JP2020532833A - Multi-layer reflector for direct backlight - Google Patents

Abstract

In close proximity to a substrate having a first main surface that emits light and a second main surface vice versa, at least one light source optically coupled to the substrate, and a first or second main surface of the substrate. A positioned reflector, the reflector having two or more layers of reflective material, each of which has a first zone and a second zone, the first zone thereof. A light guide assembly with a backlit unit with a reflector is disclosed herein which is more reflective than the second area and the second area is more transparent than the first area. There is.

Description

priority

This application is based on its content and is cited in its entirety here, with priority under US Code 35, Article 119 of US Provisional Patent Application No. 62/551491 filed on August 29, 2017. It claims the benefits of rights.

The present disclosure broadly relates to a backlight unit and a display device or illuminating device including such a backlight unit, and more particularly to a backlight unit including a patterned glass light guide plate and a pattern reflective layer.

Liquid crystal displays (LCDs) are commonly used in a variety of electronic devices such as mobile phones, laptop computers, electronic tablets, televisions, and computer monitors. The LCD may include a backlight unit (BLU) for producing light, which can then be transformed, filtered, and / or polarized to produce the desired image. The BLU may include edge illumination, eg, a light source coupled to the edge of a light guide plate (LGP), or rear illumination, eg, a two-dimensional array of light sources located behind an LCD panel.

An LCD can also be considered a light valve system display in which the display panel comprises a series of individually addressable light valves using a pair of polarizing plates and an electrically controlled liquid crystal layer. The BLU needs to generate a radiated image from the LCD. Due to the high efficiency and small size of modern light emitting diodes (LEDs), modern BLUs utilize LEDs. There are two types of BLU. The edge illumination BLU comprises a linear LED array coupled at an edge to a light guide plate (LGP) that emits light from its surface. The direct BLU comprises a 2D array of LEDs directly behind the LCD panel. Direct BLUs will have the advantage of improved dynamic contrast compared to edge-illuminated BLUs. For example, a display with a direct BLU can independently adjust the brightness of each LED in order to optimize the dynamic range of brightness over the image. This is commonly known as local dimming. However, in order to achieve the desired light uniformity and / or avoid hotspots in the direct BLU, the light source is positioned at some distance from the LGP and / or diffuse film and therefore the entire display. The thickness may be thicker than the thickness of the edge illumination BLU. Lenses positioned above the LED have also been proposed to improve the lateral diffusion of light in a direct BLU, but the optical distance between the LED and the diffuse film in such a configuration, eg, about. Even at distances of 15-20 mm, the overall thickness of the display becomes undesirably thick, and / or these assemblies can cause unwanted optical loss when the thickness of the BLU is reduced. The edge illumination BLU may be thinner, but the light from each LED can spread over a large area of the LGP so that turning off the individual LEDs or groups of LEDs has minimal effect on the dynamic contrast ratio. The direct type BLU, which can turn off the LED in the dark area of the screen, also has an advantage that the dynamic contrast can be improved by using 2D local dimming.

Therefore, it would be convenient to provide a thin BLU with improved local dimming efficiency without adversely affecting the uniformity of the light emitted by the BLU.

The present disclosure is a design and method for manufacturing a multilayer pattern reflector having two or more layers in various embodiments, each of which is a first zone and a second zone. With respect to the design and method, the first area is more reflective than the second area and the second area is more permeable than the first area.

The multi-layer pattern reflector diffuses the light of individual LED sources within the plane of the backlight by multiple reflections between the pattern reflector and the uniform backplane reflector, thereby illuminating with uniform brightness. Can be optimized for use in thin direct LCD backlights that work to provide LCD panels.

The method of manufacturing a multi-layer pattern reflector is to use reflective white paint or ink and apply the paint or ink to a suitable glass or plastic substrate by printing the multi-layer continuously using digital printing technology. Can include. The pattern reflector may have several layers that can be easily and inexpensively manufactured by printing with a highly reflective ink, each of which is patterned at a relatively low resolution. When such reflectors are used in direct backlights, they are smaller in thickness, have better light utilization efficiency, and have better brightness uniformity than prior art direct backlights that use variable reflectors. can do.

In an embodiment in which the pattern reflector is manufactured on the top surface of the light guide plate, the same printing process can be used to manufacture the light extraction features.

Additional features and advantages of this disclosure are set forth in the detailed description below, some of which will be readily apparent to those skilled in the art, or the detailed description below, claims, It will also be recognized by implementing methods such as those described herein, including the accompanying drawings.

Both the general description above and the detailed description below present various embodiments of the present disclosure and are intended to provide an overview or gist for understanding the nature and characteristics of the claims. You should understand that. The accompanying drawings are included to give a further understanding of the present disclosure and are included in the specification and constitute a part thereof. The drawings show various embodiments of the present disclosure and serve to explain the principles and operation of the present disclosure as well as the description.

The following detailed description can be further understood when read with the drawings below.

Explanatory drawing showing a light guide plate and a series of light sources optically coupled to the light guide plate. Explanatory diagram showing an exemplary pattern reflective layer according to a particular embodiment of the present disclosure. Cross-sectional views of an exemplary BLU according to various embodiments of the present disclosure. Cross-sectional views of an exemplary BLU according to various embodiments of the present disclosure. Explanatory drawing showing lateral diffusion of light in a light guide plate Explanatory drawing showing lateral diffusion of light in a light guide plate Graph plotting the light output efficiency of an exemplary BLU with a patterned reflective layer Graph plotting the light output efficiency of an exemplary BLU with a different patterned reflective layer Graph plotting the light output efficiency of an exemplary BLU with yet another patterned reflective layer A graph plotting the light output efficiency of an exemplary BLU with another pattern reflective layer Explanatory drawing showing a microstructure-patterned LGP according to an additional embodiment of the present disclosure. Explanatory drawing which shows the embodiment of a multilayer variable reflector according to some embodiments of the present disclosure. Explanatory drawing showing another embodiment of a multilayer variable reflector according to some embodiments of the present disclosure.

A first main surface that emits light, a second main surface opposite to it, and a light guide plate having a plurality of light extraction features; at least one light source optically coupled to the second main surface of the light guide plate; A rear reflector located close to the second main surface of the light guide plate; and a patterned reflective layer positioned close to the first main surface of the light guide plate, with at least one light reflecting component. A backlight unit including a pattern reflecting layer containing at least one light transmitting component is disclosed herein. Display and lighting devices, including such backlight units, are also disclosed herein.

Such as displays, lighting, and electronics, such as televisions, computers, phones, tablets, and other display panels, lighting fixtures, solid lighting, billboards, and other building elements, to name a few. Devices that include a good backlight are also disclosed herein.

Various embodiments of the present disclosure are discussed herein with reference to FIGS. 1-8B, which show exemplary components and embodiments of the backlight unit disclosed herein. The following general description is intended to give an overview of the apparatus described in the claims, and various aspects are discussed in more detail throughout the present disclosure with respect to the embodiments shown in a non-limiting manner. These embodiments are interchangeable within the context of the present disclosure.

FIG. 1 shows a top view of an exemplary light guide plate (LGP) 100 and a series of light sources 110 optically coupled to the LGP 100. For purposes of illustration, the light source 110 is visible through the LGP 100 of FIG. 1, but in some embodiments it may not. Alternative configurations including the positions, sizes, shapes, and / or spacing of different light sources are also intended to fall within the scope of the present disclosure. For example, the illustrated embodiment comprises a periodic or regular arrangement of light sources 110 having the same size, shape, and spacing, while other embodiments in which the arrangement is irregular or aperiodic are conceivable. Be done.

The LGP 100 may have any dimensions, such as length L and width W, which may vary depending on the display or lighting application. In some embodiments, the length L includes the entire range and a partial range in between, such as about 0.1 m to about 5 m, about 0.5 m to about 2.5 m, or about 1 m to about 2 m, and the like. , Can range from about 0.01 m to about 10 m. Similarly, the width W is from about 0.01 m, including the entire range and a partial range in between, such as about 0.1 m to about 5 m, about 0.5 m to about 2.5 m, or about 1 m to about 2 m. It can reach about 10 m. Each light source 110 in a series of light sources has a unit block (dotted line) with an associated unit length L ₀ and unit width W ₀ that may vary depending on the dimensions of the LGP 100 and the number and / or spacing of light sources 110 along the LGP 100. (Represented) may also be defined. In non-limiting embodiments, the unit width W ₀ and / or the unit length L ₀ includes the entire range and a partial range in between, from about 1 mm to about 120 mm, from about 5 mm to about 100 mm, from about 10 mm. It may be about 150 mm or less, ranging from about 80 mm, about 20 mm to about 70 mm, about 30 mm to about 60 mm, or about 40 mm to about 50 mm. The length L and width W of the LGP may, in some embodiments, be substantially equal, or they may differ. Similarly, the unit length L ₀ and the unit width W ₀ may be substantially equal, or they may be different.

