DIMMING LAYER FOR DISPLAY MODULE AND DISPLAY MODULE

The present application provides a dimming layer for a display module and the display module, wherein a side surface of the dimming layer is formed with nano-pillars arranged in an array, and wherein the dimming layer is configured to pass through incident light perpendicular to a surface of the dimming layer and is configured to absorb incident light not perpendicular to the surface of the dimming layer. A light propagation direction is modulated by the dimming layer to achieve adjustment between wide and narrow viewing angles.

TECHNICAL FIELD

The present invention relates to a field of display technology and more particularly to a dimming layer for a display module and the display module.

BACKGROUND

With rapid development of display technology, use of display devices is ubiquitous in daily life. In the past, wide viewing angles were considered to be an advantage of mobile phones and personal computers (PC). However, as consumers' awareness of privacy increases, in special situations, such as on subways, high-speed rails, airplanes, etc., people want privacy to be protected. Therefore, a single wide viewing angle of display devices can no longer meet people's requirements. It is necessary to provide a display that can be switched between a wide viewing angle mode and a narrow viewing angle mode. Thereby, people can switch their display to the narrow viewing angle mode when they do not want people around to watch content on their displays and switch their displays to the wide viewing angle mode when they do not mind people around watching content on their displays.

Therefore, there is an urgent need fora dimming layer fora display module and the display module to solve the above technical problems.

SUMMARY OF INVENTION

Technical Problem

The embodiments of the present application provide a dimming layer for a display module and the display module, to solve the above technical problems of switching the display to a narrow viewing angle mode when people don't want people around to watch content on their display, and switching the display to a wide viewing angle mode when people don't mind people around to watch content on their display.

Solution to Technical Problem

Technical Solution

In order to solve the above technical problems, the technical solutions provided by the present application are as follows:

The present application provides a dimming layer for a display module, wherein a side surface of the dimming layer is formed with nano-pillars arranged in an array, and wherein the dimming layer is configured to pass through incident light perpendicular to a surface of the dimming layer and is configured to absorb incident light not perpendicular to the surface of the dimming layer.

In one embodiment, the dimming layer includes a first dimming region and a second dimming region, and a size of the nano-pillars of the first dimming region is different from a size of the nano-pillars of the second dimming region.

In one embodiment, a greatest cross-sectional dimension of the nano-pillars ranges from 80 nm to 180 nm, and a height of the nano-pillars is 80 nm.

In one embodiment, the dimming layer includes a first dimming region and a second dimming region, and a density of the nano-pillars in the first dimming region is different from a density of the nano-pillars in the second dimming region.

In one embodiment, a distance between adjacent two of the nano-pillars ranges from 160 nm to 380 nm

In one embodiment of the present invention, the dimming layer includes a substrate, and the nano-pillars are formed on the substrate.

In one embodiment, a material of the nano-pillars is silver or titanium dioxide.

In one embodiment, a cross-sectional shape of the nano-pillars includes a circle, a rectangle, a triangle, or a trapezoid.

In one embodiment, the nano-pillars arranged in the array include a plurality of nano-pillar arrays arranged in a lattice, and wherein a geometric shape of the nano-pillar arrays includes at least one of a square, a hexagon, an octagon, or a pentagon.

The present application further provides a display module, including:a backlight module;a display panel positioned on a light-emitting side of the backlight module; anda dimming layer positioned on a light-emitting side of the display panel;wherein a side surface of the dimming layer is formed with nano-pillars arranged in an array, and wherein the dimming layer is configured to pass through incident light perpendicular to a surface of the dimming layer, and is configured to absorb incident light not perpendicular to the surface of the dimming layer.

In one embodiment, the dimming layer includes a first dimming region and a second dimming region, and a size of the nano-pillars of the first dimming region is different from a size of the nano-pillars of the second dimming region.

In one embodiment, a greatest cross-sectional dimension of the nano-pillars ranges from 80 nm to 180 nm, and a height of the nano-pillars is 80 nm.

In one embodiment, the dimming layer includes a first dimming region and a second dimming region, and a density of the nano-pillars in the first dimming region is different from a density of the nano-pillars in the second dimming region.

In one embodiment, a distance between adjacent two of the nano-pillars ranges from 160 nm to 380 nm.

In one embodiment, the dimming layer includes a substrate, and the nano-pillars are formed on the substrate.

