TW202215128A - Integrated lcd backlight units with glass circuit boards - Google Patents

Abstract

Display devices are disclosed comprising a backlight unit, wherein the light sources illuminating the display panel, for example LEDs, are integrated into the light board assembly, and more specifically on the light board substrate. The light board substrate can be a glass circuit board.

Description

Integrated LCD backlight unit with glass circuit board

This application claims the benefit of priority under the patent law from US Provisional Application Serial No. 63/080,276, filed on September 18, 2020, which is hereby incorporated by reference in its entirety on the basis of the content of this application.

The present disclosure relates to a display device, in particular a display device including a backlight unit having a light source integrated on a glass circuit board.

TFT LCD displays are the most widespread type of flat panel display technology. In order to remain competitive with OLED displays and various emerging display technologies such as QD-OLED displays, micro-LED displays, etc., TFT LCD display technology continues to innovate, resulting in improved picture quality, including higher resolution and brightness, wider color domain, and aesthetics - narrow (or zero) borders and thin form factors. Recently, sub-millimeter LEDs (mini-LEDs) have attracted attention, especially in backlight applications, because they can achieve thin form factors by reducing OD (optical distance) and high contrast by increasing the number of dimming zones , HDR's high peak brightness, and a narrow or bezel-less design. With the rapid decline in the price of sub-millimeter LEDs, the overall cost is dominated by the surface mounting technology (SMT) process. As a result, manufacturers of IT displays (monitors, notebooks, etc.) and TVs are adopting direct-lit backlight units (BLUs) with sub-millimeter LEDs.

The advent of sub-millimeter LED adaptation in BLU modules requires new materials and stacking designs. The shorter OD and narrow pitch distance between LEDs eliminates the need for additional light dispersion for a second lens. At the same time, the diffuser plate requires higher thermal stability against the heat generated by the LEDs. Smaller bond pads for sub-millimeter LEDs and higher SMT device positioning accuracy require high pattern accuracy for LED circuit boards down to <20 microns (μm) compared to about 50 microns (μm) for conventional PCBs.

Liquid crystal displays are commonly used in various electronic devices such as cell phones, laptops, electronic tablets, televisions, and computer monitors. Liquid crystal displays are light valve based displays in which the display panel contains an array of individually addressable light valves. Liquid crystal displays can include a backlight for generating light, which can then be wavelength converted, filtered, and/or polarized to generate images from the LCD panel. The backlight can be edge-lit or direct-lit. Edge-lit backlights may include an array of light emitting diodes (LEDs) edge-coupled to a light guide plate that emits light from its surface. A direct-lit backlight may include an array of two-dimensional (2D) LEDs behind the LCD panel.

Recently, glass has been used for hybrid glass and/or plastic diffusers in advanced ultra-narrow bezel TFT-LCD TVs. By using glass materials for multiple layers and/or functions (such as glass circuit boards and glass diffusers or light guides) or by integrating the functions of multiple layers into a single glass sheet, improved mechanical properties compared to polymer materials can be achieved properties and/or reduced thickness. Such an integrated glass circuit board is expected to eliminate one or more layers in the BLU design and may provide additional cost reduction opportunities.

Accordingly, a display device including a display panel and a backlight unit disposed adjacent to the display panel is disclosed. The backlight unit includes a light plate assembly, including: a light plate substrate, including a first main surface facing the display panel and a second main surface opposite to the first main surface; a plurality of patterned reflectors disposed on the first main surface of the light plate substrate ; a conductive layer disposed above the second main surface; and a plurality of light sources disposed on the second main surface, the plurality of light sources being electrically connected to the conductive layer. The conductive layer may include, for example, a plurality of electrical traces that provide electrical power to the light source.

The display device may further include a reflective layer disposed over the conductive layer. The reflective layer may include a polymer layer, for example, an epoxy layer.

The display device may include a reflective layer disposed between the light plate substrate and the conductive layer. The reflective layer may be a metal layer. In some embodiments, the display device may include an adhesive layer disposed between the optical panel substrate and the conductive layer. The adhesion layer may include metal, metal oxide or metal nitride. For example, in some embodiments, the adhesion layer may include titanium, chromium, zinc, or manganese.

