Patent Description:
In the conventional lighting devices, light converting materials (such as quantum dots) are usually excited by an input light, and the input light will be converted into another light with different wavelength. However, the conversion efficiency of light converting materials may not be <NUM>%, thereby causing the output light impure or degrading the quality. Therefore, the present disclosure proposes a lighting device that can reduce the above problems.

Document <CIT> discloses a lighting device comprising blue light source and green quantum dot light converter on a polymer substrate.

This in mind, the present disclosure aims at providing a lighting device including a light blocking substrate. A substrate in the lighting device may include the metal ions, the nanoparticles, the yellowing polymer, or combinations thereof. When the blue light unconverted by the quantum dots in the first light converting units or the second light converting units passes through the substrate, some of the unconverted blue light may be reduced. Accordingly, the lighting units in the lighting device can emit lights with the color closer to red primary color or green primary color due to the reduction of the unconverted blue light, thereby increasing the display quality.

This is achieved by a lighting device according to the independent claim. The dependent claims pertain to corresponding further developments and improvements.

As will be seen more clearly from the detailed description following below, a lighting device is provided by the present disclosure. The lighting device includes a substrate, a plurality of first light converting units, and a light source. The light source emits a light passing through the plurality of first light converting units and the substrate to generate a first spectrum including a main peak between <NUM> nanometers (nm) to <NUM> and a first sub peak between <NUM> to <NUM>, and a first transmittance of the substrate at a wavelength of the main peak is greater than a second transmittance of the substrate at a wavelength of the first sub peak.

In the following, the disclosure is further illustrated by way of example, taking reference to the accompanying drawings.

The present disclosure may be understood by reference to the following detailed description, taken in conjunction with the drawings as described below. For purposes of illustrative clarity understood, various drawings of this disclosure show a portion of the electronic device, and certain elements in various drawings may not be drawn to scale. In addition, the number and dimension of each device shown in drawings are only illustrative and are not intended to limit the scope of the present disclosure.

Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will understand, electronic equipment manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include", "comprise" and "have" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to".

When an element or layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or directly connected to the other element or layer, or intervening elements or layers may be presented. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element or layer, there are no intervening elements or layers presented.

The terms "about", "substantially", "equal", or "same" generally mean within <NUM>% of a given value or range, or mean within <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% of a given value or range.

Although terms such as first, second, third, etc., may be used to describe diverse constituent elements, such constituent elements are not limited by the terms. The terms are used only to discriminate a constituent element from other constituent elements in the specification. The claims may not use the same terms, but instead may use the terms first, second, third, etc. with respect to the order in which an element is claimed. Accordingly, in the following description, a first constituent element may be a second constituent element in a claim.

Referring to <FIG>, it is a schematic diagram illustrating a cross-sectional view of a lighting device according to a first embodiment. The lighting device may include a display device, an electronic device, a flexible device, a tile device, or other suitable devices, but not limited thereto. For example (<FIG>), the lighting device <NUM> may include organic light emitting diodes (OLED), quantum dot light emitting diodes (QLED, QDLED), but not limited thereto. The lighting device <NUM> may include a first substrate <NUM>, a second substrate <NUM>, and a light source LS. The second substrate <NUM> may be disposed opposite to the first substrate <NUM>, and the light source LS may be disposed between the first substrate <NUM> and the second substrate <NUM>, but not limited thereto. The light source LS may include at least one light emitting structure LES, a plurality of first electrodes EL1, and a second electrode EL2, but not limited thereto. For example (<FIG>), the light source LS may include two light emitting structures LES1 and LES2, and the light emitting structures LES1 or LES2 may include organic light emitting material, quantum dot light emitting material, other suitable materials or combinations thereof, but not limited thereto. In some embodiments, the light emitting structures LES1 and/or LES2 can emit blue light, UV light or other suitable light, but not limited thereto. In some embodiments, the light emitting structure LES1 and/or LES2 may be continuously, the light emitting structures LES1 and/or LES2 may extend through a plurality of lighting units (e.g. lighting units LU1, LU2, and LU3). In some embodiments (not shown), the light emitting structure LES1 and/or LES2 may have separate patterns, and one of the separate patterns may be disposed in one of the lighting units, but not limited thereto.