In one embodiment, a material of the nano-pillars is silver or titanium dioxide.

In one embodiment, a cross-sectional shape of the nano-pillars includes a circle, a rectangle, a triangle, or a trapezoid.

In one embodiment, the nano-pillars arranged in the array include a plurality of nano-pillar arrays arranged in a lattice, and wherein a geometric shape of the nano-pillar arrays includes at least one of a square, a hexagon, an octagon, or a pentagon.

In one embodiment, the display module further including a liquid crystal layer positioned in the backlight module or between the backlight module and the display panel;wherein the liquid crystal layer includes a first electrode and a second electrode oppositely arranged, and a liquid crystal molecular layer positioned between the first electrode and the second electrode, and the liquid crystal molecular layer switches between a scattering state and a transparent state under an electric field formed between the first electrode and the second electrode.

In one embodiment, a material of the liquid crystal molecular layer is polymer dispersed liquid crystal or polymer network liquid crystal.

Beneficial Effects of Invention

Beneficial Effects

One side surface of the dimming layer is formed with nano-pillars arranged in an array so that the dimming layer can transmit incident light perpendicular to the surface of the dimming layer and absorb incident light that is not perpendicular to the surface of the dimming layer, therefore, modulating a propagation direction of light by the dimming layer, and using the liquid crystal layer located in the backlight module or between the backlight module and the display panel to realize real-time control of wide and narrow viewing angles

EMBODIMENTS OF INVENTION

Detailed Description of Embodiments

The present application provides a dimming layer for a display module and the display module. In order to make the objectives, technical solutions, and effects of the present application more specific and clearer, the present application will be further described in detail below with reference to the accompanying figures and embodiments. It should be understood that the specific embodiments described here are only used to explain the present disclosure, and are not used to limit the present application.

The embodiments of the present application provide a display panel and a manufacturing method thereof. Detailed descriptions are provided below. It should be noted that an order of description in the following embodiments is not meant to limit a preferred order of the embodiments.

As shown inFIG.1, one embodiment of the present invention provides a dimming layer10for a display module, wherein a side surface of the dimming layer10is formed with nano-pillars12arranged in an array, and wherein the dimming layer10is configured to transmit incident light perpendicular to a surface of the dimming layer10and is configured to absorb incident light not perpendicular to the surface of the dimming layer10. Specifically, due to the characteristics of a structure of the nano-pillar12itself, a phase and amplitude of the incident light can be adjusted, when an incident direction of the incident light matches the structure of the nano-pillar12, the structural characteristics of the nano-pillar12can be used to change a reflection phase of the incident light. By changing the design of the nano-pillars12, reflection phase of the incident light can be changed, thereby achieving an effect of adjusting an angle of any wavelength within a visible spectrum.

A material of the nano-pillar12is not limited, and the material of the nano-pillar12should be a material with higher reflectivity, such as silver (Ag), copper (Cu), or polycarbonate resin composition.

In this embodiment, by specially designing the nano-pillars12formed on the side surface of the dimming layer10(such as adjusting a shape, a size, a direction, or a position arrangement of the nano-pillars12), control of a propagation direction of light (reflection/refraction) can be realized, thereby transmitting or absorbing light in a specific propagation direction. In this embodiment, the nano-pillars12arranged in the array can enable the dimming layer10to transmit incident light perpendicular to the surface of the dimming layer10and absorb incident light that is not perpendicular to the surface of the dimming layer10. The propagation direction of light is modulated by the dimming layer10to achieve adjustment between wide and narrow viewing angles.

A cross-sectional shape of the nano-pillars12includes patterns such as a circle, a rectangle, a triangle, or a trapezoid. The pattern arrangement parameters, length, width, height, spacing, position angle, etc. are related to angle of incident light, the present invention does not limit it.

Further, the nano-pillars12arranged in the array may include a plurality of nano-pillar arrays arranged in a lattice, and wherein a geometric shape of the nano-pillar arrays may include at least one of a square, a hexagon, an octagon, or a pentagon.

In one embodiment, an interval between adjacent two of the nano-pillars12of the nano-pillar arrays can be selected to achieve a control of a propagation (reflection/refraction) direction of light and selectively transmit or absorb light in a specific direction.