Of course, the rectangular LGP100 is shown in FIG. 1, but the LGP has any regular or irregular shape as needed to produce the desired light distribution for the selected application. You should understand that it is also good. The LGP 100 may include four edges as shown in FIG. 1 or may have more than four edges, such as a multi-sided polygon. In other embodiments, the LGP 100 may have less than four edges, eg, triangles. As a non-limiting example, LGPs may be made from rectangular, square, or diamond-shaped sheets with four edges, but other shapes and configurations, including those with one or more curved portions or edges, It is intended to fall within the scope of this disclosure.

According to various embodiments, the LGP may be made from any transparent material used in the technical field of lighting and display applications. As used herein, the term "transparent" is intended to indicate that LGP has a light transmittance of more than about 80% over a length of 500 mm in the visible region of the spectrum (about 420-750 nm). There is. For example, the illustrated transparent material has a transmittance of more than about 90%, more than about 95%, or more than about 99%, including the entire range and a partial range in between, in the visible light range over a length of 500 mm. It may have a transmittance of more than about 85%. In certain embodiments, the illustrated transparent material includes an entire range and a partial range in between, greater than about 55%, greater than about 60%, greater than about 65%, greater than about 70%, greater than about 75%, Approximately 50 in the ultraviolet (UV) region (approximately 100-400 nm) over a length of 500 mm, such as greater than about 80%, greater than about 85%, greater than about 90%, greater than about 95%, or greater than about 99% transmittance. May have a light transmittance of more than%. According to various embodiments, the LGP can have a light transmission of at least 98% with a path length of 75 mm over wavelengths ranging from about 450 nm to about 650 nm.

The optical properties of LGP can be affected by the refractive index of the transparent material. According to various embodiments, the LGP includes the entire range and a partial range in between, from about 1.35 to about 1.7, from about 1.4 to about 1.65, from about 1.45 to about. It may have a refractive index ranging from about 1.3 to about 1.8, such as 1.6, or about 1.5 to about 1.55. In other embodiments, the LGP may have relatively low levels of light attenuation (eg, due to absorption and / or scattering). The light attenuation (α) of LGP may be less than about 5 dB / m for wavelengths ranging from about 420 to 750 nm, for example. For example, α is less than about 4 dB / m, less than about 3 dB / m, less than about 2 dB / m, about including the entire range and a partial range in between, eg, about 0.2 dB / m to about 5 dB / m. It may be less than 1 dB / m, less than about 0.5 dB / m, less than about 0.2 dB / m, or even less.

LGP100 may be made from plastics, such as polymethylmethacrylate (PMMA), methylmethacrylate styrene (MS), polydimethylsiloxane (PDMS), or other similar materials. LGP100 can also be made from glass materials such as aluminosilicates, alkaline aluminosilicates, borosilicates, alkaline borosilicates, aluminosilicates, alkaline aluminosilicates, soda lime, or other suitable glasses. is there. Non-limiting examples of commercially available glass suitable for use as a glass light guide include, for example, EAGLE XG®, Rotus ™, Willow®, Iris ™, from Corning Inc. And Gorilla® glass.

Some non-limiting glass compositions are about 50 mol% to about 90 mol% SiO ₂ , 0 mol% to about 20 mol% Al ₂ O ₃ , 0 mol% to about 20 mol% B ₂ It may contain O ₃ and 0 mol% to about 25 mol% R _x O, where R is at least one of Li, Na, K, Rb, Cs and x is 2. , Or R is Zn, Mg, Ca, Sr or Ba, and x is 1. In some embodiments, R _x O-Al ₂ O ₃ >0; 0 <R _x O-Al ₂ O ₃ <15; x = 2 and R _x O-Al ₂ O ₃ <15; R _x. O-Al ₂ O ₃ <2; x = 2, and R _x O-Al ₂ O _3- MgO>-15; 0 <(R _x O-Al ₂ O ₃ ) <25, -11 <(R ₂ O) -Al ₂ O ₃ ) <11 and -15 <(R ₂ O-Al ₂ O _3- MgO) <11; and / or -1 <(R ₂ O-Al ₂ O ₃ ) <2 and -6 <(R ₂ O-Al ₂ O _3- MgO) <1. In some embodiments, the glass contains less than 1 ppm Co, Ni, and Cr, respectively. In some embodiments, the concentration of Fe is less than about 50 ppm, less than about 20 ppm, or less than about 10 ppm. In other embodiments, Fe + 30Cr + 35Ni <about 60 ppm, Fe + 30Cr + 35Ni <about 40 ppm, Fe + 30Cr + 35Ni <about 20 ppm, or Fe + 30Cr + 35Ni <about 10 ppm. In other embodiments, the glass is about 60 mol% to about 80 mol% SiO ₂ , about 0.1 mol% to about 15 mol% Al ₂ O ₃ , 0 mol% to about 12 mol%. It may contain B ₂ O ₃ and about 0.1 mol% to about 15 mol% R _x O, where R is at least one of Li, Na, K, Rb, Cs and x is 2, or R is Zn, Mg, Ca, Sr or Ba, and x is 1.

In other embodiments, the glass composition comprises from about 65.79 mol% to about 78.17 mol% SiO ₂ , from about 2.94 mol% to about 12.12 mol% Al ₂ O ₃ , about. 0 mol% to about 11.16 mol% B ₂ O ₃ , about 0 mol% to about 2.06 mol% Li ₂ O, about 3.52 mol% to about 13.25 mol% Na ₂ O, from about 0 mol% to about 4.83 mol% _K 2 O, ZnO about 0 mole% to about 3.01 mol%, MgO from about 0 mole% to about 8.72 mol%, from about 0 mol% to about 4.24 mol% CaO, about 0 mol% to about 6.17 mol% SrO, about 0 mol% to about 4.3 mol% BaO, and about 0.07 mol% to about 0.11 mol% SnO ₂ may be included.

In additional embodiments, the glass may have an R _x O / Al ₂ O ₃ ratio between 0.95 and 3.23, where R is any of Li, Na, K, Rb, Cs. Or one or more, and x is 2. In a further embodiment, the glass may have an R _x O / Al ₂ O ₃ ratio between 1.18 and 5.68, where R is any of Li, Na, K, Rb, Cs. One or more and x is 2, or R is Zn, Mg, Ca, Sr or Ba, and x is 1. Also in a further embodiment, the glass may have R ₂ O-Al ₂ O ₃ -MgO between -4.25 and 4.0, where R is Li, Na, K, Rb, Cs. Any one or more of, and x is 2. In a further embodiment, the glass is about 66 mol% to about 78 mol% SiO ₂ , about 4 mol% to about 11 mol% Al ₂ O ₃ , and about 4 mol% to about 11 mol% B. ₂ O ₃ , about 0 mol% to about 2 mol% Li ₂ O, about 4 mol% to about 12 mol% Na ₂ O, about 0 mol% to about 2 mol% K ₂ O, about 0 mol% From about 2 mol% ZnO, about 0 mol% to about 5 mol% MgO, about 0 mol% to about 2 mol% CaO, about 0 mol% to about 5 mol% SrO, about 0 mol% to about It may contain 2 mol% BaO and about 0 mol% to about 2 mol% SnO ₂ .

