Display device

Abstract

The present application discloses a display device, comprising: a display panel; and a dimming device, which is located at the light-emitting side of the display panel and comprises a cholesteric liquid crystal layer; when the display device is in an anti-peeping mode, the cholesteric liquid crystal layer is in a reflective state, the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle less than or equal to half of a visible angle in the anti-peeping mode is greater than the maximum value of the reflectivity of visible light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode, the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle greater than half of the visible angle in the anti-peeping mode is less than the maximum value of the reflectivity of visible light with an incident angle greater than half of the visible angle in the anti-peeping mode, the incident angle is defined as the angle between the incident direction and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state, and the spiral axis is parallel to the thickness direction of the cholesteric liquid crystal layer.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display device. Background Art

[0002] With the advancement of technology and the iteration of consumer electronic products, users are paying more and more attention to the issue of privacy protection. In some cases, users do not want others to view the display screen on the display, which requires the display device to have an anti-peeping function. The display device with an anti-peeping function can prevent others within the viewing angle of the display device from viewing the screen content, while providing the target user with content readability at a protected viewing angle.

[0003] Traditional anti-peeping display devices cover the display screen with a layer of anti-peeping film. However, this anti-peeping film is only two-way anti-peeping. If full-viewing angle anti-peeping is to be achieved, a double-layer orthogonal anti-peeping film needs to be attached. The double-layer orthogonal anti-peeping film will cause the display brightness of the display device at a positive viewing angle to be greatly reduced. Summary of the invention

[0004] The purpose of the present application is to provide a display device to solve the problem that the display brightness of a conventional anti-peeping display device is greatly reduced at a normal viewing angle.

[0005] To achieve the above purpose, the technical solution is as follows:

[0006] A display device having an anti-peeping mode, comprising:

[0007] display panel; and

[0008] A dimming device, the dimming device is located at the light-emitting side of the display panel, the dimming device comprises a cholesteric liquid crystal layer, the cholesteric liquid crystal layer comprises cholesteric liquid crystals, and the cholesteric liquid crystal layer has a reflective state;

[0009] Wherein, when the display device is in the anti-peeping mode, the cholesteric liquid crystal layer is in the reflective state, and the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode is greater than the maximum value of the reflectivity of visible light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode, and the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle greater than half of the visible angle in the anti-peeping mode is less than the maximum value of the reflectivity of visible light with an incident angle greater than half of the visible angle in the anti-peeping mode, the incident angle is defined as the angle between the incident direction and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state, and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state is parallel to the thickness direction of the cholesteric liquid crystal layer.

[0010] In the display device of some embodiments, half of the viewing angle in the anti-peeping mode is greater than or equal to 0 degrees and less than or equal to 30 degrees.

[0011] In the display device of some embodiments, the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to visible light with an incident angle less than or equal to half of the viewing angle in the anti-peeping mode is less than or equal to 15%.

[0012] In the display device of some embodiments, the cholesteric liquid crystal layer in the reflective state has a maximum reflectivity at a wavelength greater than or equal to 760 nanometers and less than or equal to 900 nanometers for infrared light vertically incident on the cholesteric liquid crystal layer.

[0013] In the display device of some embodiments, the helical pitch of the cholesteric liquid crystal in the reflective state is greater than or equal to 460 nanometers and less than or equal to 600 nanometers.

[0014] In the display device of some embodiments, the cholesteric liquid crystal includes 10%-15% of chiral additives by weight.

[0015] In the display device of some embodiments, the reflectivity of the cholesteric liquid crystal layer in the reflective state to green light with an incident angle greater than half of the viewing angle in the anti-peeping mode is greater than the reflectivity to blue light with an incident angle greater than half of the viewing angle in the anti-peeping mode.

[0016] In the display device of some embodiments, the display device further has a sharing mode, and the cholesteric liquid crystal layer further has a transparent state;

[0017] Wherein, when the display device is in the sharing mode, the cholesteric liquid crystal layer is in a transparent state.

[0018] In the display device of some embodiments, the display device further has an enhanced sharing mode, and the cholesteric liquid crystal layer further has a haze state;

[0019] Wherein, when the display device is in the enhanced sharing mode, the cholesteric liquid crystal layer is in a foggy state.

[0020] In the display device of some embodiments, the dimming device further includes a first electrode layer and a second electrode layer, and the cholesteric liquid crystal layer is located between the first electrode layer and the second electrode layer;

[0021] When the cholesteric liquid crystal layer is in a reflective state, there is a first voltage difference between the first electrode layer and the second electrode layer;

[0022] When the cholesteric liquid crystal layer is in a transparent state, there is a second voltage difference between the first electrode layer and the second electrode layer;

[0023] When the cholesteric liquid crystal layer is in a mist state, a third voltage difference exists between the first electrode layer and the second electrode layer;

[0024] The absolute value of the first voltage difference is smaller than the absolute value of the third voltage difference, and the absolute value of the third voltage difference is smaller than the absolute value of the second voltage difference.

[0025] A display device having an anti-peeping mode, the display device comprising a liquid crystal display panel and a dimming device, the dimming device being located on a light incident side of the liquid crystal display panel, the dimming device comprising:

[0026] A cholesteric liquid crystal layer, the cholesteric liquid crystal layer includes cholesteric liquid crystals, and the cholesteric liquid crystal layer has a reflective state;

[0027] Wherein, when the display device is in the anti-peeping mode, the cholesteric liquid crystal layer is in the reflective state, and the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode is greater than the maximum value of the reflectivity of visible light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode, and the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle greater than half of the visible angle in the anti-peeping mode is less than the maximum value of the reflectivity of visible light with an incident angle greater than half of the visible angle in the anti-peeping mode, the incident angle is defined as the angle between the incident direction and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state, and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state is parallel to the thickness direction of the cholesteric liquid crystal layer.

