[go: up one dir, main page]

WO2022127444A1 - 一种防窥视背光模组 - Google Patents

一种防窥视背光模组 Download PDF

Info

Publication number
WO2022127444A1
WO2022127444A1 PCT/CN2021/129496 CN2021129496W WO2022127444A1 WO 2022127444 A1 WO2022127444 A1 WO 2022127444A1 CN 2021129496 W CN2021129496 W CN 2021129496W WO 2022127444 A1 WO2022127444 A1 WO 2022127444A1
Authority
WO
WIPO (PCT)
Prior art keywords
backlight module
guide plate
light guide
light source
light
Prior art date
Application number
PCT/CN2021/129496
Other languages
English (en)
French (fr)
Inventor
李同
武鹏
陈怡敏
Original Assignee
马鞍山晶智科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 马鞍山晶智科技有限公司 filed Critical 马鞍山晶智科技有限公司
Priority to JP2023532623A priority Critical patent/JP2023552738A/ja
Priority to EP21905373.3A priority patent/EP4235284A4/en
Priority to US18/267,097 priority patent/US11982831B2/en
Publication of WO2022127444A1 publication Critical patent/WO2022127444A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133615—Edge-illuminating devices, i.e. illuminating from the side
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/0045—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it by shaping at least a portion of the light guide
    • G02B6/0046—Tapered light guide, e.g. wedge-shaped light guide
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0053—Prismatic sheet or layer; Brightness enhancement element, sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0055—Reflecting element, sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0075—Arrangements of multiple light guides
    • G02B6/0076—Stacked arrangements of multiple light guides of the same or different cross-sectional area
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/1323—Arrangements for providing a switchable viewing angle
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
    • G02F1/133607—Direct backlight including a specially adapted diffusing, scattering or light controlling members the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Definitions