In some embodiments, the display device may include a first reflective layer disposed above the conductive layer and a second reflective layer disposed between the light plate substrate and the conductive layer. The first reflective layer can include a polymer layer and the second reflective layer can include a metal layer, but in further embodiments, the first reflective layer can include a polymer layer and the second reflective layer can include a polymer layer or a dielectric layer.

In some embodiments, the display device may include a light extraction layer on the second major surface of the light panel substrate. For example, the light extraction layer can be disposed between the light plate substrate and the conductive layer.

In some embodiments, the plurality of light sources can be optically coupled to the light panel substrate by means of an optical adhesive.

In some embodiments, the plurality of light sources can be electrically connected to the conductive layer by wires.

In some embodiments, the conductive layer includes a raised electrical contact pad adjacent to each of the plurality of light sources, each light source being electrically connected to the raised electrical contact pad by a conductive bridge.

In some embodiments, the light plate substrate may include a plurality of cavities, and a plurality of light sources are disposed in the plurality of cavities.

In some embodiments, the light plate substrate includes glass.

Both the foregoing general description and the following detailed description present embodiments intended to provide an overview or framework for understanding the nature and nature of the embodiments disclosed herein.

The drawings illustrate various embodiments of the disclosure, and together with the description explain the principles and operation of the disclosure, and are incorporated in and constitute a part of this specification. Accordingly, unless expressly stated otherwise, the relative dimensions of the various regions, portions, substrates or other components shown in the drawings should not be assumed to be proportional to their actual relative dimensions.

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments described herein.

As used herein, the term "about" means that amounts, dimensions, formulations, parameters and other quantities and characteristics are not and need not be exact, but can be approximate and/or larger or smaller as desired, reflecting tolerances, Conversion factors, rounding, measurement errors, etc., and other factors known to those of ordinary skill in the art.

Ranges may be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another embodiment includes from one particular value and/or to another particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each range are meaningful with respect to and independent of the other endpoint.

Directional terms as used herein—eg, up, down, right, left, front, back, top, bottom—are made with reference to the drawings drawn only and are not intended to imply absolute orientation.

Unless expressly stated otherwise, any method described herein is in no way intended to be construed as requiring the steps of the method to be performed in a particular order, nor in any particular orientation, by any apparatus. Thus, when the method claim does not actually recite the order in which the steps of the method are to be followed, or when any apparatus claim does not actually recite the order or orientation of the individual components, or when the claims Where steps are not otherwise specified to be limited to a specific order, or when a specific order or orientation of components of an apparatus is not recited, no order or orientation is intended in any aspect in any way. This applies to any possible unexpressed grounds of interpretation, including: matters of logic regarding the arrangement of steps, the flow of operations, the order of parts, or the orientation of parts; simple meanings derived from grammatical organization or punctuation, and; The number or type of examples.

As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, unless the context clearly dictates otherwise, reference to "a" element includes aspects having two or more of such elements.

The words "exemplary," "example," or various forms thereof are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" or "exemplary" should not be construed as preferred or advantageous over other aspects or designs. Furthermore, the examples are provided for clarity and understanding only, and are not intended to limit or limit the disclosed subject matter or relevant portions of the present disclosure in any way. It will be appreciated that numerous additional or alternative examples of varying scope may be presented, but have been omitted for the sake of brevity.

As used herein, unless otherwise indicated, the terms "including" and "comprising" and variations thereof should be construed as synonymous and open ended. A list of elements following a transition word that includes or includes is a non-exclusive list, such that elements may be present in addition to the elements specifically described in the list.

As used herein, the terms "substantially," "substantially," and variations thereof are intended to indicate that the described feature is equal to or approximately equal to the value or description. For example, a "substantially planar" surface is intended to mean a planar or nearly planar surface. Again, "substantially" is intended to mean that two values are equal or approximately equal. In some embodiments, "substantially" may mean values that are within about 10% of each other, such as values that are within about 5% of each other, or values that are within about 2% of each other.

As used herein and unless otherwise indicated, the word "on" means immediately adjacent and does not necessarily mean touching. Thus, a first layer on the surface does not preclude the presence of an intermediate layer between the first layer and the surface.

