WO2018016691A1 - Unité de rétro-éclairage et appareil d'affichage à cristaux liquides comportant ladite unité de rétro-éclairage, et procédé de gradation de l'unité de rétro-éclairage - Google Patents

Unité de rétro-éclairage et appareil d'affichage à cristaux liquides comportant ladite unité de rétro-éclairage, et procédé de gradation de l'unité de rétro-éclairage Download PDF

Info

Publication number
WO2018016691A1
WO2018016691A1 PCT/KR2016/014025 KR2016014025W WO2018016691A1 WO 2018016691 A1 WO2018016691 A1 WO 2018016691A1 KR 2016014025 W KR2016014025 W KR 2016014025W WO 2018016691 A1 WO2018016691 A1 WO 2018016691A1
Authority
WO
WIPO (PCT)
Prior art keywords
unit
light
guide plate
driving region
region
Prior art date
Application number
PCT/KR2016/014025
Other languages
English (en)
Korean (ko)
Inventor
최동원
송영웅
김민수
Original Assignee
(주)케이제이프리텍
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
Priority claimed from KR1020160092069A external-priority patent/KR101851937B1/ko
Priority claimed from KR1020160101040A external-priority patent/KR20180018867A/ko
Application filed by (주)케이제이프리텍 filed Critical (주)케이제이프리텍
Publication of WO2018016691A1 publication Critical patent/WO2018016691A1/fr

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
    • 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