In additional embodiments, the glass is about 72 mol% to about 80 mol% SiO ₂ , about 3 mol% to about 7 mol% Al ₂ O ₃ , and about 0 mol% to about 2 mol% B. ₂ O ₃ , about 0 mol% to about 2 mol% Li ₂ O, about 6 mol% to about 15 mol% Na ₂ O, about 0 mol% to about 2 mol% K ₂ O, about 0 mol% From about 2 mol% ZnO, about 2 mol% to about 10 mol% MgO, about 0 mol% to about 2 mol% CaO, about 0 mol% to about 2 mol% SrO, about 0 mol% to about It may contain 2 mol% BaO and about 0 mol% to about 2 mol% SnO ₂ . In certain embodiments, the glass is about 60 mol% to about 80 mol% SiO ₂ , about 0 mol% to about 15 mol% Al ₂ O ₃ , about 0 mol% to about 15 mol% B. ₂ O ₃ and may contain from about 2 mol% to about 50 mol% R _x O, where R is at least one of Li, Na, K, Rb, Cs and x is 2. Or R is Zn, Mg, Ca, Sr or Ba, x is 1, and Fe + 30Cr + 35Ni <about 60 ppm.

In some embodiments, the LGP100 is about 0.005 to about 0.015 (eg, about 0.005, 0.006, 0.007, 0.008, 0.009, 0.010, 0. It can have a color shift Δy of less than 0.015, such as 011, 0.012, 0.013, 0.014, or 0.015). In other embodiments, the LGP may have a color shift of less than 0.008. Color shifts may be characterized by measuring variations in x and y chromaticity coordinates along length L using the CIE 1931 standard for color measurement. For LGP, the color shift Δy can be reported as Δy = y (L ₂ ) −y (L ₁ ), where L ₂ and L ₁ are the Z positions along the panel or substrate direction away from the light source. And L _2- L ₁ = 0.5 meters. An exemplary LGP has Δy <0.01, Δy <0.005, Δy <0.003, or Δy <0.001. According to certain embodiments, the LGP is less than about 3 dB / m, less than about 2 dB / m, less than about 1 dB / m, less than about 0.5 dB / m, about 0 dB / m for wavelengths ranging from about 420 to 750 nm. Due to light attenuation α ₁ (eg, absorption loss and / or scattering loss) ranging from less than about 4 dB / m, such as about 0.2 dB / m to about 4 dB / m, such as less than 2 dB / m, or even less. ) Can have.

LGP100 may be made from chemically fortified, eg, ion-exchanged glass in some embodiments. During the ion exchange process, ions in the glass sheet at or near the surface of the glass sheet may be exchanged for larger metal ions, for example from a salt bath. The inclusion of larger ions in the glass can strengthen the sheet by creating compressive stress in the region near the surface. A corresponding tensile stress can be evoked within the central region of the glass sheet to balance its compressive stress.

Ion exchange may be performed, for example, by immersing the glass in a molten salt bath for a predetermined period of time. Illustrated salt baths include, but are not limited to, KNO ₃ , LiNO ₃ , NaNO ₃ , RbNO ₃ , and combinations thereof. The temperature and treatment period of the molten salt bath can vary. It is within the ability of one of ordinary skill in the art to determine the time and temperature according to the desired application. As a non-limiting example, the temperature of the molten salt bath may range from about 400 ° C to about 800 ° C, such as about 400 ° C to about 500 ° C, and the predetermined period is about 4 hours, such as about 4 hours to about 10 hours. It can range from time to about 24 hours, but other temperature and time combinations are also envisioned. As a non-limiting example, the glass can be immersed in a KNO ₃ bath, for example, at about 450 ° C. for about 6 hours to obtain a K-rich layer that imparts surface compressive stress.

Referring to FIG. 2, which shows a top view of an exemplary pattern reflective layer 120, the reflective layer may have at least two regions with different optical properties. For example, the pattern reflective layer may contain a light reflecting component 120A (represented by white dots), which may have a higher light reflectance than that of the light transmitting component 120B (represented by black dots). Some and / or the transmissive component 120B may have a higher light transmittance than that of the reflective component 120A. Again, for explanatory purposes, two exemplary light sources 110 are visible through the pattern reflective layer 120 in FIG. 2, but may not be in some embodiments.

In certain embodiments, the first region 125A may be more densely populated with reflective components 120A in the area corresponding to at least one light source 110, as shown in FIG. Similarly, the second region 125B may be more densely packed with transmission components 120B in the area between the light sources 110, as shown in FIG. During assembly, the high reflectance and / or low transmittance first region 125A can be distributed more densely over each individual light source 110 in a series of light sources, with low reflectance and / or high. The second region 125B of transmittance may be more densely distributed in the area adjacent to or in between the light sources.

The pattern reflective layer 120 may be made of any material that can change the light output from the LGP 100 at least to some extent. In some embodiments, the pattern reflective layer 120 may include a patterned metal film, a multilayer dielectric film, or any combination thereof. In certain examples, the reflective and transmissive components 120A, 120B and / or the first and second regions 125A, 125B of the pattern reflective layer 120 may have different diffuse or specular reflectances. In other embodiments, the pattern reflective layer 120 may regulate the amount of light transmitted through the LGP 100. For example, the reflective and transmissive components 120A, 120B and / or the first and second regions 125A, 125B of the pattern reflective layer 120 may have different transmittances.

According to various embodiments, the first reflectance of the first region 125A may be about 50% or more, and the second reflectance of the second region 125B is about 20% or less. There is. For example, its first reflectance ranges from about 50% to 100%, including the entire range and a partial range in between, at least about 50%, at least about 60%, at least about 70%, at least about 80. %, At least about 90%, or at least about 92%. The second reflectance is about 20% or less, about 15% or less, about 10% or less, or about 5% or less, including the entire range and a partial range in between, ranging from 0% to about 20%. May be. In some embodiments, the first reflectance is at least about 2.5, such as about 2.5 to about 20 times greater than the second reflectance, including the entire range and a partial range in between. It can be twice as large, for example, about three times larger, about four times larger, about five times larger, about ten times larger, about 15 times larger, or about 20 times larger. The reflectance of the pattern reflective layer 120 may be measured, for example, by a UV / Vis spectrometer commercially available from PerkinElmer.

In additional non-limiting embodiments, the first transmittance of the first region 125A may be about 50% or less, and the second transmittance of the second region 125B may be about 80% or more. There may be. For example, the first transmittance is about 50% or less, about 40% or less, about 30% or less, about 20%, including the entire range and a partial range between them, ranging from 0% to about 50%. Below, or may be about 10% or less. The second transmittance is 80% or more, about 85% or more, about 90% or more, or about 95% or more, including the entire range and a partial range between them, such as about 80% to 100%. There is. In some embodiments, the second transmittance is at least about 1.5, such as about 1.5 to about 20 times greater than the first transmittance, including the entire range and a partial range in between. It can be twice as large, for example, about two times larger, about three times larger, about four times larger, about five times larger, about ten times larger, about 15 times larger, or about 20 times larger. The transmittance of the pattern reflective layer 120 may be measured, for example, by a UV / Vis spectrometer commercially available from PerkinElmer.

Reflective and / or transmissive components 120A, 120B may be positioned within the reflective layer 120 to produce any predetermined pattern or design, the pattern or design being, for example, random or arranged, repeating. Or it may be non-repetitive, uniform or non-uniform. Therefore, although FIG. 2 shows an exemplary iterative pattern of reflective and transmissive components 120A, 120B, other patterns, both regular and irregular, may be used and fall within the scope of the present disclosure. Should be understood as intended. In some embodiments, these components are gradients, eg, from the first region 125A to the second region 125B, from light source to light source, or from the center of each unit block to each unit block. A decreasing reflectance gradient may be formed at the edges and / or corners. In additional embodiments, the reflective and transmitted components are in the first region 125A to the second region 125B, in the area between the light sources, or from the center of each unit block to the edge of each unit block and /. Alternatively, an increasing transmission gradient can be formed, such as at the corners.

With reference to FIG. 3, which shows a cross-sectional view of an exemplary BLU, the LGP 100 may have a first main surface 100A that emits light and a second main surface 100B vice versa. Their main surfaces may, in certain embodiments, be planar or substantially planar, and / or parallel or substantially parallel. In certain embodiments, the LGP 100 is about 3 mm or less, including the entire range and a partial range in between, eg, about 0.1 mm to about 2.5 mm, about 0.3 mm to about 2 mm, about 0. It may have a thickness t extending between the first and second main surfaces, ranging from 5 mm to about 1.5 mm, or from about 0.7 mm to about 1 mm.