[0028] In the display device of some embodiments, the display device further includes a backlight module, the dimming device is located between the liquid crystal display panel and the backlight module, and the backlight module is used to emit backlight.

[0029] Beneficial effect: The present application provides a display device, wherein a dimming device is arranged on the light-emitting side of a display panel, the dimming device comprises a cholesteric liquid crystal layer in a reflective state, the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode is greater than the maximum value of the reflectivity of visible light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode, the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle greater than half of the visible angle in the anti-peeping mode is less than the maximum value of the reflectivity of the visible light with an incident angle greater than half of the visible angle in the anti-peeping mode The maximum value of the reflectivity of half of the visible light is achieved, the incident angle is defined as the angle between the incident direction and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state, the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state is parallel to the thickness direction of the cholesteric liquid crystal layer, so that the visible light emitted by the display panel with an incident angle less than or equal to half of the viewing angle in the anti-peeping mode has a large transmittance in the cholesteric liquid crystal layer in the reflective state, thereby ensuring the brightness of the picture displayed by the display device within the viewing angle range in the anti-peeping mode, and further ensuring the display effect of the display device within the viewing angle range in the anti-peeping mode.

[0030] Moreover, the transmittance of visible light emitted by the display panel with an incident angle greater than half of the viewing angle in the anti-peeping mode is small in the reflective cholesteric liquid crystal layer, resulting in a decrease in the brightness of the picture displayed by the display device at a viewing angle greater than the viewing angle in the anti-peeping mode. Combined with the fact that the visible light in the ambient light with an incident angle greater than half of the viewing angle in the anti-peeping mode has a large reflectivity in the reflective cholesteric liquid crystal layer, the visible light in the ambient light with a large reflectivity causes brightness interference to the picture displayed by the display device at a viewing angle greater than the viewing angle in the anti-peeping mode, thereby reducing the readability of the content, thereby enabling the display device to achieve a four-way anti-peeping effect at a viewing angle greater than the viewing angle in the anti-peeping mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a cross-sectional schematic diagram of a display device in an anti-peeping mode according to an embodiment of the present application;

[0032] Figure 2 It is a cross-sectional schematic diagram of a display device in a sharing mode according to an embodiment of the present application;

[0033] Figure 3 A cross-sectional schematic diagram of a display device in an enhanced sharing mode according to an embodiment of the application;

[0034] Figure 4 is a schematic diagram of a cholesteric liquid crystal layer in a reflective state reflecting incident light;

[0035] Figure 5The cholesteric liquid crystal includes 11% chiral additives and 89% nematic liquid crystals, the average refractive index of the cholesteric liquid crystal 2031 is 1.57, and the helical pitch 2P of the cholesteric liquid crystal 2031 is 509 nanometers, and the reflection spectrum under the irradiation of the D65 light source;

[0036] Figure 6 Middle (A) Figure 1 The reflection effect at a viewing angle of 0 when the display device is not working. Figure 6 Middle (B) Figure 1 The reflection effect at a viewing angle of 35 degrees when the display device is not working;

[0037] Figure 7 It is a cross-sectional schematic diagram of another embodiment of the present application when the display device is in the anti-peeping mode;

[0038] Figure 8 It is a cross-sectional schematic diagram of another embodiment of the present application showing a device in a sharing mode;

[0039] Fig. 9 This is a cross-sectional schematic diagram of another embodiment of the present application showing a device in an enhanced sharing mode. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0041] See also Figures 1 to 3 , Figure 1 This is a cross-sectional schematic diagram of a display device in an anti-peeping mode according to an embodiment of the present application. Figure 2 This is a cross-sectional schematic diagram of a display device in a sharing mode according to an embodiment of the present application. Figure 3 It is a cross-sectional schematic diagram of a display device in an enhanced sharing mode according to an embodiment of the present application.

[0042] In this embodiment, the display device 100 can be applied to a mobile phone, a tablet computer, a notebook computer screen, a desktop monitor, a car display screen, etc.

[0043] In this embodiment, the display device 100 has an anti-peeping mode, a sharing mode, and an enhanced sharing mode, and the display device 100 can dynamically switch between the anti-peeping mode, the sharing mode, and the enhanced sharing mode. Among them, the anti-peeping mode is a narrow viewing angle mode, and the sharing mode and the enhanced sharing mode are both wide viewing angle sharing modes.

[0044] In this embodiment, if Figure 1 As shown, the viewing angle of the display device 100 in the anti-peeping mode is 2β, and 2β is greater than or equal to 0 degrees and less than or equal to 60 degrees, so as to meet the viewing angle requirements of the target user in the anti-peeping mode while ensuring that the display device 100 in the anti-peeping mode has an anti-peeping effect at a viewing angle greater than the viewing angle.

[0045] It can be understood that the viewing angle 2β in the anti-peeping mode may also be greater than or equal to 4 degrees and less than or equal to 50 degrees, or the viewing angle 2β in the anti-peeping mode may also be greater than or equal to 10 degrees and less than or equal to 40 degrees, or the viewing angle 2β in the anti-peeping mode may also be greater than or equal to 16 degrees and less than or equal to 36 degrees, or the viewing angle 2β in the anti-peeping mode may also be greater than or equal to 20 degrees and less than or equal to 30 degrees.

[0046] For example, the viewing angle 2β in the anti-peeping mode may be 60 degrees, 50 degrees, 40 degrees, 30 degrees, 20 degrees, 16 degrees or 12 degrees.

[0047] It should be noted that the viewing angle refers to the angle at which the content displayed by the display device 100 can be clearly seen. When the viewing angle of the display device 100 in the anti-peeping mode is 2β, the content displayed by the display device 100 can be clearly seen within a viewing angle range of half the viewing angle 2β on both sides of the normal line of the display surface.

