CN116540450A - Backlight module, display device and control method thereof - Google Patents

Backlight module, display device and control method thereof Download PDF

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Publication number
CN116540450A
CN116540450A CN202310564874.9A CN202310564874A CN116540450A CN 116540450 A CN116540450 A CN 116540450A CN 202310564874 A CN202310564874 A CN 202310564874A CN 116540450 A CN116540450 A CN 116540450A
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CN
China
Prior art keywords
light
backlight
emitting surface
incident
angle
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Pending
Application number
CN202310564874.9A
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Chinese (zh)
Inventor
王秋里
董瑞君
张�浩
陈丽莉
马鑫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BOE Technology Group Co Ltd
Beijing BOE Display Technology Co Ltd
Original Assignee
BOE Technology Group Co Ltd
Beijing BOE Display Technology Co Ltd
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 BOE Technology Group Co Ltd, Beijing BOE Display Technology Co Ltd filed Critical BOE Technology Group Co Ltd
Priority to CN202310564874.9A priority Critical patent/CN116540450A/en
Publication of CN116540450A publication Critical patent/CN116540450A/en
Pending legal-status Critical Current

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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
    • 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
    • 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
    • G02B6/0078—Side-by-side arrangements, e.g. for large area displays
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
    • G03H1/2202—Reconstruction geometries or arrangements
    • G03H1/2205—Reconstruction geometries or arrangements using downstream optical component
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source
    • G09G3/342—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
    • G09G3/3426—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines the different display panel areas being distributed in two dimensions, e.g. matrix

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Computer Hardware Design (AREA)
  • Theoretical Computer Science (AREA)
  • Planar Illumination Modules (AREA)

Abstract

The application discloses a backlight module, a display device and a control method thereof, wherein the backlight module comprises a plurality of backlight partitions, each backlight partition comprises at least one backlight unit, each backlight unit comprises a light source, a light guide element and a holographic element, the light guide element comprises a first light emitting surface and a second light emitting surface which are oppositely arranged, the light source is arranged on one side of the light guide element, and the light source is used for emitting incident light rays to the light guide element; the holographic element is arranged on the first light-emitting surface and is used for receiving and reflecting light rays incident from the first light-emitting surface; the light guide element is used for receiving incident light rays of the light source and emitting the incident light rays into the holographic element through the first light emitting surface for reflection and then emitting the light rays out of the second light emitting surface, and the light rays emitted out of the second light emitting surface are collimated parallel light.

Description

Backlight module, display device and control method thereof
Technical Field
The present disclosure relates generally to the field of display technologies, and in particular, to a backlight module, a display device and a control method thereof.
Background
The liquid crystal display device is a passive light emitting device, which does not emit light, and needs to cooperate with a backlight source to provide a light source, so that the liquid crystal panel displays an image.
However, as the PPI (pixel density) of the lcd increases, the size of the opening unit of the display panel decreases more and more, and the PPI reaches more than 1400 um, the short side of the opening size of the sub-pixel has decreased to about 5um, so that most of the light of the backlight source is absorbed by other light shielding layers, and thus a high-brightness collimated backlight is required, so that more light can pass through the display panel.
The existing backlight sources can be divided into side-in backlight and direct-down backlight, for the side-in backlight, the collimation is generally carried out by directly adding a reflecting lampshade or a collimating lens on an LED lamp, for the direct-down backlight, the collimation is generally carried out by adding a parabolic or similar surface reflecting lamp cup on an LED unit, and a lens array is used for carrying out light path collimation, so that the thickness of a backlight module is larger due to the collimation mode, and the lightening and thinning of a display device are not facilitated.
Disclosure of Invention
In view of the foregoing drawbacks or shortcomings in the prior art, it is desirable to provide a backlight module, a display device and a control method thereof, which can achieve not only collimation of side-entry light sources, but also partition control of backlight.