  • the invention relates to a backlight module for a liquid crystal display, in particular to an anti-peeping backlight module.
  • liquid crystal displays have been widely used in various display devices, and are more and more closely related to people's lives. Since the liquid crystal display cannot emit light by itself, it needs to be equipped with a backlight module that can provide backlight. Among them, in all special usage scenarios or the privacy needs of some users, it is not expected that others can see the content on their screen, so there is an application of anti-privacy screen.
  • there are two modes of privacy screen one is static privacy protection, which is realized by the grating structure arranged side by side. At a certain angle, the transmitted light is blocked by the grating and will not be emitted.
  • the second is dynamic privacy protection, which mainly includes the following:
  • 3M privacy film is installed in the ordinary backlight module, PDLC, smectic phase dimming film, etc. are installed between the 3M privacy film and the display screen, and the dimming film is used to switch between the fully transparent state and the scattering state. Switch between private state and shared state.
  • the problem with this solution is that the price of 3M privacy film is high, and the viewing angle of PDLC in the fully transparent state is poor, which will affect the effect of privacy state; the driving voltage of smectic phase dimming film is high and the response speed at low temperature is too slow .
  • the anti-peep display system based on the liquid crystal light valve by setting two pairs of electrodes with different shapes on both sides of the liquid crystal light valve, displays the fast switching between the private state and the shared state.
  • This scheme has an efficiency loss due to the requirement for the angle of the incident light.
  • the emission angles of the above solutions can basically only be fixed in a certain range in one dimension, and cannot take into account two dimensions.
  • the angle range is not adjustable, and the range of use is limited.
  • the technical problem to be solved by the present invention is to provide an anti-peeping backlight module, which can realize two-dimensional anti-peeping with adjustable angle, and can switch two display modes of anti-peeping and wide-angle, with fast switching speed, almost no response time, and overall transparency. Overrate is high.
  • an anti-peeping backlight module which is composed of an upper backlight module, a lower backlight module, and a reflective film arranged below the lower backlight module.
  • the upper backlight module is a transparent module
  • the lower backlight module is a transparent module or a non-transparent module
  • the upper backlight module is a collimation backlight module or a diffusion backlight module
  • the The lower backlight module is a collimated backlight module or a diffused backlight module
  • the upper backlight module and the lower backlight module have different properties.
  • the collimating backlight module comprises a first light guide plate and a first light source arranged on the side of the first light guide plate, a first microprism array arranged on the upper surface of the first light guide plate, and the The first microprism array is arranged along the light transmission direction of the first light source.
  • the diffused backlight module includes a second light guide plate and a second light source arranged on the side of the second light guide plate.
  • a second microprism array is arranged on the upper surface of the two light guide plates, and the second microprism array is arranged along the light transmission direction of the second light source.
  • the upper backlight module is a collimated backlight module
  • the lower backlight module is a diffused backlight module
  • the first microprism array and the second microprism array are orthogonal or parallel to each other.
  • the upper backlight module is a diffused backlight module
  • the lower backlight module is a collimated backlight module
  • the first microprism array and the second microprism array are orthogonal or parallel to each other.
  • the first light guide plate is a parallel flat plate, the first light source is arranged on one side of the first light guide plate, and a first reflection surface is arranged on the side opposite to the first light source.
  • the first light guide plate is a parallel flat plate, the first light source is arranged on one side of the first light guide plate, and a first auxiliary light source is arranged on the side opposite to the first light source.
  • the first light guide plate is a wedge-shaped plate, and the first light source is arranged on the thick end side of the wedge-shaped plate.
  • the wedge angle of the wedge-shaped light guide plate is less than or equal to 5°.
  • the rear end side of the wedge-shaped plate is provided with a reflective surface.
  • the first light guide plate is a bidirectional wedge-shaped plate, and the first light source is arranged on the two thick end sides of the wedge-shaped plate.
  • the first microprism array is uniformly arranged or non-uniformly arranged.
  • the first microprism array refracts the light incident from the first light guide plate out of the first microprism array in a convergent manner.
  • the second light guide plate is a parallel flat plate, the second light source is arranged on one side of the second light guide plate, and a second reflection surface is arranged on the side opposite to the second light source.
  • the second light guide plate is a parallel flat plate, the second light source is arranged on one side of the second light guide plate, and a second auxiliary light source is arranged on the side opposite to the second light source.
  • the lower interface of the bidirectional wedge-shaped light guide plate may be linear or non-linear.
  • the side profiles of the first microprism array and the second microprism array may be straight lines, arcs or multiple line segments.
  • the arc or multi-segment profile may be concave (convergence), convex (divergence), or a combination of concave and convex.
  • the upper backlight module is a diffused backlight module
  • the lower backlight module is a collimated backlight module
  • the collimated backlight module includes a first light guide plate and a first light source
  • the diffused backlight module includes a second light guide plate and a second light source
  • the second light guide plate is a parallel flat plate
  • a second microprism array is arranged on the upper surface of the second light guide plate
  • the second microprism array is along the The light transmission directions of the second light source are arranged
  • the second light source is arranged on one side of the second light guide plate, the side opposite to the second light source is arranged with a second auxiliary light source
  • the The first light guide plate is a wedge-shaped plate
  • the first light source is arranged on the thick end side of the wedge-shaped plate
  • a rhombus prism film is arranged between the first light guide plate and the second light guide plate .
  • the upper backlight module is a diffused backlight module
  • the lower backlight module is a collimated backlight module
  • the collimated backlight module includes a first light guide plate and a first light source
  • the diffused backlight module includes a second light guide plate and a second light source
  • the second light guide plate is a parallel flat plate
  • a second microprism array is arranged on the upper surface of the second light guide plate
  • the second microprism array is along the The light transmission directions of the second light source are arranged
  • the second light source is arranged on one side of the second light guide plate, the side opposite to the second light source is arranged with a second auxiliary light source
  • the The first light guide plate is a wedge-shaped plate
  • the first light source is arranged on the thick end side of the wedge-shaped plate
  • an inverse prism film is arranged between the first light guide plate and the second light guide plate.
  • An anti-peep film is arranged between the inverse prism film and the second light guide plate.
  • Example 1 is a schematic diagram of the light path of the first structure of the single light source collimating backlight module in Example 1 of the embodiment of the present invention
  • Example 2 is a schematic diagram of the light path of the second structure of the single light source collimating backlight module in Example 1 of the embodiment of the present invention
  • Example 4 is a schematic structural diagram of a single light source diffused backlight module in Example 1 of an embodiment of the present invention
  • Example 5 is a schematic diagram of the optical path of the first structure of the dual light source collimating backlight module in Example 2 of the embodiment of the present invention.
  • FIG. 6 is a schematic diagram of the optical path of the second structure of the dual light source collimating backlight module in Example 2 of the embodiment of the present invention.
  • Example 7 is a schematic diagram of the optical path of the third structure of the dual light source collimating backlight module in Example 2 of the embodiment of the present invention.
  • Example 8 is a schematic structural diagram of a dual light source diffused backlight module in Example 2 of the embodiment of the present invention.
  • FIG. 9 is a schematic diagram of the first structure of the dual light source backlight module according to the third embodiment of the present invention.
  • FIG. 10 is a schematic diagram of the second structure of the dual light source backlight module according to the third embodiment of the present invention.
  • FIG. 11 is a schematic diagram of the light path of a specific combination of a diffused backlight module and a collimated backlight module of the second structure of the dual light source backlight module according to the third embodiment of the present invention