In addition, the emitting structure LES1 and/or LES2 may be disposed between the first electrodes EL1 and the second electrode EL2. One of the first electrodes EL1 may be disposed in (or correspond to) one of the lighting units (e.g. LU1,LU2, or LU3), and the second electrode EL2 be continuously, the second electrode EL2 may extend through the lighting units LU1, LU2, and LU3, but not limited thereto. The second electrode EL2 may be one of cathode and anode, and the first electrodes EL1 may be another one of cathode and anode. The material of the second electrode EL2 may include transparent conductive material, such as indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), antimony tin oxide (ATO), antimony zinc oxide (AZO), any other suitable materials or combinations thereof , but not limited thereto. The material of the first electrodes EL1 may include reflective conductive material (e.g. metal or alloy), but not limited thereto. Additionally, the lighting device <NUM> may include a plurality of walls <NUM> (e.g. the unit (pixel) definition layer) disposed between the at least one light emitting structure (the light emitting structure LES1 or LES2) and the second substrate <NUM>. Specifically, the walls <NUM> may be disposed between the second electrode EL2 and the light emitting structure LES1 (or LES2). In some embodiments, the light emitting structure LES1 (or LES2) may be disposed on the plurality of walls <NUM>. In some embodiments, the lighting units may be defined by the walls, but not limited. In some embodiments, the lighting units may be defined by other suitable material, such as shielding structure <NUM> (the details will be explained below). The material of the walls <NUM> may include opaque insulating material, such as reflective materials or light shielding materials, but not limited thereto.

An active matrix layer AM may be disposed on the first substrate <NUM>. The active matrix layer AM may include plural transistors Tr. The lighting units LU1, LU2, and LU3 may respectively include at least one transistor Tr, and the first electrodes EL1 may be electrically connected to the corresponding transistor Tr, but not limited thereto. The transistor Tr may include an active layer <NUM>, a gate electrode <NUM>, a source electrode/drain electrode <NUM>. The active matrix layer AM may also include signal lines (such as scan line, data line, power line or reference line), insulating layers or other components. The first substrate <NUM> may be an array substrate. The first substrate <NUM> and/or the second substrate <NUM> may include a rigid substrate (such as a glass substrate or a quartz substrate) or a flexible substrate (such as a plastic substrate), but not limited thereto. The material of the plastic substrate may include polyimide (PI), polycarbonate (PC) or polyethylene terephthalate (PET), but not limited thereto.

A shielding structure <NUM> may be adjacent to the light converting units. The shielding structure <NUM> may include a plurality of apertures, and one light converting unit (such as the first light converting unit LCU1, the second light converting unit LCU2 or the third light converting unit LCU3) may be disposed in (or correspond to) the corresponding aperture of the shielding structure <NUM>. The material of the shielding structure <NUM> may include black photoresist, black printing ink, black resin, other suitable material or combinations thereof, but not limited thereto. In addition, a planarization layer <NUM> may be disposed between the shielding structure <NUM> and the light source LS. In some embodiments, the planarization layer <NUM>, the shielding structure <NUM>, the first light converting unit LCU1, the second light converting unit LCU2, and the third light converting unit LCU3 may be formed on the second substrate <NUM>, and the second substrate <NUM> may be a so-called color filter substrate or protective substrate, but not limited. The first light converting units LCU1, the second light converting units LCU2, and the third light converting units LCU3 may be disposed between the second substrate <NUM> and the light source LS, but not limited thereto. In some embodiments, the shielding structure <NUM>, the first light converting unit LCU1, the second light converting unit LCU2, or the third light converting unit LCU3 may be formed on the first substrate <NUM>. In some embodiments, an adhesion layer <NUM> may be disposed between the planarization layer <NUM> and the light source LS. In addition, an anti-reflection layer <NUM> may be disposed on a surface of the second substrate <NUM>, and the surface may be away from the light source LS.