In a first aspect, the present application provides a backlight module, including a plurality of backlight partitions, each backlight partition including at least one backlight unit, each backlight unit including a light source, a light guiding element, and a hologram element, the light guiding element including a first light-emitting surface and a second light-emitting surface disposed opposite to each other, wherein,
the light source is arranged on one side of the light guide element and is used for emitting incident light rays to the light guide element;
the holographic element is arranged on the first light-emitting surface and is used for receiving and reflecting light rays incident from the first light-emitting surface;
the light guide element is used for receiving incident light rays of the light source and emitting the incident light rays into the holographic element through the first light emitting surface for reflection and then emitting the light rays out of the second light emitting surface, and the light rays emitted out of the second light emitting surface are collimated parallel light.
Optionally, the light sources on a plurality of the backlight partitions are arranged in parallel;
the light source is a white light LED, and the incident angle of the incident light of the light source is 110-120 degrees.
Optionally, the light guiding element includes a right angle prism, where the right angle prism includes a first right angle edge, a second right angle edge, and a hypotenuse, where the length of the first right angle edge is smaller than that of the second right angle edge, the first right angle edge is used to receive incident light of the light source, the second right angle edge is a second light-emitting surface, and the hypotenuse is a first light-emitting surface;
the included angle between the bevel edge and the first right-angle edge is 8-15 degrees.
Optionally, the light guiding element is a light guiding plate, and the light guiding plate is configured to totally reflect the incident light, and the first light emitting surface and the second light emitting surface are arranged in parallel;
the light guide plate is provided with a plurality of lattice points on the first light-emitting surface, and the lattice points are used for enabling the total reflection light to be incident to the holographic element when passing through the lattice points.
Optionally, the light guide plate is provided with an inclined plane at one side close to the light source, and the light source is obliquely arranged and fixedly arranged at one side of the inclined plane;
the inclined plane is inclined upwards from the first light-emitting surface to the second light-emitting surface, and an included angle between the inclined plane and the second light-emitting surface is 80-85 degrees.
Optionally, the first light emitting surface is provided with a total reflection area at a side close to the light source, and the total reflection area is used for performing total reflection on the incident light.
Optionally, a plurality of the backlight units are arranged side by side to form two backlight columns, the light source on each backlight column is arranged on the same side of the light guide element, and the light sources on different backlight columns are oppositely arranged;
the anti-interference film is arranged on the adjacent side face of at least one of the light guide elements, the anti-interference film is white glue or a reflecting film, and the reflectivity of the reflecting film is not higher than 60%.
Optionally, the holographic element comprises a recording medium recorded with a holographic image; the holographic image is formed by recording reference light and object light which are respectively incident from two sides of the holographic element, and the reference light and the object light are coherent light;
the light source is used for providing the reproduction light of the holographic image reproduction; the reproduction light has the same frequency and optical path as those of the reference light at the time of forming the hologram image.
Optionally, the object light is collimated parallel light;
when the corresponding light guide element is a right-angle prism, an incidence angle exists between the object light and the plane of the holographic element, and the incidence angle is equal to the angle between the bevel edge and the right-angle edge on the right-angle prism;
when the corresponding light guide element is a light guide plate, the object light is incident perpendicular to the plane of the holographic element.
Optionally, the recording medium in the holographic element records a plurality of holographic images formed by reference light and object light with different polarization directions; and/or
The recording medium in the hologram element records a plurality of hologram images formed by reference light and object light of different wavelengths.
In a second aspect, the present application provides a display device, including a display panel and a backlight module as described in any one of the above, where the display panel includes a plurality of display partitions, and the display partitions and the backlight partitions are in one-to-one correspondence.
In a third aspect, the present application provides a control method of a display device, applied to a display device as described in any one of the above, the method comprising:
and controlling the backlight information of the backlight partition corresponding to the display partition according to the display information of each display partition.
The technical scheme provided by the embodiment of the application can comprise the following beneficial effects:
according to the backlight module provided by the embodiment of the application, the plurality of backlight partitions are arranged, and one or more backlight units are arranged in each partition, so that the partition control of the backlight module can be realized; the backlight unit adopts a holographic element mode, so that the collimation of light rays of the opposite side-entering type light source can be realized, a plurality of optical components are not required to be arranged, and the size of the backlight module can be reduced.
