Display panel with switchable wide and narrow visual angles, display device and driving method

Abstract

The invention discloses a wide and narrow visual angle switchable display panel, a display device and a driving method. The display panel comprises a dimming box, and the projection of the alignment direction of a first liquid crystal layer in the dimming box on a second substrate is a first direction; a first visual angle control electrode is arranged on a first substrate of the dimming box, and a first electrode strip of a second visual angle control electrode and a second electrode strip of a third visual angle control electrode in the dimming box extend along a first direction; and the light transmission axes of the first polaroid and the second polaroid on the upper side and the lower side of the dimming box are parallel to each other. The extension of the first electrode strip and the extension of the second electrode strip are both parallel to the alignment direction of the first liquid crystal layer, the light-transmitting axis of the first polaroid and the light-transmitting axis of the second polaroid are parallel to each other, and when liquid crystal molecules in the first liquid crystal layer are controlled to be in an inclined posture, the dimming box has the light receiving effect, and a narrow-view-angle mode is achieved; when the liquid crystal molecules in the first liquid crystal layer are controlled to be in a disordered state, the dimming box has a light scattering effect, and a wide viewing angle mode is achieved.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a display panel, display device, and driving method with switchable wide and narrow viewing angles. Background Technology

[0002] With the continuous advancement of LCD technology, the viewing angle of monitors has expanded from around 120° to over 160°. While enjoying the visual experience brought by a wider viewing angle, people also want to effectively protect trade secrets and personal privacy to avoid business losses or embarrassment caused by the leakage of screen information. Therefore, in addition to the need for a wide viewing angle, many situations also require display devices to have the function of switching between wide and narrow viewing angles.

[0003] Currently, the main method used is to attach a Venetian blind film to the display screen to achieve the switching between wide and narrow viewing angles. When privacy is required, the screen can be covered with the Venetian blind film to narrow the viewing angle. However, this method requires an extra Venetian blind film, which causes great inconvenience to the user. Moreover, a Venetian blind film can only achieve one viewing angle. Once the Venetian blind film is attached, the viewing angle is fixed in the narrow viewing angle mode, making it impossible to switch freely between the wide and narrow viewing angle modes. In addition, the privacy film will reduce the brightness and affect the aesthetics.

[0004] Existing technologies also employ a dual-cell structure, utilizing a dimming box and a display panel to switch between wide and narrow viewing angles. The display panel handles normal image display, while the dimming box controls the viewing angle switching. The dimming box includes an upper substrate, a lower substrate, and a liquid crystal layer between them. Viewing angle control electrodes on the upper and lower substrates apply a vertical electric field to the liquid crystal molecules, causing them to deflect vertically, achieving a narrow viewing angle mode. By controlling the voltage on the viewing angle control electrodes, switching between wide and narrow viewing angles can be achieved. However, this display device requires a privacy screen protector or prism structure, and the alignment direction of the dimming box and the extension direction of the electrode strips need to be at a specific angle to the light-receiving direction of the privacy screen protector. This results in high manufacturing difficulty, high cost, and a thicker box. Furthermore, because this display device requires a privacy screen protector or prism structure to achieve the narrow viewing angle effect, the wide viewing angle effect is poor, making it difficult to effectively balance both wide and narrow viewing angles. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a display panel, display device and driving method with switchable wide and narrow viewing angles, so as to solve the problems that the existing technology requires the dimming box to be matched with a privacy film or prism structure to achieve the narrow viewing angle effect, which has the problems of high manufacturing difficulty, high cost, thick box, and inability to well balance wide and narrow viewing angles.

[0006] The objective of this invention is achieved through the following technical solution: The present invention provides a display panel with switchable wide and narrow viewing angles, including a dimming box. The dimming box includes a first substrate, a second substrate disposed opposite to the first substrate, and a first liquid crystal layer disposed between the first substrate and the second substrate. The alignment direction of the first liquid crystal layer is projected onto the second substrate as a first direction. The first substrate has a first viewing angle control electrode on the side facing the first liquid crystal layer, and the second substrate has a second viewing angle control electrode and a third viewing angle control electrode that cooperate with the first viewing angle control electrode on the side facing the first liquid crystal layer. The second viewing angle control electrode includes a plurality of first electrode strips, and the third viewing angle control electrode includes a plurality of second electrode strips. The projections of the first electrode strips and the second electrode strips on the second substrate are parallel to each other and both extend along the first direction. A first polarizer is provided on the first substrate, and a second polarizer is provided on the second substrate. The transmission axes of the first polarizer and the second polarizer are parallel to each other. In the narrow viewing angle mode, the liquid crystal molecules in the first liquid crystal layer are tilted and have a light-collecting effect; in the wide viewing angle mode, the liquid crystal molecules in the first liquid crystal layer are in a disordered and scattered state and have a light-scattering effect.

[0007] Furthermore, the first liquid crystal layer uses positive liquid crystal molecules, the initial pretilt angle of the first liquid crystal layer near the first substrate is 83° to 90°, the initial pretilt angle of the first liquid crystal layer near the second substrate is 0° to 7°, and the transmission axis of the first polarizer and the transmission axis of the second polarizer are both perpendicular to the first direction.

[0008] Furthermore, the initial pretilt angle of the first liquid crystal layer on the side closer to the first substrate is 89°, and the initial pretilt angle of the first liquid crystal layer on the side closer to the second substrate is 4.5°.

[0009] Furthermore, the first liquid crystal layer uses positive liquid crystal molecules, and the initial pretilt angle of the first liquid crystal layer on the side closer to the first substrate and the initial pretilt angle on the side closer to the second substrate are both 0° to 7°.