  • FIG. 12 is a schematic diagram of the light path of a specific combination of a diffused backlight module, a privacy film and a collimated backlight module of the second structure of the dual light source backlight module according to the third embodiment of the present invention
  • FIG. 13 is a schematic plan view of the vertical structure of the upper and lower backlight modules in the dual-light source backlight module according to the third embodiment of the present invention.
  • FIG. 14 is a schematic three-dimensional structural diagram of the first structure in which the upper and lower backlight modules are vertically arranged in the dual light source backlight module according to the third embodiment of the present invention.
  • FIG. 15 is a schematic three-dimensional structural diagram of the second structure in which the upper and lower backlight modules are vertically arranged in the dual-light source backlight module according to the third embodiment of the present invention.
  • 16 is a schematic three-dimensional structural diagram of a dual-light source backlight module according to the third embodiment of the present invention, wherein the upper and lower backlight modules are vertically arranged in the first structure and a privacy film is added;
  • 17 is a schematic diagram of the first structure of the backlight module according to the fourth embodiment of the present invention.
  • FIG. 18 is a schematic diagram of the second structure of the backlight module according to the fourth embodiment of the present invention.
  • FIG. 19 is a schematic diagram of the light emission spectrum of the dual light source backlight module according to the embodiment of the present invention.
  • a backlight module with a controllable light angle is composed of an upper backlight module, a lower backlight module, and a reflective film arranged below the lower backlight module.
  • the group is a transparent module
  • the lower backlight module can be a transparent module or a non-transparent module
  • the upper backlight module can be a collimated backlight module or a diffused backlight module
  • the lower backlight module can be a collimated backlight module or a diffused backlight module.
  • the backlight module, and the upper backlight module and the lower backlight module have different properties.
  • the collimating backlight module includes a first light guide plate and a first light source arranged on the side of the first light guide plate.
  • a microprism array the first microprism array is arranged along the light transmission direction of the first light source
  • the diffusion backlight module includes a second light guide plate and a second light source arranged on the side of the second light guide plate, and the upper surface of the second light guide plate is arranged
  • the second microprism array is arranged along the light transmission direction of the second light source.
  • Example 1 A collimated backlight module or a diffused backlight module with a single light source structure:
  • the first light guide plate 32 is a parallel flat plate
  • the first microprism array 33 is arranged on the surface of the first light guide plate 32
  • the first light source 31 is arranged on the One side surface 321 of the first light guide plate 32 and the side surface 324 opposite to the first light source 31 are provided with a first reflective film 34.
  • the surface of the first reflective film 34 is a first reflective surface with a certain reflectivity.
  • the bases of the light plate 32 and the first microprism array 33 are optical materials.
  • the first light guide plate 32 After another light 302 emitted from the first light source 31 enters the first light guide plate 32, according to Snell's law, its light path trajectory is continuously reflected between the upper and lower interfaces 322 and 323 and travels forward. During the traveling process, the first microprism array 33 is not encountered, and is reflected by the first reflective film 34 on the side 324 and travels in the first light guide plate 32 from the opposite direction. The reflected light 302 meets the lower end of the microprism 332 on the return journey and enters the microprism 332 , and the light is refracted out of the surface 333 of the first microprism array 33 at the side surface 3321 of the microprism 332 .
  • the first light guide plate 53 adopts a wedge-shaped structure, and the first light source 51 is arranged at the thick end of the wedge-shaped plate (positive wedge shape).
  • 90- ⁇ is greater than ⁇ , the condition of total reflection is satisfied, so it will not be emitted.
  • the angle of the wedge-shaped plate is ⁇ .
  • the angle between the light and the normal of the upper and lower interfaces 531 or 532 of the wedge-shaped plate decreases by ⁇ , and will not be emitted until the exit conditions are met. Since the wedge angle ⁇ of the first light guide plate 53 is very small in this solution, most of the light energy (such as the light 501) meets the condition of total reflection and is enveloped by the upper and lower interfaces 531 and 532.
  • the light travels in one direction, so the first microprism array 52 is arranged in one direction (asymmetrical), and the light is refracted out of the backlight module by one side surface 521 of the microprism only when it is irradiated to the opening under the microprism structure, On the other hand, the other side surface 522 of the microprism does not generate refraction.
  • FIG. 3 is a schematic diagram of the third structure of the single-light source collimating backlight module.
  • a first reflective film 55 is placed at the tail end of the wedge-shaped light guide plate to form a backlight module with bidirectional light output.
  • the first microprism arrays 54 are arranged symmetrically. , the light emitting process of the light 502 emitted from the light source 51 is the same as that of the light 501 in FIG. 2 , but the light (such as light 503 ) that is opened under the first microprism array 54 is not encountered in the forward movement.
  • the end face of the wedge-shaped plate is first reflected by the first reflection
  • the diaphragm 55 is reflected back to the wedge-shaped plate.
  • FIG. 4 is a schematic diagram of the structure of a single light source diffused backlight module.
  • the two sides of the microprisms of the second microprism array 43 are designed to emit the light refracted on the sides to different sides that are symmetrical (or asymmetrical) with respect to the surface normal of the prism array. direction.
  • the light rays 401 and 402 emitted from the second light source 41 enter the second light guide plate 42 from the side 421 and then travel in the second light guide plate 42 .
  • the light 402 is reflected by the second reflective film 44 on the other side 423 of the second light guide plate 42 back to the second light guide plate 42 because it does not encounter the opening under the microprism in the forward run, and travels in the opposite direction with the light 401
  • the lower opening of the micro-prism is encountered, and the backlight module is refracted by the side edge 431 of the micro-prism.
  • the opposite light rays 401 and 402 are refracted to two different directions by the microprism, so that there is no light in the direction of the normal line 434 of the surface 433 of the second microprism array 43, while the normal line 434 Light is distributed on both sides of the direction.
  • the degree of divergence (range) of the beam can be controlled by changing the side profile of the microprism.
  • Example 2 Collimated backlight module or diffused backlight module with dual light source structure:
  • the first light guide plate 32 is a parallel flat plate
  • the first microprism array 33 is arranged on the surface of the first light guide plate 32
  • the first light source 31 is arranged on the first light guide plate 32.
  • a first auxiliary light source 35 is disposed on one side surface 321 of the light guide plate 32 and the side surface 324 opposite to the first light source 31 .
  • the bases of the first light guide plate 32 and the microprism array 33 are optical materials.
  • the light emitted by the two light sources travels in opposite directions, and the light emitting mechanism is the same as that in Figure 2.
  • the side surface of the microprism can be designed so that the light emitting distribution is centered on the normal 334 of the light emitting surface 333 , that is, the light emitting ranges of the two directions overlap. 303 and 304, their distribution ranges coincide.
  • the first light guide plate 57 is set as two linear wedge-shaped plate structures whose thin ends are connected to form a bidirectional light-emitting module.
  • the prism arrays are arranged symmetrically.
  • the specific implementation is that when the light 504 emitted from the first auxiliary light source 56 enters the linear wedge plate, the light first encounters the structure (positive wedge) with a thickness from large to small, and the light is reflected between the upper and lower interfaces 571 and 572 Moving forward, the angle of the wedge-shaped plate is ⁇ .
  • the angle between the light and the normal of the upper and lower interfaces 571 or 572 of the wedge-shaped plate decreases by ⁇ , and will not be emitted until the exit conditions are met. Since the wedge angle ⁇ of the wedge-shaped light guide plate in this scheme is very small, most of the light energy (such as the light 504) meets the condition of total reflection and is surrounded by the upper and lower interfaces 571 and 572.
  • the backlight module is refracted from the side surface 522 of the microprism only when the lower opening of the first microprism array is opened.
  • the light rays that do not encounter the opening under the first microprism array in the wedge-shaped structure with thickness from large to small continue to move forward and enter the wedge-shaped structure (negative wedge) with thickness from small to large, and its experience is similar to that of the negative wedge.