The pattern reflective layer 120 may be positioned close to the first main surface 100A of the LGP 100. As used herein, the term "closely positioned" and its variants, where a component or layer is located near a particular surface or enumerated component, is not necessarily its. It is intended to mean that it does not need to be in direct physical contact with the surface or components. For example, in the non-limiting embodiment shown in FIG. 3, the pattern reflective layer 120 is not in direct physical contact with the first main surface 100A, eg, between these two components. There are voids. However, in some embodiments, the pattern reflective layer 120 may be integrated with the LGP 100, such as being located on the first main surface 100A of the LGP 100. As used herein, the term "placed on top" and its variants indicate that a component or layer is in direct physical contact with a particular surface or listed component. There is an intention to mean. In other embodiments, there may be one or more layers or films, such as an adhesive layer, between these two components. Therefore, the component A, which is positioned close to the surface of the component B, may or may not be in direct physical contact with the component B.

Although FIG. 3 shows one pattern reflective layer 120, it should be understood that the reflective layer 120 may include a large number of pieces, films, or layers. For example, the pattern reflective layer 120 can be a multilayer composite film or coating, such as a dielectric coating. In another embodiment, the portion of the reflective layer corresponding to the first region 125A may be applied to the LGP 100 first, and then the portion of the reflective layer corresponding to the second region 125B may be applied to the LGP. Or vice versa. Alternatively, substantially all of the LGP 100, including a portion of the LGP 100 in which a first film or layer having first optical properties is positioned on one or more portions of the LGP 100 and covered by the first film. A second film or layer with a second optical property may be overlaid so as to cover it. In such an embodiment, the first region 125A of the multilayer reflective layer may have the combined optical properties of the first and second films, while the second region 125B is the second film. Can have only optical properties, and vice versa. Therefore, the pattern reflective layer 120 may include a single film or composite film, a single layer or multiple layers, as needed to achieve the desired optical effect.

Regardless of the configuration of the patterned reflective layer, the embodiments disclosed herein have different optics in the first region 125A as compared to the second region 125B (eg, lower reflectance and / or higher transmittance). It should be understood that it may include a patterned reflective layer having at least one physical property (eg, higher reflectance and / or lower transmittance). The areal densities of the reflective and transmissive components 120A and 120B are such that the reflective component 120A exists at a higher density in the first region 125A located directly above the light source 110, and the second region positioned between the light sources 110. It can vary across the reflective layer 120 such that the transmissive component 120B is present at a lower density in 125B. Further, embodiments of BLU disclosed herein may produce substantially uniform light, eg, light emitted from a region corresponding to those light sources is emitted from a region between the light sources. It may have a brightness that is substantially equal to that of the emitted light.

As shown in FIG. 3, at least one light source 110 may be optically coupled to the second main surface 100B of the LGP 100. Non-limiting exemplary light sources include light emitting diodes (LEDs), such as blue light emitting LEDs, UV, or near UV light, such as light having a wavelength ranging from about 100 nm to about 500 nm. As used herein, the term "optically coupled" means that the light source is positioned on the surface of the LGP so that it introduces at least partially propagating light into the LGP due to total internal reflection. There is an intention to mean that. The light source 110 may be in direct physical contact with the LGP 100, as shown in FIG. However, the light source may be optically coupled to the LGP even if it is not in direct physical contact with the LGP. For example, the optical adhesive layer 150 may be used to bond the light source 110 to the second main surface 100B of the LGP 100, as shown in FIG. In certain embodiments, the optical adhesive layer may have an index of refraction matched to LGP100, eg, within 5%, within 3%, within 2%, within 1%, etc. It may have a refractive index within 10% of, or it may have the same refractive index as LGP.

With reference to FIG. 3 again, the BLU may further include a rear reflector 130 located close to the second main surface 100B of the LGP 100. Therefore, the optical distance OD of the light transmitted between the two reflectors may be defined as the distance between the pattern reflector layer 120 and the rear reflector 130. Examples of the exemplary rear reflector 130 include metal foils such as silver, platinum, gold and copper. As further shown in FIG. 4, the backlight unit may include one or more additional films or components, such as one or more auxiliary optical films and / or structural components. The exemplary auxiliary optical film 170 is not limited to the following, but to name a few, a diffuse film, a prism film, such as a brightness-increasing film (BEF), or a reflectively polarized film, such as a reflectively polarized film. A film (DBEF) can be mentioned. In some embodiments, the light source 110 and / or the rear reflector 130 may be located on the printed circuit board 140. Auxiliary optics such as a diffuse film 160, a color conversion layer 170 (including, for example, quantum dots and / or phosphors), a prism film 180, and / or a reflective polarized film 190 are provided with the pattern reflective layer 120 and the display panel 200. It may be positioned between. Although not shown in FIG. 4, the BLUs disclosed herein include display devices and lighting devices such as thin film transistor (TFT) arrays, liquid crystal (LC) layers, and color filters, to name a few exemplary components. It may contain or be combined with other components typically present within.

Returning to FIG. 3, the light rays emitted from the light source 110 are indicated by broken lines, dotted lines, and solid arrows. For explanatory purposes only, the transmission components 120B are at various dimensional points representing their density along the light guide plate, eg, at a low density above the light source 110 and at a density that increases away from the light source 110. Shown as dots. The densities of the reflective and / or transmissive components 120A, 120B can be increased or decreased by increasing the number and / or size of the components. In addition, the reflective and / or transmissive components 120A, 120B can be any shape or combination of shapes, including circular, oval, square, rectangular, triangular, or any other regular, including shapes with straight and / or curved edges. Alternatively, it may have an irregular polygon.

The first light beam (dashed arrow) injected into the LGP 100 can travel directly through the LGP without propagating laterally within the LGP 100, and is reflected and does not return through the LGP, but is a pattern reflection. a second region 120B of the layer 120 also passes through, which may first transmitted beam _{T 1} is generated. The second light beam (dotted arrow) injected into the LGP 100 can travel directly through the LGP without propagating laterally within the LGP 100, but hits the reflection component 120A in the pattern reflection layer 120 and hits the reflection component 120A. It may travel back through the LGP 100 to the rear reflector 130. Thus, the second ray will traverse the optical distance OD more than once while being reflected between the pattern reflecting layer 120 and the rear reflector 130. Finally, the second ray passes through the transmission component 120B of the pattern reflection layer 120, and the second transmission ray T ₂ is generated.

A third ray (solid arrow) can be launched into the LGP 100 until it hits the light extraction feature or hits the surface of the LGP in another way at an incident angle below the critical angle and is transmitted through the LGP. , May propagate within the LGP due to total internal reflection (TIR). Therefore, the optical distance transmitted by the third light beam can be reduced to the thickness t of the LGP 100. This third ray will undergo some optical loss during the TIR due to absorption by the LGP100, but such optical loss is compared to that of the second ray traveling the optical distance OD. Will be relatively small. Because those rays travel shorter vertical and / or horizontal distances. In particular, light rays tend to travel only about half the distance (pitch) between a plurality of light sources before they exit the LGP 100 and are extracted. In certain embodiments, the pitch of the light source can be less than or equal to about 150 mm, and even less than about 80 mm, as described with respect to FIG. 1, unit width W ₀ (shown) or unit. Can correspond to length (not shown). Finally, the third ray passes through the transmission component 120B of the pattern reflective layer, resulting in a _third transmitted ray T3.

In total internal reflection (TIR), light propagating through a first material having a first refractive index (eg, glass, plastic, etc.) has a second refractive index lower than that of the first refractive index. It is a phenomenon that can be totally reflected at the interface with the material (for example, air). TIR describes the reflection of light at the interface between two materials with different refractive indexes, Snell's law:

Can be explained using. According to Snell's law, n ₁ is the refractive index of the first material, n ₂ is the refractive index of the second material, and θ _i is the angle of light incident at the interface with respect to the normal of the interface. (Incident angle), θ _r is the angle of refraction of the refracted light with respect to the normal. When the refraction angle (θ _r ) is 90 °, for example, when sin (θ _r ) = 1, Snell's law is:

It can be expressed as. The incident angle θ _i under these conditions is sometimes referred to as the critical angle θ _c . Light having an incident angle larger than the critical angle (θ _i > θ _c ) is totally internally reflected in the first material, whereas light having an incident angle equal to or smaller than the critical angle (θ _i ≤ θ _c ). Permeates the first material.