FIG. 1 is a cross-sectional side view of an exemplary display device 10 according to an embodiment of the present disclosure. The display device 10 includes a display panel 12 , eg, a liquid crystal display (LCD) panel, and a backlight unit 14 arranged to illuminate the display panel 12 . That is, the backlight unit 14 is located behind the display panel 12 with respect to the viewer 16 of the display device 10 . The backlight unit 14 includes a light panel assembly 18 and may further include various light modifying films or layers disposed between the light panel assembly 18 and the display panel 12 . For example, in some embodiments, backlight unit 14 may include any of fluorine film 20, one or more brightness enhancement films 22, quantum dot layer 24, and/or diffusion layer 26 in any desired order one or more.

Turning now to FIG. 2 , the illustrated exemplary light panel assembly 18 includes a light panel substrate 28 including a first major surface 30 and a second major surface 32 opposite the first major surface 30 . The first major surface 30 is the forward facing surface. That is, the first major surface 30 faces the display panel 12 and the viewer 16 . The light plate substrate 28 may be a rigid substrate or a flexible substrate. The light plate substrate 28 may be a flat substrate or a curved substrate. The curved light panel substrate may have a radius of curvature of less than about 2000 mm, eg, less than about 1500 mm, less than about 1000 mm, less than about 500 mm, less than about 200 mm, or less than about 100 mm. In various embodiments, the first major surface 30 and the second major surface 32 may be parallel surfaces. The thickness of the light plate substrate 28 , for example, in a direction orthogonal to one or both of the first major surface 30 and the second major surface 32 , may range from about 100 micrometers (μm) to about one millimeter (mm). in the range.

The light plate substrate 28 may be a transparent substrate. As used herein, the term "transparent" means greater than about 70% internal light transmittance over a length of 500 millimeters in the visible region of the spectrum (about 420-750 nanometers) when measured by a spectrophotometer. Transmittance is the ratio of the intensity of incident light on a sample to the intensity of light passing through the sample. In certain embodiments, the light panel substrate 28 may have a light transmittance greater than about 50% in the ultraviolet (UV) region (about 100-400 nanometers) over a length of 500 millimeters. According to various embodiments, the light plate substrate 28 may comprise an optical transmittance of at least 95% over a path length of 50 millimeters for wavelengths ranging from about 450 nanometers to about 650 nanometers. The light plate substrate 28 may have an index of refraction ranging from about 1.3 to about 1.8. In various embodiments, the light panel substrate 28 may have a low degree of light attenuation (eg, due to absorption and/or scattering). For wavelengths ranging from about 420 to 750 nm, the light attenuation α of the light plate substrate 28 may be less than about 5 dB/meter.

The light plate substrate 28 may comprise a polymer material such as plastic (eg, polymethyl methacrylate (PMMA), methylmethacrylate styrene (MS), polydimethylsiloxane alkane (polydimethylsiloxane; PDMS), polycarbonate (PC)) or other similar materials. However, in further embodiments, the light plate substrate 28 may comprise a glass material, such as aluminosilicate glass, alkali metal aluminosilicate glass, borosilicate glass, alkali metal borosilicate glass, aluminoborosilicate glass Glass, alkali metal aluminoborosilicate glass, soda lime glass or other suitable glass. Non-limiting examples of commercially available glasses suitable for use as glazing substrates include EAGLE XG®, Lotus ^™ , Willow®, Iris ^™ and Gorilla® glasses from Corning Incorporated. In some embodiments, the light panel substrate 28 may be a laminate and include both one or more glass layers and one or more polymer layers in any arrangement.

The light panel assembly 18 includes a plurality of light sources 34 disposed on the second major surface 32 . Each light source 34 of the plurality of light sources may be an LED (eg, having a size greater than about 0.5 mm), a sub-millimeter LED (eg, having a size between about 0.1 mm and about 0.5 mm), a micro LED (eg, having a size of between about 0.1 mm and about 0.5 mm). size less than about 0.1 mm), organic LED (OLED), or any other suitable light source. Each light source 34 may emit light having wavelengths ranging from about 400 nanometers to about 750 nanometers. In other embodiments, each light source 34 may emit light with wavelengths shorter than 400 nanometers and/or longer than 750 nanometers.

The light source 34 may emit light having a Lambertian distribution pattern. However, in other embodiments, the light source 34 may emit light with an angular distribution other than the Lambertian distribution. For example, the angular distribution of light emitted from light source 34 may have a full width at half maximum of 90 degrees, 100 degrees, 110 degrees, 130 degrees, 140 degrees, 150 degrees, 160 degrees, greater than 160 degrees, or less than 90 degrees width half maximum) intensity. The angular distribution may have peak intensity along 0, 10, 20, 30, 40, 50, 60, 70, or 80 degrees, where the 0-degree direction corresponds to the normal direction of the light plate substrate 28 . The light sources 34 may be arranged over the second major surface 32 in any of a variety of array patterns. For example, in some embodiments, the light sources 34 may be arranged including a rectangular array of rows and columns of light sources. However, in further embodiments, the light sources 34 may be arranged in other geometric patterns, such as a hexagonal array.