  • the exit point from the first microprism array is in the portion of the negative wedge.
  • the case of the first light source 51 corresponding to the first auxiliary light source 56 is the same as described above.
  • FIG. 7 is a schematic diagram of the third structure of the dual light source collimating backlight module.
  • the lower interface 571 of the wedge-shaped plate may be non-linear multi-line segments. Its working principle is the same as Figure 7.
  • FIG. 8 is a schematic structural diagram of a dual light source diffused backlight module, the structure of which is basically the same as that in FIG. 5 , except that the second reflective film 44 is replaced with a second auxiliary light source 45 .
  • Example 3 As shown in FIG. 9 , a backlight module 1 with bilateral incidence (dual light sources) that can provide two solutions of collimation and large-angle (divergent) light output, including a collimated backlight module 11 that provides collimated light output As an upper backlight module, a diffused backlight module 12 that emits light is provided as a lower backlight module, and a reflective film 13 placed under the lower backlight module is used to reflect the stray light reflected downward by the optical interface back to the direction of the light to exit. The stray light is reused to improve the optical efficiency of the backlight module.
  • a backlight module 1 with bilateral incidence (dual light sources) that can provide two solutions of collimation and large-angle (divergent) light output, including a collimated backlight module 11 that provides collimated light output
  • a diffused backlight module 12 that emits light is provided as a lower backlight module, and a reflective film 13 placed under the lower backlight module is used to reflect the stray light reflected downward
  • a bilateral incident backlight module 2 that can provide two solutions of collimation and large-angle (divergent) light output includes a diffused backlight module 12 that provides divergent light output as an upper backlight module, and provides collimated light output.
  • the collimated backlight module 11 is used as the lower backlight module, and the reflective film 13 is placed under the lower backlight module.
  • the upper backlight module and the lower backlight module are placed in the same direction, that is, the light sources on the same side of the upper and lower backlight modules are stacked on top of each other, such as 111 and 121, 112 and 122.
  • the dual light source diffusion backlight module 15 is the upper backlight module
  • the bidirectional wedge-shaped collimating backlight module 16 is the lower backlight module
  • the upper and lower backlight modules 15 and 16 are combined on the reflective film 17 .
  • the following backlight module 16 is taken as an example, the light rays 601 and 602 emitted from the light sources 621 and 622 enter the wedge-shaped light guide plate and travel towards each other, and are refracted out of the lower backlight module 16 when encountering the lower opening of the microprism.
  • the light rays 601 , 602 , 603 , and 604 emitted by the collimated backlight module 16 are transmitted through the upper backlight module 15 to form beams in the collimated direction.
  • the resulting haze effect causes partial dispersion of the collimated beam.
  • the light emitted by the two light sources 611 and 612 of the upper backlight module 15 enters the parallel light guide plate and then travels towards each other.
  • the light encounters the lower opening of the microprism, it is refracted by the side of the microprism at a large angle to diffuse the backlight module 15.
  • the light rays 601 , 602 , 605 and 606 form all-angle beams.
  • the beam range is only the collimated portion 601 and 602 .
  • the switching of the viewing angle of the light beam can be realized.
  • the lower reflective film 17 is used to reflect the light leaking from the bottom of the wedge-shaped light guide plate and the light reflected downward by different interfaces in the structure of the backlight module, so as to reuse the downwardly emitted light and improve the backlight module. the overall optical efficiency.
  • the combination of this technical solution can also be the following combination: the upper backlight module is wedge-shaped, the lower backlight module is parallel plate, the upper and lower backlight modules are both parallel plates, the upper backlight module is parallel , The lower backlight modules are wedge-shaped.
  • a privacy film 18 may be added to the structure of FIG. 12 to further improve the blackness (contrast of the module) in the collimation (angle) cut-off area.
  • the lower surface 181 of the privacy protection film 18 is optically bonded to the light-emitting surface 641 of the lower backlight module 64 to reduce the interface optical loss;
  • the lower surface 631 adheres, but must maintain non-optical contact.
  • the upper and lower backlight modules are placed in an orthogonal manner, that is, the light sources such as 72 and 73 of one backlight module are arranged in the horizontal direction, and the light sources 71 and 74 of the other backlight module are arranged in the vertical direction.
  • the orthogonal arrangement allows the upper and lower modules to be more closely combined, and the light source arrangement does not interfere with each other. While realizing a compact structure design, the actual haze caused by the microprism structure of the upper module to the lower backlight module is reduced.
  • the beam law of the combination of orthogonal backlight modules is similar to that of the combination of parallel backlight modules.
  • FIG. 14 the structure of the orthogonal arrangement of the collimating backlight module 81 on the bottom and the diffusion backlight module 82 on the top is shown.
  • FIG. 15 the combination of the diffusion backlight module 82 on the bottom and the collimation backlight module 81 on the top.
  • a privacy film 84 can be added between 81 and 82 to further improve the collimation (angle) cut-off area. Blackness (the contrast ratio of the backlight unit).
  • the lower surface 841 of the privacy film 84 is optically bonded to the light emitting surface 811 of the lower backlight module 81 to reduce the interface optical loss.
  • the upper surface 842 of the privacy film 84 cannot be attached to the lower surface 821 of the diffusion backlight module 82, but must be kept in non-optical contact.
  • the backlight module consists of a non-transparent full wedge-shaped collimating backlight module 92 as the lower backlight module, and a transparent diffused backlight module 91 as the upper backlight module, wherein the upper and lower backlight modules are placed
  • the directions are the same, that is, the light sources 911 and 924 of the two backlight modules are stacked on top of each other.
  • the rhombic prism film 922, the wedge-shaped light guide plate 921 and the reflective film 923 in FIG. 17 are all separate components, and the rhombic prism film 922 and the wedge-shaped light guide plate 921 have the same refractive index. or close.
  • n 1 is the refractive index of medium 1
  • ⁇ 1 is the angle of incidence
  • n 2 is the refractive index of medium 2
  • ⁇ 2 is the angle of refraction
  • 90- ⁇ is greater than ⁇ , the condition of total reflection is satisfied, so it will not be emitted.
  • the angle of the wedge-shaped plate is ⁇ , and the angle between the light beam and the normal line of the exit surface 9211 of the wedge-shaped light guide plate 921 decreases by ⁇ every time the light passes through a reflection, and the light is emitted until the exit condition is satisfied.
  • the light exiting from the exit surface 9211 and entering the upper rhombus prism film 922 is exiting when the angle of total reflection is close to, and the direction of the light is basically the same.
  • the directions in which they are incident into the rhombic prism film 922 are substantially the same. Therefore, after being refracted by the rhombic prism film 922, the light beam exhibits a good degree of convergence in a specified direction.
  • the working mechanism of the upper diffused light guide plate 921 module 91 is similar to the above-mentioned various cases. It should be pointed out that due to the better collimation of the full wedge-shaped collimated backlight module, the light output range of the diffused backlight module will also vary accordingly. becomes larger to form a seamless full coverage with the light beam of the collimated backlight module.
  • a privacy film 93 is arranged between the transparent diffusion backlight module 91 and the non-transparent collimation backlight module 92 to further improve the collimation (angle) cut-off area. Blackness (the contrast ratio of the backlight unit).
  • the lower surface 932 of the privacy film 93 is optically bonded to the light emitting surface 9251 of the lower backlight module to reduce the interface optical loss.
  • the upper surface 931 of the privacy film 93 cannot be attached to the lower surface 9121 of the diffusion backlight module 912, and must be kept in non-optical contact.
  • the rhombic prism film above the wedge-shaped light guide plate in FIG. 17 is replaced by an inverse prism film 925, which works in the same way, refracting the light emitted from the wedge-shaped light guide plate to a specific direction by total reflection.
  • the backlight module 19 is the light emitting spectrum of the dual light source backlight module according to the embodiment of the present invention. It can be seen from the figure that when the upper and lower backlight modules work simultaneously, the backlight module provides a light emitting range profile 23 covering the entire field of view. When the divergent backlight module is turned off, the dotted line spectrum 21 no longer appears, and the backlight module only provides the light emission spectrum 22 in the collimated direction.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mathematical Physics (AREA)
  • Planar Illumination Modules (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Liquid Crystal (AREA)