Definitions

  • the present invention relates to a liquid crystal display, and more particularly, to a backlight unit and a dimming method thereof for realizing finer and more precise local dimming in the conventional local dimming of the liquid crystal display.
  • LCDs liquid crystal displays
  • these LCD displays are continuously developed and have a clearer effect on people through technology such as having 3D-like functions or increasing the number of pixels such as UHD.
  • Technological advances are being made to deliver image quality. This development requires that the backlight, which plays a role of emitting light from the back side, also has a differentiating technology.
  • Current liquid crystal display divides the backlight into multiple areas for efficient power consumption of the backlight, and the brightness is linked with the image signal, so that the dark areas of the image are turned off or the light is reduced, and the bright areas are increased.
  • a local dimming method that significantly improves the contrast ratio and power consumption has been applied.
  • the backlight driving area needs to be subdivided into a larger number, and in particular, the driving of the upper area and the lower area of the LGP must be controlled separately.
  • the present invention has been made to solve the above problems, and an object of the present invention is to provide a backlight unit capable of realizing more precise and finely divided local dimming.
  • Still another object of the present invention is to provide a backlight unit capable of further improving performances such as power consumption, brightness, visibility, contrast ratio, and the like.
  • the backlight unit according to the present invention for achieving the above object is a light source; And a light guide plate portion through which light is incident from the light source portion.
  • the light guide plate portion includes a light guide plate body, a first light incident portion formed at one side of the light guide plate body to receive light, and a second light incident portion formed at the other side portion of the light guide plate body to receive light.
  • the light source unit includes a first array composed of a plurality of light emitting elements and disposed on the side of the first light incident unit, and a second array composed of another plurality of light emitting elements and disposed on the side of the second incident light unit.
  • each of the first light incident portion and the second light incident portion includes a serration pattern formed in a sawtooth shape
  • the backlight unit has a first separation distance of 3.2 mm between the light emitting screen of the light guide plate body and the light emitting elements of the first array. It is formed less than, the second separation distance between the light-emitting screen of the light guide plate body and the light emitting device of the second array is formed less than 3.2mm, the serration pattern is formed the pitch of the tooth is less than 0.06mm.
  • a backlight unit may include a driver configured to adjust brightness of a plurality of unit light emitters, respectively; And receiving the image data signal, analyzing the image data signal for each unit driving region, finding the brightest reference pixel for each unit driving region, and determining a reference value for each unit driving region based on the position and brightness of the reference pixel. It may include a control unit for generating a control signal according to the reference value for each unit driving region and transmits the control signal.
  • the controller is further configured to find a brightest reference pixel for each unit driving region by analyzing a receiver for receiving an image data signal and the image data signal for each unit driving region, and for each unit driving region based on the position and brightness of the reference pixel. And a signal generator for generating a control signal according to the determined reference value for each unit driving region.
  • the backlight unit and the liquid crystal display device According to the backlight unit and the liquid crystal display device according to the present invention, it is possible to implement more detailed and precise local dimming compared to the conventional dimming, to further improve the brightness, contrast ratio, visibility, etc. of the display device, power consumption 5 ⁇ compared to the conventional 20% more can be saved.
  • the backlight unit and the liquid crystal display device it is possible to manufacture a backlight unit having an optical length shorter than the conventional optical length threshold, so that the bezel into a further improved one-side bezel size compared to the conventional There is an advantage that can be implemented.
  • FIG. 1 is an exploded perspective view of a liquid crystal display according to the present invention.
  • FIG. 2 is a plan view of a backlight unit according to the present invention.
  • FIG. 3 is a side view of the backlight unit according to the present invention.
  • FIG. 4 is a sectional view of a backlight unit according to the present invention.
  • FIG. 5 is a perspective view of the light guide plate portion according to the present invention.
  • FIG. 6 is a cross-sectional view showing a serration pattern in accordance with the present invention.
  • FIG. 7 is a plan view showing a unit light emitter and a unit driving region according to the present invention.
  • FIG. 8 is a simulation data showing a hot spot phenomenon for each pitch of the serration pattern of the present invention.
  • 9a and 9b are comparative graphs showing the relative sizes of hot spots for each pitch of the serration patterns of the present invention.
  • FIG. 10 is an exemplary view for explaining local dimming according to the present invention.
  • FIG. 11 is a view schematically showing an embodiment of a backlight unit according to the present invention.
  • FIG. 12 is a diagram illustrating an example of reference values for respective unit driving regions of the present invention.
  • FIG. 13 is a view illustrating luminance by location of the entire light guide plate when the unit light emitting unit of the present invention is driven.
  • FIG. 14 is a view illustrating luminance by position of a light guide plate when a corresponding unit light emitter is driven such that the luminance of a reference pixel of the reference unit driving region of the present invention is 100;
  • control unit 100 liquid crystal display panel
  • Light guide plate 150 Reflective sheet
  • on or above means to be located above or below the target portion, and does not necessarily mean to be located above the gravity direction.
  • a portion such as an area, a plate, etc. is said “on or on top of” another part, it is not only in contact with or spaced apart from another part, but also in the middle of another part. It also includes cases where there is.
  • one component when one component is referred to as “connected” or “connected” with another component, the one component may be directly connected or directly connected to the other component, but in particular It is to be understood that, unless there is an opposite substrate, it may be connected or connected via another component in the middle.
  • FIG. 1 is an exploded perspective view of a liquid crystal display according to the present invention
  • FIG. 2 is a plan view of a backlight unit according to the present invention
  • FIG. 3 is a side view of the backlight unit according to the present invention
  • FIG. 4 is a backlight unit according to the present invention
  • 5 is a perspective view of a light guide plate portion according to the present invention.
  • the liquid crystal display according to the present invention includes a liquid crystal display panel 100 on which an image is displayed and a backlight unit 140 for providing light to the liquid crystal display panel 100.