Drawings
Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the following drawings, in which:
fig. 1 is a schematic structural diagram of a backlight module according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of a backlight unit according to an embodiment of the present application;
fig. 3 is a schematic structural view of another backlight unit according to an embodiment of the present application;
FIG. 4 is a schematic view of a holographic recording light provided in an embodiment of the present application;
FIG. 5 is a schematic view of another holographic recording light provided by embodiments of the present application;
fig. 6 is a schematic structural diagram of a display panel according to an embodiment of the present disclosure;
fig. 7 is a schematic state diagram of a display device according to an embodiment of the present application.
Detailed Description
The present application is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be noted that, for convenience of description, only the portions related to the invention are shown in the drawings.
It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
Referring to fig. 1 in detail, the present application provides a backlight module, which includes a plurality of backlight partitions D1, each backlight partition D1 includes at least one backlight unit 100, each backlight unit 100 includes a light source 10, a light guiding element 20, and a hologram element 30, the light guiding element 20 includes a first light emitting surface 101 and a second light emitting surface 102 disposed opposite to each other, wherein,
the light source 10 is disposed at one side of the light guide element 20, and the light source 10 is configured to emit incident light U1 to the light guide element 20;
the hologram element 30 is disposed on the first light-emitting surface 101, and the hologram element 30 is configured to receive and reflect light incident from the first light-emitting surface 101;
the light guide element 20 is configured to receive the incident light U1 of the light source 10 and reflect the incident light U1 by entering the hologram element 30 through the first light exit surface 101, and then emit the light from the second light exit surface 102, and the light U2 emitted from the second light exit surface 102 is collimated parallel light.
It can be understood that the backlight 10 used in the conventional display is the whole area light source 10, and the whole image can be simultaneously lightened or darkened when the brightness is adjusted, in addition, a large number of optical components are needed for the side-entry light source 10 to form a large optical system so as to expand and collimate the light source 10, thereby resulting in a larger size of the backlight module and being unfavorable for the light and thin of the display device.
The backlight module provided in the embodiment of the application can realize the partition control of the backlight module by setting a plurality of backlight partitions D1 and setting one or a plurality of backlight units 100 in each partition; the backlight unit 100 adopts the hologram element 30 to achieve light collimation of the side-entry light source 10, and no optical components are required, so that the volume of the backlight module can be reduced.
Holographic refers to the entire information of the light wave, namely the amplitude information and the phase information of the light wave. The hologram 30 is an optical element made according to the principle of holography, and is typically made on a photosensitive film material, and the hologram optical element can pass interference information of the reference light P1 and the object light P2.
According to the interference principle, all information (amplitude information and phase information) of the object light P2 is stored in the recording medium at the time of recording; when the recording medium is irradiated with the reproduction light wave, the original object light P2 can be reproduced according to the diffraction principle. During holographic recording, coherent reference light P1 and object light P2 are used for being incident into the photorefractive crystal from different angles, interference fringes are generated at the intersection part of the reference light P1 and the object light P2, and information is recorded in a recording medium by using the photorefractive effect to form a holographic image; in the case of hologram reproduction, the incidence angle, frequency, and optical path of the reference light P1 are kept unchanged, and the reference light P1 is made incident as reproduction light to the photorefractive crystal on which the hologram image is recorded, so that the reproduction light is kept unchanged.
In the present application, since the reference light P1 used in recording the hologram is collimated parallel light, when the reproduction light is realized, the collimated light of the reference light P1 can be reproduced by using the light of the same optical wave information as the reference light P1 as the incident light U1. As will be described in detail below.
It should be noted that, in the embodiment of the present application, the number and the division manner of the backlight partitions D1 are not limited, and are determined according to needs in different embodiments. Also, the number of backlight units 100 on each backlight section D1 is not limited, and the present application describes exemplary embodiments in which each backlight section D1 includes one backlight unit 100.
In this application, the light source 10 may be a Light Emitting Diode (LED) chip, the light source 10 is a point light source 10, and the emitted light is scattered in a conical shape, and the type of the emitted light of the light source 10 may be red, green, blue or white, which is not limited in this application, and in this application, the light source 10 is exemplified as a white LED. The white LED light source 10 may implement visible white light using a blue chip plus phosphor. For example, the incident angle θ1 of the incident light ray U1 of the light source 10 is 110 ° to 120 °, preferably 120 °.