[0010] Furthermore, the transmission axis of both the first polarizer and the second polarizer is parallel or perpendicular to the first direction.

[0011] Furthermore, the initial pretilt angle of the first liquid crystal layer on the side closer to the first substrate and the initial pretilt angle on the side closer to the second substrate are both 4.5°.

[0012] Furthermore, the display panel includes a display liquid crystal cell stacked on top of the dimming box. A third polarizer is provided on the side of the display liquid crystal cell away from the dimming box. The light transmission axes of the first polarizer and the second polarizer are both perpendicular to the light transmission axis of the third polarizer.

[0013] Furthermore, the display liquid crystal cell includes a color filter substrate, an array substrate disposed opposite to the color filter substrate, and a second liquid crystal layer located between the color filter substrate and the array substrate. The array substrate is provided with pixel electrodes, and the color filter substrate or the array substrate is provided with a common electrode that cooperates with the pixel electrodes.

[0014] This application also provides a display device, including the display panel described above.

[0015] This application also provides a driving method for a display panel, used to drive the display panel as described above, the driving method comprising: A first voltage signal is applied to the first view control electrode, a second voltage signal is applied to the second view control electrode, and a third voltage signal is applied to the third view control electrode; In the narrow viewing angle mode, there is a first voltage difference between the first voltage signal and the second voltage signal, and between the first voltage signal and the third voltage signal. The first voltage difference is greater than or equal to a first preset value, which causes the liquid crystal molecules in the first liquid crystal layer to be tilted and have a light-collecting effect. In wide viewing angle mode, there is a second voltage difference between the first voltage signal and the second voltage signal, a third voltage difference between the first voltage signal and the third voltage signal, and a fourth voltage difference between the second voltage signal and the third voltage signal. The second voltage difference and the third voltage difference are both greater than a second preset value, and the fourth voltage difference is greater than or equal to the third preset value, so that the liquid crystal molecules in the first liquid crystal layer are in a disordered and scattered state and have a scattering effect on light.

[0016] The beneficial effects of this invention are as follows: By setting the extensions of the first and second electrode strips to be parallel to the alignment direction of the first liquid crystal layer, and setting the transmission axes of the first and second polarizers to be parallel to each other, the dimming box has a light-gathering function when the liquid crystal molecules in the first liquid crystal layer are controlled to be in a tilted state, thus achieving a narrow viewing angle mode; when the liquid crystal molecules in the first liquid crystal layer are controlled to be in a disordered and scattered state, the dimming box has a light-diffusing function, thus achieving a wide viewing angle mode. Therefore, the dimming box in this application does not need to be equipped with a privacy film or prism structure to achieve a narrow viewing angle effect, reducing the difficulty of manufacturing, manufacturing cost, and the thickness of the display panel; moreover, since no privacy film or prism structure is needed, the wide viewing angle effect is not affected, and both wide and narrow viewing angle effects can be well balanced. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the display device in its initial state according to Embodiment 1 of the present invention.

[0018] Figure 2 This is a schematic diagram of the planar structure of the second-view control electrode and the third-view control electrode in Embodiment 1 of the present invention.

[0019] Figure 3 This is a schematic diagram of the planar structure of the array substrate in Embodiment 1 of the present invention.

[0020] Figure 4 This is a waveform diagram of the viewing angle control signal of the display device in narrow viewing angle mode in Embodiment 1 of the present invention.

[0021] Figure 5 This is a schematic diagram of the display device in narrow viewing angle mode according to Embodiment 1 of the present invention.

[0022] Figure 6 This is a schematic diagram of the dimming box in another direction in the narrow viewing angle mode of Embodiment 1 of the present invention.

[0023] Figure 7 This is a schematic diagram comparing the effect of the dimming box in the narrow viewing angle mode of Embodiment 1 of the present invention with that in the prior art.

[0024] Figure 8 This is a waveform diagram of the viewing angle control signal of the display device in wide viewing angle mode in Embodiment 1 of the present invention.

[0025] Figure 9 This is a schematic diagram of the display device in wide viewing angle mode according to Embodiment 1 of the present invention.

[0026] Figure 10 This is a schematic diagram of the liquid crystal tilt angle of the display device in wide viewing angle mode according to Embodiment 1 of the present invention.

[0027] Figure 11 This is a schematic diagram of the liquid crystal tilt angle of a display device in wide viewing angle mode in the prior art.

[0028] Figure 12 This is a schematic diagram of the display device in its initial state according to Embodiment 2 of the present invention.

[0029] Figure 13 This is a schematic diagram of the display device in narrow viewing angle mode according to Embodiment 2 of the present invention.

[0030] Figure 14 This is a schematic diagram of the dimming box in another direction in the narrow viewing angle mode of Embodiment 2 of the present invention.

[0031] Figure 15This is a schematic diagram comparing the effect of Embodiment 2 of the present invention with that of the dimming box in the narrow viewing angle mode in the prior art.

[0032] Figure 16 This is a schematic diagram of the display device in wide viewing angle mode according to Embodiment 2 of the present invention.

[0033] Figure 17 This is one of the schematic diagrams of the planar structure of the display device in this invention.

[0034] Figure 18 This is the second schematic diagram of the planar structure of the display device in this invention. Detailed Implementation

[0035] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation methods, structures, features, and effects of the wide and narrow viewing angle switchable display panel, display device, and driving method proposed according to the present invention: [Example 1] Figure 1 This is a schematic diagram of the display device in its initial state according to Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of the planar structure of the second-view control electrode and the third-view control electrode in Embodiment 1 of the present invention. Figure 3 This is a schematic diagram of the planar structure of the array substrate in Embodiment 1 of the present invention.