  • the liquid crystal display panel 100 includes a pair of substrates disposed to face each other and a liquid crystal layer interposed between the pair of substrates, and a pixel region is defined by a plurality of gate lines and data lines arranged in a matrix form on the substrate. do.
  • a thin film transistor for controlling a signal supplied to each pixel and a pixel electrode connected to the thin film transistor are formed on a substrate where the gate line and the data line cross each other, and a color filter and a common electrode are formed on the other substrate.
  • polarizers may be provided on the rear surfaces of the two substrates, respectively.
  • the backlight unit 140 may include a light source unit 130 for emitting light, a light guide plate unit 145 for changing a distribution of light provided from the light source unit 130, and a light guide unit 145.
  • the optical sheets 110 and 120 to uniform the luminance distribution and improve the vertical incidence, and the reflective sheet 150 for injecting light emitted to the rear of the light guide plate body 10 into the light guide plate.
  • the light source unit 130 includes a plurality of light emitting devices disposed on both side surfaces of the light guide plate 145, and a reflecting plate reflecting light emitted from the light emitting device toward the light guide plate.
  • the light emitting device is preferably composed of a point light source such as an LED (Light Emitting Diode (LED)), but may be a tube light source such as a cold cathode tube (fluorescent lamp) that emits white light.
  • the light source unit 130 may be divided into a first array 20 disposed on one side of the light guide plate 145 and a second array 22 disposed on the other side.
  • the first array 20 is composed of a plurality of light emitting elements 21, and the light emitting elements 21 are arranged in a line at a distance from each other on the same axis.
  • the first array 20 is disposed on the first light incident part 31 side of the light guide plate 145. More specifically, in the first array 20, the light emitting device 21 configuring the same is disposed to face the light incident surface 35 of the first light incident portion 31, that is, the serration pattern SP to be described later. Preferably, the light exit surface of the light emitting element 21 is disposed in contact with the light incident surface 35.
  • the second array 22 is made up of another plurality of light emitting elements 23, and the light emitting elements 23 are arranged in a row at a distance from each other on the same axis.
  • the second array 22 is disposed on the second light incident part 32 side of the light guide plate 145. More specifically, in the second array 22, the light emitting device 23 configuring the same is disposed to face the light incident surface 37 of the second light incident part 32, that is, the serration pattern SP to be described later.
  • the light exit surface of the light emitting element 23 is disposed in contact with the light incident surface 37.
  • the optical sheet may include a diffusion sheet 120 for diffusing light incident from the light guide plate body 10 toward the liquid crystal display panel 100 and a prism sheet 110 for condensing the diffused light to improve vertical incidence.
  • a diffusion sheet 120 for diffusing light incident from the light guide plate body 10 toward the liquid crystal display panel 100
  • a prism sheet 110 for condensing the diffused light to improve vertical incidence.
  • Reflective sheet 150 is for reflecting the light emitted to the lower portion of the light guide plate body 10 to be re-incident into the light guide plate body 10, any conventional reflective sheet used in the art can be used without particular limitation. .
  • the light guide plate 145 includes a light guide plate body 10 and light receiving parts 31 and 32, and the light guide parts 31 and 32 are formed on both side surfaces of the light guide plate body 10, respectively.
  • the light guide plate body 10 is configured to uniformly change the optical distribution concentrated in a narrow area over a large area.
  • the surface light source having uniform luminance by repeating total reflection and refraction of point light or linear light incident from the light source unit 130 inside After converting to the outside, exiting.
  • the surface light source emission area of the light guide plate body 10 is referred to as an "effective screen or effective area of the backlight unit 140".
  • an effective screen or an effective area (Light Area) of the backlight unit 140 will be referred to as a light output screen (L / A).
  • the light exit screen L / A may correspond to the remaining areas of the entire upper surface of the light guide plate except for the area where the light exit is shielded by the shielding layer 40.
  • the active area A / A refers to an effective area in which an image is substantially displayed on the liquid crystal display panel 100. In general, a portion of the light exit screen L / A is used as the active area A / A. .
  • the liquid crystal display generally has a larger size of the light exit screen L / A than the active area A / A, and typically has the active area A / A several mm on one side K1. For example, an area grown 0.3 mm corresponds to the light exit screen L / A.
  • the light guide plate body 10 is a thin plate or film member formed of a transparent resin material, the shape of which may be formed in a rectangular shape, and as a usable resin material, an acrylic resin such as polymethyl methacrylate (PMMA) is typically used.
  • PMMA polymethyl methacrylate
  • polycarbonate resin, styrene resin, olefin resin, polyester resin, etc. can be used besides this.
  • the light guide plate body 10 may have light scattering patterns 11 and 13 formed on at least one surface to supply a uniform surface light source.
  • the light scattering patterns 11 and 13 may be formed in an embossed pattern such as a dot / round-prism / triangular-prism pattern / lenticular pattern or in an intaglio pattern such as a U cut / V cut / lenticular pattern. .
  • the light scattering patterns 11 and 13 may be provided for light scattering and may be integrally formed on the light guide plate body 10, and may be formed by a direct processing method, an etching method, a laser processing method, or a sand blasting method.
  • the light scattering patterns 11 and 13 are configured to have a structure in which the spacing between neighboring intaglios (or reliefs) decreases toward the central portion C1 and is gradually densely arranged. In other words, as the distance from the light source unit 130 increases, the gap becomes dense.
  • the light source portions 130 are provided at both sides of the light guide plate body 10, and the left light scattering pattern 11 based on the central portion C1 is the first array as shown in FIG. 3.
  • the pattern spacing gradually becomes denser as it faces from the 20 to the center portion C1, and the pattern spacing gradually becomes denser as the other light scattering pattern 13 faces the center portion C1 from the second array 22, so that the light guide plate body 10 In the center of the c).
  • the light scattering pattern may be configured to gradually increase the size of the embossed (or intaglio pattern) toward the central portion (C1) of the light guide plate body 10.
  • the light incident part is an area in which light emitted from the light source part 130 is incident, and is formed in one side part (lower side part in FIG. 2) of the light guide plate body 10 to receive light emitted from the first array 20.
  • the first light incident part 31 and the second light incident part 32 formed on the other side part of the light guide plate main body 10 (upper side part in FIG. 2) to which light emitted from the second array 22 is incident are formed.