Wherein the light sources 10 on the plurality of backlight partitions D1 are arranged in parallel; if there are multiple backlight units 100 in each backlight partition D1, the light sources 10 on the multiple backlight units 100 may be connected in series or in parallel, which is not limited in this application. The light sources 10 arranged in parallel can control the light sources 10 to be independently lightened, control the luminous brightness and the like, so that the backlight control mode is optimized, and the backlight control mode is set according to requirements in different embodiments.
In an exemplary embodiment, as shown in fig. 2, the light guiding element 20 includes a right angle prism 210, where the right angle prism 210 includes a first right angle edge 201, a second right angle edge 202, and a hypotenuse 203, the first right angle edge 201 is shorter than the second right angle edge 202, the first right angle edge 201 is configured to receive the incident light U1 of the light source 10, the second right angle edge 202 is the second light-emitting surface 102, and the hypotenuse 203 is the first light-emitting surface 101.
When in use, the second right-angle side 202 of the right-angle prism 210 is parallel to the display panel 200, the first right-angle side 201 is perpendicular to the display panel 200, the hologram element 30 is fixedly disposed on the oblique side 203 of the right-angle prism 210, and the hologram element 30 may be fixed by optical cement or the like, or may be directly fabricated on the right-angle prism 210 by coating or the like.
The light emitted by the LED of the point light source 10 can be further diffused through the right angle prism 210, so that the light emitted by the LED can propagate in the right angle prism 210 and be refracted at the hypotenuse 203 onto the holographic element 30 arranged on the hypotenuse 203. When the light beam is arranged, the LEDs are arranged on the shorter right-angle side of the right-angle prism 210, and the light beam emitted after being diffracted by the holographic element 30 is emitted through the second right-angle side 202, so that the emitted light beam U2 is emitted vertically, the emitting area of the light beam can be increased, stray light can be reduced, and the light collimation degree can be improved.
It should be noted that, when the incident light U1 emitted from the LED enters the hypotenuse 203, if the incident angle is greater than a certain critical angle (the light is far from the normal line), a total reflection phenomenon will occur, so that the light is directly emitted from the second right-angle side 202 without being coupled in the hologram element 30. To avoid total emission of light from the LED inside the prism, the thickness of the prism is typically thicker to reduce the angle of incidence of the incident light ray U1 at the hypotenuse 203 and thus achieve reduced total reflection at the hypotenuse 203. In order to avoid that the light emitted from the LED light source 10 directly exits from the second right-angle side 202, a certain gap is generally provided between the LED light source 10 and the right-angle prism 210, so that the incident light U1 emitted from the LED light source 10 enters the hypotenuse 203 after being incident on the second right-angle side 202 for total reflection, thereby improving the light utilization rate and collimation.
The rectangular prism 210 may be formed of a transparent material such as glass or resin, and the refractive index may be in the range of 1.5-2.0. The included angle θ2 between the oblique side 203 and the first right-angle side 201 is 8 ° to 15 °.
It can be understood that, in the embodiment of the present application, the hologram element 30 is disposed on the hypotenuse 203 of the right angle prism 210, the light reflected from the hologram element 30 needs to be incident into the right angle prism 210 again, and the light emitted from the hologram element 30 can be emitted onto the second right angle side 202 (the second light-emitting surface 102) perpendicularly, so as to achieve light collimation of the backlight unit 100, that is, an included angle θ2 exists between the reflected light of the hologram element 30 and the hologram element 30, and the included angle θ2 is equal to the included angle θ2 between the hypotenuse 203 and the first right angle side 201.
In another exemplary embodiment, as shown in fig. 3, the light guiding element 20 is a light guiding plate 310, and the light guiding plate 310 is configured to totally reflect the incident light ray U1; the light guide plate 310 is provided with a plurality of dots on the first light-emitting surface 101, and the dots are used for making the total reflection light incident on the holographic element 30 when passing through the dots.