Abstract

一种防窥视背光模组，由上背光模组、下背光模组和设置在下背光模组下方的反射膜叠合组成，上背光模组是透明模组，下背光模组是透明模组或非透明模组，上背光模组是准直背光模组或扩散背光模组，下背光模组是准直背光模组或扩散背光模组，且上背光模组和下背光模组性质不同，优点是可以同时实现分束和准直两种出光方向，可应用于多种背光模组中，分束角度可调，效率高，可独立控制。

Description

一种防窥视背光模组 技术领域
本发明涉及一种液晶显示器的背光模组，尤其是涉及一种防窥视背光模组。
背景技术
近年来，液晶显示器已经广泛运用到各种显示装置中，与人们的生活相关性越来越密切。液晶显示器，由于自身无法发光，需要配置可以提供背光的背光模组。其中，在一切特殊的使用场景或者一些使用者的隐私性需求，不希望他人能看到自己屏幕上的内容，因此有了防窥屏的应用。目前防窥屏有两种模式，一种是静态防窥，通过并列排布的光栅结构实现，在一定的角度，透过的光线被光栅拦阻，不会出射。这种结构虽然能实现一定角度的防窥效果，但是整体透过率低，整体较暗，使用者的体验感不好，并且不能实现防窥和广角显示的选择。第二种是动态防窥，主要有以下几种：
1)在普通背光模组中搭载3M防窥膜，在3M防窥膜和显示屏之间搭载PDLC、近晶相调光膜等，利用调光膜在全透明态和散射态之间切换来进行隐私态和共享态之间的切换。该方案存在的问题是3M防窥膜价格偏高，而且PDLC在全透明态下的视角差，会影响隐私态的效果；近晶相调光膜的驱动电压高且低温下的响应速度过慢。
2)在准直背光模组中搭载PDLC、近晶相调光膜等，该方案存在的问题是准直背光的成本高且良率低。
3)基于液晶光阀的防窥显示系统，通过在液晶光阀两侧设置两对不同形态的电极，显示隐私态和共享态的快速切换。此方案因为对入射光的角度有要求，存在效率损失。
以上几个方案出射角度基本只能在一个维度固定在一定的范围，不能兼顾两维，角度范围不可调，使用范围有局限性。
发明内容
本发明所要解决的技术问题是提供一种防窥视背光模组，可以实现角度可调两维防窥，并且可以切换防窥和广角两种显示模式，切换速度快，几乎没有响应时间，整体透过率高。
本发明解决上述技术问题所采用的技术方案为：一种防窥视背光模组，由上背光模组和下背光模组和设置在所述的下背光模组下方的反射膜叠合组成，所述的上背光模组是透明模组，所述的下背光模组是透明模组或非透明模组，所述的上背光模组是准直背光模组或扩散背光模组，所述的下背光模组是准直背光模组或扩散背光模组，且所述的上背光模组和所述的下背光模组性质不同。
所述的准直背光模组包括第一导光板和设置在所述的第一导光板侧面的第一光源，所述的第一导光板的上表面设置的第一微棱镜阵列，所述的第一微棱镜阵列沿所述的第一光源的光线传输方向排列，所述的扩散背光模组包括第二导光板和设置在所述的第二导光板侧面的第二光源，所述的第二导光板的上表面设置的第二微棱镜阵列，所述的第二微棱镜阵列沿所述的第二光源的光线传输方向排列。
所述的上背光模组为准直背光模组，所述的下背光模组为扩散背光模组，所述的第一微棱镜阵列和所述的第二微棱镜阵列相互正交或相互平行。
所述的上背光模组为扩散背光模组，所述的下背光模组为准直背光模组，所述的第一微棱镜阵列和所述的第二微棱镜阵列相互正交或相互平行。
所述的第一导光板为平行平板，所述的第一光源为设置在所述的第一导光板的一个侧面，所述的第一光源对面的侧面上设置有第一反射面。
所述的第一导光板为平行平板，所述的第一光源为设置在所述的第一导光板的一个侧面，所述的第一光源对面的侧面上设置有第一辅助光源。
所述的第一导光板是楔形板，所述的第一光源设置在所述的楔形板的厚端侧面。所述的楔形导光板的楔角为小于等于5°。
所述的楔形板的尾端侧面设置有反射面。
所述的第一导光板是双向楔形板，所述的第一光源设置在所述的楔形板的两个厚端侧面。
所述的第一微棱镜阵列为梯形或杯状结构，所述的第一微棱镜阵列与所述的第一导光板互为一体。
所述的第一微棱镜阵列是均匀排列或不均匀排列。
所述的第一微棱镜阵列将由所述的第一导光板入射的光线以会聚的方式折射出所述的第一微棱镜阵列。
所述的第二导光板为平行平板，所述的第二光源为设置在所述的第二导光板的一个侧面，所述的第二光源对面的侧面上设置有第二反射面。
所述的第二导光板为平行平板，所述的第二光源为设置在所述的第二导光板的一个侧面，所述的第二光源对面的侧面上设置有第二辅助光源。
所述的第二微棱镜阵列将由所述的第二导光板入射的光线以发散的方式折射出所述的第一微棱镜阵列。
所述的下背光模组的上表面上贴合有防窥膜，所述的防窥膜与所述的上背光模组的下表面之间设置有空气间隙。
所述的双向楔形导光板的下界面可以是线性的，也可以是非线性的。
所述的第一微棱镜阵列和所述的第二微棱镜阵列的侧面轮廓可以是直线也可以是弧线或者多线段。
所述的弧线或者多线段轮廓可以是内凹的(会聚)，可以是内凸的(发散)，也可以是凹凸结合的。
所述的上背光模组为扩散背光模组，所述的下背光模组为准直背光模组，所述的准直背光模组包括第一导光板和第一光源，所述的扩散背光模组包括第二导光板和第二光源，所述的第二导光板为平行平板，所述的第二导光板的上表面设置的第二微棱镜阵列，所述的第二微棱镜阵列沿所述的第二光源的光线传输方向排列，所述的第二光源设置在所述的第二导光板的一个侧面，所述的第二光源对面的侧面上设置有第二辅助光源，所述的第一导光板是楔形板，所述的第一光源设置在所述的楔形板的厚端侧面，所述的第一导光板与所述的第二导光板之间设置有斜方棱镜膜。
所述的上背光模组为扩散背光模组，所述的下背光模组为准直背光模组，所述的准直背光模组包括第一导光板和第一光源，所述的扩散背光模组包括第二导光板和第二光源，所述的第二导光板为平行平板，所述的第二导光板的上表面设置的第二微棱镜阵列，所述的第二微棱镜阵列沿所述的第二光源的光线传输方向排列，所述的第二光源设置在所述的第二导光板的一个侧面，所述的第二光源对面的侧面上设置有第二辅助光源，所述的第一导光板是楔形板，所述的第一光源设置在所述的楔形板的厚端侧面，所述的第一导光板与所述的第二导光板之间设置有逆棱镜膜。
所述的逆棱镜膜与所述的第二导光板之间设置防窥膜。
与现有技术相比，本发明的优点在于可以同时实现分束和准直两种出光方向，可应用于多种背光模组中。分束角度可调，效率高，可独立控制。通过双侧入光和入光头的设计实现分束功能，并且通过出光面微棱镜结构的设计，例如从边缘到中心逐步变密实现均匀出光，以解决传统面板中间颜色较浅不够亮的问题。
附图说明
图1为本发明实施例示例一中的单光源准直背光模组第一种结构的光路示意图；
图2为本发明实施例示例一中的单光源准直背光模组第二种结构的光路示意图；
图3为本发明实施例示例一中的单光源准直背光模组第三种结构的光路示意图；
图4为本发明实施例示例一中的单光源扩散背光模组的结构示意图；
图5为本发明实施例示例二中的双光源准直背光模组第一种结构的光路示意图；
图6为本发明实施例示例二中的双光源准直背光模组第二种结构的光路示意图；
图7为本发明实施例示例二中的双光源准直背光模组第三种结构的光路示意图；
图8为本发明实施例示例二中的双光源扩散背光模组的结构示意图；
图9为本发明的实施例示例三的双光源背光模组第一种结构的示意图；
图10为本发明的实施例示例三的双光源背光模组第二种结构的示意图；
图11为本发明的实施例示例三的双光源背光模组第二种结构的具体的扩散背光模组与准直背光模组组合的光路示意图；
图12为本发明的实施例示例三的双光源背光模组第二种结构的具体的扩散背光模组、防窥膜与准直背光模组组合的光路示意图；
图13为本发明的实施例示例三的双光源背光模组中上、下背光模组垂直设置的平面结构示意图；
图14为本发明的实施例示例三的双光源背光模组中上、下背光模组垂直设置的第一种结构的立体结构示意图；
图15为本发明的实施例示例三的双光源背光模组中上、下背光模组垂直设置的第二种结构的立体结构示意图；
图16为本发明的实施例示例三的双光源背光模组中上、下背光模组垂直设置第一种结构中加入防窥膜的立体结构示意图；
图17为本发明的实施例示例四的背光模组第一种结构的示意图；
图18为本发明的实施例示例四的背光模组第二种结构的示意图；
图19为本发明的实施例的双光源背光模组的出光光谱示意图。
具体实施方式
以下结合附图实施例对本发明作进一步详细描述。
实施例：一种光线角度可控的背光模组，该光线角度可控的背光模组由上背光模组、下背光模组和设置在下背光模组下方的反射膜叠合组成，上背光模组是透明模组，下背光模组可以是透明模组或非透明模组，上背光模组可以是准直背光模组或扩散背光模组，下背光模组是准直背光模组或扩散背光模组，且上背光模组和下背光模组性质不同，准直背光模组包括第一导光板和设置在第一导光板侧面的第一光源，第一导光板的上表面设置的第一微棱镜阵列，第一微棱镜阵列沿第一光源的光线传输方向排列，扩散背光模组包括第二导光板和设置在第二导光板侧面的第二光源，第二导光板的上表面设置的第二微棱镜阵列，第二微棱镜阵列沿第二光源的光线传输方向排列。
示例一：单光源结构的准直背光模组或扩散背光模组：
图1是单光源准直背光模组的第一种结构的示意图，第一导光板32为平行平板，第一微棱镜阵列33设置在第一导光板32的表面，第一光源31为设置在第一导光板32的一个侧面321，第一光源31对面的侧面324上设置有第一反射膜片34，第一反射膜片34的表面是具有一定反射率的第一反射面，第一导光板32和第一微棱镜阵列33的基体为光学材料。
从图中可以看出，当从第一光源31出射的光线301从端面321进入第一导光板32后，根据斯涅尔定律(n 1sinθ 1＝n 2sinθ 2，式中n 1为介质1的折射率，θ 1为入射角，n 2为介质2的折射率，θ 2为折射角)，其光路轨迹为在上下2个界面322和323间被连续反射、并前行，直到301从第一微棱镜阵列33的下开口进入折射其中的一个微棱镜331，并在微棱镜331的侧面3311上被折射出第一微棱镜阵列33的微棱镜331表面333。从第一光源31出射的另一条光线302进入第一导光板32后，同样根据斯涅尔定律，其光路轨迹为在上下2个界面322、323间被连续反射、并前行，由于其在行进的过程中没有遇见第一微棱镜阵列33，在侧面324被第一反射膜片34反射从反向再在第一导光板32中行进。被反射的光线302在返程中遇见微棱镜332的下端并进入微棱镜332，光线 在微棱镜332侧面3321被折射出第一微棱镜阵列33的表面333。