  • the "lower side part” refers to one side edge portion of the light guide plate body 10
  • the "upper side part” refers to the opposite edge portion of the "lower side portion”.
  • the first light incidence part 31 and the second light incidence part 32 may be integrally formed on the light guide plate body 10, or may be separately molded to have a lens shape adjacent to or in contact with both sides of the light guide plate body 10. It can also be configured.
  • serration patterns in the form of saw teeth are formed on the light incident surface 35 of the first light incident portion 31 and the light incident surface 37 of the second light incident portion 32.
  • the serration pattern increases the angle at which light enters and widens the scattering range.
  • FIG. 6 is a cross-sectional view showing a serration pattern according to the present invention. Referring to Figure 6 will be described in detail with respect to the features of the serration (Serration) pattern of the present invention.
  • the serration patterns are provided on the light receiving surfaces 35 and 37, the light radiated radially from the light source unit 130 is incident on the light guide plate 145, and is then refracted and diffused while passing through the serration pattern SP. Will be minimized.
  • the serration pattern SP may be formed in a sawtooth shape or a semicircular cross-sectional shape along the length direction of the light incident surface.
  • the optical length of the backlight unit is reduced to less than 3.2 mm, the light emitted from the light source unit 130 is not diffused in the light guide plate body 10 and the front surface of the BLU screen.
  • the phenomenon to be irradiated that is, a hot spot phenomenon occurs.
  • the optical length of the backlight unit is a distance L1 between the light emitting screen L / A of the light guide plate body 10 and the light emitting elements 21 and 23 of the light source unit 130 as shown in FIG. 4. L2).
  • the optical lengths L1 and L2 are the distances from the ends of the light emitting elements 21 and 23 (that is, the light emitting element portions in contact with the light receiving surfaces 35 and 37) to one end of the shielding layer 40. It may be defined as.
  • the shielding layer 40 refers to a portion located in the vertical upper portion of the light guide plate body 10 of the bezel (Bezel) region, the "one end of the shielding layer 40" is such a shielding layer 40 ) Means the lengthwise end.
  • a light source is installed only on one side of the light guide plate, and accordingly, a bezel region of about 5.5 mm is formed.
  • a light emitting device having a capacity corresponding thereto should be configured.
  • a bezel of about 5.5 mm may be used. Area is required.
  • an optical length of 3.2 mm or more was provided along with this. This is because, according to the conventional backlight unit structure, when the optical length is less than 3.2 mm, a hot spot phenomenon is strongly generated and the display performance is drastically degraded.
  • the light source unit 130 is divided into two (that is, the first and second arrays), and each of the two light source units 130 is one on each side of the light guide plate unit 145. It is made of a structure that is installed. Accordingly, the first array 20 may be configured as a light emitting device having a smaller capacity than the conventional light source, thereby reducing the bezel area to a value smaller than that of the conventional 5.5 mm, and specifically, a bezel area of about 3.0 mm. It can be configured to have. In addition to the bezel region of about 3.0 mm, the optical lengths L1 and L2 may also be smaller than the conventional values, that is, less than 3.2 mm.
  • the present inventors set the pitch P1 of the serration pattern SP. When it is reduced below the threshold and the inclination angle of the serration pattern SP is formed within a predetermined angle range, it has been found that the hot spot phenomenon due to the reduction of the optical lengths L1 and L2 can be improved.
  • the optical length of the backlight unit 140 that is, the light exit screen L / A of the light guide plate main body 10 may be defined by the light source unit structure which is separated into two conditions and a condition to be described below of the serration pattern SP.
  • the separation distance L1 between the light emitting devices of the first array 20 may be less than 3.2 mm, and may be reduced to a maximum of 1.35 mm.
  • the separation distance L2 between the light emitting screen L / A of the light guide plate body 10 and the light emitting devices of the second array 22 may also be reduced to a range of 3.2 mm to 1.35 mm.
  • the first light incident portion 31 and the second light incident portion 32 of the present invention are respectively applied to the corresponding light incident surfaces (35, 37) A serration pattern that satisfies the condition is formed.
  • the pitch P1 of the teeth is formed to be 0.06 mm or less, and the angle ⁇ 1 between the neighboring teeth is 85 ° to 95 °.
  • the "pitch pitch P1 of the teeth” means the maximum width of one tooth, which may also be expressed as the distance between the center of the first tooth and the center of the second tooth immediately adjacent thereto.
  • the "interval between teeth ( ⁇ 1)” means an angle between a pair of teeth adjacent to each other. Accordingly, when the angle ⁇ 1 between the teeth is formed at 90 °, one tooth is configured to have an upwardly inclined surface of 45 °.
  • FIG. 8 is experimental data showing a hot spot phenomenon for each pitch of the serration pattern SP when the aforementioned optical lengths L1 and L2 are formed to be less than 3.2 mm (1.35 mm in FIG. 8), and FIGS. 9A and 9B. Is a comparison graph showing the relative magnitudes of the hot spots for each pitch of FIG. 8.
  • the angle ⁇ 1 of the liver is formed at 90 °.
  • the inventors of the present invention make the tooth pitch P1 of the serration pattern SP less than 0.1 mm (that is, 0,08 mm) even when the optical lengths L1 and L2 are configured to be 1.35 mm, which is considerably smaller than the conventional 3.2 mm.
  • the hot spot phenomenon is slightly improved (see Fig. 8 (c)), and in particular, when formed at 0.06 mm or less (preferably 0.04 mm or less), the hot spot value is reduced to the level required for a conventional liquid crystal display. And it was found.
  • the hot spot value starts to drop sharply, most preferably.
  • the hot spot phenomenon is drastically improved as shown in FIG. 8 (e), thereby satisfying the normal display performance required for the liquid crystal display device.
  • the backlight unit 140 by separating the light source unit into two, the size of the lower bezel of the display device can be further reduced, and in particular, the optical length ( Even if L1 and L2 are also reduced, the above-described serration pattern (SP) structure can improve the hot spot value to a level suitable for a normal display device.
  • SP serration pattern
  • the backlight unit 140 of the present invention is configured such that the first array 20 and the second array 22 can be controlled to be turned on independently of each other, and the driving region is at least an upper region and a lower region of the light guide plate body 10. It is characterized by being divided.
  • the first array 20 is composed of N light emitting elements, and the N light emitting elements are grouped by M units, and N / M (where N ⁇ M, where N / M is a natural number) first A unit light emitter is formed, and each of the N / M first unit light emitters is configured so that its lighting and light amount are individually controlled.