[0048] Among them, half of the viewing angle 2β in the anti-peeping mode is β, and half of the viewing angle 2β in the anti-peeping mode is greater than or equal to 0 degrees and less than or equal to 30 degrees.

[0049] In this embodiment, the viewing angle of the display device 100 in the sharing mode is greater than the viewing angle of the display device 100 in the anti-peeping mode, and the viewing angle of the display device 100 in the enhanced sharing mode is greater than the viewing angle of the display device 100 in the sharing mode.

[0050] In this embodiment, the display device 100 includes a display panel 10 and a dimming device 20 . The dimming device 20 is located at the light emitting side of the display panel 10 .

[0051] The display panel 10 is a liquid crystal display panel, but is not limited thereto. The display panel 10 may also be any one of an organic light emitting diode display panel, a quantum dot display panel, a micro light emitting diode display panel, and a sub-millimeter light emitting diode display panel.

[0052] Specifically, the display panel 10 is a common liquid crystal display panel, in other words, the display panel 10 includes an array substrate 101, an opposing substrate 102, and a liquid crystal layer 103 disposed between the array substrate 101 and the opposing substrate 102. It is understandable that the display panel 10 may also be a field sequential liquid crystal display panel.

[0053] Among them, the array substrate 101 may include a driving circuit and a pixel electrode, the pixel electrode is connected to the driving circuit, and the opposing substrate 102 may include a color filter layer and a common electrode, and the common electrode and the pixel electrode are arranged opposite to each other; or, the array substrate 101 may also include a driving circuit, a pixel electrode and a common electrode, the pixel electrode is electrically connected to the driving circuit, the pixel electrode and the common electrode are used to form a horizontal electric field, and the opposing substrate 102 may include a color filter layer; or, the array substrate 101 may also include a driving circuit, a pixel electrode, a common electrode and a color filter layer, the pixel electrode is electrically connected to the driving circuit, and the pixel electrode and the common electrode are used to form a horizontal electric field.

[0054] It should be noted that if Figures 1 to 3 As shown, when the display panel 10 is a liquid crystal display panel, the display device 100 further includes a backlight module 30, which is located on the side of the display panel 10 away from the dimming device 20. The backlight module 30 is used to emit a backlight B, which is incident on the display panel 10 and then emitted by the display panel 10 for display. The backlight module 30 may be a direct-type backlight module, or the backlight module 30 may be an edge-type backlight module. When the display panel 10 is an organic light-emitting diode display panel, a quantum dot display panel, a micro light-emitting diode display panel, or a sub-millimeter light-emitting diode display panel, the display panel 10 does not need to be provided with a backlight module 30.

[0055] In this embodiment, the dimming device 20 includes a first transparent substrate 201, a second transparent substrate 202, a cholesteric liquid crystal layer 203, a first electrode layer 204, and a second electrode layer 205. The first transparent substrate 201 and the second transparent substrate 202 are arranged opposite to each other, the first electrode layer 204 is arranged on the surface of the first transparent substrate 201 close to the second transparent substrate 202, the second electrode layer 205 is arranged on the surface of the second transparent substrate 202 close to the first transparent substrate 201, and the cholesteric liquid crystal layer 203 is arranged between the first electrode layer 204 and the second electrode layer 205.

[0056] The first transparent substrate 201 and the second transparent substrate 202 are both transparent glass substrates, but are not limited thereto, and both may also be transparent polymer substrates.

[0057] The first electrode layer 204 and the second electrode layer 205 are both transparent electrode layers, and both include transparent conductive materials, such as indium zinc oxide or indium tin oxide.

[0058] The cholesteric liquid crystal layer 203 includes a cholesteric liquid crystal 2031, which is a mixture of a nematic liquid crystal and a chiral additive. When the chiral additive is a left-handed chiral additive, the cholesteric liquid crystal is a left-handed cholesteric liquid crystal. When the chiral additive is a right-handed chiral additive, the cholesteric liquid crystal is a right-handed cholesteric liquid crystal. The chiral additive can be selected from existing common chiral additives.

[0059] The average refractive index of the cholesteric liquid crystal 2031 is n, n = (ne + 2no) / 3, ne is the refractive index of the nematic liquid crystal in the long axis direction, and no is the refractive index of the nematic liquid crystal in the short axis direction. The average refractive index n of the cholesteric liquid crystal 2031 is greater than or equal to 1.5 and less than or equal to 1.6. For example, the average refractive index n of the cholesteric liquid crystal 2031 can be 1.51, 1.52, 1.53, 1.55, 1.57, 1.59 or 1.6.

[0060] In this embodiment, the voltage difference between the first electrode layer 204 and the second electrode layer 205 is adjusted to enable the cholesteric liquid crystal layer 203 to dynamically switch between the reflective state, the foggy state and the transparent state.

[0061] In this embodiment, if Figure 1 As shown, when the display device is in the anti-peeping mode, there is a first voltage difference V1 between the first electrode layer 204 and the second electrode layer 205, and the absolute value of the first voltage difference V1 is 0 or approaches 0. For example, when the first electrode layer 204 and the second electrode layer 205 are not powered, the cholesteric liquid crystal 2031 in the cholesteric liquid crystal layer 203 is not affected by the electric field, and the cholesteric liquid crystal 2031 is in a planar texture state. The long axis of the cholesteric liquid crystal 2031 of each layer is parallel to the plane of the layer. The multiple layers of cholesteric liquid crystals 2031 overlap in a spiral structure, and the direction perpendicular to the planes of the cholesteric liquid crystals 2031 of each layer is called the spiral axis I of the cholesteric liquid crystal. The spiral axis I of the cholesteric liquid crystal 2031 is perpendicular to the first transparent substrate 201 and the second transparent substrate 202 and parallel to the thickness direction of the cholesteric liquid crystal layer 203. The cholesteric liquid crystal layer 203 is in a reflective state, and the cholesteric liquid crystal layer 203 selectively reflects light with different incident angles and different wavelengths.