图2是单光源准直背光模组的第二种结构的示意图，第一导光板53采用楔形结构，第一光源51设置在楔形板厚端(正楔形)。假定第一导光板53的折射率为1.58，光线入射进楔形板后角度范围为α＝±arcsin(1/1.58)＝±40°，在楔形板中传播时与楔形板上下两个反射面的法线夹角90-α大于等于50°，而全反射角为γ＝arcsin(1/1.58)＝40°，90-α大于γ时满足全反射条件，所以不会出射。楔形板的角度为β，光线每经过一次与上下界面531或532的反射，光线与楔形板的上下界面531或532的法线夹角减少β，直至满足出射条件才会出射。由于该方案中第一导光板53的楔角β很小，绝大多数光线能量(如光线501)在前进中都满足全反射条件而被上下2个界面531和532包络住，由于在本示例中光线是单向行进，所以第一微棱镜阵列52呈单向排列(非对称)，光线只有在照射到微棱镜结构下开口时才会由微棱镜的一个侧面521折射出背光模组，而微棱镜的另一个侧面522则不会产生折射。
图3是单光源准直背光模组的第三种结构的示意图，在楔形导光板尾端置第一反射膜片55，形成双向出光的背光模组，第一微棱镜阵列54呈对称的排列，从光源51出射的光线502出光过程与图2中的光线501雷同，但是在前行中没有遇见第一微棱镜阵列54下开口的光线(如光线503)在楔形板的端面被第一反射膜片55反射回楔形板，其在楔形板的上下两个反射面531、532间反射前行时与相向的过程正好相反(负楔形)，光线每经过一次与上下界面531或532的反射，光线与楔形板的上下界面531或532的法线的夹角增大β，所以光线与界面的法线夹角会变得越来越大，直到返回的光线遇见第一微棱镜阵列54的下开口后由微棱镜的侧面523反射出第一微棱镜阵列54。
图4是单光源扩散背光模组的结构示意图，第二微棱镜阵列43的微棱镜的两个侧面设计为将在侧面折射的光线射向以棱镜阵列表面法线对称(或不对称)的不同方向。从第二光源41射出的光线401、402从侧面421进入第二导光板42后在第二导光板42中前行，其中光线401遇见微棱镜下开口后由侧边432折射出背光模组。而光线402由于在前行中未遇到微棱镜下开口而在第二导光板42的另一侧面423被第二反射膜片44反射回第二导光板42反向而行，在与光线401相向而行的过程中遇见微棱镜的下开口，而被微棱镜的侧边431折射出背光模组。通过改变微棱镜的侧面轮廓，相向而行的光线401和402被微棱镜折射到2个不同的方向，因此实现与第二微棱镜阵列43表面433的法线434方向没有光线，而法线434方向的两侧分布着光线。光束的发散程度(范围) 可以通过改变微棱镜的侧面轮廓来控制。
示例二：双光源结构的准直背光模组或扩散背光模组：
图5是双光源准直背光模组的第一种结构的示意图，第一导光板32为平行平板，第一微棱镜阵列33设置在第一导光板32的表面，第一光源31设置在第一导光板32的一个侧面321，第一光源31对面的侧面324上设置有第一辅助光源35。第一导光板32和微棱镜阵列33的基体为光学材料。
从图中可以看出，两个光源发出的光相向而行，其出光机理与图2相同。在图6中，微棱镜的侧面可以设计为其出光分布是以出光面333的法线334为中心分布的，既两个方向行进的光线出光范围重叠，如图6中的光线301、302与303、304，它们的分布范围重合。
图6是双光源准直背光模组的第二种结构的示意图，第一导光板57设为薄端相连的两个线性楔形板结构，形成双向出光模组，在这种案例中第一微棱镜阵列呈对称的排列。具体实施方案为，从第一辅助光源56出射的光线504射入线性楔形板时，光线首先遇见的是厚度由大到小的结构(正楔形)，光线在上下两个界面571、572间反射中前行，楔形板的角度为β，光线每经过一次与上下界面571或572的反射，光线与楔形板的上下界面571或572的法线夹角减少β，直至满足出射条件才会出射。由于该方案中楔形导光板的楔角β很小，绝大多数光线能量(如光线504)在前进中都满足全反射条件而被上下2个界面571和572包络住，光线只有在照射到第一微棱镜阵列的下开口时才会由微棱镜侧面522折射出背光模组。在厚度由大到小的楔形结构中没有遇见第一微棱镜阵列下开口的光线继续前行，进入厚度由小到大的楔形结构(负楔形)，其经历与负楔形情形雷同，如光线505从第一微棱镜阵列的出射点在负楔形的部分。与第一辅助光源56相对应的第一光源51的情形与上述相同。
图7是双光源准直背光模组的第三种结构的示意图，在双向楔形导光板方案中，楔形板的下界面571可以是非线性多线段的。其工作原理与图7雷同。
图8是双光源扩散背光模组的结构示意图，其结构与图5基本相同，不同的是将第二反射膜片44替换为第二辅助光源45。
示例三：如图9所示，一种能提供准直和大角度(发散)出光两种方案的双边入射(双光源)的背光模组1，包括提供准直出光的准直背光模组11作为上背光模组，提供发散出光的扩散背光模组12作为下背光模组，及置于下背光模组下方的反射膜13用于 将由光学界面向下反射的杂散光反射回出光的方向以重复利用杂散光，提高背光模组的光学效率。
如图10所示，一种能提供准直和大角度(发散)出光两种方案的双边入射背光模组2，包括提供发散出光的扩散背光模组12作为上背光模组，提供准直出光的准直背光模组11作为下背光模组，及置于下背光模组下方的反射膜13。在图10和图11的示例三中，上背光模组和下背光模组按同一方向放置，即上下两个背光模组同一侧的光源上下叠置，如111和121、112和122。
如图11所示，双光源扩散背光模组15为上背光模组，以双向楔形准直背光模组16为下背光模组，上下背光模组15、16组合置于反射膜17之上。以下背光模组16为例，从光源621和622射出的光线601和602进入楔形导光板后相向而行，并在遇见微棱镜下开口时被折射出下背光模组16。准直背光模组16出射的光线601、602、603、604透射上背光模组15后形成准直方向的光束，但其在透射上背光模组时由于上背光模组15中的微棱镜结构所产生的雾度效应会造成准直光束的部分离散。同样，上背光模组15的两个光源611、612发出的光线进入平行导光板后相向而行，当光线遇到微棱镜下开口时被微棱镜侧面以大角度折射出扩散背光模组15，如光线605、606。这样光线601、602、605、606形成了全角度光束，当上背光模组15关闭时，光束范围只有准直部分601、602。控制上背光模组15的光源的开关，就能够实现光束视角的切换。本案例中下置的反射膜17是用于反射从楔形导光板下方漏出的光线、及背光模组结构中不同的界面向下反射的光线，以重复利用向下出射的光线，提高背光模组的整体光学效率。本技术方案的组合除了上背光模组平行平板、下背光模组楔形；也可以是下列组合：上背光模组楔形、下背光模组平行平板，上、下模背光组均为平行平板，上、下背光模组均为楔形。
如图12所示，图12的结构中可以加入防窥膜18，以进一步提高准直(角度)截止区域的黑度(模组的对比度)。在这种构架中防窥膜18的下表面181与下背光模组64的出光面641做光学贴合以减少界面光学损耗；同时防窥膜18的上表面182不能与扩散背光模组63的下表面631贴合，而必须保持非光学接触。
如图13所示，上、下背光模组以正交的方式放置，即其中一个背光模组的光源如72、73在水平方向，另一个背光模组的光源71、74在垂直方向布置。正交布置使得上下两个模组可以更紧密的结合，同时光源布置不相互干扰。在实现紧凑的结构设计的同 时，减小了上模组微棱镜结构对下背光模组产生的实际雾度。正交背光模组组合的光束规律与平行背光模组组合雷同。
如图14所示的是正交布置准直背光模组81在下，扩散背光模组82在上的构架。而图15所示的是扩散背光模组82在下，准直背光模组81在上的组合。
如图16所示，在准直背光模组81在下、扩散背光模组82在上的构架中，可以在81、82之间加入防窥膜84，以进一步提高准直(角度)截止区域的黑度(背光模组的对比度)。在这种构架中防窥膜84的下表面841与下背光模组81的出光面811做光学贴合以减少界面光学损耗。同时防窥膜84的上表面842不能与扩散背光模组82的下表面821贴合，而必须保持非光学接触。
示例四：
如图17所示，背光模组由非透明的全楔形准直背光模组92为下背光模组、透明的扩散背光模组91为上背光模组，其中上、下两背光模组的放置方向相同，即两背光模组的光源911、924互为上下叠置。与一体型楔形模组结构不同，图17中斜方棱镜膜922、楔形导光板921、与反射膜923均为分离器件，其中斜方棱镜膜922与楔形导光板921两种材料的折射率相同或接近。其工作原理如下：光源924发出的光线901、902由楔形导光板921前端入射，光线在楔形导光板921(例如n＝1.58)中传播时，遵循斯涅耳折射定律：
n 1sinθ 1＝n 2sinθ 2
式中n 1为介质1的折射率，θ 1为入射角，n 2为介质2的折射率，θ 2为折射角。
光线入射进楔形导光板921后角度范围为α＝±arcsin(1/1.58)＝±40°，在楔形导光板921中传播时与楔形导光板921的上下两个反射面9211、9212的法线夹角90-α大于等于50°，而全反射角为γ＝arcsin(1/1.58)＝40°，90-α大于γ时满足全反射条件，所以不会出射。楔形板的角度为β，光线每经过一次反射与楔形导光板921的出射面9211的法线夹角减少β，直至满足出射条件才会出射。可以理解，从出射面9211出射进入上方斜方棱镜膜922的光，均为接近全反射角时出射，光线方向基本一致，即不管光线901和902在楔形导光板921中的起始方向怎样，它们入射到斜方棱镜膜922中的方向基本一致。因此经过斜方棱镜膜922的折射后，光束呈现很好的在指定方向上的会聚度。这种构架在对准直度要求高的应用中尤其必要。在此，上扩散导光板921模组91的工作机理与上述各种案例雷同，需要指出的是由于全楔形准直背光模组的准直性更 好，扩散背光模组的出光范围也相应会变大，以与准直背光模组的出光光束形成无缝的全覆盖。
如图18所示，在图17的结构中，在透明的扩散背光模组91与非透明的准直背光模组92之间设置防窥膜93，以进一步提高准直(角度)截止区域的黑度(背光模组的对比度)。在这种构架中防窥膜93的下表面932与下背光模组的出光面9251做光学贴合以减少界面光学损耗。同时防窥膜93的上表面931不能与扩散背光模组912的下表面9121贴合，而必须保持非光学接触。此处，图17中楔形导光板上方的斜方棱镜膜由逆棱镜膜925取代，其工作原理雷同，将楔形导光板的出光由全反射的方式折射到特定的方向上。
图19是为本发明的实施例的双光源背光模组的出光光谱，从图中可以看出，当上下背光模组同时工作时，背光模组提供一个涵盖整个视场的出光范围轮廓23。当发散背光模组关闭后，虚线光谱21不再出现，背光模组仅提供准直方向的出光光谱22。