It should be noted that, one of the lighting units LU1, LU2, or LU3 may correspond to one of the apertures of the shielding structure <NUM>. For example, one lighting unit (such as the lighting unit LU1, LU2, or LU3) may correspond to all elements (or layers) in a vertical region of one aperture of the shielding structure <NUM> in the normal direction V of the first substrate <NUM> (or a normal direction V of the second substrate <NUM>). In some embodiments, the lighting unit may be a sub-pixel (such as red sub-pixel, green sub-pixel, or blue sub-pixel, but not limited thereto).

The first light converting unit LCU1 may include a light converting structure LCS1 and a filter layer FL1, and the second light converting unit LCU2 may include a light converting structure LCS2 and a filter layer FL2. The filter layer FL1 (or the filter layer FL2) may disposed between the light converting structure LCS1 (or the light converting structure LCS2) and the second substrate <NUM>, but not limited. The light converting structure LCS1 or the light converting structure LCS2 inlcudes quantum dots and may further include fluorescent materials, phosphorescent materials, color filter layer, other suitable materials or combinations thereof, but not limited thereto. The quantum dots may be made of a semiconductor nano-crystal structure, and can include CdSe, CdS, CdTe, ZnSe, ZnTe, ZnS, HgTe, InAs, Cd1-xZnxSe1-ySy, CdSe/ZnS, InP or GaAs, but not limited thereto. Quantum dots have a particle size between <NUM> nanometer (nm) and <NUM>, <NUM> and <NUM>, or <NUM> and <NUM>. The quantum dots are excited by an input light emitted by the light source LS, the input light will be converted into an emitted light with different wavelength. The color (or wavelength) of the emitted light may be adjusted by the material or size of the quantum dots. In other embodiments, the quantum dots may include sphere particles, rod particles or particles with any other suitable shapes as long as the quantum dots could emit light with suitable color (or wavelength). In addition, the filter layers FL1 and FL2 may include color filter layers. For example, the filter layer FL1 may include a green color filter layer, the filter layer FL2 may include a red color filter layer, but not limited thereto. In some embodiments, the filter layers FL1 and FL2 may include Bragg layers. In some embodiments, the filter layers FL1 and FL2 may selectively be deleted or replaced.

As shown in <FIG>, the light converting structure LCS1 may include quantum dots QD1, the quantum dots QD1 are excited by a portion of the input light IL1, and the portion of the input light IL1 is converted into a light CL1 by the quantum dots QD1. A first light OL1 is the mixture of the light CL1 and the unconverted input light IL1. In the first lighting unit LU1 shown in <FIG>, the intensity of the unconverted input light IL1 can be reduced by the filter layer FL1 and the second substrate <NUM> when the unconverted input light IL1 penetrates through (or pass through) the filter layer FL1 and the second substrate <NUM>. The second substrate <NUM> can reduce at least part of the unconverted input lights IL1. Accordingly, the first light OL1 may be an output light emitted from the first lighting unit LU1. The output light could be regarded as the final visual light of the lighting device <NUM> perceived by the observer. The light converting structure LCS2 may include quantum dots QD2, the quantum dots QD2 can be excited by a portion of the input light IL2, and the portion of the input light IL2 may be converted into a light CL2 by the quantum dots QD2. The quantum dots QD2 may be different from the quantum dots QD1. A second light OL2 may be the mixture of the light CL2 and the unconverted input light IL2. In the second lighting unit LU2 shown in <FIG>, the intensity of the unconverted input light IL2 can be reduced by the filter layer FL2 and the second substrate <NUM> when the unconverted input light IL2 penetrates through (or pass through) the filter layer FL2 and the second substrate <NUM>. Accordingly, the second light OL2 may be an output light emitted from the second lighting unit LU2.

A third light OL3 emitted by the lighting unit LU3 can be blue light, but not limited. In some embodiments, the light source LS emits blue light, the third light converting unit LCU3 may include a transparent layer, which has no quantum dots therein. Additionally, the third light converting unit LCU3 may also include some scattering particles <NUM>, but not limited thereto. In some embodiments, the third light converting unit LCU3 may include a blue color filter layer. In some embodiment, the third light converting unit LCU3 is not included in the lighting unit LU3. In some embodiments, the third light converting unit LCU3 may include suitable type of quantum dots to adjust the wavelength of the third light OL3.