The light guide plate 310 may be formed of a transparent material such as glass or resin, and the refractive index may be in the range of 1.5-2.0. The shape and number of the dots are not limited in this application, the dots may be printed dots or other forms, and by disposing the dots on the first light-emitting surface 101 of the light guide plate 310, when light is incident on the dots, one light is scattered into multiple light rays, so that total reflection of the light on the first light-emitting surface 101 is destroyed, the light rays are scattered from the first light-emitting surface 101 of the light guide plate 310 and enter the holographic element 30, reflected by the holographic element 30, and then emitted from the second light-emitting surface 102 of the light guide plate 310, and the emitted light ray U2 is emitted vertically.
The light guide plate 310 has an upper surface 301 and a lower surface 302 disposed in parallel, the lower surface 302 is a first light-emitting surface 101, the upper surface 301 is a second light-emitting surface 102, and the first light-emitting surface 101 and the second light-emitting surface 102 are disposed in parallel with the display panel 200. In the present embodiment, the incident light ray U1 of the LED light source 10 may have a specific range of incidence angles with respect to the upper surface 301 and/or the lower surface 302 of the light guide plate 310, which may be larger than the total reflection angle of the upper surface 301, so that total reflection may occur at the upper surface 301 of the light guide plate 310 (e.g., due to the refractive index of the light guide plate 310 being larger than the medium above it, such as air or other transparent medium), so that light rays may only exit from the dots of the lower surface 302 thereof.
The light guide plate 310 is provided with an inclined surface 303 at a side close to the light source 10, and the inclined surface 303 is obliquely arranged on the light source 10 and fixedly arranged at one side of the inclined surface 303; the inclined surface 303 is inclined upward from the first light-emitting surface 101 to the second light-emitting surface 102, and an included angle θ3 between the inclined surface 303 and the second light-emitting surface 102 is 80 ° to 85 °, and is adjusted according to needs in different embodiments.
The light guide plate 310 changes the transmission direction of the point light source 10, so that the point light source 10 becomes the surface light source 10, and the light emitting area of the light source 10 is increased. The inclined surface 303 may be used to adjust the angle of light emitted by the light source 10, and the light emitted by the light source 10 is diffused after being totally reflected by the second light emitting surface 102 by the light source 10 and the inclined surface 303, so that light loss caused by back and forth reflection of the light in the horizontal direction is reduced, in this embodiment, the inclination angle of the inclined surface 303 is not limited, and the inclination angle can be adjusted as required in specific application.
In this application, an arrangement manner of the backlight unit 100 is illustrated, a plurality of the backlight units 100 are arranged side by side to form two backlight columns, the light sources 10 on each backlight column are arranged on the same side of the light guiding element 20, and the light sources 10 on different backlight columns are oppositely arranged.
The opposite arrangement of the light sources 10 on different backlight columns in the present application is preferably such that the backlight units 100 on two adjacent backlight columns are symmetrically arranged, i.e. the light source 10 on the left backlight column is located on the left side of the backlight column, and the light source 10 on the right backlight column is located on the right side of the backlight column. By providing the double backlight columns, the light sources 10 can be fixed to the edges of the display panel 200, respectively, and the arrangement can be simplified. The division manner of the backlight partition D1 is not limited in this application, and the backlight partition D1 may include one or more backlight units 100.
The adjacent two light guide elements 20 on each backlight column are provided with anti-interference films on adjacent sides of at least one light guide element 20, the anti-interference films are white glue or reflective films, and the reflectivity of the reflective films is not higher than 60%.
The reflective film is used to block light in the backlight unit 100 from being incident into other adjacent backlight units 100, and reflect light emitted toward the reflective film into the light guide element 20 to improve light utilization, and the reflective film is made of a reflective but opaque material. Also, the white glue may also be somewhat less light incident to the adjacent other backlight units 100.
The hologram element 30 includes therein a recording medium having a hologram image recorded therein; wherein the hologram image is recorded by reference light P1 and object light P2 respectively incident from both sides of the hologram element 30, the reference light P1 and the object light P2 being coherent light; the light source 10 is used for providing the reproduction light of the holographic image reproduction; the reproduction light has the same frequency and optical path as those of the reference light P1 at the time of forming the hologram image.