[0036] like Figures 1 to 3 As shown in Embodiment 1 of the present invention, a display panel with switchable wide and narrow viewing angles includes a dimming box 10 and a display liquid crystal cell 20 stacked on top of each other. There is one dimming box 10 and one display liquid crystal cell 20. The dimming box 10 is located below the display liquid crystal cell 20, meaning the dimming box 10 and the display liquid crystal cell 20 are arranged sequentially in the direction facing the external environment. The dimming box 10 is used to control the wide and narrow viewing angles of the display device, and the display liquid crystal cell 20 is used to control the display device to display a normal image. Alternatively, the dimming box 10 can be located above the display liquid crystal cell 20, i.e., on the light-emitting side of the display liquid crystal cell 20.

[0037] The dimming box 10 includes a first substrate 11, a second substrate 12 disposed opposite to the first substrate 11, and a first liquid crystal layer 13 disposed between the first substrate 11 and the second substrate 12. A first polarizer 31 is disposed on the first substrate 11, and a second polarizer 32 is disposed on the second substrate 12. The transmission axes of the first polarizer 31 and the second polarizer 32 are parallel to each other. A third polarizer 33 is disposed on the side of the display liquid crystal cell 20 away from the dimming box 10. The transmission axes of both the first polarizer 31 and the second polarizer 32 are perpendicular to the transmission axis of the third polarizer 33. For example, the first polarizer 31 is disposed between the dimming box 10 and the display liquid crystal cell 20, and the second polarizer 32 is disposed on the side of the dimming box 10 away from the display liquid crystal cell 20.

[0038] In this embodiment, the first liquid crystal layer 13 uses positive liquid crystal molecules, that is, liquid crystal molecules with positive dielectric anisotropy. The positive liquid crystal molecules have a dielectric constant Δn = ne - no, where Δn > 0. A larger Δn is more beneficial for light scattering over a wide viewing angle. The range of Δn is 0.2 to 0.3, preferably Δn = 0.27. The optical path difference (Retardation) is greater than 700 nm. The thickness of the first liquid crystal layer 13 is, for example, 11 μm. Figure 1 As shown, in the initial state, the initial pretilt angle of the first liquid crystal layer 13 near the first substrate 11 is 83° to 90°, and the initial pretilt angle of the first liquid crystal layer 13 near the second substrate 12 is 0° to 7°. The projection of the alignment direction of the first liquid crystal layer 13 onto the second substrate 12 is the first direction T1. For example, the initial pretilt angle of the first liquid crystal layer 13 near the first substrate 11 is 89°, and the initial pretilt angle of the first liquid crystal layer 13 near the second substrate 12 is 4.5°. That is, the initial pretilt angles of the first liquid crystal layer 13 near the first substrate 11 and near the second substrate 12 are approximately perpendicular. With this alignment method, not only can the response speed of switching between wide and narrow viewing angles be improved, but also, in wide viewing angle mode, the liquid crystal molecules can be made more scattered, thus improving the astigmatism effect of wide viewing angle.

[0039] Optionally, the transmission axes of the first polarizer 31 and the second polarizer 32 are both parallel to the second direction T2, and the transmission axis of the third polarizer 33 is parallel to the first direction T1. The first direction T1 and the second direction T2 are perpendicular to each other, that is, the transmission axes of the first polarizer 31 and the second polarizer 32 are both perpendicular to the first direction T1. In other words, the transmission axes of the first polarizer 31 and the second polarizer 32 are both perpendicular to the projection of the alignment direction of the first liquid crystal layer 13 onto the second substrate 12, and the transmission axis of the third polarizer 33 is parallel to the projection of the alignment direction of the first liquid crystal layer 13 onto the second substrate 12, thereby making the refractive index of the entire first liquid crystal layer 13 in the initial state no. Since the light transmission axis of the first polarizer 31 and the light transmission axis of the second polarizer 32 are both perpendicular to the projection of the alignment direction of the first liquid crystal layer 13 onto the second substrate 12, setting the initial pretilt angle of the first liquid crystal layer 13 near the first substrate 11 to 83° to 90° and the initial pretilt angle of the first liquid crystal layer 13 near the second substrate 12 to 0° to 7° can also ensure that the minor axis of the entire first liquid crystal layer 13 in the initial state is parallel to the light transmission axis of the first polarizer 31, that is, the refractive index of the entire first liquid crystal layer 13 in the initial state is no.

[0040] In this embodiment, the first substrate 11 has a first viewing angle control electrode 111 on the side facing the first liquid crystal layer 13, and the second substrate 12 has a second viewing angle control electrode 121 and a third viewing angle control electrode 122 cooperating with the first viewing angle control electrode 111 on the side facing the first liquid crystal layer 13. The second viewing angle control electrode 121 includes a plurality of first electrode strips 121a, and the third viewing angle control electrode 122 includes a plurality of second electrode strips 122a. The projections of the first electrode strips 121a and the second electrode strips 122a on the second substrate 12 are parallel to each other and both extend along the first direction T1, that is, the first electrode... The extension directions of electrode strip 121a and second electrode strip 122a are parallel to the projection of the alignment direction of the first liquid crystal layer 13 onto the second substrate 12. Thus, when a wide viewing angle is reached, a corresponding wide viewing angle signal is applied to the first electrode strip 121a and second electrode strip 122a to drive the positive liquid crystal molecules in the first liquid crystal layer 13 to deflect in the horizontal direction toward the second direction T2. ​​That is, the long axis of the positive liquid crystal molecules in the first liquid crystal layer 13 deflects in the direction parallel to the light transmission axis of the first polarizer 31, so that the refractive index of the positive liquid crystal molecules in the first liquid crystal layer 13 is between no and ne, thereby achieving a light scattering effect. In other words, in this application, the alignment direction and initial pretilt angle of the first liquid crystal layer 13, the extension direction of the first electrode strip 121a and the second electrode strip 122a, and the light transmission axis setting direction of the first polarizer 31 and the second polarizer 32 need to be related to each other. Only in this way can the response speed of switching to the narrow viewing angle mode be improved, and the light collection effect of the narrow viewing angle and the light scattering effect of the wide viewing angle be maximized, so as to better balance the wide and narrow viewing angles.