[0062] In addition, when the cholesteric liquid crystal layer 203 is in a reflective state, the long axis arrangement of the cholesteric liquid crystals 2031 of different layers rotates 360 degrees along the spiral axis I and then returns to the initial orientation. This periodic interlayer spacing is called the spiral pitch 2P of the cholesteric liquid crystal 2031.

[0063] It should be noted that neither the first electrode layer 204 nor the second electrode layer 205 is powered, so that the cholesteric liquid crystal layer 203 is in a reflective state, and thus the display device 100 is in an anti-peeping mode, which is beneficial to saving power consumption of the display device.

[0064] In this embodiment, when the cholesteric liquid crystal layer 203 is in the reflective state, the wavelength λ of the incident light, the average refractive index n of the cholesteric liquid crystal 2031, the incident angle α of the incident light, and the half pitch P of the cholesteric liquid crystal 2031 satisfy λ=2nPcosα. The incident angle α is defined as the angle between the incident direction of the incident light and the helical axis I of the cholesteric liquid crystal 2031 of the cholesteric liquid crystal layer 203 in the reflective state. In addition, the reflection bandwidth Δλ=ΔnP, Δn=ne-no of the cholesteric liquid crystal 2031 in the reflective state.

[0065] Among them, combined with the formula λ=2nPcosα, it can be known that when the average refractive index n and the half pitch P are constant, when the incident angle α is 0 degrees, the wavelength λ of the incident light reflected by the cholesteric liquid crystal layer 203 in the reflective state is the largest, and in the process of increasing the incident angle α from 0 degrees to 90 degrees, the wavelength λ of the incident light reflected by the cholesteric liquid crystal layer 203 gradually decreases.

[0066] According to the present application, the cholesteric liquid crystal layer 203 in a reflective state has selective reflection characteristics for both the incident angle α and the incident wavelength λ. By adjusting the concentration of the chiral additive in the cholesteric liquid crystal 2031 to control the half pitch P of the cholesteric liquid crystal, the cholesteric liquid crystal layer 203 has the maximum reflectivity for infrared light when the incident angle α is 0 degrees. As the incident angle α gradually increases to 90 degrees, the wavelength λ of the incident light with the maximum reflectivity gradually decreases. At a specific incident angle between 0 degrees and less than 90 degrees, the incident light with the maximum reflectivity is converted from infrared light to visible light. In other words, the cholesteric liquid crystal layer 203 reflects infrared light with an incident angle less than or equal to the specific incident angle, but has a high transmittance for other light such as visible light. The cholesteric liquid crystal layer 203 reflects visible light with an incident angle greater than the specific incident angle, but has a high transmittance for other light such as infrared light.

[0067] In the present embodiment, the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to infrared light with an incident angle α less than or equal to half of the viewing angle 2β in the anti-peeping mode is greater than the maximum value of the reflectivity of visible light with an incident angle α less than or equal to half of the viewing angle 2β in the anti-peeping mode, so that the visible light emitted by the display panel 10 with an incident angle α less than or equal to half of the viewing angle 2β in the anti-peeping mode has a higher transmittance in the cholesteric liquid crystal layer 203 in the reflective state, so as to ensure the display brightness of the display device 100 in the anti-peeping mode within the viewing angle range of 2β in the anti-peeping mode, thereby ensuring that the picture displayed by the display device 100 in the anti-peeping mode is visible within the viewing angle range of 2β.

[0068] At the same time, the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to infrared light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode is less than the maximum value of the reflectivity to visible light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode, so that the visible light emitted by the display panel 10 with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode has a low transmittance in the reflective cholesteric liquid crystal layer 203, and the display device 100 in the anti-peeping mode has a darker brightness at a viewing angle greater than the viewing angle 2β in the anti-peeping mode, resulting in reduced readability of the content of the display device 100 in the anti-peeping mode at a viewing angle greater than the viewing angle 2β in the anti-peeping mode, thereby enabling the display device 100 to achieve anti-peeping at a viewing angle greater than the viewing angle 2β in the anti-peeping mode. Moreover, the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to infrared light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode is lower than the maximum value of the reflectivity to visible light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode, which also makes the ambient visible light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode have a higher reflectivity on the cholesteric liquid crystal layer 203 in the reflective state, and the reflected ambient visible light interferes with the visible light emitted by the display panel 10, causing the readability of the content displayed by the display device 100 at a viewing angle greater than the viewing angle 2β in the anti-peeping mode to be further reduced, thereby further improving the anti-peeping effect of the display device 100 at a viewing angle greater than the viewing angle 2β in the anti-peeping mode.

[0069] like Figure 4 As shown, it is a schematic diagram of the cholesteric liquid crystal layer in the reflective state reflecting the incident light. When the cholesteric liquid crystal layer 203 is in the reflective state, when the incident angle α is greater than or equal to 0 degrees and less than or equal to half of the visible angle 2β in the anti-peeping mode, the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 to infrared light is greater than the maximum value of the reflectivity to visible light. In other words, the interval where the incident angle α of the incident light is greater than or equal to 0 degrees and less than or equal to half of the visible angle 2β in the anti-peeping mode is the infrared reflection area A1 that mainly reflects infrared light. When the incident angle α is greater than half of the visible angle 2β in the anti-peeping mode and less than or equal to 90 degrees, the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 to visible light is greater than the maximum value of the reflectivity to infrared light. In other words, the interval where the incident angle α is greater than half of the visible angle 2β in the anti-peeping mode and less than or equal to 90 degrees is the visible light reflection area that mainly reflects visible light.