The hologram 30 is prepared by externally introducing the reference light P1 and the object light P2 related to the reference light P1 by using the interference principle, and recording the amplitude and phase information of the object light P2 on a certain medium in the form of interference fringes by interfering the reference light P1 and the object light P2 on the recording medium; then, the original object light P2 is reproduced by utilizing the principle of light wave diffraction through light wave diffraction, so that the light collimation function is realized. The type of recording medium is not limited in the embodiments of the present application, and photorefractive crystals or other photosensitive materials, etc. may be employed in some embodiments.
For example, in the case of optical recording, a beam of reference light P1 is used to interfere with the object light P2 during the recording stage, and a pattern generated by the interference of the object light P2 with the reference light P1 is recorded on a recording medium (photorefractive crystal), and the interference pattern carries information about the characteristics of the object light P2. When the optical path of the reference light P1 is set, the reference light P1 may be formed by a beam splitter and a reflecting mirror, and the reference light P1 may be as close as possible to the emission direction and the divergence of the light on the first light emitting surface 101 on the light guide element 20, and of course, the same setting manner as the optical path of the light source 10 on the backlight module may be adopted, for example, the light guide element 20 is adopted, and when the optical path is restored, the light source 10 and the light guide element 20 may consider the object light P2 to be reproduced, and the object light P2 uses collimated parallel light, so that the object light P2 satisfies the expected requirement of the emission direction (for example, the divergence) and the intensity of the light, and the hologram may be recorded on the medium to produce the hologram.
In particular, when different light guide elements 20 are used, the incident angle of the object light P2 onto the holographic material is different. By adjusting the incident angle of the object light P2, the reproduction light on the hologram element 30 can be controlled to be perpendicularly incident on the second light exit surface 102 when the object light P2 is reproduced.
When the corresponding light guiding element 20 is a right angle prism 210, as shown in fig. 4, an incident angle exists between the object light P2 and the plane of the holographic element 30, and the incident angle is equal to an angle between the oblique side 203 and the right angle side (the second right angle side 202) of the right angle prism 210; when the object light P2 is reproduced on the hologram element 30 by controlling the incident angle of the object light P2, an angle θ2 exists between the reflected light on the hologram element 30 and the hologram element 30, so that the reflected light can be perpendicularly incident on the second right-angle side 202 on the right-angle prism 210, and light collimation can be realized.
When the corresponding light guide element 20 is a light guide plate 310, as shown in fig. 5, the object light P2 is incident perpendicular to the plane of the hologram element 30. And further, the reflected light on the holographic element 30 is perpendicularly incident on the second light emitting surface 102 of the light guide plate 310, so as to realize light collimation.
Alternatively, the recording medium in the hologram element 30 records a plurality of hologram images formed of the reference light P1 and the object light P2 having different polarization directions; and/or a recording medium in the hologram element 30 records a plurality of hologram images formed of reference light P1 and object light P2 having different wavelengths.
It should be noted that, since the wavelengths of the light rays of different colors are different, the wavelengths are related to the frequency. Therefore, in order to achieve a light collimation function when a white LED is used as the reproduction light, a plurality of types of photorefractive crystals may be included in the hologram element 30, and different types of photorefractive crystals may allow different colors of light (red, green, blue, etc. monochromatic light) to perform object light P2 reproduction, so that white light reproduction may be achieved when the backlight unit 100 is provided with the white LED. Thus, coherent light of different wavelengths may be used for construction during holographic recording and construction.
Likewise, in the hologram recording and construction process, coherent light in different polarization states can be used for hologram construction, so that the light utilization rate can be improved when the LED light source 10 provides the reproduction light.
In an application scenario, the application provides a backlight unit is applied to non-holographic liquid crystal display panel that shows, and backlight unit sets up in the one side that display panel deviates from the display surface, can realize light direction adjustment and light collimation to side income formula light source through setting up light guide element and holographic element, follow in the application backlight unit the light that the second goes out the emergent light of plain noodles is the parallel light of collimation can normally incident display panel, realizes display panel normal display.
It can be understood that holographic display is a process of realizing stereoscopic display, where holographic display can be realized by modeling and algorithm to obtain a holographic function, complete a recording process and display through a display panel, for example, a plurality of sub-pixels arranged on the display panel are respectively used for displaying a plurality of images with different depth of field, so that different views with horizontal parallax are respectively provided for the left eye and the right eye of a user, and a stereoscopic image with depth sense is finally formed through the fusion action of the brain.