[0041] In this embodiment, the first viewing angle control electrode 111 is a planar electrode covering the entire surface of the first substrate 11, and the second viewing angle control electrode 121 and the third viewing angle control electrode 122 are slit electrodes covering the entire surface of the second substrate 12, that is, the second viewing angle control electrode 121 and the third viewing angle control electrode 122 continuously cover the entire surface of the second substrate 12. Optionally, the second viewing angle control electrode 121 and the third viewing angle control electrode 122 are located in different layers and separated from each other by an insulating layer, thereby avoiding the problem of short circuit between the second viewing angle control electrode 121 and the third viewing angle control electrode 122, and at the same time reducing the gap between the first electrode strip 121a and the second electrode strip 122a. Figure 2As shown, the second viewing angle control electrode 121 further includes a first wire 121b, which conductively connects multiple first electrode strips 121a. The third viewing angle control electrode 122 further includes a second wire 122b, which conductively connects multiple second electrode strips 122a. Both the first wire 121b and the second wire 122b are multiple, to reduce the resistance of the second viewing angle control electrode 121 and the third viewing angle control electrode 122. The extension direction of the first wire 121b is perpendicular to the extension direction of the first electrode strips 121a, and the extension direction of the second wire 122b is also perpendicular to the extension direction of the second electrode strips 122a. Of course, in other embodiments, the second viewing angle control electrode 121 and the third viewing angle control electrode 122 can also be located on the same layer and insulated from each other. In this case, the first wire 121b and the second wire 122b need to be positioned in the non-display area at the edge of the display panel. The widths a1 and a2 of the first electrode strip 121a and the second electrode strip 122a are 3–10 μm, for example, 4.5 μm; the distance d between the first electrode strip 121a and the second electrode strip 122a is 0–3 μm, for example, 2 μm. With these numerical settings, more vertical electric fields can be formed at narrow viewing angles to improve the narrow viewing angle effect; simultaneously, at wide viewing angles, more horizontal electric fields can be formed, making the liquid crystal molecules more dispersed and improving the astigmatism effect at wide viewing angles.

[0042] The display liquid crystal cell 20 includes a color filter substrate 21, an array substrate 22 disposed opposite to the color filter substrate 21, and a second liquid crystal layer 23 located between the color filter substrate 21 and the array substrate 22. Preferably, the second liquid crystal layer 23 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 second liquid crystal layer 23 are aligned parallel to the color filter substrate 21 and the array substrate 22. The alignment direction of the positive liquid crystal molecules near the color filter substrate 21 is parallel or antiparallel to the alignment direction of the positive liquid crystal molecules near the array substrate 22. In other embodiments, the array substrate 22 and the first substrate 11 may share a single substrate to reduce the cell thickness of the display panel.

[0043] The color filter substrate 21 has color resist layers 212 arranged in an array and black matrix 211 separating the color resist layers 212. The color resist layers 212 include color resist materials of red (R), green (G) and blue (B) colors, and correspondingly form sub-pixels of red (R), green (G) and blue (B) colors.

[0044] The array substrate 22 has multiple pixel units SP defined by multiple scan lines and multiple data lines that are mutually insulated and intersecting on the side facing the second liquid crystal layer 23. Each pixel unit SP has a pixel electrode 222 and a thin-film transistor. The pixel electrode 222 is electrically connected to the data line of the adjacent thin-film transistor through the thin-film transistor. The thin-film transistor includes a gate, an active layer, a drain, and a source. The gate and the scan line are located on the same layer and are electrically connected. The gate and the active layer are isolated by an insulating layer. The source is electrically connected to the data line, and the drain is electrically connected to the pixel electrode 222 through a contact hole.

[0045] like Figure 1 As shown, in this embodiment, a common electrode 221 is further provided on the side of the array substrate 22 facing the second liquid crystal layer 23. The common electrode 221 and the pixel electrode 222 are located on different layers and are insulated from each other by an insulating layer. The common electrode 221 can be located above or below the pixel electrode 222. Figure 1 The diagram shows the common electrode 221 located below the pixel electrode 222. Preferably, the common electrode 221 is a planar electrode with its entire surface, and the pixel electrode 222 is a slit electrode with multiple electrode strips in each pixel unit SP to form a fringe field switching (FFS) mode. Of course, in other embodiments, the pixel electrode 222 and the common electrode 221 may be located on the same layer, but they are insulated from each other. Each of the pixel electrode 222 and the common electrode 221 may include multiple electrode strips, and the electrode strips of the pixel electrode 222 and the electrode strips of the common electrode 221 are arranged alternately to form an in-plane switching (IPS) mode; or, in other embodiments, the array substrate 22 has a pixel electrode 222 on the side facing the second liquid crystal layer 23, and the color filter substrate 21 has a common electrode 221 on the side facing the second liquid crystal layer 23 to form a TN mode or a VA mode. For further descriptions of the TN mode and VA mode, please refer to the prior art, which will not be repeated here.