[0070] The visible light reflection area includes a red light reflection area A2, a yellow light reflection area A3, a green light reflection area A4, and a blue light reflection area A5, which are arranged in sequence. The red light reflection area A2 is arranged adjacent to the infrared reflection area A1. The interval of the incident angle corresponding to the red light reflection area A2 is greater than the interval of the incident angle corresponding to the green light reflection area A4. The interval of the incident angle corresponding to the green light reflection area A4 is greater than the interval of the incident angle corresponding to the blue light reflection area A5. The cholesteric liquid crystal layer 203 in the reflective state in the red light reflection area A2 is sensitive to the red light. The maximum value of the reflectivity of the cholesteric liquid crystal layer 203 to yellow light is greater than the maximum value of the reflectivity of other light; the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 to yellow light in the reflective area A3 is greater than the maximum value of the reflectivity of other light; the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 to yellow light in the reflective area A4 is greater than the maximum value of the reflectivity of other light; the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 to blue light in the reflective area A5 is greater than the maximum value of the reflectivity of other light.

[0071] like Figure 1 As shown, when the dimming device 20 is located on the light-emitting side of the display panel 10, the first visible light K1 emitted by the display panel 10 with an incident angle α greater than or equal to 0 degree and less than or equal to half of the visible angle 2β in the anti-peeping mode passes through the cholesteric liquid crystal layer 203, thereby ensuring the brightness of the picture displayed by the display device 100 in the anti-peeping mode within the range of the visible angle 2β in the anti-peeping mode, and further ensuring the display effect of the display device 100 within the range of the visible angle 2β in the anti-peeping mode.

[0072] At the same time, the second visible light K2 emitted by the display panel 10 with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode is reflected, so that the brightness of the picture displayed by the display device at a viewing angle greater than half of the viewing angle 2β in the anti-peeping mode in the off-axis direction is low and a dark picture is presented, thereby presenting an anti-peeping effect at a viewing angle greater than the viewing angle 2β in the anti-peeping mode. Moreover, the infrared light H(R) in the ambient light with an incident angle α greater than or equal to 0 degrees and less than or equal to half of the viewing angle 2β in the anti-peeping mode is reflected but does not affect the display effect. The third visible light H(K3) in the ambient light with an incident angle greater than half of the viewing angle 2β in the anti-peeping mode is reflected and interferes with the visible light emitted by the display panel 10, further reducing the readability of the display picture at a viewing angle greater than half of the viewing angle 2β in the anti-peeping mode in the off-axis direction, and further improving the anti-peeping effect at a viewing angle greater than the viewing angle 2β in the anti-peeping mode.

[0073] In the display device of this embodiment, the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle less than or equal to half of the viewing angle in the anti-peeping mode is greater than the maximum value of the reflectivity to visible light with an incident angle less than or equal to half of the viewing angle in the anti-peeping mode, and the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle greater than half of the viewing angle in the anti-peeping mode is less than the maximum value of the reflectivity to visible light with an incident angle greater than half of the viewing angle in the anti-peeping mode. The incident angle is defined as the angle between the incident direction and the helical axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state, and the helical axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state is parallel to the thickness direction of the cholesteric liquid crystal layer, so that the visible light emitted by the display panel with an incident angle less than or equal to half of the viewing angle in the anti-peeping mode has a large transmittance in the cholesteric liquid crystal layer in the reflective state, thereby ensuring the brightness of the picture displayed by the display device within the viewing angle range in the anti-peeping mode, and further ensuring the display effect of the display device within the viewing angle range in the anti-peeping mode.

[0074] Moreover, the transmittance of visible light emitted by the display panel with an incident angle greater than half of the viewing angle in the anti-peeping mode is small in the reflective cholesteric liquid crystal layer, resulting in a decrease in the brightness of the picture displayed by the display device at a viewing angle greater than the viewing angle in the anti-peeping mode. Combined with the fact that the visible light in the ambient light with an incident angle greater than half of the viewing angle in the anti-peeping mode has a large reflectivity in the reflective cholesteric liquid crystal layer, the visible light in the ambient light with a large reflectivity causes brightness interference to the picture displayed by the display device at a viewing angle greater than the viewing angle in the anti-peeping mode, thereby reducing the readability of the content, thereby enabling the display device to achieve a four-way anti-peeping effect at a viewing angle greater than the viewing angle in the anti-peeping mode.

[0075] It should be noted that when the display device 100 is in the anti-peeping mode, the maximum reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to visible light with an incident angle less than or equal to half of the viewing angle 2β in the anti-peeping mode is less than or equal to 30%, which can ensure that the picture displayed by the display device within the viewing angle 2β range in the anti-peeping mode is visible. In addition, when the display device 100 is in the anti-peeping mode, the maximum reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to visible light with an incident angle greater than half of the viewing angle 2β in the anti-peeping mode is greater than 30% and less than or equal to 50%, which can ensure that the picture displayed by the display device 100 at a viewing angle greater than the viewing angle 2β in the anti-peeping mode is invisible.

[0076] Furthermore, the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to visible light with an incident angle α less than or equal to half of the viewing angle 2β in the anti-peeping mode is less than or equal to 15%, thereby further ensuring that the cholesteric liquid crystal layer 203 in the reflective state has a high transmittance to visible light with an incident angle α less than or equal to half of the viewing angle 2β in the anti-peeping mode, thereby further improving the display effect of the display device in the anti-peeping mode within the viewing angle range in the anti-peeping mode.