  • the second array 22 is composed of N 'light emitting elements, and N' light emitting elements are grouped by M 'units, and N' / M '(where N' ⁇ M' and N '/ M' Natural unit) second unit light emitters, and the N '/ M' second unit light emitters are configured so that their lighting and light amount are individually controlled.
  • the lower region of the light guide plate body 10 of the backlight unit 140 is divided into N / M driving regions (ie, lighting regions) by N / M first unit emitters, and the upper region is N '.
  • the driving area i.e., the lighting area
  • / M '' drive area hereinafter, referred to as 'unit drive area').
  • the N / M first unit emitters and the N '/ M' second unit emitters have a predetermined luminance determined according to a value of current / voltage applied to each unit emitter, and local dimming is performed based on the values. It is composed.
  • the light source unit 130 of FIG. 7 includes a first array 20 of 12 (N) light emitting devices and a second array 22 of 12 (N ′) light emitting devices.
  • the first array 20 is configured to have a first unit emitter composed of a total of 4 (N / M) and grouped into 3 (M) units
  • the second array 22 is grouped into 3 (M ') units. It was configured to have a second unit light-emitting body consisting of a total of 4 (N '/ M').
  • the driving area of the display screen (that is, the light guide plate body 10) is largely divided into an upper area controlled by the first array 20 and a lower area controlled by the second array 22.
  • the lower region is divided into four unit driving regions (1 to 4 of FIG. 7) in detail
  • the upper region is divided into four unit driving regions (5 to 8 of FIG. 7) in detail.
  • the driving (ie, lighting and luminance) of the first unit driving region 1 is controlled by the first unit light emitting body including a plurality of '21a' light emitting elements, and the second unit driving region 2 ) Is driven by the first unit light emitting body consisting of a plurality of '21b' light emitting devices (ie, lighting and luminance), and the third unit driving region 3 is the first unit consisting of a plurality of '21c' light emitting devices.
  • the driving (i.e., lighting and luminance) is controlled by the unit light emitting body, and the fourth unit driving region (4) is driving (i.e., lighting and luminance) by the first unit light emitting body composed of a plurality of '21d' light emitting elements. This is controlled.
  • the driving of the fifth unit driving area 5 is controlled by a second unit light emitting body including a plurality of '23a' light emitting devices (that is, lighting and luminance), and the sixth unit driving area 6 includes a plurality of driving units.
  • Its driving i.e., lighting and luminance
  • the seventh unit driving region 7 is controlled by the second unit light-emitting body made up of the plurality of '23c' light emitting devices
  • the driving i.e., lighting and luminance
  • the driving i.e., lighting and luminance
  • the driving is controlled in the eighth unit driving region (8) by a second unit light emitting body composed of a plurality of '23d' light emitting elements.
  • the backlight unit 140 of the present invention analyzes an image signal in a program to control brightness of a certain portion of the screen and compares and calculates the cell light amount in each unit driving region, and calculates the light amount in each unit driving region. It is configured to finally convert the screen dimming by converting the power value applied to the light emitter.
  • the LCD is configured to compare and calculate brightness values for each unit driving region divided into a plurality, as illustrated in FIGS. 7 and 10.
  • the brightness value may be calculated as a relative ratio (%) with respect to the maximum brightness (that is, the maximum amount of light) of the light emitting device.
  • the right display area is displayed as a screen having normal brightness, and the brightness value is calculated as '100%'.
  • the left display area is displayed as a darker screen than the right display area.
  • the brightness value is less than the maximum light amount (eg, 20%).
  • the brightness value of '100%' means that the unit light emitter, that is, the light emitting device is turned on at the maximum amount of light.
  • each display area ie, the unit driving area
  • the brightness value of each display area may be calculated by analyzing an image data signal by an image analyzer
  • the image analyzer may be provided in a controller
  • the controller may be a CPU or MCU. Can be configured.
  • the backlight unit 140 is controlled to calculate the power value to be applied to each unit light emitter.
  • the brightness values are compared and calculated for each unit driving region.
  • the unit driving regions corresponding to 3, 4, 7, and 8 of FIG. The value is 100%, and the unit driving area corresponding to 1, 2, 5, and 6 may have a brightness value of 20%.
  • the brightness value of each unit driving region calculated as described above is converted into a power value of the corresponding unit driving region.
  • the "power value of the unit driving region” means a power value to be applied to the unit light emitting body in charge of the corresponding unit driving region in order to implement the brightness value calculated through image data analysis.
  • the controller is configured to implement local dimming by individually controlling each unit light emitter according to the power value.
  • the maximum power for the maximum amount of light (ie, 100% of the brightness value) of the unit light emitter may be defined as 0.21 mW (10.5v, 20mA), in which case, 3 0.21mW of power is supplied to each unit illuminant in the unit driving regions of 4, 7, and 8, and 0.042 (0.21mW ⁇ 20%) to each unit illuminant in the unit driving regions of 1, 2, 5 and 6.
  • 0.21 mW (10.5v, 20mA)
  • 3 0.21mW of power is supplied to each unit illuminant in the unit driving regions of 4, 7, and 8, and 0.042 (0.21mW ⁇ 20%) to each unit illuminant in the unit driving regions of 1, 2, 5 and 6.
  • the backlight unit of the present invention is uniform in the amount of light in a direction away from the light source due to the gradation effect caused by the change in the amount of light, especially when performing partial dimming (e.g., dividing dimming) in which only some of the unit emitters are turned on and other units are not lit.
  • partial dimming e.g., dividing dimming
  • the problem of deterioration may occur.
  • the backlight unit of the present invention is configured so that the opposite unit light emitter opposite to the light unit light emitter also emits weak light to compensate for the change in the amount of light of the light unit light emitter.
  • the controller of the backlight unit includes a unit driving region corresponding to the brightness value '0' (hereinafter, referred to as a 'black region') among brightness values calculated by analyzing brightness values of unit driving regions of the input image data.
  • a unit driving region corresponding to the brightness value '0'
  • the unit light emitter may be defined as follows. Configured to control.
  • control unit when the condition is satisfied, is configured to apply power for turning on the first light amount to the first unit light emitter (or the second unit light emitter) in charge of the lighting area, and to display the second unit light emitter in charge of the black area ( Alternatively, the first unit light emitter controls to apply power for turning on the second light amount less than the first light amount.
  • the brightness value of the image corresponding to the second unit driving region 2 is '0' (that is, a black image) and is positioned on the vertical upper portion of the second unit driving region 2.
  • the brightness value of the image corresponding to the 6 unit driving region 6 is '100' (that is, the display image).