[0046] The first substrate 11, the second substrate 12, the color filter substrate 21, and the array substrate 22 can be made of materials such as glass, acrylic, and polycarbonate. The first viewing angle control electrode 111, the second viewing angle control electrode 121, the third viewing angle control electrode 122, the common electrode 221, and the pixel electrode 222 can be made of materials such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0047] This application also provides a display device, including a backlight module 40 and a display panel as described above. The backlight module 40 is disposed on the side of the dimming box 10 away from the display liquid crystal cell 20. Since the dimming box 10 has a light-gathering effect at narrow viewing angles, the backlight module 40 only needs to be a conventional diffused backlight module; however, a light-gathering backlight module can also be used. The backlight module 40 can be an edge-lit backlight module or a collimated backlight module.

[0048] This embodiment also provides a driving method for a display panel, used to drive the display panel described above. The driving method includes: A first voltage signal V1 is applied to the first viewing angle control electrode 111, a second voltage signal V2 is applied to the second viewing angle control electrode 121, and a third voltage signal V3 is applied to the third viewing angle control electrode 122. By applying corresponding viewing angle control voltages to the first viewing angle control electrode 111, the second viewing angle control electrode 121, and the third viewing angle control electrode 122, the liquid crystal molecules in the first liquid crystal layer 13 are tilted, and with the first polarizer 31 and the second polarizer 32 whose light transmission axes are parallel to each other, they have a light-gathering effect and narrow the viewing angle range to achieve a privacy protection effect; or the liquid crystal molecules in the first liquid crystal layer 13 are made into a disordered and scattered state and have a light-scattering effect, and the light scattering effect of the dimming box 10 expands the viewing angle range to achieve a wide viewing angle effect.

[0049] Figure 4 This is a waveform diagram of the viewing angle control signal of the display device in narrow viewing angle mode in Embodiment 1 of the present invention. Figure 5 This is a schematic diagram of the display device in narrow viewing angle mode according to Embodiment 1 of the present invention. Figure 6 This is a schematic diagram of the dimming box in another direction in the narrow viewing angle mode of Embodiment 1 of the present invention. Figures 4 to 6 As shown, in the narrow viewing angle mode, the liquid crystal molecules in the first liquid crystal layer 13 are tilted. Specifically, there is a first voltage difference between the first voltage signal V1 and the second voltage signal V2, and between the first voltage signal V1 and the third voltage signal V3. The first voltage difference is greater than or equal to a first preset value (e.g., 2.6V). For example, the first voltage signal V1 is a DC common voltage signal, and the second voltage signal V2 and the third voltage signal V3 are both AC voltage signals greater than or equal to 2.6V and with the same frequency. The polarities of the second voltage signal V2 and the third voltage signal V3 are the same, thereby creating a strong vertical electric field between the first viewing angle control electrode 111 and the second viewing angle control electrode 121, and between the first viewing angle control electrode 111 and the third viewing angle control electrode 122. Figure 5 and Figure 6The positive liquid crystal molecules in the first liquid crystal layer 13 are tilted, which has a light-absorbing effect and narrows the viewing angle range to achieve a privacy protection effect. Since the initial pretilt angle of the first liquid crystal layer 13 near the first substrate 11 is 89°, the initial pretilt angle of the first liquid crystal layer 13 gradually decreases from the first substrate 11 toward the second substrate 12, resulting in a faster response speed when switching to the narrow viewing angle mode.

[0050] Figure 7 This is a schematic diagram comparing the simulation effects of Embodiment 1 of the present invention with those of a dimming box in the prior art in narrow viewing angle mode. For example... Figure 7 As shown in the figure, the dashed curve represents the simulation curve of the narrow viewing angle of the prior art, and the solid curve represents the simulation curve of the narrow viewing angle of this application. Among them, the brightness of the relative center brightness at a field of view of 45° in this application is 4.5%, while that of the prior art is 6.6%, thus providing a better privacy protection effect. Moreover, the prior art has strong light leakage brightness when the field of view is between 55° and 80°. Although it has a privacy protection effect, it will affect the user experience, especially in low ambient light conditions.

[0051] Figure 8 This is a waveform diagram of the viewing angle control signal of the display device in wide viewing angle mode in Embodiment 1 of the present invention. Figure 9 This is a schematic diagram of the display device in wide viewing angle mode according to Embodiment 1 of the present invention. Figure 8 and Figure 9As shown, in wide viewing angle mode, the liquid crystal molecules in the first liquid crystal layer 13 are in a disordered and scattered state and have a scattering effect on light. Specifically, there is a second voltage difference between the first voltage signal V1 and the second voltage signal V2, a third voltage difference between the first voltage signal V1 and the third voltage signal V3, and a fourth voltage difference between the second voltage signal V2 and the third voltage signal V3. The second voltage difference and the third voltage difference are both greater than a second preset value (e.g., 5V), and the fourth voltage difference is greater than or equal to a third preset value (e.g., 10V). For example, the first voltage signal V1 is a DC common voltage signal, and the second voltage signal V2 and the third voltage signal V3 are both AC voltage signals greater than or equal to 5V and with the same frequency. The polarities of the second voltage signal V2 and the third voltage signal V3 are opposite. At this time, a strong vertical electric field will be formed between the first viewing angle control electrode 111 and the second viewing angle control electrode 121, as well as between the first viewing angle control electrode 111 and the third viewing angle control electrode 122. A strong horizontal electric field will also be formed between the second viewing angle control electrode 121 and the third viewing angle control electrode 122. Under the action of the vertical and horizontal electric fields, the positive liquid crystal molecules can be driven to deflect in the horizontal and vertical directions in the preset direction, so that the liquid crystal molecules in the first liquid crystal layer 13 are in a disordered and scattered state. At this time, the refractive index of the liquid crystal molecules with different tilt angles is different, with a refractive index of no to ne, and has a scattering effect to achieve a wide viewing angle effect. Since the initial pretilt angle of the first liquid crystal layer 13 near the first substrate 11 is 89° and the initial pretilt angle of the first liquid crystal layer 13 near the second substrate 12 is 4.5°, the response speed is faster when switching to wide viewing angle mode. This alignment method can also make the liquid crystal molecules more scattered, thus improving the scattering effect of wide viewing angle.