[0077] It can be understood that the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to visible light with an incident angle α less than or equal to half of the viewing angle 2β can be less than or equal to 12%; or, the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to visible light with an incident angle α less than or equal to half of the viewing angle 2β is less than or equal to 8%.

[0078] For example, the maximum reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to visible light with an incident angle α less than or equal to half of the viewing angle 2β is 15%, 12%, 10%, 8%, 6% or 4%.

[0079] In this embodiment, the cholesteric liquid crystal layer 203 in the reflective state has a maximum reflectivity within a wavelength band greater than or equal to 760 nanometers and less than or equal to 900 nanometers for infrared light vertically incident on the cholesteric liquid crystal layer 203. At the same time, the cholesteric liquid crystal layer 203 in the reflective state has a reflectivity greater than or equal to 25% for infrared light vertically incident on the cholesteric liquid crystal layer 203 and a reflection bandwidth greater than or equal to 100 nanometers and less than or equal to 150 nanometers.

[0080] In this embodiment, the pitch 2P of the cholesteric liquid crystal 2031 in the reflective state is greater than or equal to 460 meters and less than or equal to 600 nanometers, so that the cholesteric liquid crystal layer 203 in the reflective state has a maximum reflectivity within a band with a wavelength greater than or equal to 760 nanometers and less than or equal to 900 nanometers for infrared light vertically incident on the cholesteric liquid crystal layer 203.

[0081] It can be understood that the pitch 2P of the cholesteric liquid crystal 2031 in the reflective state can be greater than or equal to 475 nanometers and less than or equal to 600 nanometers, or, the pitch 2P of the cholesteric liquid crystal 2031 in the reflective state can be greater than or equal to 500 nanometers and less than or equal to 580 nanometers, or, the pitch 2P of the cholesteric liquid crystal 2031 in the reflective state can be greater than or equal to 520 nanometers and less than or equal to 560 nanometers.

[0082] In this embodiment, the cholesteric liquid crystal 2031 includes 10%-15% chiral additives and 85%-90% nematic liquid crystals by weight, so that the helical pitch 2P of the cholesteric liquid crystal 2031 in the reflective state is greater than or equal to 460 meters and less than or equal to 600 nanometers.

[0083] Specifically, see Figure 5 , which is a cholesteric liquid crystal including 11% chiral additives and 89% nematic liquid crystal, the average refractive index of the cholesteric liquid crystal 2031 is 1.57, and the reflection spectrum of the cholesteric liquid crystal 2031 under the D65 light source when the pitch 2P is 509 nanometers. Figure 5 As shown, the cholesteric liquid crystal layer 203 in the reflective state has a maximum reflectivity of 49.2% at a wavelength of 800 nanometers for infrared light vertically incident on the cholesteric liquid crystal layer 203 , and at the same time, the reflection bandwidth with a reflectivity greater than or equal to 25% is 130 nanometers.

[0084] In this embodiment, the reflective cholesteric liquid crystal layer 203 in the reflective state has a greater reflectivity for green light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode than for blue light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode.

[0085] Since green light is easier for the human eye to recognize than blue light, the effect of reflecting green light on improving the anti-peeping effect is greater than that of reflecting blue light. The reflective cholesteric liquid crystal layer 203 in the reflective state has a higher reflectivity for green light with an incident angle greater than half of the visible angle 2β in the anti-peeping mode than for blue light with an incident angle greater than half of the visible angle 2β in the anti-peeping mode. This improves the reflectivity of green light that is easily recognized by the human eye at a viewing angle greater than the visible angle 2β in the anti-peeping mode, thereby ensuring that the display device 100 in the anti-peeping mode has a better anti-peeping effect at a viewing angle greater than the visible angle 2β in the anti-peeping mode.

[0086] In this embodiment, the maximum value of the reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to green light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode is greater than 40% and less than 50%, so that the reflectivity of the cholesteric liquid crystal layer 203 in the reflective state to green light with an incident angle greater than half of the viewing angle 2β in the anti-peeping mode is higher.

[0087] In this embodiment, the reflective cholesteric liquid crystal layer 203 in the reflective state has a higher reflectivity for red light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode than for blue light with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode.

[0088] See also Figure 6 In (A) and (B), Figure 6 Middle (A) Figure 1The reflection effect at a viewing angle of 0 degrees when the display device is not working. Figure 6 Middle (B) Figure 1 The display device shown is not working when the reflection effect at a viewing angle of 35 degrees.

[0089] like Figure 6 As shown in (A), at a viewing angle of 0 degrees, that is, in the positive viewing direction of the display device 100, the display device 100 is transparent because the dimming device 20 reflects the vertically incident infrared light in the ambient light, while the vertically incident visible light in the ambient light passes through the dimming device 20.

[0090] like Figure 6 As shown in (B), at a viewing angle of 35 degrees, the display device 100 reflects red light because the dimming device 20 reflects the visible red light in the ambient light in the direction of the viewing angle of 35 degrees, while the infrared light in the ambient light passes through the dimming device 20 .

[0091] In the present embodiment, when the display device 100 is in the sharing mode, when there is a second voltage difference V2 between the first electrode layer 204 and the second electrode layer 205, the absolute value of the second voltage difference V2 is greater than the absolute value of the first voltage difference V1. For example, when the absolute value of the second voltage difference V2 is greater than or equal to 15V and less than or equal to 30V, the second voltage difference V2 is large enough to make the electric field applied to the cholesteric liquid crystal 2031 large enough, the cholesteric liquid crystal 2031 is arranged along the direction of the electric field, the cholesteric liquid crystal layer 203 is in a transparent state, the selective reflection characteristics of the cholesteric liquid crystal layer 203 in the transparent state disappear, the cholesteric liquid crystal layer 203 is transparent when observed from all directions, the cholesteric liquid crystal layer 203 in the transparent state has a transmittance of visible light greater than or equal to 85%, and a haze less than or equal to 4%.