The first light OL1 is green light, the second light OL2 can be red light, and the third light OL3 can be blue light, but not limited thereto. In some embodiments, the lighting device <NUM> may include other lighting units emitting a light with different colors (or wavelengths).

The second substrate <NUM> includes a plurality of metal ions or a plurality of nanoparticles. The metal ions may include the first transition series, second transition series, third transition series, or fourth transition series, but not limited thereto. For example, the metal ions may include titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, molybdenum, silver, cadmium, platinum, gold, other suitable materials or combinations thereof, but not limited thereto. In some embodiments, the metal ions may be introduced by adding metal salts into the second substrate <NUM>.

The nanoparticles may include metal oxide nanoparticles or metal nanoparticles. The metal oxide nanoparticles may include nanoparticles of titanium dioxide (TiO<NUM>), zirconium dioxide (ZrO<NUM>), aluminum oxide (Al<NUM>O<NUM>), indium oxide (In<NUM>O<NUM>), zinc oxide (ZnO), tin oxide (SnO<NUM>), antimony oxide (Sb<NUM>O<NUM>), or silicon dioxide (SiO<NUM>), but not limited thereto. The metal oxide nanoparticles may absorb (or filter) at least part of the input lights (such as blue lights). The metal nanoparticles may include nanoparticles of gold, silver, copper, platinum, iron, cobalt, nickel, or manganese, but not limited thereto. The metal nanoparticles may scatter at least part of the blue lights. In some embodiments, the metal nanoparticles may scatter at least part of the blue lights to the quantum dots, thereby increasing the conversion efficiency. In some embodiments, the nanoparticles may be formed as a thin film (or layer) on at least one of the surfaces of the second substrate <NUM>. In some embodiments, a patterning process may be performed so that the nanoparticle thin film may have patterns (not shown), and at least part of the nanoparticle thin films (or layers) can overlap with the light converting structure LCS1 (or the light converting structure LCS2) in the normal direction V of the second substrate <NUM>, but not limited thereto.

The yellowing polymer may include epoxy resins with high molecular weights or unsaturated polyester resins, but not limited thereto. For example, the material of the second substrate <NUM> includes acrylic or PI, and the epoxy resin with high molecular weight or the unsaturated polyester resin may be added in the second substrate <NUM>, but not limited thereto. In some embodiments, an aging process may be performed to the second substrate <NUM> for reducing the blue light. The aging process may include chemical aging or physical aging, but not limited thereto.

Referring to <FIG>, it is a schematic diagram illustrating the transmittance (the vertical axis on the left side indicates the transmittance (%)) of the second substrate <NUM> and a first spectrum of the first light OL1 emitted by the first lighting unit LU1 according to the first embodiment. In <FIG>, dash-dotted lines TL1 represent the transmittance of the second substrate <NUM> including at least one of the above metal ions, the nanoparticles, or the yellowing polymers. Dashed lines TL2 represent a transmittance of a common substrate, which is untreated. For example, the common substrate does not include the metal ions, the nanoparticles or the yellowing polymer. In <FIG>, the solid line represents a first spectrum of the first light OL1, and the first spectrum may include a main wave MW11 and a sub-wave SW11. In some embodiments, the first spectrum may be a spectrum of a light emitted by the light source LS and passing through the first light converting units LCU1 and the second substrate <NUM>. The main wave MW11 represents the light CL1 (the light is converted by the first light converting unit LCU1) after passing through the second substrate <NUM>. The sub-wave SW11 represents the unconverted input light IL1 (e.g. blue light), after passing through the second substrate <NUM>.

In <FIG>, the main wave MW11 has a main peak PM11 and the sub-wave SW11 has a first sub peak PS11, the main peak PM11 is between <NUM> nanometers (nm) to <NUM> and the first sub peak PS11 is between <NUM> to <NUM>, and the intensity (the vertical axis on the right side indicates the intensity) of the main peak PM11 is greater than the intensity of the first sub peak PS11. Additionally, "Main peak" is defined as a crest of the main wave, and "Sub peak" is defined as a highest intensity in the corresponding range of wavelength, such as the highest intensity in the range from <NUM> to <NUM>, but not limited thereto. "Main peak" and "Sub peak" in other light spectrums may also be defined by the same way described above.