  • the second unit light emitter 23b that is in charge of the sixth unit driving area 6 is supplied with power for the first light amount corresponding to the brightness value '100', and is in charge of the second unit driving area 2.
  • the first unit light emitter 21b is applied with power so as to emit less light than the first light amount.
  • the unit illuminant in charge of the unit driving region corresponding to the black image is also controlled to be lit with a relatively small amount of light, thereby correcting light quantity non-uniformity due to lighting of some screens. I can do it.
  • FIG. 11 is a view schematically showing an embodiment of a backlight unit according to the present invention.
  • a backlight unit according to the present invention includes a light guide plate body 10, a light source unit including a first array 20 and a second array 22, a driver 60, and a controller ( 70).
  • the light guide plate body 10 is divided into a plurality of unit driving regions.
  • the unit driving regions are divided into a total of eight unit driving regions 1 to 8, but the number of unit driving regions may be adjusted as necessary.
  • the light source unit includes a first array 20 and a second array 22, and each of the first array 20 and the second array 22 includes a plurality of unit light emitters 20a to 20d and 22a to 22d, respectively. Include.
  • the light source unit includes a first array 20 and a second array 22, and the first array 20 includes four first unit emitters 20a, 20b, 20c, and 20d. Each of the first unit light emitters 20a, 20b, 20c, and 20d includes a plurality of light emitting devices.
  • the second array 22 includes four second unit emitters 22a, 22b, 22c, and 22d, and each of the second unit emitters 22a, 22b, 22c, and 22d includes a plurality of light emitting devices. .
  • the first unit light emitter and the second unit light emitter correspond to the plurality of unit driving regions in one-to-one correspondence.
  • the driver 60 controls the brightness of each of the first unit light emitters 20a, 20b, 20c and 20d and the second unit light emitters 22a, 22b, 22c and 22d.
  • the driver 60 supplies power to each of the first unit light emitters 20a, 20b, 20c, and 20d and the second unit light emitters 22a, 22b, 22c, and 22d according to the control signal received from the controller 70. Adjust the brightness of each unit illuminant.
  • the controller 70 includes a receiver, an analyzer, and a signal generator.
  • the receiver receives an image data signal to be displayed on the display unit.
  • the analysis unit analyzes the image data signal by frame unit for each unit driving region (1 to 8), compares the luminance value of each pixel in the corresponding frame for each unit driving region (1 to 8), and compares the luminance of the pixel having the highest luminance.
  • the position and the luminance value of the pixel are calculated as the reference value of the unit driving area.
  • the reference value may be represented by an X, Y coordinate value and a luminance value of the pixel.
  • the right two unit driving regions 4 and 8 are unlit regions, and the luminance values of the pixels (x4 and y4) of the first unit driving region 1 in the lower row are the brightest at 100.
  • the signal generator generates a control signal through reference values for each unit driving area (1 ⁇ 8).
  • the control signal can be generated by directly using the reference value of each unit driving region. That is, control to adjust the power applied to the first unit light emitters 20a, 20b, 20c, and 20d and the second unit light emitters 22a, 22b, 22c, and 22d so that the pixel of the reference value has a corresponding luminance value. You can generate a signal.
  • a signal generator including a memory unit, a reference region selector, a first control signal generator, and a second control signal generator may be used to generate a control signal in the following manner. It may be.
  • luminance of each position of the light guide plate main body 10 is applied to each unit light emitter. Measure or simulate by varying the amount of power applied.
  • the measurement or simulation information is stored in a memory unit or in a table in the form of a contour graph as shown in FIG. 13.
  • the unit driving region of the light guide plate body 10 is brightened. Referring to FIGS. 11 and 13, when the first unit light emitter 20a at the lower left is driven, the lower left near the first unit light emitter 20a is the brightest and becomes darker as it is farther away.
  • the reference region selector sets one of the plurality of unit driving regions 1 to 8 as the reference unit driving region.
  • the controller generates a control signal of the corresponding unit light emitter according to the reference value of the unit driving region analyzed by the analyzer.
  • the first control signal generator generates the first or second unit light emitter control signal so that the pixel having the highest luminance in the reference unit driving region has the corresponding luminance value.
  • a unit driving region including a pixel having the largest luminance value may be selected.
  • the second control signal generator generates a control signal of the first or second unit light emitter corresponding to the unit driving regions disposed around the reference unit driving region.
  • the second control signal generator subtracts the luminance value of the corresponding pixel due to the light emission of the unit emitter corresponding to the reference unit driving region from the luminance value of the pixel having the highest luminance of the unit driving region around the reference unit driving region.
  • the control signal for driving the first or second unit light emitting body corresponding to the corresponding unit driving region is generated based on the difference by the subtraction, that is, the remaining value.
  • the luminance applied to the (x1, y1) pixel by driving the second unit light emitter 22a corresponding to the unit driving region (5) in the upper left corner is sufficient to drive the second unit light emitter 22a so that is approximately 20.
  • the (x5, y5) pixels which are the reference pixels of the unit driving region 2 adjacent to the right side of the reference unit driving region 1, have a luminance of about 65 by turning on the reference unit driving region 1, the luminance It has a brightness over 30 which is the reference value of.
  • control signals of the first or second unit light emitters corresponding to the unit driving regions spaced one space from the reference unit driving region may be generated in the same manner.
  • the control signal is generated in consideration of the luminance value caused by the lighting of the adjacent unit driving region instead of the reference unit driving region.
  • the pixel of the reference unit driving region may be brightened by the lighting of the peripheral unit driving region.
  • the backlight unit of the present invention may cause a problem that the light quantity uniformity may be lowered due to the gradation effect caused by the light quantity change, particularly when dividing dimming is performed in which only some unit light emitters are turned on and other unit light emitters are not lit. .
  • the backlight unit of the present invention is configured such that the opposite unit light emitter facing the light unit light emitter also lights up a relatively small amount of light so as to correct luminance uniformity for image display.
  • the backlight unit of the present invention is configured to control as follows.
  • the backlight unit of the present invention is applied to the unit light emitter in charge of the lighting area for the first light amount is turned on, the unit light emitter in charge of the black area is less than the first light amount It is controlled so that electric power for turning on the second light amount is applied.