[0092] like Figure 2 As shown, when the display device 100 is in the sharing mode, the cholesteric liquid crystal layer 203 is in a transparent state, and the fourth visible light K4 emitted by the display panel 10 and parallel to the thickness direction of the cholesteric liquid crystal layer 203 and the fifth visible light K5 emitted by the display panel 10 and intersecting with the thickness direction of the cholesteric liquid crystal layer 203 both pass through the transparent cholesteric liquid crystal layer 203, so that the visible light emitted by the display panel 10 has a high transmittance in the cholesteric liquid crystal layer 203, and the display device 100 has a good display effect at both the positive viewing angle of 0 degrees and the off-axis viewing angle greater than 0 degrees, and the viewing angle of the display device 100 in the sharing mode is greater than the viewing angle of the display device 100 in the anti-peeping mode.

[0093] In the present embodiment, when the display device 100 is in the enhanced sharing mode, when there is a third voltage difference V3 between the first electrode layer 204 and the second electrode layer 205, the absolute value of the third voltage difference V3 is greater than the absolute value of the first voltage difference V1 and less than the absolute value of the second voltage difference V2. For example, the absolute value of the third voltage difference V3 is greater than or equal to 10V and less than or equal to 15V. At this time, the cholesteric liquid crystal 2031 is in a focal conic state, the spiral axis of the cholesteric liquid crystal 2031 is parallel to the first transparent substrate 201 and the second transparent substrate 202, the cholesteric liquid crystal layer 203 is in a foggy state, and the haze of the cholesteric liquid crystal layer 203 in the foggy state is greater than or equal to 60%. The cholesteric liquid crystal layer 203 in the foggy state can scatter incident light.

[0094] like Figure 3 As shown, when the display device 100 is in the enhanced sharing mode, the sixth visible light K6 emitted by the display panel 10 is incident on the cholesteric liquid crystal layer 203 and then scattered by the cholesteric liquid crystal layer 203 to become the seventh visible light K7. The emission angle of the seventh visible light K7 is greater than the emission angle of the sixth visible light K6, so that the viewing angle of the display device 100 in the enhanced sharing mode is larger than the viewing angle in the sharing mode, and the enhanced sharing mode is an enhanced sharing state.

[0095] It should be noted that the cholesteric liquid crystal 2031 is in a steady state when it is in the focal conic texture state, and the cholesteric liquid crystal 2031 can be maintained in the focal conic texture state without continuously applying the third voltage difference, thereby making the cholesteric liquid crystal layer 203 in a foggy state. In addition, when the voltage difference between the first electrode layer 204 and the second electrode layer 205 is between the first voltage difference and the third voltage difference, the cholesteric liquid crystal 2031 of the cholesteric liquid crystal 2031 is in a state of a mixture of a planar state and a focal conic state, and as the voltage difference increases, the proportion of the focal conic state increases, and when the voltage difference is the third voltage difference, it is in a complete focal conic state.

[0096] In this embodiment, in the process of the voltage difference applied to the cholesteric liquid crystal increasing from the first voltage difference to the third voltage difference and then to the second voltage difference, the cholesteric liquid crystal layer switches from the reflective state to the foggy state and then to the transparent state in sequence. Correspondingly, the display device switches from the narrow-viewing angle anti-peeping mode to the enhanced sharing mode and then to the sharing mode, so that the display device can achieve dynamic four-way anti-peeping.

[0097] See also Figures 7 to 9 , Figure 7 This is a cross-sectional schematic diagram of another embodiment of the present application when the display device is in an anti-peeping mode. Figure 8 This is a cross-sectional schematic diagram of another embodiment of the present application showing a device in a sharing mode. Fig. 9 This is a cross-sectional schematic diagram of another embodiment of the present application showing a device in an enhanced sharing mode.

[0098] Figures 7 to 9The display device 100 is Figures 1 to 3 The display device 100 shown is basically similar, and the similarities are not repeated here. The differences include that the dimming device 20 is located between the backlight module 30 and the display panel 10 , and the cholesteric liquid crystal layer 203 of the dimming device 20 only adjusts the backlight B emitted by the backlight module 30 .

[0099] like Figure 7 As shown, when the display device 100 is in the anti-peeping mode, the cholesteric liquid crystal layer 203 in the reflective state transmits the first backlight B1 with an incident angle α less than or equal to half of the viewing angle 2β, while the cholesteric liquid crystal layer 203 in the reflective state transmits the first backlight B1 with an incident angle α less than or equal to half of the viewing angle 2β. The second backlight B2 with an incident angle greater than half of the viewing angle 2β is reflected, so that the first backlight B1 with an incident angle α less than or equal to half of the viewing angle 2β is emitted from the display panel 10, thereby ensuring the display brightness within the viewing angle 2β range in the anti-peeping mode. At the same time, the second backlight B2 with an incident angle α greater than half of the viewing angle 2β in the anti-peeping mode cannot be incident on the display panel 10, resulting in a decrease in brightness at a viewing angle greater than the viewing angle 2β in the anti-peeping mode. The decrease in brightness causes the brightness of the displayed picture to be darker at a viewing angle greater than the viewing angle 2β in the anti-peeping mode, so as to achieve an anti-peeping effect at a viewing angle greater than the viewing angle 2β in the anti-peeping mode. The display device 100 is in a narrow-viewing angle anti-peeping mode.

[0100] It should be noted that the above Figure 1 The design of the dimming device 20 when the dimming device 20 is located at the light emitting side of the display panel 10 is also applicable to the design of the dimming device 20 when the dimming device 20 is located between the backlight module 30 and the display panel 10, which will not be repeated here.