For the exemplary interface between air (n ₁ = 1) and glass (n ₂ = 1.5), the critical angle (θ _c ) can be calculated as 41 °. Therefore, when the light propagating in the glass hits the interface between the air and the glass at an incident angle larger than 41 °, all of the incident light is reflected from the interface at an angle equal to the incident angle. When the reflected light encounters a second interface having the same refractive index relationship as the first interface, the light incident on the second interface is reflected again at a reflection angle equal to the incident angle.

According to various embodiments, the first and / or second main surfaces 100A, 100B of the LGP 100 may be patterned by a plurality of light extraction features. As used herein, the term "patterned" is arbitrary, where multiple light extraction features may be, for example, random or arranged, repetitive or non-repetitive, uniform or non-uniform. It is intended to mean that it is present on or below the surface of the LGP in a given pattern or design of. In other embodiments, the light extraction feature may be located within the base metal of the LGP, adjacent to the surface, eg, below the surface. For example, light extraction features may be distributed over the surface, eg, as textured surface features that make up a rough or raised surface, or within and throughout the LGP or portion thereof, eg, a laser. It may be distributed as a damaged site or characteristic structure. Suitable methods for creating such light extraction features include printing such as inkjet printing, screen printing, microprinting, microstructuring, mechanical roughening, etching, injection molding, coating, laser damage, or optional. The combination of. Non-limiting examples of such methods include, for example, acid etching of the surface, surface coating with TiO ₂ , and laser damage to the substrate by focusing the laser on the surface or in the matrix of the substrate.

The LGP is disclosed in any method known in the art, eg, PCT / US2103 / 063622 and PCT / US2014 / 070771, co-pending and same applicant, each of which is cited herein in its entirety. It may be processed to create light extraction features according to the methods used. For example, the surface of LGP may be ground and / or polished to achieve the desired thickness and / or surface quality. The surface may then be cleaned, if desired, and / or the surface to be etched may be subjected to a process of removing contaminants, such as exposing the surface to ozone. .. The form of the surface to be etched, non-limiting, acid bath, for example, from about 1: 1 to about 9: a mixture of glacial acetic acid ratio ranging 1 (GAA) and ammonium fluoride (NH 4 _F) May be exposed. The etching time can range from, for example, about 30 seconds to about 15 minutes, and the etching can be done at room temperature or high temperature. Process parameters such as acid concentration / ratio, temperature, and / or time can affect the size, shape, and distribution of the resulting extraction features. It is within the ability of one of ordinary skill in the art to change these parameters to achieve the desired surface extraction characteristics.

The light extraction feature pattern may be selected to improve the uniformity of light extraction along the length and width of the LGP 100, but the region of the LGP corresponding to the individual light source is the light with higher intensity. It is also possible that the overall light output of the LGP may not be uniform, for example. Therefore, the pattern reflective layer 120 may be implemented in regions with various optical properties in order to further homogenize the light output. For example, the pattern reflective layer 120 has increased reflectance and / or decreased transmittance in the first region 125A corresponding to the light source, and increased transmittance and / or decreased in the second region 125B between the light sources. May give reflectance. Such a configuration allows the diffuse film or other optical film to be placed closer to the light source without adversely affecting the light uniformity produced by the BLU or the illumination or display device, thus resulting in the entire BLU and as a result. Lighting or display devices to be used could be made thinner.

In a conventional direct assembly, the smaller the optical distance between the rear reflector and the pattern reflecting layer, the more times light is reflected, which increases the optical loss. However, in the BLUs disclosed herein, the incorporation of an LGP optically coupled to the light source results in reduced optical loss compared to a device that relies solely on a reflector to diffuse light laterally. , Can allow lateral diffusion of light along the length of the LGP.

In a basic assembly in which light is laterally diffused only by a reflector, eg, in the assembly of FIG. 3 that does not include LGP, light with an angle of incidence (θ) is reflected more than once between the two reflective layers. By passing through the above, the lateral distance (X) may be transmitted over the vertical distance (d). The number of reflections (N) can be expressed by N = X / d * tan (θ). Assuming that both reflectors have a reflectance of 98%, the light has a reserve of 98% ^N after N reflections. For different combinations of incident angle (θ) and ratio X / d, Table 1 below shows the number of reflections, and Table 2 shows the residual ratio of light output.

Light loss due to multiple reflections between reflectors becomes significantly more significant as the ratio X / d increases. As mentioned earlier, the pitch between the light sources can be as large as 150 mm. As the vertical distance decreases, the ratio X / d can increase exponentially, often exceeding 50. When X / d = 50, the residual power of light at an incident angle θ = 10 ° is less than 1%.

Referring to FIG. 5A, the light beam is emitted from the light source 110 at the emission angle θ _LED and enters the LGP 100. The light beam is incident on the light emitting surface of the _LGP at an incident angle θ _LGP , and this incident angle does not exceed the critical angle θ _c and therefore does not result in TIR within the LGP 100. Part of the light is a lateral distance X expressed as X ₁ = t * tan (sin ^-1 (θ) / n)), where n is the refractive index of LGP and t is the thickness of LGP 100. transmitted by _one is transmitted as the first transmission _{T 1.} The smaller portion of the light is transmitted by the second lateral distance X ₂ represented by X ₂ = 3 X ₁ and is transmitted as the second transmission T ₂ . Table 3 below, assuming that the refractive index of the LGP (n) is 1.5, different radiation angles _{θ LED = 20 °, 41 °} , and 60 ° about a first reflection _{R 1,} a second The percentages of luminous flux of the reflection R ₂ , the first transmission T ₁ , and the second transmission T ₂ are listed. The higher order reflected R ₃ and transmitted T ₃ (see FIG. 5B) are insignificant as the total luminous flux is less than 1%. Most of the light travels only the lateral distance X _{1 and} is transmitted as T _{1 and} less than 1% of the light is transmitted as T ₂ regardless of the radiation angle. Even the light transmitted as T ₂ travels only the maximum lateral distance of X ₂ = 3 X _{1 in} the illustrated configuration.

Referring to FIG. 5B, the light beam is emitted from a light source 110 optically coupled to the _LGP 100 so that the emission angle θ _LED is substantially equal to the incident angle θ _LGP . For example, optical coupling using optical adhesives with a matching index of refraction allows at least a portion of the light to travel laterally along the length of the LGP for TIR. A part of the light is transmitted by the lateral distance X ₁ represented by X ₁ = t * tan (θ), where t is the thickness of LGP 100, and is transmitted as the first transmission T ₁ . A part of the light is transmitted by the second lateral distance X ₂ represented by X ₂ = 3 X ₁ due to the reflection between them, and is transmitted as the second transmission T ₂ . Once the angle of incidence exceeds the critical angle, for example above about 42 ° in the illustrated configuration, the light beam can pass through the TIR, which allows the light to pass through the LGP before it is extracted and disappears. It can travel a significantly larger lateral distance. In this way, a portion of the light can travel only a distance of X ₃ due to TIR and is transmitted as a _third transmission T ₃ .

Table 4 below shows the first reflection R ₁ and the second reflection R _{2 for} different emission angles θ _LEDs = 20 ° and 41 °, assuming that the index of refraction (n) of the LGP is 1.5. , The first transmitted T ₁ , the second transmitted T ₂ , the third reflected R ₃ , and the third transmitted T ₃ have a percentage of luminous flux. In both Tables 3 and 4, the radiation angle θ _LED = 20 °, most of the light is transmitted as _{T 1.} However, in Table 3 (without optical coupling), X ₁ = 0.23t, and in Table 4 (with optical coupling), X ₂ = 0.36t, light with the same emission angle (20 °). It is shown that it travels only a longer lateral distance within the LGP optically coupled to the light source. For an emission angle θ _LED = 41 °, the light is optically coupled (Table 3) as compared to the uncoupled LGP (Table 3), as suggested by the larger T ₂ and T ₃ values in Table 4. In Table 4), it travels a much longer lateral distance.