In another embodiment, a size of the nano-pillars12of the nano-pillar array can be selected to achieve control of a propagation (reflection/refraction) direction of light and selectively transmit or absorb light in a specific propagation direction.

In one specific implementation method, one embodiment of the present invention provides a dimming layer10for a display module. The dimming layer10includes a substrate14, and the nano-pillars12are formed on the substrate14, wherein the substrate14can be a separate film, or can be a residual film from an embossing process. Because glue has a certain refractive index, glue with a corresponding refractive index can be selected according to actual needs to prevent affecting a propagation direction of light.

In one embodiment, the nano-pillars12can be manufactured by using electron beam etching or other appropriate nano-level writing technology and/or devices. In another embodiment, the nano-pillars12may be molded onto the appropriate substrate14by printing, impressing, relief, embossing, molding, or other forming methods to form the dimming layer10.

In one specific implementation method, one embodiment of the present invention provides a dimming layer10for a display module, wherein the dimming layer10includes a first dimming region and a second dimming region, and a size of the nano-pillars12of the first dimming region is different from a size of the nano-pillars12of the second dimming region. Specifically, as shown inFIG.1, the dimension parameters of the nano-pillars12may include a maximum cross-sectional dimension (L) and a height (H). In this embodiment, the maximum cross-sectional dimension of the nano-pillars12may be determined according to a propagation direction of the incident light. By designing a size of the nano-pillars12in the dimming layer10in partitions, precise partition control of a propagation direction of light can be achieved.

Optionally, the greatest cross-sectional dimension (L) of the nano-pillars12ranges from 80 nm to 180 nm, and the height (H) of the nano-pillar12is 80 nm.

In one specific implementation method, one embodiment of the present invention provides a dimming layer10for a display module. The dimming layer10includes a first dimming region and a second dimming region, and a density of the nano-pillars12in the first dimming region is different from a density of the nano-pillars12in the second dimming region. By designing the density of the nano-pillars12in the dimming layer10in partitions, it can achieve an effect of precise partition control of a propagation direction of light, which significantly improves a light utilization rate.

Optionally, a distance (D) between adjacent two of the nano-pillars12ranges from 160 nm to 380 nm.

In one specific implementation method, one embodiment of the present invention provides a dimming layer10for a display module, and a material of the nano-pillars12is silver or titanium dioxide, wherein titanium dioxide is a dielectric material with high refractive index in a visible light range, which can phase-modulate incident light within a range from 0° to 360°.

In one specific implementation method, one embodiment of the present invention provides a display module. As shown inFIG.2, the display module1includes a backlight module20, a display panel40positioned on a light-emitting side of the backlight module20, and a dimming layer10positioned on a light-emitting side of the display panel40, wherein the dimming layer10is the dimming layer10in the above-mentioned embodiment. The backlight module20is disposed under the display panel40and is configured to provide a light source in a direction of the display panel40. The dimming layer10modulates a light propagation direction on the light-emitting side of the display panel40to realize adjustment between the wide and narrow viewing angles of the display module.

In the display module provided by the embodiment of the present invention, the backlight module20includes a light guiding plate and a light source. Optionally, the light source may be an edge light source or a direct light source. Correspondingly, the light guiding plate may also be an edge light guiding plate or a direct light guiding plate. Further, the backlight module20may also include a prism sheet, a diffuser sheet, a reflective sheet, and a sealant, wherein the prism sheet, the diffuser sheet, the light guiding plate, and the reflective sheet are stacked in sequence along a light-emitting direction away from the display panel40, and the sealant is set around the light guiding plate. The prism sheet is configured to improve a luminous efficiency of an entire backlight system; the diffuser sheet can be used to enhance optical quality and can also be used to improve an adsorption phenomenon of the film and other parts of the display panel40; the light guiding plate is configured to guide the light emitted by the light source and then provide uniform backlight to the display panel40; the reflective sheet is configured to control reflection and refraction of light, so that the light path is controllable, and the brightness of the display panel40can be more uniform, disposing the above film layers can make the display panel40achieve a better display effect with lower power consumption.