The backlight module is applied to a liquid crystal display panel for two-dimensional display, the LCD product is an inactive light-emitting electronic device, the LCD product does not have light-emitting characteristics, the display performance can be obtained only by means of the emission of a light source in the backlight module, and when the backlight source is applied to the lower part of the display panel, the backlight source is provided for the display panel, namely, collimated backlight light is provided to enter the liquid crystal display panel, so that the normal display function of the liquid crystal display panel is realized. Of course, in other application scenarios, the backlight module provided by the application can also be applied to a holographic display device to provide a backlight source for a holographic display panel.
Based on the same inventive concept, the present application provides a display device, including a display panel 200 and a backlight module as described in any one of the above, the display panel 200 includes a plurality of display partitions D2, and the display partitions D2 are in one-to-one correspondence with the backlight partitions D1. The display device may be a portable electronic device such as a mobile phone, a tablet computer, a wristwatch, a bracelet, etc., but is not limited thereto, and may be a display device such as a television, a desktop computer, etc. The display panel 200 may be a liquid crystal LCD display panel, and collimated parallel light is provided to the display panel 200 through a backlight module.
The brightness of a general LCD is determined by a backlight module thereof, and the display device provided in the embodiments of the present application can control the backlight partition to make collimated parallel light incident to the display partition through the backlight partition corresponding to the display partition, thereby controlling the display brightness of the display partition, and improving the display effect.
As shown in fig. 6, the display panel 200 includes a plurality of sub-pixels P arranged in an array, and the display partition D2 may include one or more sub-pixels P, which is not limited in the dividing manner of the display partition D2 in this application, where the dividing manner of the display partition D2 and the dividing manner of the backlight partition D1 are the same, and a single collimated light beam may be provided to one display partition D2 through one backlight partition D1, so as to control one display partition D2 to perform display control. While the sub-pixels and the backlight unit 100 do not have a strict correspondence, each display area D2 may include a plurality of sub-pixels P, each backlight area D1 may include one or more backlight units 100, that is, a plurality of sub-pixels may be simultaneously provided with collimated light beams by one backlight unit 100, which is not limited in this application.
The application also provides a control method of the display device, which is applied to the display device, and the method comprises the following steps:
and controlling the backlight information of the backlight partition D1 corresponding to the display partition D2 according to the display information of each display partition D2.
The display panel 200 in the application is a liquid crystal display panel 200, and the working principle is that under the action of an electric field, the arrangement direction of liquid crystal molecules is changed, so that the light transmittance of a backlight module is changed, the electro-optical conversion is completed, and the color reproduction of a time domain and a space domain is completed through red, green and blue three-primary color filter films. The brightness of the backlight partition D1 at the corresponding position is adjusted according to the display content of the display panel 200, and it is understood that the backlight information in the present application includes, but is not limited to, information such as backlight on/off, backlight brightness, and the like. As shown in fig. 7, one of the backlight partitions D1 is individually controlled to be lit up to control the display of the sub-pixels P within the display partition D2 corresponding to the backlight partition D1.
It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are merely for convenience in describing and simplifying the description based on the orientation or positional relationship shown in the drawings, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular implementations only and is not intended to be limiting of the invention. Terms such as "disposed" or the like as used herein may refer to either one element being directly attached to another element or one element being attached to another element through an intermediate member. Features described herein in one embodiment may be applied to another embodiment alone or in combination with other features unless the features are not applicable or otherwise indicated in the other embodiment.
The present invention has been described in terms of the above embodiments, but it should be understood that the above embodiments are for purposes of illustration and description only and are not intended to limit the invention to the embodiments described. Those skilled in the art will appreciate that many variations and modifications are possible in light of the teachings of the invention, which variations and modifications are within the scope of the invention as claimed.