Claims (20)

  1. 一种防窥视背光模组，其特征在于该光线角度可控的背光模组由上背光模组和下背光模组和设置在所述的下背光模组下方的反射膜叠合组成，所述的上背光模组是透明模组，所述的下背光模组是透明模组或非透明模组，所述的上背光模组是准直背光模组或扩散背光模组，所述的下背光模组是准直背光模组或扩散背光模组，且所述的上背光模组和所述的下背光模组性质不同。
  2. 如权利要求1所述的一种防窥视背光模组，其特征在于所述的准直背光模组包括第一导光板和设置在所述的第一导光板侧面的第一光源，所述的第一导光板的上表面设置的第一微棱镜阵列，所述的第一微棱镜阵列沿所述的第一光源的光线传输方向排列，所述的扩散背光模组包括第二导光板和设置在所述的第二导光板侧面的第二光源，所述的第二导光板的上表面设置的第二微棱镜阵列，所述的第二微棱镜阵列沿所述的第二光源的光线传输方向排列。
  3. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的上背光模组为准直背光模组，所述的下背光模组为扩散背光模组，所述的第一微棱镜阵列和所述的第二微棱镜阵列相互正交或相互平行。
  4. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的上背光模组为扩散背光模组，所述的下背光模组为准直背光模组，所述的第一微棱镜阵列和所述的第二微棱镜阵列相互正交或相互平行。
  5. 如权利要求2～4中任一项权利要求所述的一种防窥视背光模组，其特征在于所述的第一导光板为平行平板，所述的第一光源设置在所述的第一导光板的一个侧面，所述的第一光源对面的侧面上设置有第一反射面。
  6. 如权利要求2～4中任一项权利要求所述的一种防窥视背光模组，其特征在于所述的第一导光板为平行平板，所述的第一光源为设置在所述的第一导光板的一个侧面，所述的第一光源对面的侧面上设置有第一辅助光源。
  7. 如权利要求2～4中任一项权利要求所述的一种防窥视背光模组，其特征在于所述的第一导光板是楔形板，所述的第一光源设置在所述的楔形板的厚端侧面。
  8. 如权利要求7所述的一种防窥视背光模组，其特征在于所述的楔形板的楔角为小于等于5°。
  9. 如权利要求7所述的一种防窥视背光模组，其特征在于所述的楔形板的尾端侧面设置有反射面。
  10. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的第一导光板是双向楔形板，所述的第一光源设置在所述的楔形板的两个厚端侧面。
  11. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的第一微棱镜阵列为梯形或杯状结构，所述的第一微棱镜阵列与所述的第一导光板互为一体。
  12. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的第一微棱镜阵列是均匀排列或不均匀排列。
  13. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的第一微棱镜阵列将由所述的第一导光板入射的光线以会聚的方式折射出所述的第一微棱镜阵列。
  14. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的第二导光板为平行平板，所述的第二光源为设置在所述的第二导光板的一个侧面，所述的第二光源对面的侧面上设置有第二反射面。
  15. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的第二导光板为平行平板，所述的第二光源为设置在所述的第二导光板的一个侧面，所述的第二光源对面的侧面上设置有第二辅助光源。
  16. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的第二微棱镜阵列将由所述的第二导光板入射的光线以发散的方式折射出所述的第一微棱镜阵列。
  17. 如权利要求2所述的一种防窥视背光模组，其特征在于所述的下背光模组的上表面上贴合有防窥膜，所述的防窥膜与所述的上背光模组的下表面之间设置有空气间隙。
  18. 如权利要求1所述的一种防窥视背光模组，其特征在于所述的上背光模组为扩散背光模组，所述的下背光模组为准直背光模组，所述的准直背光模组包括第一导光板和第一光源，所述的扩散背光模组包括第二导光板和第二光源，所述的第二导光板为平行平板，所述的第二导光板的上表面设置的第二微棱镜阵列，所述的第二微棱镜阵列沿所述的第二光源的光线传输方向排列，所述的第二光源设置在所述的第二导光板的一个侧面，所述的第二光源对面的侧面上设置有第二辅助光源，所述的第一导光板是楔形板， 所述的第一光源设置在所述的楔形板的厚端侧面，所述的第一导光板与所述的第二导光板之间设置有斜方棱镜膜。
  19. 如权利要求1所述的一种防窥视背光模组，其特征在于所述的上背光模组为扩散背光模组，所述的下背光模组为准直背光模组，所述的准直背光模组包括第一导光板和第一光源，所述的扩散背光模组包括第二导光板和第二光源，所述的第二导光板为平行平板，所述的第二导光板的上表面设置的第二微棱镜阵列，所述的第二微棱镜阵列沿所述的第二光源的光线传输方向排列，所述的第二光源设置在所述的第二导光板的一个侧面，所述的第二光源对面的侧面上设置有第二辅助光源，所述的第一导光板是楔形板，所述的第一光源设置在所述的楔形板的厚端侧面，所述的第一导光板与所述的第二导光板之间设置有逆棱镜膜。
  20. 如权利要求19所述的一种防窥视背光模组，其特征在于所述的逆棱镜膜与所述的第二导光板之间设置防窥膜。
PCT/CN2021/129496 2020-12-15 2021-11-09 一种防窥视背光模组 WO2022127444A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2023532623A JP2023552738A (ja) 2020-12-15 2021-11-09 覗き見防止バックライトモジュール
EP21905373.3A EP4235284A4 (en) 2020-12-15 2021-11-09 ANTI-SPY BACKLIGHT MODULE
US18/267,097 US11982831B2 (en) 2020-12-15 2021-11-09 Anti-peeping backlight module