The light panel assembly 18 further includes a conductive layer 36 disposed on or over the second major surface 32 . The conductive layer 36 need not be a continuous layer. For example, conductive layer 36 may include a plurality of electrical traces (conductors) disposed over second major surface 32 and configured to supply current to plurality of light sources 34 . In some embodiments, conductive layer 36 may include copper. However, in further embodiments, conductive layer 36 may comprise a material that is more reflective of light than copper, such as aluminum, gold, or silver.

As shown in FIG. 3 , in some embodiments, an adhesive layer 38 may be used between the conductive layer 36 and the second major surface 32 to facilitate adhesion between the conductive layer 36 and the second major surface 32 . For example, the adhesion layer 38 may include a metal layer such as a titanium, chromium or manganese layer, a metal oxide layer such as titanium oxide (eg TiOx) or zinc oxide (ZnO), or a metal nitride layer such as nitride Titanium (TiN).

In some embodiments, the light source 34 may be optically coupled to the light plate substrate 28 by an index matching optically clear adhesive (OCA) 40 such that the light source 34 is emitted into and through the light plate substrate 28 . Solder connections 42 may be provided to attach each light source 34 directly to the conductive layer 36 . In various embodiments, so-called bottom emitting light sources (eg, bottom emitting LEDs) may be used so that they may be flip-chip bonded (surface mounted by soldering) at the second major surface 32, eg, to a conductive Layer 36. Alternatively, a top emitting light source can be adapted according to the purpose.

In some embodiments, as shown in FIG. 4, the light source 34 may be mounted to the light panel substrate 28 by wire bonds 44, which may be used to route the drive current from the conductive layer 36 (eg, the solder joints 46 on the electrical traces). ) to the light sources, eg, to the contact pads 48 on each light source 34 . Although adhesive layer 38 is not shown in the embodiment of FIG. 4, adhesive layer 38 may be used if desired as indicated in FIG. 3 and as described above.

In yet other embodiments, as shown in FIG. 5 , raised contact pads 50 may be fabricated on conductive layer 36 . Printed conductive ink or jetted solder bridges 52 may then be used to contact the light source and deliver drive current from conductive layer 36 (eg, electrical traces) to light source 34 . Although adhesive layer 38 is not shown in the embodiment of Figure 5, adhesive layer 38 may be used if desired as indicated in Figure 3 and described above.

In yet other embodiments, as shown in FIG. 6 , the cavity 54 may be pre-machined (or pre-etched) in the light plate substrate 28 . Cavity 54 may be any suitable geometry required to accommodate light source 34 . For example, the cavity 54 may be rectangular or circular. The light source 34 , for example, a top emitting LED chip, can be embedded in the cavity, for example, by means of an index-matched optically clear adhesive 40 . Since light laterally emitted not only from the top surface of the light source (the surface facing the light source of the display panel 12 ) but also laterally from the side of the light source can be efficiently injected into the light plate substrate 28 , the light efficiency can be further improved. The light source 34 may be electrically connected to the conductive layer 36 via the bonding pads 56 . In addition, since the bottom surface of the light source 34 (the surface of the light source facing away from the display panel 12 where the bonding pad 56 is located) can be made substantially flush with the second main surface 32 of the light plate substrate 28 . Thus, implementing the electrical contact technique as depicted in FIG. 6 can be implemented without the need for raised contact pads. Although adhesive layer 38 is not shown in the embodiment of FIG. 6, adhesive layer 38 may be used if desired as indicated in FIG. 3 and described above.