With reference to FIGS. 6A-D, the side of the light by comparing the backlight assembly with the rear reflector, the patterned reflector, at least one LED, and the LGP located between those reflectors. The effect of TIR on directional diffusion can be further demonstrated. I studied four cases:
(A) The bottom reflector has a Lambertian reflectance of 98% and an absorptivity of 2%;
(B) LEDs have a Lambertian reflectance of 60% and an absorptivity of 40%;
(C) The LGP is made of glass with a refractive index of 1.5 and varying thicknesses from 0.1 mm to 5 mm and is optically coupled to the LED;
(D) The patterned reflector has one of four different properties:
(I) Case I: 98% specular reflectance and 2% absorption rate (Fig. 6A);
(Ii) Case II: 92% specular reflectance and 8% absorption (Fig. 6B);
(Iii) Case III: 98% Lambertian reflectance and 2% absorption (Fig. 6C); or (iv) Case IV: 92% Lambertian reflectance and 8% absorption (Fig. 6D).

The assembly with LGP was compared to the same assembly without LGP and instead with voids having a distance corresponding to the thickness of the LGP.

With reference to FIGS. 6A-D, where the light extraction efficiency is plotted as a function of LGP / void thickness, in all four cases, the light extraction efficiency of the assembly with voids increases as the thickness t decreases. ,Decrease. In comparison, the light extraction efficiency of the assembly with LGP increases as the thickness t decreases from 5 mm to about 0.7 mm. In all cases, the light extraction efficiency of the assembly with LGP is significantly higher than that of the assembly with voids for a thickness of about 2 mm or less. As consumer demand for thinner display devices increases, improvements that reduce the total thickness of the BLU are equally desirable. By positioning the LGP optically coupled between the pattern reflector and the rear reflector, the optical loss that would otherwise occur as the distance between the reflectors decreases can be reduced. , The total thickness of BLU can be effectively reduced.

In additional embodiments such as the configuration shown in FIG. 7, it may be desirable to have one or more microstructures 105 on the first main surface 100A of the LGP 100. These microstructures 105, in some embodiments, to further promote lateral diffusion of light from the light source and / or to reduce optical loss due to absorption by the light source, eg, LED. In addition, it can act to re-direct the vertically incident light toward the off-axis angle. Its light extraction efficiency ranges from about 1% to about 4%, or about 2% to about 3%, including the entire range and a partial range in between, as compared to configurations that do not contain microstructures on the LGP. It can be as large as 5%.

In certain embodiments, the microstructure 105 may have a pyramidal shape, which may be an individual raised feature (as shown) or a linear groove. The raised microstructure can be constructed from materials that are the same as or different from LGP, such as glass and plastic. This raised microstructure can be produced, for example, by molding or microprinting the microstructure on the first main surface 100A. In a further embodiment, the microstructure can be imprinted or etched on the first main surface 100A. According to a further embodiment, the base angle Θ _M whose microstructure forms with the first main surface 100A is from about 25 ° to about 35 °, or about 30 °, including the entire range and a partial range in between. Etc., which can range from about 20 ° to about 40 °.

8A-8B show some embodiments of the multilayer variable reflector according to some embodiments of the present disclosure. Referring to FIG. 8A, one non-limiting embodiment with an LED size of about 1 mm × 1 mm and an LGP thickness of about 1 mm is shown. The LED pitch (center-to-center distance) in this non-limiting embodiment is 100 mm, and the size of the individual 2D dimming area or the area illuminated by one LED is 100 mm x 100 mm. As shown in FIG. 8A, the LED emitted outside the escape cone, which has an angle of about 42 degrees or more with respect to the surface normal (when the LGP index of refraction is 1.5). The rays are totally internally reflected and thereby captured by the LGP. The rays in the cone would leak without the upper reflector. The intersection of the leaking cone with the LGP top surface in this non-limiting embodiment is about 3 mm x 3 mm, or about 1/1000 of the size of the dimming area. At the same time, for emitters with a Lambert angular light distribution, about 45% of the total luminous flux is in the leaking cone. Therefore, if the reflector shown in FIG. 8A accurately covers the leaking cone, about 0.1% and about 0% of the light that hits it in order to achieve uniform illumination above the LGP. It will only need to be transmitted between 2% (depending on the exact value of reflectance and other design parameters that determine the backlight efficiency). Therefore, for a 3 mm x 3 mm square, if one pattern feature or "hole" is made in the reflector, the feature will be between about 95 μm x about 95 μm and about 134 μm x 134 μm in size. Having only one feature inevitably results in a brighter area above the feature (hot spot) and a more blurry area around the feature (cold spot). In practice, in some embodiments, it will be necessary to make multiple pattern features of correspondingly smaller sizes in order to improve the brightness uniformity over the 3 mm x 3 mm area. Producing such small features will typically require some form of photolithography process. When making variable reflectors using highly reflective paints or inks, it may also be necessary to accumulate a thickness of 100 μm or greater before reaching high reflectance.

Reference to FIG. 8B shows another non-limiting embodiment having a reflector with two or more layers. In some embodiments, the exemplary reflective coating may transmit about 95% of the incident light, and if the first layer of the reflector exposes only 5% of that light, thus the first. Layer 2 should transmit between 2% and 4% of the incident light. In an embodiment in which the second layer is completely opaque, this corresponds to the pattern feature size of the second layer between about 0.42 mm × 0.42 mm and about 0.6 mm × 0.6 mm. There will be. Such feature sizes may be easier to manufacture and more likely to achieve more uniform brightness than the embodiments shown in FIG. 8A.

Thus, FIGS. 8A and 8B show, on the one hand, pattern features (eg, "holes" or "inland") in order to keep the feature size ratio to layer thickness within the accessible print range. ”), And the other is the transmittance / reflectance for each of the reflective layers, indicating that two characteristics can be altered in the exemplary embodiments. Depending on the type of reflective ink or paint available, any suitable digital printing technique can be used, such as inkjet printing, screen printing, flexographic printing. In some embodiments, the advantage of using a white paint or ink as the reflective material in a thin backlight design is that the paint typically has diffuse reflectance rather than specular reflectance, which is why It helps to prevent too much reflected light from returning to the LED source, further increasing the backlight efficiency.

The exemplary variable reflectors, when used in the thin backlight design disclosed herein, are the top surface of the LGP, as well as any other suitable surface on top of the LGP, such as an optical diffuser, diffuser sheet, or. It can be printed on the bottom surface of the brightness increasing film (BEF). When printing an exemplary variable reflector on an LGP, an additional advantage given to the corresponding display is that the white paint is widely known in the art as an efficient light extractor, so that the variable reflector The ability to print light extraction features in the same path as the first layer.

In some embodiments, the presence of the LGP may not be necessary if the exemplary variable reflector is printed on the bottom of the BEF, diffuser, or other component of the backlight other than the LGP. However, it can still offer the advantages of ease of manufacture and higher brightness uniformity.

To illustrate some embodiments, a large number of samples were prepared by printing a commercially available white ink LH-100 on glass of different thickness d with a Mimaki UJF7151 plus printer. One sample had d = 0, i.e. no white ink; the second sample had d = d0 = 0.025 μm; the other sample was between 0 and 6 × d0. It had an ink thickness. Imaging Surface for Sample and Appearance (IS-SA) detector (available from Radiant Imaging, Inc.) and vertically incident light source at a wavelength of 550 nm (zero degree ccBTDF (0) for transmission intensity are good metrics. The cosine-corrected bidirectional transmission distribution function (ccBTDF) was measured for each sample according to (determined to be). The cosine-corrected bidirectional reflection distribution function (ccBRDF) was also measured with the same device. In vertical incidence, ccBRDF (0) was not obtained because the reflected and incident beams overlap in space; however, total integral scattering (TIS_R) from ccBRDF is a good metric for quantifying reflected light. Was determined to be.

Table 5 below gives TIS_R and ccBTDF (0) at zero degrees with respect to the relative ink thickness d / d0 for a wavelength of 550 nm.

With reference to Table 5, it can be observed that the transmitted light intensity of the vertically incident, which is quantified by ccBTDF (0), can be changed by more than three orders of magnitude by controlling the thickness of the white ink. It should be noted that if the ink thickness is thicker than 2 × d0, the transmitted light intensity may be too low to measure accurately. The total integral scattering of reflected light can vary from about 21% to about 93%. Therefore, these experimental results show exemplary variable reflectors with different reflections and transmissions and spatially varying thicknesses of white ink.

The BLU disclosed herein can be used in a variety of display devices, including but not limited to televisions, computers, telephones, portable devices, billboards, or other display screens. The BLU disclosed herein can also be used in a variety of luminaires, such as luminaires or solid-state luminaires.