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202011473055.6A CN112882286A (zh) 2020-12-15 2020-12-15 一种防窥视背光模组
CN202011473055.6 2020-12-15

Publications (1)

Publication Number Publication Date
WO2022127444A1 true WO2022127444A1 (zh) 2022-06-23

Family

ID=76043280

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/129496 WO2022127444A1 (zh) 2020-12-15 2021-11-09 一种防窥视背光模组

Country Status (5)

Country Link
US (1) US11982831B2 (zh)
EP (1) EP4235284A4 (zh)
JP (1) JP2023552738A (zh)
CN (1) CN112882286A (zh)
WO (1) WO2022127444A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024060250A1 (zh) * 2022-09-23 2024-03-28 京东方科技集团股份有限公司 背光模组及显示装置

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112882286A (zh) * 2020-12-15 2021-06-01 马鞍山晶智科技有限公司 一种防窥视背光模组
CN113556532B (zh) * 2021-07-20 2024-07-30 北京京东方显示技术有限公司 一种显示装置
TWI826042B (zh) * 2022-10-12 2023-12-11 達運精密工業股份有限公司 可切換式背光模組

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5956107A (en) * 1996-09-20 1999-09-21 Sharp Kabushiki Kaisha Diffusion optical guide plate, and backlight source and liquid crystal display apparatus using the same
CN1987606A (zh) * 2005-12-23 2007-06-27 群康科技(深圳)有限公司 背光模组与液晶显示模组
CN103226261A (zh) * 2013-03-26 2013-07-31 苏州晶智科技有限公司 一种用于液晶显示器的二维准直背光模组
CN105065976A (zh) * 2015-06-02 2015-11-18 苏州晶智科技有限公司 一种用于液晶显示器的背光模组
CN106597599A (zh) * 2017-01-17 2017-04-26 京东方科技集团股份有限公司 背光模组、显示面板及显示装置
CN109870836A (zh) * 2019-03-28 2019-06-11 合肥京东方光电科技有限公司 背光模组及其制造方法、显示装置及其控制方法
CN112882286A (zh) * 2020-12-15 2021-06-01 马鞍山晶智科技有限公司 一种防窥视背光模组

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006031545A1 (en) * 2004-09-09 2006-03-23 Fusion Optix, Inc. Enhanced lcd backlight
KR101318497B1 (ko) * 2009-12-02 2013-10-16 미쓰비시덴키 가부시키가이샤 액정 표시 장치
KR101747297B1 (ko) * 2010-08-04 2017-06-27 삼성전자주식회사 백라이트 유닛 및 이를 포함한 2차원 겸용 3차원 영상 디스플레이 장치
KR101956522B1 (ko) * 2015-11-27 2019-03-08 시옵티카 게엠베하 자유 및 제한 작동 모드를 위한 스크린
CN107179627B (zh) * 2016-03-09 2020-10-23 台湾扬昕股份有限公司 光源模块以及显示装置
TWI589966B (zh) * 2016-05-12 2017-07-01 揚昇照明股份有限公司 光源模組及顯示裝置
US11002998B2 (en) * 2019-01-31 2021-05-11 Sharp Kabushiki Kaisha Enhanced privacy switchable backlight system

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5956107A (en) * 1996-09-20 1999-09-21 Sharp Kabushiki Kaisha Diffusion optical guide plate, and backlight source and liquid crystal display apparatus using the same
CN1987606A (zh) * 2005-12-23 2007-06-27 群康科技(深圳)有限公司 背光模组与液晶显示模组
CN103226261A (zh) * 2013-03-26 2013-07-31 苏州晶智科技有限公司 一种用于液晶显示器的二维准直背光模组
CN105065976A (zh) * 2015-06-02 2015-11-18 苏州晶智科技有限公司 一种用于液晶显示器的背光模组
CN106597599A (zh) * 2017-01-17 2017-04-26 京东方科技集团股份有限公司 背光模组、显示面板及显示装置
CN109870836A (zh) * 2019-03-28 2019-06-11 合肥京东方光电科技有限公司 背光模组及其制造方法、显示装置及其控制方法
CN112882286A (zh) * 2020-12-15 2021-06-01 马鞍山晶智科技有限公司 一种防窥视背光模组

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4235284A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024060250A1 (zh) * 2022-09-23 2024-03-28 京东方科技集团股份有限公司 背光模组及显示装置

Also Published As

Publication number Publication date
EP4235284A4 (en) 2024-05-15
EP4235284A1 (en) 2023-08-30
US11982831B2 (en) 2024-05-14
JP2023552738A (ja) 2023-12-19
CN112882286A (zh) 2021-06-01
US20240012192A1 (en) 2024-01-11

Similar Documents

Publication Publication Date Title
WO2022127444A1 (zh) 一种防窥视背光模组
US5359691A (en) Backlighting system with a multi-reflection light injection system and using microprisms
WO2019184906A1 (zh) 背光模组和显示设备
US8149495B2 (en) Reflective display having improved brightness and contrast
WO2018205788A1 (zh) 导光板、光学模组及全反显示装置
US6369950B1 (en) Liquid-crystal display device and light pipe
CN102809105A (zh) 背光模组及显示装置
US20140347602A1 (en) Backlight module for liquid crystal display
JP2001166150A (ja) 導光板、面光源装置及び液晶表示装置
JP2003057653A (ja) 液晶表示装置
KR102244847B1 (ko) 초집광 도광필름 및 이를 이용한 평판 표시장치용 박막형 백 라이트 유닛
JP2019200862A (ja) 導光板、面光源装置および表示装置
WO2022213909A1 (zh) 一种透明单向出光光源模组
CN113156707B (zh) 面光源装置和平板显示装置
JPH11174214A (ja) 指向性反射板およびそれを用いた反射型表示装置
CN214375703U (zh) 一种防窥视背光模组
CN207946547U (zh) 一种防窥透镜、防窥装置及显示装置
CN110032004B (zh) 一种用于准直背光模组的楔形板及准直背光模组
WO2022252285A1 (zh) 背光模组及显示装置
JP2023520474A (ja) 表示装置用透明光源システム
CN112764151B (zh) 面光源装置和液晶显示装置
JP2003114430A (ja) フロントライト型液晶ディスプレイ
CN217112967U (zh) 一种准直型背光模组及液晶显示装置
CN219302714U (zh) 用于背光模组的双面棱镜膜片、侧入背光模组及显示装置
CN110208983B (zh) 一种侧入式背光模组

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21905373

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2023532623

Country of ref document: JP

WWE Wipo information: entry into national phase

Ref document number: 18267097

Country of ref document: US

ENP Entry into the national phase

Ref document number: 2021905373

Country of ref document: EP

Effective date: 20230526

NENP Non-entry into the national phase

Ref country code: DE