In general, it is desirable for the second major surface 32 to be highly reflective to allow "reuse" of light from the optical film located above the glass light guide (between the light plate substrate 28 and the display panel 12). The relatively low spectral reflectance of copper typically used for electrical traces, especially at blue and green wavelengths, can negatively impact the overall light efficiency and color shift of the backlight. To improve light efficiency and color uniformity, highly reflective metals such as aluminum or silver can be selected as electrical traces. Alternatively, a thin layer of a more reflective material can be deposited between the optical panel substrate and the electrical traces to increase reflectivity. In some embodiments, the conductive traces are patterned with minimal gaps therebetween such that a substantial portion of the second major surface 32 is covered by metal to avoid significant loss of light efficiency when light is directed through the light panel substrate, which may Will suffice. For additional efficiency, a reflective film or coating can be added over the LEDs and/or electrical traces. Such a reflective coating can be a multilayer dielectric reflector, or a multilayer dielectric or metallic reflector, or in the simplest case a layer of highly reflective white ink or paint.

Thus, in some embodiments, for example, any one or more of the foregoing embodiments, the light plate assembly 18 may include a reflective layer 58 overlying the top of the conductive layer 36 . By way of example and not limitation, FIG. 7 depicts the embodiment of FIG. 2 including reflective layer 58 . The reflective layer 58 may be epoxy, such as epoxy solder mask material. In some embodiments, reflective layer 58 may include liquid photoimageable solder mask (LPSM or LPI) or dry film photoimageable solder mask (DFSM) or laminated dry film light Laminate dry film resist (DFR). Suitable reflective coating materials for reflective layer 58 and applied over conductive layer 36 (eg, electrical traces) can be other materials as long as they are highly reflective and can withstand subsequent chemical and thermal processes, such as acid etching and reflow (reflow) process. In an embodiment, the reflective layer 58 is not a conductive layer, thereby avoiding electrical shorts across electrical traces. Thus, the reflective layer 58 can coat the entire backside of the light panel substrate, including the light source 34 . In some embodiments, the reflective layer 58 may be white, eg, a white ink, eg, a white epoxy material.

As shown in FIG. 8 , in some embodiments, for example, any one or more of the foregoing embodiments, a reflective layer 60 may be disposed between the second major surface 32 and the conductive layer 36 . The reflective layer 60 may include a reflective metal, such as aluminum, gold, or silver, but in further embodiments, the reflective layer 60 may include a dielectric layer or an ink layer (eg, an epoxy layer). When measured by a spectrophotometer, the reflective layer 60 may exhibit a reflectivity of greater than 70%, for example, a reflectivity of greater than 80%, over a wavelength range from about 450 nanometers (nm) to about 700 nm, at The change in reflectivity in this wavelength range is not more than 10%. Reflectance is the ratio of the intensity of light incident on a surface to the intensity of light reflected from that surface. The reflective layer 60 may be applied to the optical panel substrate prior to metallization (eg, deposition of electrical traces). In the case of direct printing of electrical traces, a highly reflective white polymer material may be selected to facilitate adhesion, and/or catalytic inks may be used for subsequent electroless plating of the conductive layer. If the reflective layer 60 is a metal layer, the reflective layer 60 may be patterned together with the conductive layer 36 . That is, reflective layer 60 can be deposited, then conductive layer 36 can be deposited on top of reflective layer 60, and the combined reflective and conductive layers can then be patterned, such as by photolithography. Accordingly, reflective layer 60 may exhibit the same pattern as conductive layer 36 (eg, electrical traces), thereby minimizing the likelihood of the metal reflective layer creating shorts between electrical traces. On the other hand, this opens up the space between adjacent traces so that reflections in the open space are reduced. Thus, in other embodiments, as described above, the reflective layer 60 may be a non-conductive layer deposited prior to metallization. Care should be taken to ensure that the holes are created so that light from the light source 34 can be successfully injected into the light panel substrate 28 . For example, FIG. 9 is a bottom view of an exemplary light plate assembly 18 illustrating a plurality of apertures 62 positioned in a rectangular array of columns and rows to match a rectangular array of light sources (not shown), the apertures 62 extending through the reflector Layer 60. Therefore, the light source 34 is mounted to the light plate substrate 28 at the position coincident with the hole 62 .

In some embodiments, as shown in FIG. 10 , the light plate assembly may include a first reflective layer 58 over the top of the conductive layer 36 and a second reflective layer 60 between the conductive layer 36 and the second major surface 32 .