Landscapes

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

Abstract

La présente invention concerne une unité de rétro-éclairage et un appareil d'affichage à cristaux liquides comportant ladite unité de rétro-éclairage. L'unité de rétro-éclairage peut réaliser une gradation locale plus subdivisée et précise par rapport à l'état de la technique, et peut en outre améliorer la consommation d'énergie, la luminance, la visibilité, un rapport de contraste ou similaire(s) par rapport à l'état de la technique. L'unité de rétro-éclairage, selon la présente invention, comprend : une partie de source de lumière; et une partie de plaque de guidage de lumière sur laquelle la lumière est incidente à partir de la partie de source de lumière. La partie de plaque de guidage de lumière comprend : un corps principal de plaque de guidage de lumière; une première partie d'incidence de lumière qui est formée sur une partie de surface latérale du corps principal de plaque de guidage de lumière et sur laquelle la lumière est incidente; et une seconde partie d'incidence de lumière qui est formée sur l'autre partie de surface latérale du corps principal de plaque de guidage de lumière et sur laquelle la lumière est incidente. La partie de source de lumière est caractérisée en ce qu'elle comporte un premier réseau composé d'une pluralité de dispositifs émetteurs de lumière et disposé sur le côté de la première partie d'incidence de lumière, et un second réseau composé d'une autre pluralité de dispositifs émetteurs de lumière et disposé sur le côté de la seconde partie d'incidence de lumière.
PCT/KR2016/014025 2016-07-20 2016-12-01 Unité de rétro-éclairage et appareil d'affichage à cristaux liquides comportant ladite unité de rétro-éclairage, et procédé de gradation de l'unité de rétro-éclairage WO2018016691A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR10-2016-0092069 2016-07-20
KR1020160092069A KR101851937B1 (ko) 2016-07-20 2016-07-20 백라이트 장치 및 백라이트 장치의 디밍 방법
KR1020160101040A KR20180018867A (ko) 2016-08-09 2016-08-09 백라이트 유닛 및 이를 구비하는 액정 표시 장치
KR10-2016-0101040 2016-08-09

Publications (1)

Publication Number Publication Date
WO2018016691A1 true WO2018016691A1 (fr) 2018-01-25

Family

ID=60993165

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2016/014025 WO2018016691A1 (fr) 2016-07-20 2016-12-01 Unité de rétro-éclairage et appareil d'affichage à cristaux liquides comportant ladite unité de rétro-éclairage, et procédé de gradation de l'unité de rétro-éclairage

Country Status (1)