[0052] Figure 10 This is a schematic diagram of the liquid crystal tilt angle of the display device in wide viewing angle mode according to Embodiment 1 of the present invention. Figure 11 This is a schematic diagram of the liquid crystal tilt angle in wide-viewing-angle mode of existing display devices. For example... Figure 10 and Figure 11 As shown, the vertical axis represents the angle, and the horizontal axis is parallel to the dimming box 10. Since the widths a1 and a2 of the first electrode strip 121a and the second electrode strip 122a in this application are set to 4.5 μm, and the distance d between the first electrode strip 121a and the second electrode strip 122a is set to 2 μm, this numerical setting can create a larger horizontal electric field, making the liquid crystal molecules more dispersed and improving the wide-viewing-angle astigmatism effect.

[0053] In narrow viewing angle mode and wide viewing angle mode, the display liquid crystal cell 20 is used to control the display device to display a normal image. Specifically, a corresponding grayscale voltage is applied to the pixel electrode 222, forming a voltage difference between the pixel electrode 222 and the common electrode 221 and generating a horizontal electric field. Figure 5 , Figure 6 , Figure 9 The positive liquid crystal molecules are deflected in the horizontal direction in a direction parallel to the horizontal electric field (E1). The gray level voltage includes 0 to 255 gray level voltages. When different gray level voltages are applied to the pixel electrode 222, the pixel unit presents different brightness, thereby displaying different images, so as to realize the normal display of the display device under wide and narrow viewing angles.

[0054] [Example 2] Figure 12 This is a schematic diagram of the display device in its initial state according to Embodiment 2 of the present invention. Figure 12 As shown, the wide and narrow viewing angle switchable display panel, display device, and driving method provided in Embodiment 2 of the present invention are the same as those in Embodiment 1. Figures 1 to 11 The wide and narrow viewing angle switchable display panels, display devices, and driving methods in the above are basically the same, the difference being: In this embodiment, the first liquid crystal layer 13 uses positive liquid crystal molecules. In the initial state, the initial pretilt angle of the first liquid crystal layer 13 near the first substrate 11 and the initial pretilt angle near the second substrate 12 are both 0° to 7°. For example, the initial pretilt angle of the first liquid crystal layer 13 near the first substrate 11 and the initial pretilt angle near the second substrate 12 are both 4.5°, that is, the first liquid crystal layer 13 is aligned approximately parallel to the first substrate 11 and the second substrate 12, and the alignment direction of the first liquid crystal layer 13 near the first substrate 11 is parallel to the alignment direction near the second substrate 12. Through this alignment method, the transmission axis of the first polarizer 31 and the transmission axis of the second polarizer 32 can both be parallel to the first direction T1, that is, the transmission axis of the first polarizer 31 and the transmission axis of the second polarizer 32 are both parallel to the projection of the alignment direction of the first liquid crystal layer 13 onto the second substrate 12, thereby making the refractive index of the entire first liquid crystal layer 13 in the initial state ne. At a wide viewing angle, a corresponding wide viewing angle signal is applied to the first electrode strip 121a and the second electrode strip 122a, driving the positive liquid crystal molecules in the first liquid crystal layer 13 to deflect in the horizontal direction toward the second direction T2. ​​That is, the long axis of the positive liquid crystal molecules in the first liquid crystal layer 13 deflects in the direction perpendicular to the light transmission axis of the first polarizer 31, so that the refractive index of the positive liquid crystal molecules in the first liquid crystal layer 13 is between ne and no, thereby achieving a light-scattering effect. Since the first liquid crystal layer 13 is aligned approximately parallel to the first substrate 11 and the second substrate 12, the thickness of the first liquid crystal layer 13 can be set to 4 μm, thereby reducing the cell thickness of the dimming cell 10. Of course, in other embodiments, the light transmission axis of the first polarizer 31 and the light transmission axis of the second polarizer 32 can both be perpendicular to the first direction T1, that is, the light transmission axis of the first polarizer 31 and the light transmission axis of the second polarizer 32 are both perpendicular to the projection of the alignment direction of the first liquid crystal layer 13 onto the second substrate 12, so that the refractive index of the entire first liquid crystal layer 13 in the initial state is no.

[0055] This embodiment also provides a driving method for a display panel, used to drive the display panel described above. The driving method includes: A first voltage signal V1 is applied to the first viewing angle control electrode 111, a second voltage signal V2 is applied to the second viewing angle control electrode 121, and a third voltage signal V3 is applied to the third viewing angle control electrode 122. By applying corresponding viewing angle control voltages to the first viewing angle control electrode 111, the second viewing angle control electrode 121, and the third viewing angle control electrode 122, the liquid crystal molecules in the first liquid crystal layer 13 are tilted, and with the first polarizer 31 and the second polarizer 32 whose light transmission axes are parallel to each other, they have a light-gathering effect and narrow the viewing angle range to achieve a privacy protection effect; or the liquid crystal molecules in the first liquid crystal layer 13 are made into a disordered and scattered state and have a light-scattering effect, and the light scattering effect of the dimming box 10 expands the viewing angle range to achieve a wide viewing angle effect.