Claims (11)

1. A backlight module is characterized by comprising a plurality of backlight partitions, each backlight partition comprises at least one backlight unit, each backlight unit comprises a light source, a light guide element and a holographic element, the light guide element comprises a first light-emitting surface and a second light-emitting surface which are oppositely arranged, wherein,
the light source is arranged on one side of the light guide element and is used for emitting incident light rays to the light guide element;
the holographic element is arranged on the first light-emitting surface and is used for receiving and reflecting light rays incident from the first light-emitting surface;
the light guide element is used for receiving incident light rays of the light source and emitting the incident light rays into the holographic element through the first light emitting surface for reflection and then emitting the light rays out of the second light emitting surface, and the light rays emitted out of the second light emitting surface are collimated parallel light.
2. The backlight module according to claim 1, wherein the light sources on a plurality of the backlight partitions are arranged in parallel;
the light source is a white light LED, and the incident angle of the incident light of the light source is 110-120 degrees.
3. The backlight module according to claim 1, wherein the light guiding element comprises a right-angle prism, the right-angle prism comprises a first right-angle side, a second right-angle side and a hypotenuse, the length of the first right-angle side is smaller than that of the second right-angle side, the first right-angle side is used for receiving incident light rays of the light source, the second right-angle side is a second light-emitting surface, and the hypotenuse is a first light-emitting surface;
the included angle between the bevel edge and the first right-angle edge is 8-15 degrees.
4. The backlight module according to claim 1, wherein the light guide element is a light guide plate, the light guide plate is configured to totally reflect the incident light, and the first light emitting surface and the second light emitting surface are disposed in parallel;
the light guide plate is provided with a plurality of lattice points on the first light-emitting surface, and the lattice points are used for enabling the total reflection light to be incident to the holographic element when passing through the lattice points.
5. The backlight module according to claim 4, wherein the light guide plate is provided with an inclined surface at a side close to the light source, and the light source is obliquely arranged and fixedly arranged at a side of the inclined surface;
the inclined plane is inclined upwards from the first light-emitting surface to the second light-emitting surface, and an included angle between the inclined plane and the second light-emitting surface is 80-85 degrees.
6. A backlight module according to claim 1, wherein a plurality of the backlight units are arranged side by side to form two backlight columns, the light sources on each backlight column are arranged on the same side of the light guide element, and the light sources on different backlight columns are arranged oppositely;
the anti-interference film is arranged on the adjacent side face of at least one of the light guide elements, the anti-interference film is white glue or a reflecting film, and the reflectivity of the reflecting film is not higher than 60%.
7. The backlight module according to claim 1, wherein the hologram element includes therein a recording medium having a hologram image recorded therein; the holographic image is formed by recording reference light and object light which are respectively incident from two sides of the holographic element, and the reference light and the object light are coherent light;
the light source is used for providing the reproduction light of the holographic image reproduction; the reproduction light has the same frequency and optical path as those of the reference light at the time of forming the hologram image.
8. The backlight module according to claim 7, wherein the object light is collimated parallel light;
when the corresponding light guide element is a right-angle prism, an incidence angle exists between the object light and the plane of the holographic element, and the incidence angle is equal to the angle between the bevel edge and the right-angle edge on the right-angle prism;
when the corresponding light guide element is a light guide plate, the object light is incident perpendicular to the plane of the holographic element.
9. The backlight module according to claim 7, wherein the recording medium in the hologram element records a plurality of hologram images formed by reference light and object light having different polarization directions; and/or
The recording medium in the hologram element records a plurality of hologram images formed by reference light and object light of different wavelengths.
10. A display device, comprising a display panel and a backlight module according to any one of claims 1-9, wherein the display panel comprises a plurality of display partitions, and the display partitions are in one-to-one correspondence with the backlight partitions.
11. A control method of a display device, characterized in that it is applied to the display device according to claim 10, the method comprising:
and controlling the backlight information of the backlight partition corresponding to the display partition according to the display information of each display partition.
CN202310564874.9A 2023-05-18 2023-05-18 Backlight module, display device and control method thereof Pending CN116540450A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310564874.9A CN116540450A (en) 2023-05-18 2023-05-18 Backlight module, display device and control method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310564874.9A CN116540450A (en) 2023-05-18 2023-05-18 Backlight module, display device and control method thereof

Publications (1)

Publication Number Publication Date
CN116540450A true CN116540450A (en) 2023-08-04

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Family Applications (1)

Application Number Title Priority Date Filing Date
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