In some embodiments, a substrate having a first main surface that emits light and a second main surface vice versa, at least one light source optically coupled to the substrate, and a first or first surface of the substrate. A reflector positioned close to the two main surfaces, the reflector having two or more layers of reflective material, each of which forms a first area and a second area. Provided is a backlight unit with a reflector that has, the first area is more reflective than the second area, and the second area is more transparent than the first area. In some embodiments, the substrate is made of glass. The glass is expressed in mole% on an oxide basis, 50-90 mol% SiO ₂ , 0-20 mol% Al ₂ O ₃ , 0-20 mol% B ₂ O ₃ , and 0-25 mol. % R _x O, where x is 2 and R is selected from Li, Na, K, Rb, Cs, and combinations thereof, or x is 1, and R is Zn. , Mg, Ca, Sr, Ba, and combinations thereof, may contain compositions. In some embodiments, the substrate has a color shift Δy of less than about 0.015. In other embodiments, the substrate has a thickness ranging from about 0.1 mm to about 2 mm. In some embodiments, the reflective material is a white ink, and the total integral scattering of reflections from the white ink varies between 4% and 93%. In some embodiments, the substrate is a volume diffusing plate, a surface diffusing sheet, a light guide plate, a brightness increasing film, or a reflective polarizer. In some embodiments, the at least one light source is optically coupled to a second main surface of the light guide plate through an optical adhesive layer.

A further embodiment is a substrate having a first main surface that emits light and a second main surface vice versa, a plurality of individual light sources, a reflector positioned close to the second main surface, and the like. A multi-layer pattern reflector located close to the first main surface, each layer having a first area and a second area, the first area being more reflective than the second area. Provide a backlight unit with a multi-layer pattern reflector, the second area of which is more transparent than the first area. In some embodiments, the individual light sources are located below the multi-layer pattern reflector and above the bottom reflectors, and the light emitted by those light sources is the bottom reflectors and Due to the large number of reflections on the reflective surface of the pattern reflector, it travels laterally between the bottom reflector and the pattern reflector. In some embodiments, the substrate is made of glass. The glass is expressed in mole% on an oxide basis, 50-90 mol% SiO ₂ , 0-20 mol% Al ₂ O ₃ , 0-20 mol% B ₂ O ₃ , and 0-25 mol. % R _x O, where x is 2 and R is selected from Li, Na, K, Rb, Cs, and combinations thereof, or x is 1, and R is Zn. , Mg, Ca, Sr, Ba, and combinations thereof, may contain compositions. In some embodiments, the substrate has a color shift Δy of less than about 0.015. In other embodiments, the substrate has a thickness ranging from about 0.1 mm to about 2 mm. In some embodiments, the substrate is a volume diffusing plate, a surface diffusing sheet, a light guide plate, a brightness increasing film, or a reflective polarizer. In some embodiments, the individual light source is optically coupled to a second main surface of the light guide plate through an optical adhesive layer.

An additional embodiment is a substrate having a plurality of pattern features on a first main surface that emits light, a second main surface vice versa, and the first or second main surface thereof, and a plurality of individual light sources. And a reflector positioned close to its second main surface and a multi-layer pattern reflector positioned close to its first main surface, each of which is a first A multi-layer pattern reflector that has an area and a second area, the first area being more reflective than the second area and the second area being more transparent than the first area. Provide a equipped backlight unit. In some embodiments, the individual light sources are located directly behind the patterned substrate, and the light from the individual light sources is made of patterned glass for the first portion of that light due to total internal reflection. It travels laterally in the light guide and is extracted by the pattern of the light extractor, and a second portion of that light is with the bottom reflector due to the numerous reflections on the bottom reflector and the reflective surface of the pattern reflector. It is optically coupled to a patterned glass light guide so that it travels laterally to and from the pattern reflector. In some embodiments, the substrate is made of glass. The glass is expressed in mole% on an oxide basis, 50-90 mol% SiO ₂ , 0-20 mol% Al ₂ O ₃ , 0-20 mol% B ₂ O ₃ , and 0-25 mol. % R _x O, where x is 2 and R is selected from Li, Na, K, Rb, Cs, and combinations thereof, or x is 1, and R is Zn. , Mg, Ca, Sr, Ba, and combinations thereof, may contain compositions. In some embodiments, the substrate has a color shift Δy of less than about 0.015. In other embodiments, the substrate has a thickness ranging from about 0.1 mm to about 2 mm. In some embodiments, the substrate is a volume diffusing plate, a surface diffusing sheet, a light guide plate, a brightness increasing film, or a reflective polarizer. In some embodiments, the separate light source is optically coupled to a second main surface of the light guide plate through an optical adhesive layer. In some embodiments, the substrate is a patterned glass light guide plate having a pattern of light extractors on both the first and second main surfaces.

It will be appreciated that the various disclosed embodiments may include specific features, components or steps described for that particular embodiment. A particular feature, component or process is described for one particular embodiment, but may be exchanged for or combined with an alternative embodiment in various unexplained combinations or sequences. Will also be recognized.

As used herein, it is also understood that nouns refer to "at least one" object and should not be limited to "only one" unless explicitly stated otherwise. Yeah. Therefore, for example, the reference to "light source" includes an example of having two or more such light sources, unless otherwise specified. Similarly, "plurality" or "series" is intended to indicate "two or more." Thus, a "plurality of light scattering features" includes two or more such features, such as three or more such features, and a "series of holes" includes three or more such features, etc. Includes two or more such holes.

The range can be expressed herein as "about" from one particular value and / or "about" another particular value. When such a range is expressed, the example includes from that one particular value and / or to the other particular value. Similarly, it should be understood that when a value is expressed as an approximation using the antecedent "about", that particular value forms another aspect. It will be further understood that each endpoint of the range is significant both in relation to the other endpoint and independently of the other endpoint.

It is intended to note that the terms "substantial", "substantially", and variations thereof as used herein are that the described features are equal to or nearly equal to a value or description. For example, a "substantially flat" surface is intended to indicate a flat or substantially flat surface. Furthermore, "substantially similar" is intended to indicate that the two values are equal or nearly equal. In some embodiments, "substantially similar" may indicate values that are within about 10% of each other, such as within about 5% of each other, or within about 2% of each other.

Various features, components or steps of a particular embodiment can be disclosed using the transition phrase "contains", but using the transition phrase "consisting of" or "consisting of substantially". It should be understood that alternative embodiments, including those that can be described, are implied. Thus, for example, alternative embodiments implied for devices comprising A + B + C include embodiments in which the device comprises A + B + C and embodiments in which the device substantially comprises A + B + C.

It will be apparent to those skilled in the art that various modifications and changes to this disclosure may be made without departing from the spirit and scope of this disclosure. This disclosure is the scope of the accompanying claims and their equivalents, as modifications, combinations, partial combinations and modifications of embodiments of the disclosure, including the spirit and substance of the disclosure, will be recalled to those skilled in the art. It should be interpreted as including everything within the scope of.

Hereinafter, preferred embodiments of the present invention will be described in terms of terms.

Embodiment 1
In the backlight unit
A substrate having a first main surface that emits light and a second main surface vice versa.
At least one light source optically coupled to the substrate and a reflector positioned close to the first or second main surface of the substrate, wherein the reflector is two or more of reflective materials. Each of the layers has a first area and a second area, the first area is more reflective than the second area, and the second area is the second area. Reflector, which is more permeable than area 1.
Backlight unit with.

Embodiment 2
The backlight unit according to the first embodiment, wherein the substrate is made of glass.

Embodiment 3
The glass is represented by an oxide-based molar%.
50-90 mol% SiO ₂ ,
0-20 mol% Al ₂ O ₃ ,
0 to 20 mol% of B ₂ O ₃ , and 0 to 25 mol% of R _x O,
Including
Here, x is 2, and R is selected from Li, Na, K, Rb, Cs, and combinations thereof, or
The backlight unit according to the second embodiment, wherein x is 1, and R is a composition selected from Zn, Mg, Ca, Sr, Ba, and a combination thereof.

Embodiment 4
The backlight unit according to the first embodiment, wherein the substrate has a color shift Δy of less than about 0.015.

Embodiment 5
The backlight unit according to the first embodiment, wherein the substrate has a thickness ranging from about 0.1 mm to about 2 mm.

Embodiment 6
The backlight unit according to the first embodiment, wherein the reflective material is white ink, and the total integral scattering of reflections from the white ink varies between 4% and 93%.