[0056] Figure 13 This is a schematic diagram of the display device in narrow viewing angle mode according to Embodiment 2 of the present invention. Figure 14 This is a schematic diagram of the dimming box in another direction in the narrow viewing angle mode of Embodiment 2 of the present invention. Figure 4 , Figure 13 and Figure 14 As shown, in the narrow viewing angle mode, the liquid crystal molecules in the first liquid crystal layer 13 are tilted. Specifically, there is a first voltage difference between the first voltage signal V1 and the second voltage signal V2, and between the first voltage signal V1 and the third voltage signal V3. The first voltage difference is greater than or equal to a first preset value (e.g., 2.6V). For example, the first voltage signal V1 is a DC common voltage signal, and the second voltage signal V2 and the third voltage signal V3 are both AC voltage signals greater than or equal to 2.6V and with the same frequency. The polarities of the second voltage signal V2 and the third voltage signal V3 are the same, thereby creating a strong vertical electric field between the first viewing angle control electrode 111 and the second viewing angle control electrode 121, and between the first viewing angle control electrode 111 and the third viewing angle control electrode 122. Figure 13 and Figure 14 E2) causes the positive liquid crystal molecules in the first liquid crystal layer 13 to be tilted, which has the effect of light absorption and narrowing the viewing angle range, so as to achieve the privacy protection effect.

[0057] Figure 15 This is a schematic diagram comparing the simulation effects of Embodiment 2 of the present invention and the existing dimming box in narrow viewing angle mode. For example... Figure 15As shown in the figure, the dashed curve represents the simulation curve of the narrow viewing angle of the prior art, and the solid curve represents the simulation curve of the narrow viewing angle of this application. Among them, compared with the prior art, the privacy angle of this application is reduced from 45° to 40°, thus improving the privacy effect. Since the light transmission axis of the first polarizer 31 and the light transmission axis of the second polarizer 32 in this application are both parallel to the projection of the alignment direction of the first liquid crystal layer 13 onto the second substrate 12, this application has a certain light leakage brightness when the field of view is 50° to 70°. However, compared with the prior art, the light leakage brightness is weaker when the field of view is 55° to 80°, which can improve the user experience compared with the prior art.

[0058] Figure 16 This is a schematic diagram of the display device in wide viewing angle mode according to Embodiment 2 of the present invention. Figure 8 and Figure 16 As shown, in wide viewing angle mode, the liquid crystal molecules in the first liquid crystal layer 13 are in a disordered and scattered state and have a scattering effect on light. Specifically, there is a second voltage difference between the first voltage signal V1 and the second voltage signal V2, a third voltage difference between the first voltage signal V1 and the third voltage signal V3, and a fourth voltage difference between the second voltage signal V2 and the third voltage signal V3. The second voltage difference and the third voltage difference are both greater than a second preset value (e.g., 5V), and the fourth voltage difference is greater than or equal to a third preset value (e.g., 10V). For example, the first voltage signal V1 is a DC common voltage signal, and the second voltage signal V2 and the third voltage signal V3 are both AC voltage signals greater than or equal to 5V and with the same frequency. The polarities of the second voltage signal V2 and the third voltage signal V3 are opposite. At this time, a strong vertical electric field will be formed between the first viewing angle control electrode 111 and the second viewing angle control electrode 121, as well as between the first viewing angle control electrode 111 and the third viewing angle control electrode 122. A strong horizontal electric field will also be formed between the second viewing angle control electrode 121 and the third viewing angle control electrode 122. Under the action of the vertical and horizontal electric fields, the positive liquid crystal molecules can be driven to deflect in the horizontal and vertical directions in the preset direction, so that the liquid crystal molecules in the first liquid crystal layer 13 are in a disordered and scattered state. At this time, the refractive index of the liquid crystal molecules with different tilt angles is different, with a refractive index of ne to no, and has a scattering effect to achieve a wide viewing angle effect.

[0059] In narrow viewing angle mode and wide viewing angle mode, the display liquid crystal cell 20 is used to control the display device to display a normal image. Specifically, a corresponding grayscale voltage is applied to the pixel electrode 222, forming a voltage difference between the pixel electrode 222 and the common electrode 221 and generating a horizontal electric field. Figure 13 , Figure 14 , Figure 16The positive liquid crystal molecules are deflected in the horizontal direction in a direction parallel to the horizontal electric field (E1). The gray level voltage includes 0 to 255 gray level voltages. When different gray level voltages are applied to the pixel electrode 222, the pixel unit presents different brightness, thereby displaying different images, so as to realize the normal display of the display device under wide and narrow viewing angles.

[0060] Those skilled in the art should understand that the remaining structures and working principles of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0061] Figure 17 and Figure 18 This is a schematic diagram of the planar structure of the display device in an embodiment of the present invention. Please refer to... Figure 17 and Figure 18 The display device is equipped with a viewing angle switching button 50, which allows the user to request a viewing angle switch from the display device. The viewing angle switching button 50 can be a physical button (such as...). Figure 17 As shown), it can also be used for software control or application programs (APP) to implement switching functions (such as... Figure 18 As shown, for example, a slider is used to set the wide and narrow viewing angles. When a user needs to switch between wide and narrow viewing angles, they can send a viewing angle switching request to the display device by operating the viewing angle switching button 50. Ultimately, the driver chip 60 controls the electrical signals applied to the first viewing angle control electrode 111, the second viewing angle control electrode 121, and the third viewing angle control electrode 122. The display device can then switch between narrow and wide viewing angle modes. When switching to a narrow viewing angle, the driving method corresponding to the narrow viewing angle mode is used; when switching to a wide viewing angle, the driving method corresponding to the wide viewing angle mode is used. Therefore, the display device of this embodiment has strong operational flexibility and convenience, achieving a multi-functional display device that integrates entertainment video and privacy protection.