Referring to <FIG>, it is a schematic diagram illustrating the transmittance of the second substrate <NUM> and a second spectrum of a second light OL2 emitted by the second lighting unit LU2 according to the first embodiment, the second lighting unit as such is not covered by the scope of the claims. In <FIG>, the solid line represents a second spectrum of the second light OL2, and the second spectrum may include a main wave MW2 and a sub-wave SW2. In this embodiment, the second spectrum may be a spectrum of a light emitted by the light source LS and passing through the second light converting units LCU2 and the second substrate <NUM>. The main wave MW2 may represent the light CL2 (the light converted by the second light converting unit LCU2) after passing through the second substrate <NUM>. The sub-wave SW2 may represent the unconverted input light IL2 (e.g. blue light) after passing through the second substrate <NUM>. Referring to <FIG> (the vertical axis on the right side indicates the intensity), the main wave MW2 has a main peak PM2 and the sub-wave SW2 has a sub peak PS2, the main peak PM2 is between <NUM> to <NUM> and the sub peak PS2 is between <NUM> to <NUM>, and the intensity of the main peak PM2 is greater than the intensity of the sub peak PS2.

As shown in the dash-dotted lines TL1 in <FIG>, a first transmittance T1 of the second substrate <NUM> at a wavelength of the main peak PM11 is greater than a second transmittance T2 of the second substrate <NUM> at a wavelength of the first sub peak PS11, or a fourth transmittance T4 of the second substrate <NUM> at a wavelength of the main peak PM2 is greater than a fifth transmittance T5 of the second substrate <NUM> at a wavelength of the sub peak PS2. In some embodiments, the first transmittance T1 (or the fourth transmittance T4) may be in a range from <NUM>% to <NUM>% (<NUM>% ≦ transmittance ≦ <NUM>%), and the second transmittance T2 and/or the fifth transmittance T5 may be less than the first transmittance T1 (or the fourth transmittance T4). As shown in the dashed lines TL2 in <FIG>, when the common substrate is untreated, a transmittance T1' of the common substrate at a wavelength of the main peak PM11 and a transmittance T2' of the common substrate at a wavelength of the first sub peak PS11 are approximately the same, or a transmittance T4' of the common substrate at a wavelength of the main peak PM2 and a transmittance T5' of the common substrate at a wavelength of the sub peak PS2 are approximately the same. When the second substrate <NUM> is treated, for example, the second substrate <NUM> may include the metal ions, the nanoparticles, or the yellowing polymer, the transmittance of the second substrate <NUM> at the wavelength of the first sub peak PS11 (or second sub peak PS2) may be reduced.

Table <NUM> illustrates the second transmittance T2 (or the fifth transmittance T5) of the second substrate <NUM> when the second substrate <NUM> includes one of the metal ions or the nanoparticles (for example, groups A, E in the table <NUM>), or the second substrate <NUM> may include the combination of two of these materials (for example, groups B, C D, F, G and H in the table <NUM>). Taking the group A as an example, the value represents the transmittance of the second substrate <NUM> when it includes <NUM>-20wt% metal ions, and the second transmittance T2 (or the fifth transmittance T5) may be in a range from <NUM>-<NUM>% (<NUM>% ≦ transmittance ≦ <NUM>%). Taking the group B as an example, the value represents the transmittance of the second substrate <NUM> with <NUM>-20wt% metal ions and <NUM>-20wt% nanoparticles, and the second transmittance T2 (or the fifth transmittance T5) may be in a range from <NUM>-<NUM>% (<NUM>% ≦ transmittance ≦ <NUM>%). Other groups (such as groups C-I) are similar, so not be repeated.