Turning now to FIG. 11 , in some embodiments, including any one or more of the foregoing embodiments, the light plate assembly 18 may include a light extraction layer 63 on the second major surface 32 . For example, by way of illustration and not limitation, FIG. 11 depicts the embodiment of FIG. 10 including a light extraction layer 63 disposed between conductive layer 36 and light plate substrate 28 . The light extraction layer 63 may include a plurality of reflective dots deposited on the second major surface 32 . In some embodiments, the light extraction layer 63 may be paint or ink, such as white paint or ink. For example, the reflective paint or ink can be deposited by screen printing, by ink jet printing, or by any other suitable deposition method known in the art. Alternatively or additionally, depending on the material of the photoplate substrate (eg, an etchable material such as silicate glass), the light extraction layer 63 may be an etched layer, wherein the top surface of the second major surface 32 is etched with a suitable etchant is etched to roughen the second surface and create a light scattering surface. Other methods of roughening the surface known in the art can be used. In various embodiments, the light extraction layer 63 may be located between the conductive layer 36 and the light plate substrate 28 , for example, between the reflective layer 60 and the light plate substrate 28 .

In some embodiments, including any one or more of the foregoing embodiments, the light plate assembly 18 may include a plurality of discrete patterned reflectors 64 deposited on the first major surface 30 of the light plate substrate 28 . In some embodiments, the patterned reflector 64 may be deposited directly on and in contact with the first major surface 30 . In some embodiments, the plurality of patterned reflectors 64 may be optically coupled to the first major surface 30 by an adhesive, while in other embodiments, the plurality of patterned reflectors 64 may be deposited directly on the first major surface 30, such as by printing on a major surface 30 . For example, the plurality of patterned reflectors 64 may include metal foils such as silver, platinum, gold, copper, etc.; dielectric materials (eg, polymers such as polytetrafluoroethylene (PTFE)); porous polymers materials, such as polyethylene terephthalate (PET), poly(methyl methacrylate) (PMMA), polyethylene naphthalate (polyethylene naphthalate) ( PEN), polyethersulfone (PES), etc.; multilayer dielectric interference coatings or reflective inks, including inks containing white inorganic particles such as titanium dioxide, barium sulfate, etc., or other methods suitable for reflecting light and tuning reflected and transmitted light Colored materials, such as color pigments.

As best seen in FIG. 12 , in some embodiments, each patterned reflector 64 may include a thickness profile that includes a substantially flat portion 66 and a curved portion 68 . That is, the curved portion 68 may represent the thickness variation of the patterned reflector. FIG. 12 depicts a portion of an exemplary light panel substrate 28 (portion A of FIG. 2 ) and depicts a single patterned reflector 64 with thickness variations deposited on the first major surface 30 . The substantially flat portion 66 may be more reflective than the curved portion 68 , and the curved portion 68 may be more transmissive than the substantially flat portion 66 . Each curved portion 68 may have properties that vary in a continuous, smooth manner with distance from the substantially flat portion 66 . In some embodiments, the patterned reflector 64 may include a plurality of discrete reflection points arranged in a predetermined pattern, while in other embodiments, the discrete reflection points may be randomly distributed. Each patterned reflector 64 may be circular, while in other embodiments, each patterned reflector 64 may have another suitable shape (eg, rectangular, hexagonal, etc.). A patterned reflector 64 fabricated directly on the first major surface 30 of the light panel substrate 28 diffusely reflects light back to the light source 34 and towards the side to be directed in the light panel substrate. Away from the light source location, the patterned reflector extracts light that is directed in the light panel substrate 28 . The patterned reflector 64 can hide the light source 34 from the viewer 16 of the display device 10 and can be fabricated directly on the first main surface 30 of the light plate substrate 28. The patterned reflector 64 can also be fabricated in the thickness direction of the backlight unit 14 (compared to the first main surface 30). one or both of the surface 30 or the second major surface 32 are orthogonal) to save space. As shown in FIG. 4 , the light panel assembly 18 may further include individual (discrete) reflective spots 70 disposed on the first major surface 30 of the light panel substrate 28 . Figure 13 is a top view of a light plate substrate 28 including a plurality of patterned reflectors 64 and randomly distributed reflective spots 70 deposited thereon in an array (eg, a rectangular array, a hexagonal array, etc.). Reflective spots 70 may be at least partially transmissive. The reflective spots 70 may exhibit uniform reflectivity. The reflective dots 70 may function as a light extraction layer.