In one specific implementation method, one embodiment of the present invention provides a display module. As shown inFIG.2, the display module1further includes a liquid crystal layer30positioned in the backlight module20or between the backlight module20and the display panel40, wherein the liquid crystal layer30includes a first electrode31and a second electrode32oppositely arranged, and a liquid crystal molecular layer33positioned between the first electrode31and the second electrode32, and the liquid crystal molecular layer33switches between a scattering state and a transparent state under influence of an electric field formed between the first electrode31and the second electrode32. Specifically, under the influence of the electric field formed by the first electrode31and the second electrode32, the liquid crystal molecular layer33is in a transparent state, and the light from the light-emitting side of the backlight module does not scatter or refract when passing through the liquid crystal layer30, and the light is emitted according to the original path at this time; when there is no electric field between the first electrode31and the second electrode32, the liquid crystal molecular layer33is in the scattering state, and when the light from the light-emitting side of the backlight module passes through the liquid crystal layer30, the light path changes and the light is scattered into light in various directions.

The first electrode31and the second electrode32are both transparent electrodes. Optionally, a material of the first electrode31and the second electrode32is nano silver, graphene, ITO (indium tin oxide), nano-material composite film or two-dimensional material film.

Illustratively inFIG.2, the liquid crystal layer30is positioned between the backlight module20and the display panel40. In other implementation methods, the liquid crystal layer30may also be positioned in the backlight module20. As shown inFIG.2, when an electric field is formed between the first electrode31and the second electrode32, the liquid crystal molecular layer33is in a transparent state, and the light from the light-emitting side of the backlight module20does not scatter or refract when passing through the liquid crystal layer30. At this time, the light is emitted according to an original path. The light emitted from the display panel40is mainly light perpendicular to the surface of the display panel, and a small amount of light whose propagation direction is not perpendicular to the surface of the display panel is emitted and the light propagation direction is modulated by the dimming layer10. The light perpendicular to the surface of the dimming layer10is directly transmitted therethrough, while the small amount of light that is not perpendicular to the surface of the dimming layer10is absorbed by the dimming layer10. Finally, only the light perpendicular to the surface of the dimming layer10is emitted from the display module1. In observers' fields of vision, only from a front view direction can they see the display, while from other angles they cannot see the display, so as to achieve narrow viewing angle display. When there is no electric field between the first electrode31and the second electrode32, the liquid crystal molecular layer33is in a scattering state, when the light on the light-emitting side of the backlight module20passes through the liquid crystal layer30, the light path changes and is scattered into light in various directions. Therefore, the light through and emitted from the display panel40is also scattered light, and finally passes through the dimming layer10. Due to the dimming layer10can only absorb a small amount of light incident non-perpendicular to its surface, the remaining light incident non-perpendicular to its surface passes through the dimming layer10directly. Shown in the observers' fields of vision, not only can the display be observed from the front view, but the display can also be observed from other directions, so as to achieve wide viewing angle display. In this embodiment, the display module1can realize freely switching between wide viewing angle and narrow viewing angle, which makes up for the defect that current display devices cannot switch between a wide viewing angle mode and a narrow viewing angle mode.

The display module1provided by the embodiments of the present invention uses disposition of the liquid crystal molecular layer33that can be switched between the transparent state and the scattering state and the dimming layer10configured to adjust the light propagation paths to realize wide and narrow viewing angle modulation. When the liquid crystal molecular layer33is in the transparent state, the light perpendicular to the surface of the dimming layer10is directly transmitted, while a small amount of light that is not perpendicular to the surface of the dimming layer10is absorbed by the dimming layer10to realize narrow viewing angle display of the display module; when the liquid crystal molecular layer33is in the scattering state, a large amount of light that is not perpendicular to its surface directly passes through the side of the dimming layer10, to realize the wide viewing angle display of the display module1. Thereby the display module1can be freely switched between the wide viewing angle mode and the narrow viewing angle mode, which makes up for the defect that current display devices cannot switch between the wide viewing angle mode and the narrow viewing angle mode.

In one specific implementation method, one embodiment of the present invention provides a display module, the liquid crystal layer30includes a driving circuit, and the driving circuit is electrically connected to the first electrode31and the second electrode32, the driving circuit is configured to control the liquid crystal molecular layer33to switch between the transparent state and the scattering state. Specifically, when the display module1is used for wide viewing angle display, the first electrode31and the second electrode32are driven by the driving circuit to switch the liquid crystal molecular layer33into the scattering state, a light path of the light on the light-emitting side of the backlight module20passes through the liquid crystal layer30is changed and is scattered into light in various directions; when the display module1is used for narrow viewing angle display, the driving circuit provides a driving voltage to the first electrode31and the second electrode32, to switch the liquid crystal molecular layer33into the transparent state. The light on the light-emitting side of the backlight module20does not scatter or refract when passing through the liquid crystal layer30, and the light is emitted according to the original path at this time.