[0062] In this document, the directional terms such as up, down, left, right, front, and back are defined according to the position of the structures in the accompanying drawings and the relative positions of the structures, and are only used for clarity and convenience in expressing the technical solution. It should be understood that the use of these directional terms should not limit the scope of protection claimed in this application. It should also be understood that the terms "first" and "second," etc., used herein are only used for distinction in name and are not used to limit the number or order.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content without departing from the scope of the technical solution of the present invention, which are equivalent embodiments with equivalent changes. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A display panel with switchable wide and narrow viewing angles, characterized in that, The device includes a dimming box (10), which includes a first substrate (11), a second substrate (12) disposed opposite to the first substrate (11), and a first liquid crystal layer (13) disposed between the first substrate (11) and the second substrate (12). The alignment direction of the first liquid crystal layer (13) is projected onto the second substrate (12) as a first direction (T1). The first substrate (11) has a first viewing angle control electrode (111) on the side facing the first liquid crystal layer (13), and the second substrate (12) has a second viewing angle control electrode (121) and a third viewing angle control electrode (122) cooperating with the first viewing angle control electrode (111) on the side facing the first liquid crystal layer (13). The second viewing angle control electrode (121) includes a plurality of first electrode strips (121a), and the third viewing angle control electrode (122) includes a plurality of second electrode strips (122a). The projections of the first electrode strips (121a) and the second electrode strips (122a) on the second substrate (12) are parallel to each other and both extend along the first direction (T1). The first substrate (11) is provided with a first polarizer (31) and the second substrate (12) is provided with a second polarizer (32). The light transmission axis of the first polarizer (31) and the light transmission axis of the second polarizer (32) are parallel to each other. In the narrow viewing angle mode, the liquid crystal molecules in the first liquid crystal layer (13) are tilted and have a light-collecting effect; in the wide viewing angle mode, the liquid crystal molecules in the first liquid crystal layer (13) are in a disordered and scattered state and have a light-scattering effect.

2. The display panel with switchable wide and narrow viewing angles according to claim 1, characterized in that, The first liquid crystal layer (13) uses positive liquid crystal molecules. The initial pretilt angle of the first liquid crystal layer (13) near the first substrate (11) is 83° to 90°. The initial pretilt angle of the first liquid crystal layer (13) near the second substrate (12) is 0° to 7°. The light transmission axis of the first polarizer (31) and the light transmission axis of the second polarizer (32) are both perpendicular to the first direction (T1).

3. The display panel with switchable wide and narrow viewing angles according to claim 2, characterized in that, The initial pretilt angle of the first liquid crystal layer (13) near the first substrate (11) is 89°, and the initial pretilt angle of the first liquid crystal layer (13) near the second substrate (12) is 4.5°.

4. The display panel with switchable wide and narrow viewing angles according to claim 1, characterized in that, The first liquid crystal layer (13) uses positive liquid crystal molecules, and the initial pretilt angle of the first liquid crystal layer (13) on the side near the first substrate (11) and the initial pretilt angle on the side near the second substrate (12) are both 0° to 7°.

5. The display panel with switchable wide and narrow viewing angles according to claim 4, characterized in that, The light transmission axis of the first polarizer (31) and the light transmission axis of the second polarizer (32) are both parallel or perpendicular to the first direction (T1).

6. The display panel with switchable wide and narrow viewing angles according to claim 4, characterized in that, The initial pretilt angle of the first liquid crystal layer (13) near the first substrate (11) and the initial pretilt angle near the second substrate (12) are both 4.5°.

7. The wide and narrow viewing angle switchable display panel according to any one of claims 1-6, characterized in that, The display panel includes a display liquid crystal cell (20) stacked on top of the dimming box (10). A third polarizer (33) is provided on the side of the display liquid crystal cell (20) away from the dimming box (10). The light transmission axis of the first polarizer (31) and the light transmission axis of the second polarizer (32) are both perpendicular to the light transmission axis of the third polarizer (33).

8. The display panel with switchable wide and narrow viewing angles according to claim 7, characterized in that, The display liquid crystal cell (20) includes a color filter substrate (21), an array substrate (22) disposed opposite to the color filter substrate (21), and a second liquid crystal layer (23) located between the color filter substrate (21) and the array substrate (22). The array substrate (22) is provided with a pixel electrode (222), and the color filter substrate (21) or the array substrate (22) is provided with a common electrode (221) that cooperates with the pixel electrode (222).

9. A display device, characterized in that, Includes the display panel as described in any one of claims 1-8.

10. A driving method for a display panel, characterized in that, The driving method for driving the display panel as described in any one of claims 1-8 includes: A first voltage signal (V1) is applied to the first view control electrode (111), a second voltage signal (V2) is applied to the second view control electrode (121), and a third voltage signal (V3) is applied to the third view control electrode (122). In the narrow viewing angle mode, there is a first voltage difference between the first voltage signal (V1) and the second voltage signal (V2) and between the first voltage signal (V1) and the third voltage signal (V3). The first voltage difference is greater than or equal to a first preset value, so that the liquid crystal molecules in the first liquid crystal layer (13) are tilted and have a light-collecting effect. In the wide viewing angle mode, there is a second voltage difference between the first voltage signal (V1) and the second voltage signal (V2), a third voltage difference between the first voltage signal (V1) and the third voltage signal (V3), and a fourth voltage difference between the second voltage signal (V2) and the third voltage signal (V3). The second voltage difference and the third voltage difference are both greater than a second preset value, and the fourth voltage difference is greater than or equal to the third preset value, so that the liquid crystal molecules in the first liquid crystal layer (13) are in a disordered and scattered state and have a scattering effect on light.

Images