Depending on the desired function, each patterned reflector 64 or discrete reflective dot 70 may be printed, for example, by printing with white ink, black ink, metallic ink, or other suitable ink (eg, ink jet printing, screen printing , micro-printing, etc.) pattern to form. Each patterned reflector 64 or discrete reflective spot 70 may also be formed by first depositing a continuous layer of white or metallic material, for example, by physical vapor deposition (PVD) or another coating Techniques such as, for example, slot coating or spray coating, and then patterning this layer by lithography or other known methods of regioselective material removal.

As shown in FIG. 14, in other embodiments, each patterned reflector 64 may include a first (central) solid portion 72, a plurality of second solid portions 74 surrounding the first solid portion 72, and a plurality of the same The second solid portion 74 is staggered with a plurality of opening portions 76 . Each second solid portion 74 and each open portion 76 may be annular, such as circular, oval, or another suitable shape. For example, in various embodiments, the second solid portion 74 and the open portion 76 may be annular and concentric with the first solid portion 72 .

The area ratio A(r) of each second solid portion 74 may be equal to As(r) / (As(r) + Ao(r)), where r is the distance from the center of the corresponding patterned reflector, and As( r) is the area of the corresponding second solid portion 74 and Ao(r) is the area of the corresponding open portion 76 . The area ratio A(r) of each second solid portion 74 decreases with the distance r, and the reduction rate decreases with the distance r.

The dimension (ie, width or diameter) of each first solid portion 72 as indicated at 80 (in a plane parallel to light panel substrate 28 ) may be greater than the dimension (ie, width or diameter) of each corresponding light source 34 . diameter). The dimension 80 of each first solid portion 72 may be less than the dimension of each corresponding light source 34 multiplied by a predetermined value. In certain exemplary embodiments, the predetermined value may be about two or about three when the size of each light source 34 is greater than or equal to about 0.5 millimeters, such that the size of each first solid portion 72 is smaller than the size of each light source 34 three times the size. When the size of each light source 34 is less than about 0.5 mm, the predetermined value may be determined by the alignment capability between the light source 34 and the patterned reflector 64 such that each first solid portion 72 of each patterned reflector 64 The dimensions are in the range between about 100 micrometers and about 300 micrometers larger than the dimensions of each light source 34 . Each first solid portion 72 is large enough so that each patterned reflector 64 can be aligned with the corresponding light source 34 and small enough to achieve suitable brightness uniformity and color uniformity.

As used herein, the terms "aligned" and variations used with respect to a light source and a patterned reflector mean that the patterned reflector is positioned above (coinciding with) a particular light source and positioned such that the center of the patterned reflector is located across the The line passing through the center of the light output distribution of the light source and normal to the surface of the light plate substrate (where the light source is coupled to (eg, deposited on) the surface of the light plate substrate). One or more patterned reflectors may be aligned with one or more light sources, one patterned reflector being aligned with one light source. Similarly, a patterned reflector that "corresponds" to a particular light source is a patterned reflector located above the particular light source.

The patterned reflector 64 can have both varying layer thickness and surface coverage, which can serve two different purposes. Directly above the light source, the pattern can suppress "hot spots" from the corresponding light source by diffusing the light back to the light source and towards the side to be directed in the light panel substrate. Away from the light source location, the pattern can be used to extract light that is directed in the light panel substrate. The overall function of the backlight unit is to make the brightness of the light emitted from the backlight unit toward the display panel uniform over the entire emitting surface of the backlight unit.

It will be apparent to those of ordinary skill in the art that various modifications and variations can be made in the embodiments of the present disclosure without departing from the spirit and scope of the disclosure. Accordingly, it is intended that this disclosure covers such modifications and variations as fall within the scope of the appended claims and their equivalents.

10: Display device 12: Display panel 14: Backlight unit 16: Viewer 18: Light board components 20: Pills film 22: Brightening film 24: Quantum Dot Layer 26: Diffusion layer 28: Light board substrate 30: First main surface 32: Second main surface 34: Light source 36: Conductive layer 38: Adhesive layer 40: Optically clear adhesive 42: Solder connection 44: Wire Bonding 46: Welding point 48: Contact pad 50: Raised Contact Pad 52: Printed conductive ink or jetted solder bridge 54: Cavity 56: Solder pad 58: Reflective layer 60: Reflective layer 62: Hole 63: Light extraction layer 64: Patterned reflector 66: Substantially flat part 68: Bend part 70: Reflection point 72: First (central) solid part 74: Second solid part 76: Opening part 80: Dimensions of the first solid part