The driving circuit may be formed on a flexible circuit board.

It is understandable that, as described above, the liquid crystal molecular layer33is in the transparent state by applying a voltage on the first electrode31and the second electrode32, so that the first electrode31and the second electrode32are in the transparent state. The control method of controlling the liquid crystal molecular layer33in the scattering state without an electric field is only an example, and other control methods may also be adopted. For example, the first electrode31and the second electrode32can be under influence of a voltage difference to make the liquid crystal molecular layer33be in the transparent state, the first electrode31and the second electrode32can make the liquid crystal molecular layer33be in the scattering state under another voltage difference, as long as the electric field between the first electrode31and the second electrode32controls the liquid crystal molecular layer33to switch between the transparent state and the scattering state.

In one specific implementation method, one embodiment of the present invention provides a display module, wherein a material of the liquid crystal molecular layer33is polymer dispersed liquid crystal or polymer network liquid crystal. By utilizing the characteristic of polymer dispersed liquid crystal or polymer network liquid crystal that they can be switched between the transparent state and the scattering state, combined with the function of the dimming layer10of modulating the light propagation direction, real-time regulation of the wide and narrow viewing angles of the display module1is realized.

Polymer dispersed liquid crystal (PDLC)/Polymer network liquid crystal (PNLC) are all polymer/liquid crystal composite films. PDLC is a mixture of low-molecular liquid crystal and prepolymer, under certain conditions, after polymerization, a formation of micron-sized liquid crystal particles35uniformly dispersed in a polymer network, and then use a dielectric anisotropy of the liquid crystal molecules to obtain electro-optic response characteristics of the material. PDLC has a structure in which the liquid crystal is dispersed through the polymer, i.e., the liquid crystal is phase separated in the polymer; PNLC has a structure in which liquid crystals are dispersed in the polymer network, and the liquid crystals in the polymer network have a continuous phase. As the polymer layer, a light-curing resin can be used. For example, PNLC includes irradiating a solution in which a liquid crystal is mixed with a photopolymerizable polymer precursor (monomer) with ultraviolet rays to polymerize the monomer to form a polymer, and the liquid crystal is dispersed in the polymer network.

For PNLC, in an off state, i.e., when an electric field is zero, since the liquid crystal exists in a multi-domain state in the network, a director distribution of each liquid crystal domain is random, and the incident light is scattered due to a discontinuous change of the refractive index at the interface between the domain and the domain, and the PNLC appears as a scattered state; when a voltage is applied to the PNLC, the electric field causes the directors in all the liquid crystal domains to be arranged in a single domain state along a direction of the electric field. For incident light, it is a medium with a uniform refractive index, the PNLC transmits light under sufficient voltage, in the case, if the electric field has sufficient intensity, a vertical transmittance of the PNLC will reach a maximum, and the PNLC will be in the transparent state.

As shown inFIGS.3and4, taking the material of the liquid crystal molecular layer33as a polymer dispersed liquid crystal as an example, in this embodiment, the polymer liquid crystal includes liquid crystal particles35uniformly distributed therein. Specifically, when no electric field is formed between the first electrode31and the second electrode32, optical axis orientations of the liquid crystal particles35in the PDLC are random, at this time, the PDLC is in the scattering state. When an electric field is formed between the first electrode31and the second electrode32, the liquid crystal in the PDLC is oriented perpendicular to the display panel40along the direction of the electric field, and an effective refractive index of the liquid crystal particles35basically matches a refractive index of the polymer. At this time, the PDLC is in the transparent state. Through the electric field between the first electrode31and the second electrode32, the dimming layer311can be controlled to switch between the transparent state and the scattering state.