Embodiment 7
The backlight unit according to the first embodiment, wherein the substrate is selected from the group consisting of a volume diffusing plate, a surface diffusing sheet, a light guide plate, a brightness increasing film, and a reflective polarizer.

8th Embodiment
The backlight unit according to the first embodiment, wherein the at least one light source is optically coupled to a second main surface of the light guide plate through an optical adhesive layer.

Embodiment 9
A display or lighting device comprising the backlight unit according to the first embodiment.

Embodiment 10
In the backlight unit
A substrate having a first main surface that emits light and a second main surface vice versa.
Multiple individual light sources,
A reflector positioned close to the second main surface and a multilayer pattern reflector positioned close to the first main surface, each layer having a first area and a second area. A multi-layer pattern reflector, wherein the first area is more reflective than the second area and the second area is more transparent than the first area.
Backlight unit with.

Embodiment 11
The individual light source is located below the multilayer pattern reflector and above the bottom reflector, and the light emitted by the light source is the reflecting surface of the bottom reflector and the pattern reflector. The backlight unit according to embodiment 10, wherein the back light unit is transmitted laterally between the bottom reflector and the pattern reflector for a large number of reflections in.

Embodiment 12
The backlight unit according to a tenth embodiment, wherein the substrate is made of glass.

Embodiment 13
The glass is represented by an oxide-based molar%.
50-90 mol% SiO ₂ ,
0-20 mol% Al ₂ O ₃ ,
0 to 20 mol% of B ₂ O ₃ , and 0 to 25 mol% of R _x O,
Including
Here, x is 2, and R is selected from Li, Na, K, Rb, Cs, and combinations thereof, or
The backlight unit according to embodiment 12, wherein x is 1, and R is a composition selected from Zn, Mg, Ca, Sr, Ba, and combinations thereof.

Embodiment 14
The backlight unit according to the tenth embodiment, wherein the substrate has a color shift Δy of less than about 0.015.

Embodiment 15
10. The backlight unit according to embodiment 10, wherein the substrate has a thickness ranging from about 0.1 mm to about 2 mm.

Embodiment 16
The backlight unit according to a tenth embodiment, wherein the substrate is selected from the group consisting of a volume diffusing plate, a surface diffusing sheet, a light guide plate, a brightness increasing film, and a reflective polarizer.

Embodiment 17
The backlight unit according to embodiment 10, wherein the individual light sources are optically coupled to a second main surface of the light guide plate through an optical adhesive layer.

Embodiment 18
A display or lighting device comprising the backlight unit according to the tenth embodiment.

Embodiment 19
In the backlight unit
A substrate having a plurality of pattern features on a first main surface that emits light, a second main surface vice versa, and the first or second main surface.
With multiple individual light sources
A reflector located close to the second main surface and
A multi-layer pattern reflector located close to the first main surface, each of which has a first area and a second area, the first area being the second area. A multi-layer pattern reflector, which is more reflective than the first area and the second area is more transparent than the first area.
Backlight unit with.

20th embodiment
The individual light source is located directly behind the pattern substrate, and the light from the individual light source is lateral in a patterned glass light guide for a first portion of the light for total internal reflection. Propagated in the direction and extracted by the pattern of the light extractor, the second portion of the light is the bottom reflector and the pattern due to the large number of reflections on the bottom reflector and the reflective surfaces of the pattern reflector. 19. The backlight unit according to embodiment 19, which is optically coupled to the patterned glass light guide so as to be transmitted laterally to and from the reflector.

21st embodiment
The backlight unit according to embodiment 19, wherein the substrate is made of glass.

Embodiment 22
The glass is represented by an oxide-based molar%.
50-90 mol% SiO ₂ ,
0-20 mol% Al ₂ O ₃ ,
0 to 20 mol% of B ₂ O ₃ , and 0 to 25 mol% of R _x O,
Including
Here, x is 2, and R is selected from Li, Na, K, Rb, Cs, and combinations thereof, or
21. The backlight unit of embodiment 21, wherein x is 1 and R is a composition selected from Zn, Mg, Ca, Sr, Ba, and combinations thereof.

23rd Embodiment
The backlight unit according to embodiment 19, wherein the substrate has a color shift Δy of less than about 0.015.

Embodiment 24
The backlight unit according to embodiment 19, wherein the substrate has a thickness ranging from about 0.1 mm to about 2 mm.

25.
19. The backlight unit according to embodiment 19, wherein the substrate is selected from the group consisting of a volume diffusing plate, a surface diffusing sheet, a light guide plate, a brightness increasing film, and a reflective polarizer.

Embodiment 26
The backlight unit according to embodiment 19, wherein the separate light source is optically coupled to a second main surface of the light guide plate through an optical adhesive layer.

Embodiment 27
A display or lighting device comprising the backlight unit according to embodiment 19.

28.
19. The backlight unit according to embodiment 19, wherein the substrate is a patterned glass light guide plate having a pattern of light extractors on both the first and second main surfaces.

100 light guide plate (LGP)
110 Light source 120 Reflective layer 120A Light reflection component 120B Light transmission component 125A First area 125B Second area 130 Rear reflector 140 Printed substrate 150 Optical adhesive layer 160 Diffusion film 170 Color conversion layer 180 Prism film 190 Reflection modification film 200 display panel

Claims (14)

In the backlight unit
A substrate having a first main surface that emits light and a second main surface vice versa.
At least one light source optically coupled to the substrate and a reflector positioned close to the first or second main surface of the substrate, wherein the reflector is two or more of reflective materials. Each of the layers has a first area and a second area, the first area is more reflective than the second area, and the second area is the second area. Reflector, which is more permeable than area 1.
Backlight unit with. The backlight unit according to claim 1, wherein the substrate is made of glass. The glass is represented by an oxide-based molar%.
50-90 mol% SiO ₂ ,
0-20 mol% Al ₂ O ₃ ,
0 to 20 mol% of B ₂ O ₃ , and 0 to 25 mol% of R _x O,
Including
Here, x is 2, and R is selected from Li, Na, K, Rb, Cs, and combinations thereof, or
The backlight unit according to claim 2, wherein x is 1, and R is a composition selected from Zn, Mg, Ca, Sr, Ba, and a combination thereof. The backlight unit according to claim 1, wherein the reflective material is white ink, and the total integral scattering of reflections from the white ink varies between 4% and 93%. The backlight unit according to claim 1, wherein the substrate is selected from the group consisting of a volume diffusing plate, a surface diffusing sheet, a light guide plate, a brightness increasing film, and a reflective polarizer. The backlight unit according to claim 1, wherein the at least one light source is optically coupled to the second main surface of the light guide plate through an optical adhesive layer. A display or lighting device including the backlight unit according to claim 1. In the backlight unit
A substrate having a first main surface that emits light and a second main surface vice versa.
Multiple individual light sources,
A reflector positioned close to the second main surface and a multilayer pattern reflector positioned close to the first main surface, each layer having a first area and a second area. A multi-layer pattern reflector, wherein the first area is more reflective than the second area and the second area is more transparent than the first area.
Backlight unit with. The individual light source is located below the multilayer pattern reflector and above the bottom reflector, and the light emitted by the light source is the reflecting surface of the bottom reflector and the pattern reflector. The backlight unit according to claim 8, wherein the back light unit is transmitted laterally between the bottom reflector and the pattern reflector due to a large number of reflections in. The backlight unit according to claim 8, wherein the substrate is made of glass. The glass is represented by an oxide-based molar%.
50-90 mol% SiO ₂ ,
0-20 mol% Al ₂ O ₃ ,
0 to 20 mol% of B ₂ O ₃ , and 0 to 25 mol% of R _x O,
Including
Here, x is 2, and R is selected from Li, Na, K, Rb, Cs, and combinations thereof, or
10. The backlight unit of claim 10, wherein x is 1 and R is a composition selected from Zn, Mg, Ca, Sr, Ba, and combinations thereof. The backlight unit according to claim 8, wherein the substrate is selected from the group consisting of a volume diffusing plate, a surface diffusing sheet, a light guide plate, a brightness increasing film, and a reflective polarizer. The backlight unit according to claim 8, wherein the individual light sources are optically coupled to the second main surface of the light guide plate through an optical adhesive layer. A display or lighting device including the backlight unit according to claim 8.

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