Figure 1 is a cross-sectional side view (exploded view) of an exemplary display device;

2 is a cross-sectional side view of an embodiment of a light panel assembly according to the present disclosure;

FIG. 3 is a cross-sectional side view of another embodiment of the optical panel assembly according to the present disclosure, wherein the adhesive layer is disposed between the conductive layer and the optical panel substrate;

4 is a cross-sectional side view of an embodiment of a light panel assembly according to the present disclosure, wherein the light source is electrically connected to the conductive layer by wire bonds;

5 is a cross-sectional side view of an embodiment of a light plate assembly according to the present disclosure, wherein the conductive layer includes raised pads, and the light source is electrically connected to the raised pads;

FIG. 6 is a cross-sectional side view of an embodiment of a light panel assembly according to the present disclosure, wherein the light source is disposed in the cavity of the light panel substrate;

7 is a cross-sectional side view of an embodiment of an optical panel assembly according to the present disclosure, wherein the reflective layer is disposed over the conductive layer;

FIG. 8 is a cross-sectional side view of an embodiment of an optical panel assembly according to the present disclosure, wherein a reflective layer is disposed between the optical panel substrate and the conductive layer;

Figure 9 is a bottom view of an exemplary light plate assembly illustrating apertures in the reflective layer of Figure 8 that allow light to transmit from the plurality of light sources through the reflective layer;

FIG. 10 is a cross-sectional side view of an embodiment of an optical panel assembly according to the present disclosure, wherein the first reflective layer is disposed above the conductive layer, and the second reflective layer is disposed between the optical panel substrate and the conductive layer;

FIG. 11 is a cross-sectional side view of the embodiment of FIG. 10 and includes a light extraction layer disposed between the second reflective layer and the light plate substrate;

FIG. 12 is a cross-sectional side view of portion A of the optical panel substrate from FIG. 2 illustrating a patterned reflector disposed on the first major surface of the optical panel substrate;

FIG. 13 is a top view of an embodiment of a light panel assembly according to the present disclosure, illustrating an exemplary distribution of patterned reflectors; and

14 is a top view of another exemplary patterned reflector according to the present disclosure.

Domestic storage information (please note in the order of storage institution, date and number) none Foreign deposit information (please note in the order of deposit country, institution, date and number) none

18: Light board components

28: Light board substrate

30: First main surface

32: Second main surface

34: Light source

36: Conductive layer

40: Optically clear adhesive

42: Solder connection

64: Patterned reflector

66: Substantially flat part

68: Bend part

70: Reflection point

Claims (14)

A display device, comprising: a display panel; a backlight unit disposed adjacent to the display panel, the backlight unit comprising: A light board assembly, including: a light plate substrate including a first main surface facing the display panel and a second main surface opposite to the first main surface; a plurality of patterned reflectors disposed on the first main surface of the light plate substrate; a conductive layer disposed over the second main surface; and A plurality of light sources are disposed on the second main surface, and the plurality of light sources are electrically connected to the conductive layer. The display device of claim 1, further comprising a reflective layer disposed above the conductive layer. The display device of claim 2, wherein the reflective layer comprises a polymer layer. The display device of claim 3, wherein the reflective layer comprises an epoxy resin. The display device of claim 1, further comprising a reflective layer disposed between the light plate substrate and the conductive layer. The display device of claim 5, wherein the reflective layer comprises a metal layer. The display device of claim 1, further comprising a first reflective layer disposed above the conductive layer and a second reflective layer disposed between the light plate substrate and the conductive layer. The display device of claim 1, further comprising a light extraction layer on the second main surface of the light plate substrate. The display device of claim 1, wherein the plurality of light sources are optically coupled to the light plate substrate through an optical adhesive. The display device as claimed in claim 1, wherein the plurality of light sources are electrically connected to the conductive layer through leads. The display device of claim 1, wherein the conductive layer includes a raised electrical contact pad adjacent to each of the plurality of light sources, and each light source is electrically connected to the raised electrical contact by a conductive bridge pad. The display device according to claim 1, wherein the light plate substrate comprises a plurality of cavities, and the plurality of light sources are arranged in the plurality of cavities. The display device of claim 1, wherein the conductive layer includes a plurality of electrical traces. The display device of any one of claim 1 to claim 13, wherein the light plate substrate comprises glass.

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