In addition, Table <NUM> illustrates the ratio of the second transmittance T2 to the first transmittance T1 (or the ratio of the fifth transmittance T5 to the fourth transmittance T4) when the second substrate <NUM> includes one of the metal ions or the nanoparticles (for example, groups A, E in the table <NUM>), or the combination of two of these materials (for example, groups B, C D, F, G and H in the table <NUM>). Taking the group A as an example, the value represents a ratio of the second transmittance T2 to the first transmittance T1 (T2/T1) (or a ratio of the fifth transmittance T5 to the fourth transmittance T4 (T5/T4)) when the second substrate <NUM> includes <NUM>-<NUM> wt% metal ions, and the ratio may be in a range from <NUM>% to <NUM>% (<NUM>% ≦ ratio ≦ <NUM>%). Taking the group B as an example, the value represents a ratio of the second transmittance T2 to the first transmittance T1 (T2/T <NUM>) (or a ratio of the fifth transmittance T5 to the fourth transmittance T4 (T5/T4)) when the second substrate <NUM> includes <NUM>-20wt% metal ions and <NUM>-20wt% nanoparticles, and the ratio may be in a range from <NUM>% to <NUM>% (<NUM>% ≦ ratio ≦ <NUM>%). Other groups (such as groups C-I) are similar, so not be repeated. According to groups A-I in table <NUM>, the ratio of the second transmittance T2 to the first transmittance T1 may be in a range from <NUM>% to <NUM>%.

Referring to <FIG>, it is a schematic diagram illustrating the transmittance of a second substrate <NUM> and a first spectrum of a first light OL1 emitted by a first lighting unit LU1 according to a variant embodiment of the first embodiment. Different from the <FIG>, the first spectrum (<FIG>) may include a sub-wave SW12 and the sub-wave SW11, and the sub-wave SW12 may represent different portions of the unconverted input light IL1 in the first light OL1. Referring to <FIG> (the vertical axis on the right side indicates the intensity), the sub-wave SW12 has a second sub peak PS12 between <NUM> to <NUM>, and the intensity of the second sub peak PS12 is less than the intensity of the main peak PM11. "First sub peak" and "Second sub peak" are defined as the highest intensities in the corresponding ranges of wavelength, such as the highest intensity in the range from <NUM> to <NUM> and the highest intensity in the range from <NUM> to <NUM>, but not limited thereto. As shown in the dash-dotted line TL1 in <FIG>, a first transmittance T1 of the second substrate <NUM> at the wavelength of the main peak PM11 is greater than a third transmittance T3 of the second substrate <NUM> at a wavelength of the second sub peak PS12, and a ratio of the third transmittance T3 to the first transmittance T1 (T3/T1) is in a range from <NUM>% to <NUM>% (<NUM>% ≦ ratio ≦ <NUM>%). In <FIG>, the third transmittance T3 may be greater than the second transmittance T2 and less than the first transmittance T1, but not limited thereto. When the second substrate <NUM> includes the metal ions, the nanoparticles, or the yellowing polymer, the first transmittance T1 may be in a range from <NUM>% to <NUM>% (<NUM>% ≦ first transmittance T1 ≦ <NUM>%), and the second transmittance T2 and the third transmittance T3 may be less than the first transmittance T1. As shown in the dashed line TL2 in <FIG>, when the common substrate does not include the metal ions, the nanoparticles, nor the yellowing polymer, the transmittance T1' and the transmittance T2' of the common substrate are approximately the same, or the transmittance T1' and the transmittance T3' of the common substrate are approximately the same.

Referring to <FIG>, it is a CIE <NUM> chromaticity diagram, and color gamut may be commonly represented by an area in the CIE <NUM> chromaticity diagram. The numbers marked along a curved edge CE may represent the wavelengths. A region CS can represent the color space of the lighting device <NUM>, a point G may represent the green primary color, a point R may represent the red primary color. In the lighting units LU1, the intensity of the unconverted input light (such as blue light) can be reduced by the filter layer FL1 or the second substrate <NUM>, the x-y coordinate of the first light OL1 can be close to the point G, as indicated by an arrow AG in <FIG>. For example, a green x-coordinate value in a CIE <NUM> color gamut of the lighting device <NUM> is in a range from <NUM> to <NUM> (<NUM> ≦ x ≦ <NUM>), and a green y-coordinate value in the CIE <NUM> color gamut of the lighting device <NUM> is in a range from <NUM> to <NUM> (<NUM> ≦ y ≦ <NUM>). In addition, in the lighting units LU2, since the intensity of the unconverted input light (such as blue light) can be reduced by the filter layer FL2 or the second substrate <NUM>, the x-y coordinate of the second light OL1 can be close to the point R, as indicated by an arrow AR in <FIG>. For example, a red x-coordinate value in the CIE <NUM> color gamut of the lighting device <NUM> is in a range from <NUM> to <NUM> (<NUM> ≦ x ≦ <NUM>), and a red y-coordinate value in the CIE <NUM> color gamut of the lighting device <NUM> is in a range from <NUM> to <NUM> (<NUM> ≦ y ≦ <NUM>). Accordingly, the lighting units LU1 or LU2 in the lighting device <NUM> can emit light with the color close to the red or green primary color, thereby increasing the lighting quality (or display quality).