Country Link
WO (1) WO2018016691A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108363241A (zh) * 2018-02-12 2018-08-03 深圳创维－Rgb电子有限公司 一种背光模组及具有该背光模组的液晶显示器
CN109188778A (zh) * 2018-10-31 2019-01-11 京东方科技集团股份有限公司 背光模组、显示装置及其驱动方法
CN109545090A (zh) * 2018-12-29 2019-03-29 联想(北京)有限公司 显示屏及电子设备

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20110015921A (ko) * 2009-08-10 2011-02-17 엘지디스플레이 주식회사 백라이트 유닛과 이를 이용한 액정표시장치
KR20120106309A (ko) * 2011-03-18 2012-09-26 (주)켐리치 광고 간판 장치용 배광 유닛의 도광판 제조 방법
JP2013127966A (ja) * 2011-12-16 2013-06-27 Chi Mei Corp 導光板及びこれを用いたエッジライト型バックライト
KR20140075322A (ko) * 2012-12-11 2014-06-19 엘지디스플레이 주식회사 백라이트 유닛 및 이를 이용한 액정 표시 장치
KR20150026414A (ko) * 2013-09-03 2015-03-11 엘지전자 주식회사 액정표시장치와 그 구동방법

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20110015921A (ko) * 2009-08-10 2011-02-17 엘지디스플레이 주식회사 백라이트 유닛과 이를 이용한 액정표시장치
KR20120106309A (ko) * 2011-03-18 2012-09-26 (주)켐리치 광고 간판 장치용 배광 유닛의 도광판 제조 방법
JP2013127966A (ja) * 2011-12-16 2013-06-27 Chi Mei Corp 導光板及びこれを用いたエッジライト型バックライト
KR20140075322A (ko) * 2012-12-11 2014-06-19 엘지디스플레이 주식회사 백라이트 유닛 및 이를 이용한 액정 표시 장치
KR20150026414A (ko) * 2013-09-03 2015-03-11 엘지전자 주식회사 액정표시장치와 그 구동방법

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108363241A (zh) * 2018-02-12 2018-08-03 深圳创维－Rgb电子有限公司 一种背光模组及具有该背光模组的液晶显示器
CN108363241B (zh) * 2018-02-12 2021-06-29 深圳创维－Rgb电子有限公司 一种背光模组及具有该背光模组的液晶显示器
CN109188778A (zh) * 2018-10-31 2019-01-11 京东方科技集团股份有限公司 背光模组、显示装置及其驱动方法
CN109545090A (zh) * 2018-12-29 2019-03-29 联想(北京)有限公司 显示屏及电子设备
US11129285B2 (en) 2018-12-29 2021-09-21 Lenovo (Beijing) Co., Ltd. Display and electronic device

Similar Documents

Publication Publication Date Title
WO2010147293A1 (fr) Dispositif d'affichage
WO2010140749A1 (fr) Unité de rétroéclairage à del et dispositif d'affichage
US7898613B2 (en) Backlight unit and liquid crystal display device comprising light guide panel having prism patterns
KR101287636B1 (ko) 백라이트 유닛 및 이를 구비한 액정표시장치
WO2011025114A1 (fr) Afficheur
CN101858532B (zh) 背光单元及使用该背光单元的液晶显示器
US8089582B2 (en) Liquid crystal display device comprising at least one groove having an end portion that stops short of the non-adjacent opposite side surfaces and extends in a direction perpendicular to the non-adjacent side surfaces
KR100964467B1 (ko) 디스플레이 장치
WO2011025175A2 (fr) Unité de rétroéclairage et dispositif d'affichage
WO2013055020A1 (fr) Ensemble optique, unité de retro-éclairage équipée de celui-ci et appareil d'affichage associé
WO2011115351A1 (fr) Unité de rétroéclairage et appareil d'affichage la comportant
WO2011048830A1 (fr) Dispositif de rétro-éclairage, appareil d'affichage d'images comprenant celui-ci, et procédé de contrôle
WO2011013885A1 (fr) Unité de rétroéclairage et appareil d'affichage la comprenant
WO2018016691A1 (fr) Unité de rétro-éclairage et appareil d'affichage à cristaux liquides comportant ladite unité de rétro-éclairage, et procédé de gradation de l'unité de rétro-éclairage
WO2010147294A1 (fr) Dispositif d'affichage
WO2011013889A1 (fr) Unité de rétroéclairage et appareil d'affichage la comprenant
JP2018081145A (ja) 表示装置及び照明装置
WO2013129882A1 (fr) Plaque de guide de lumière et unité de rétroéclairage
JP2021144790A (ja) 照明装置および表示装置
US8199281B2 (en) Backlight of liquid crystal display device
Käläntär et al. Spatio‐temporal scanning backlight mode for field‐sequential‐color optically‐compensated‐bend liquid‐crystal display
KR20140068291A (ko) 양면 표시 장치 및 앙면 표시 장치의 구동 방법
WO2021141193A1 (fr) Dispositif d'affichage
WO2023195642A1 (fr) Appareil d'affichage et procédé de commande associé
KR101560400B1 (ko) 에지형 백라이트 유닛 및 이를 구비한 액정표시장치

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: 16909606

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16909606

Country of ref document: EP

Kind code of ref document: A1