[0101] like Figure 8 As shown, when the display device 100 is in the sharing mode, the cholesteric liquid crystal layer 203 in a transparent state can allow the backlight B emitted by the backlight module 30 to enter the display panel 10 without interference, and the display device 100 has a good display effect at both the normal viewing angle of 0 degrees and the off-axis viewing angle greater than 0 degrees. The viewing angle of the display device 100 in the sharing mode is greater than the viewing angle of the display device 100 in the anti-peeping mode.

[0102] like Fig. 9 As shown, when the display device 100 is in the enhanced sharing mode, the cholesteric liquid crystal layer 203 in a foggy state scatters the backlight B emitted by the backlight module 30. The scattered backlight B is incident on the display panel 10 and then emitted by the display panel 10. The emission angle of the visible light emitted by the display panel 10 is increased, so that the viewing angle of the display device 100 in the enhanced sharing mode is greater than the viewing angle of the display device 100 in the sharing mode.

[0103] It is understandable that when the display panel 10 is a liquid crystal display panel, the dimming device 20 can also be provided on both the light emitting side and the light incident side of the display panel 10 to achieve a better anti-peeping effect when the display device 100 is in the anti-peeping mode.

[0104] The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technical personnel in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A display device, characterized in that: The display device has an anti-peeping mode, and the display device includes: display panel; and A dimming device, the dimming device is located at the light-emitting side of the display panel, the dimming device comprises a cholesteric liquid crystal layer, the cholesteric liquid crystal layer comprises cholesteric liquid crystals, and the cholesteric liquid crystal layer has a reflective state; Wherein, when the display device is in the anti-peeping mode, the cholesteric liquid crystal layer is in the reflective state, and the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode is greater than the maximum value of the reflectivity of visible light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode, and the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle greater than half of the visible angle in the anti-peeping mode is less than the maximum value of the reflectivity of visible light with an incident angle greater than half of the visible angle in the anti-peeping mode, the incident angle is defined as the angle between the incident direction and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state, and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state is parallel to the thickness direction of the cholesteric liquid crystal layer.

2. The display device according to claim 1, characterized in that Half of the viewing angle in the anti-peeping mode is greater than or equal to 0 degrees and less than or equal to 30 degrees.

3. The display device according to claim 1 or 2, characterized in that: The maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to visible light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode is less than or equal to 15%.

4. The display device according to claim 1, characterized in that The cholesteric liquid crystal layer in the reflective state has a maximum reflectivity within a wavelength range of greater than or equal to 760 nanometers and less than or equal to 900 nanometers for infrared light vertically incident on the cholesteric liquid crystal layer.

5. The display device according to claim 4, characterized in that: The helical pitch of the cholesteric liquid crystal in the reflective state is greater than or equal to 460 nanometers and less than or equal to 600 nanometers.

6. The display device according to claim 5, characterized in that: Calculated by weight percentage, the cholesteric liquid crystal includes 10%-15% of chiral additives.

7. The display device according to claim 1 or 2, characterized in that: The cholesteric liquid crystal layer in the reflective state has a greater reflectivity to green light with an incident angle greater than half of the viewing angle in the anti-peeping mode than to blue light with an incident angle greater than half of the viewing angle in the anti-peeping mode.

8. The display device according to claim 1, characterized in that: The display device also has a sharing mode, and the cholesteric liquid crystal layer also has a transparent state; Wherein, when the display device is in the sharing mode, the cholesteric liquid crystal layer is in a transparent state.

9. The display device according to claim 8, characterized in that: The display device also has an enhanced sharing mode, and the cholesteric liquid crystal layer also has a foggy state; Wherein, when the display device is in the enhanced sharing mode, the cholesteric liquid crystal layer is in a foggy state.

10. The display device according to claim 9, characterized in that: The dimming device further comprises a first electrode layer and a second electrode layer, and the cholesteric liquid crystal layer is located between the first electrode layer and the second electrode layer; When the cholesteric liquid crystal layer is in a reflective state, there is a first voltage difference between the first electrode layer and the second electrode layer; When the cholesteric liquid crystal layer is in a transparent state, there is a second voltage difference between the first electrode layer and the second electrode layer; When the cholesteric liquid crystal layer is in a mist state, a third voltage difference exists between the first electrode layer and the second electrode layer; The absolute value of the first voltage difference is smaller than the absolute value of the third voltage difference, and the absolute value of the third voltage difference is smaller than the absolute value of the second voltage difference.

11. A display device, characterized in that: The display device has an anti-peeping mode, and includes a liquid crystal display panel and a dimming device, wherein the dimming device is located on a light incident side of the liquid crystal display panel, and the dimming device includes: A cholesteric liquid crystal layer, the cholesteric liquid crystal layer includes cholesteric liquid crystals, and the cholesteric liquid crystal layer has a reflective state; Wherein, when the display device is in the anti-peeping mode, the cholesteric liquid crystal layer is in the reflective state, and the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode is greater than the maximum value of the reflectivity of visible light with an incident angle less than or equal to half of the visible angle in the anti-peeping mode, and the maximum value of the reflectivity of the cholesteric liquid crystal layer in the reflective state to infrared light with an incident angle greater than half of the visible angle in the anti-peeping mode is less than the maximum value of the reflectivity of visible light with an incident angle greater than half of the visible angle in the anti-peeping mode, the incident angle is defined as the angle between the incident direction and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state, and the spiral axis of the cholesteric liquid crystal of the cholesteric liquid crystal layer in the reflective state is parallel to the thickness direction of the cholesteric liquid crystal layer.

12. The display device according to claim 11, characterized in that: The display device further comprises a backlight module. The dimming device is located between the liquid crystal display panel and the backlight module. The backlight module is used for emitting backlight.

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