As shown inFIG.3, after the external voltage is applied, the optical axis of the liquid crystal particles35is aligned perpendicular to the PDLC surface, i.e., consistent with the direction of the electric field. The effective refractive index of the liquid crystal particles basically matches the refractive index of the polymer, therefore there is no obvious interface, forming a basically uniform medium, so the incident light will not be scattered. At this time, the liquid crystal molecular layer33is in the transparent state, and there is no scattering or refraction when the light from the light-emitting side of the backlight module passes through the liquid crystal layer30. At this time, the light is emitted according to the original path, therefore the light emitted from the display panel40is mainly the light perpendicular to the surface of the display panel40, and a small amount of light that is not perpendicular to the surface of the display panel40is emitted, and then the dimming layer modulates a propagation direction of the small amount of light that is not perpendicular to the surface of the display panel40. Therefore, the light perpendicular to the surface of the dimming layer10is directly transmitted, while the small amount of light that is not perpendicular to the surface of the dimming layer10is absorbed by the dimming layer10, and finally only the light perpendicular to the surface of the dimming layer10is emitted from the display module1and is shown in the observers' fields of vision, the display can be seen only in a direction of the front viewing angle, while the display cannot be seen in other viewing angles, thus achieving narrow viewing angle display.

In the case of no applied voltage, as shown inFIG.4, the optical axis orientation of the liquid crystal particles35are random and presented in a disorderly state. The effective refractive index of the liquid crystal particles35does not match the refractive index of the polymer, which causes the incident light to be strongly scattered. At this time, the liquid crystal molecular layer33is in the scattering state, and the path of the light from the light-emitting side of the backlight module20changes when passing through the liquid crystal layer30and is scattered into light in various directions. By the display panel40, the light emitted from the display panel40is also scattered light and finally passes through the dimming layer10. Since the dimming layer10can only absorb a small amount of incident light non-perpendicular to its surface, the remaining non-perpendicular light on the surface passes the dimming layer10directly and is shown in the observers' fields of vision. Not only can the display be observed from the front viewing angle, but the display can also be observed from other directions, thereby realizing wide viewing angle display. In this embodiment, the characteristic that the polymer dispersed liquid crystal or the polymer network liquid crystal can be switched between the transparent state and the scattering state, combined with the function of the dimming layer10of modulating the light propagation direction, the display module1realizes freely switching between the wide and narrow viewing angles and makes up for the defect that current display devices cannot be switched between the wide viewing angle mode and the narrow viewing angle mode.

The embodiment of the present invention provides a driving method of a display module for driving the display module as described above, wherein the driving circuit is electrically connected to the first electrode31and the second electrode32, so the driving circuit is configured to control the liquid crystal molecular layer33to switch between the transparent state and the scattering state. The display module1has a wide viewing angle mode and a narrow viewing angle mode. In the wide viewing angle mode, the liquid crystal molecular layer33is switched into the scattering state, and light is incident on the dimming layer10, and the dimming layer10absorbs a small amount of light not perpendicular to the surface of the dimming layer10, and the remaining large amount of light that is not perpendicular to the dimming layer10surface passes through the dimming layer10directly, thereby achieving wide viewing angle display. In the narrow viewing angle mode, the liquid crystal molecular layer33is switched into the transparent state, and the light perpendicular to the surface of the dimming layer10is directly transmitted, while a small amount of light that is not perpendicular to the surface of the dimming layer10is absorbed by the dimming layer10, thereby realizing narrow viewing angle display.

The driving method of the display device includes the following steps: in the wide viewing angle mode, the liquid crystal molecular layer33is driven by the driving circuit to be switched into the scattering state, so that a large amount of light that is not perpendicular to the dimming layer10surface directly passes through the side of the dimming layer10to realize wide viewing angle display of module1. In the narrow viewing angle mode, a driving voltage is provided, and the liquid crystal molecular layer33is driven by the driving circuit to be switched into the transparent state, so that the light perpendicular to the surface of the dimming layer10is directly transmitted, a small amount of light that is not perpendicular to the surface of the dimming layer10is absorbed by the dimming layer10to realize narrow viewing angle display of the display module1.

With this driving method, the display module1can realize free switching between the wide viewing angle mode and the narrow viewing angle mode, thereby providing selective privacy content protection for the display, allowing surrounding viewers to watch the content that the controller wants to let them watch, thereby realizing intelligent control.

It can be understood that, for those of ordinary skill in the art, equivalent replacements or changes can be made according to the technical solution of the present application and its inventive concept, and all these changes or replacements shall fall within the protection scope of the appended claims of the present application.