and working principles of this embodiment are the same as those of Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, and Embodiment 5, and will not be described in detail here.

[0067] 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.

[0068] The above 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 this 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 change and modification 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 still fall within the protection scope of the technical solution of the present invention.

Claims

1. A display device capable of switching between transmission and reflection, characterized in that: It comprises an OLED display panel (20) and a liquid crystal display panel (10) arranged on the light-emitting side of the OLED display panel (20); The liquid crystal display panel (10) comprises a first substrate (11), a second substrate (12) arranged opposite to the first substrate (11), and a liquid crystal layer (13) located between the first substrate (11) and the second substrate (12); the first substrate (11) is located on a side of the liquid crystal layer (13) away from the OLED display panel (20); the second substrate (12) is located on a side of the liquid crystal layer (13) facing the OLED display panel (20); a linear polarizing plate (141) and a quarter wave plate (142) are provided on the first substrate (11); the quarter wave plate (142) is located on a side of the linear polarizing plate (141) facing the liquid crystal layer (13); a light transmission axis of the linear polarizing plate (141) and a fast-slow axis of the quarter wave plate (142) are at 45 degrees; a control electrode (121) is provided on the second substrate (12); and a common electrode (112) matched with the control electrode (121) is provided on the first substrate (11) or the second substrate (12); The OLED display panel (20) comprises a substrate (21), and an anode (22), a light-emitting layer (23), and a cathode (24) sequentially arranged on the substrate (21), wherein the anode (22) and the cathode (24) are used to control the light-emitting state of the light-emitting layer (23); In the transmission mode, the liquid crystal molecules (131) in the entire liquid crystal layer (13) are all in a standing posture, the ambient light reflected by the cathode (24) is absorbed by the linear polarizer (141), the OLED display panel (20) is turned on and displays a picture, and the light emitted by the OLED display panel (20) can pass through the liquid crystal display panel (10); in the reflection mode, the OLED display panel (20) is turned off, the liquid crystal molecules (131) in the liquid crystal layer (13) in a dark state area are all in a standing posture, the ambient light reflected by the cathode (24) in the dark state area is absorbed by the linear polarizer (141), the liquid crystal molecules (131) in the liquid crystal layer (13) in a bright state area are all in a lying posture and have a phase delay of λ / 4, and the ambient light reflected by the cathode (24) in the bright state area can be emitted from the linear polarizer (141).

2. The display device capable of switching between transmission and reflection according to claim 1, characterized in that: The display device comprises a diffuse reflection structure (122), and the diffuse reflection structure (122) is arranged on the light emitting side of the OLED display panel (20).

3. The display device capable of switching between transmission and reflection according to claim 2, characterized in that: The diffuse reflection structure (122) is arranged on a side of the second substrate (12) facing the liquid crystal layer (13); Alternatively, the diffuse reflection structure (122) is arranged on a side of the second substrate (12) away from the liquid crystal layer (13); Alternatively, the diffuse reflection structure (122) is arranged on a side of the OLED display panel (20) facing the liquid crystal display panel (10).

4. The display device capable of switching between transmission and reflection according to claim 2, characterized in that: The diffuse reflection structure (122) has a plurality of protruding structures, or the diffuse reflection structure (122) is a PDLC liquid crystal cell or a PNLC liquid crystal cell.

5. The display device capable of switching between transmission and reflection according to claim 1, characterized in that: The second substrate (12) is provided with a plurality of scanning lines (1), a plurality of data lines (2) and a plurality of thin film transistors (3); the scanning lines (1) and the data lines (2) are insulated from each other and cross-defined to form a plurality of first pixel units (P1) distributed in a matrix; the control electrode (121) comprises pixel electrodes corresponding to the first pixel units (P1) one by one; the pixel electrodes are electrically connected to the scanning lines (1) and the data lines (2) adjacent to the thin film transistors (3) through the thin film transistors (3).

6. The display device capable of switching between transmission and reflection according to claim 1, characterized in that: The display device has a pattern area (110) and a background area (120); the control electrode (121) comprises a first electrode (121a) and a second electrode (121b) which are insulated from each other; the first electrode (121a) corresponds to the pattern area (110), and the second electrode (121b) corresponds to the background area (120).

7. The display device capable of switching between transmission and reflection according to any one of claims 1 to 6, characterized in that: A black matrix (111) and a color resist layer (113) are provided on the first substrate (11); the black matrix (111) is used to space the plurality of color resist layers (113) from each other; the liquid crystal display panel (10) has a first pixel unit (P1) corresponding to the color resist layer (113); the OLED display panel (20) has a second pixel unit (P2) corresponding to the light-emitting layer (23); and the first pixel unit (P1) corresponds to the second pixel unit (P2) one by one.

8. The display device capable of switching between transmission and reflection according to any one of claims 1 to 6, characterized in that: The common electrode (112) matched with the control electrode (121) is provided on the first substrate (11); the liquid crystal molecules (131) in the liquid crystal layer (13) are aligned parallel to the first substrate (11) and the second substrate (12); the alignment direction of the liquid crystal molecules (131) close to the first substrate (11) and the alignment direction of the liquid crystal molecules (131) close to the second substrate (12) are perpendicular to each other; and the liquid crystal layer (13) has a phase delay of λ / 4 in an initial state; Alternatively, the common electrode (112) matched with the control electrode (121) is provided on the first substrate (11), and the liquid crystal molecules (131) in the liquid crystal layer (13) are aligned perpendicularly to the first substrate (11) and the second substrate (12), and when the liquid crystal molecules (131) are in a flat position, the long axis of the liquid crystal molecules (131) is at 45° with the light transmission axis of the linear polarizer (141), and at this time, the liquid crystal layer (13) has a phase delay of λ / 4.

9. The display device capable of switching between transmission and reflection according to any one of claims 1 to 6, characterized in that: The liquid crystal layer (13) comprises liquid crystal molecules (131) and nanoparticles (132) that are mixed with each other, the refractive index of the nanoparticles (132) is different from the refractive index of the liquid crystal molecules (131), and the nanoparticles (132) and the liquid crystal molecules (131) cooperate with each other and are capable of reflecting and scattering light.

10. The display device capable of switching between transmission and reflection according to claim 9, characterized in that: The refractive index of the nanoparticles (132) differs from the refractive index of the liquid crystal molecules (131) by more than 0.1; And / or, the nanoparticles (132) are spherical or strip-shaped; and / or, the diameter of the nanoparticle (132) is 5 nm to 500 nm; And / or, the nanoparticles (132) are white or transparent.

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