Since the second substrate <NUM> is provided, the thickness of the filter layers FL1 and FL2 may be reduced to be less than three micrometers. Additionally, the filter layers FL1 and FL2 may be removed in some embodiments for reducing the thickness of the lighting device <NUM>.

The technical features in different embodiments described in this disclosure can be replaced, recombined, or mixed. For making it easier to compare the difference between these embodiments, the following description will detail the dissimilarities among different embodiments and the identical features will not be redundantly described.

Referring to <FIG>, it is a schematic diagram illustrating a cross-sectional view of a lighting device according to a second embodiment. Different from the first embodiment, the lighting device <NUM> may be a liquid crystal display device, but not limited thereto. The first substrate <NUM> may be disposed between the light source LS and the second substrate <NUM>, and a light modulating layer <NUM> may be disposed between the first substrate <NUM> and the second substrate <NUM>. The light modulating layer <NUM> may be a liquid crystal layer, and some spacers <NUM> may be disposed between the first substrate <NUM> and the second substrate <NUM>. An alignment layer <NUM>, an electrode <NUM>, and a planarization layer <NUM> may be disposed between the second substrate <NUM> and the light modulating layer <NUM>, but not limited. An alignment layer <NUM>, a plurality of electrodes <NUM>, and the active matrix layer AM may be disposed between the light modulating layer <NUM> and the first substrate <NUM>, but not limited.

The alignment layers <NUM> and <NUM> may be PI layers, but not limited thereto. The electrode <NUM> may be the common electrode and the electrodes <NUM> may be pixel electrodes, and the electrodes <NUM> may be electrically connected to at least one transistor of the active matrix layer AM, but not limited thereto. The material of the shielding structure <NUM> or the spacers <NUM> may include black photoresist, black printing ink, black resin or other suitable material or combinations thereof, but not limited thereto. The optical films <NUM> may include dual brightness enhancement film (DBEF), prism film, other suitable optical films, or combinations thereof, but not limited thereto. In <FIG>, the light source LS may emit blue light, and the third light converting unit LCU3 may be replaced by a transparent layer, which has no quantum dots or scattering particles therein, but not limited thereto.

The lighting device <NUM> may further include a polarizer <NUM> and a polarizer <NUM>. The polarizer <NUM> may be disposed between the planarization layer <NUM> and the light converting units, the polarizer <NUM> may be disposed between the first substrate <NUM> and the light source LS. However, the polarizer <NUM> and the polarizer <NUM> are not limited to be disposed at the above-mentioned locations. In some embodiments, the light modulating layer <NUM> may be disposed between two polarizers for adjusting gray scale. In some embodiments, the polarizer <NUM> and/or the polarizer <NUM> may be disposed between the first substrate <NUM> and light converting units, for example the polarizer <NUM> and/or the polarizer <NUM> may include metal wires, which can be so-called wire grid polarizer (WGP), but is not limited thereto. The material of metal wire includes metal, metal alloy, other suitable materials or combinations thereof, but is not limited thereto. In addition, the lighting device <NUM> may further include at least one optical film <NUM> disposed between the polarizer <NUM> and the light source LS. In some embodiments, the optical film <NUM> may include dual brightness enhancement film (DBEF), prism film, other suitable optical films, or combinations thereof, but not limited thereto.

In <FIG>, the light source LS may be a backlight module. The light source LS may include a light emitting source <NUM> and at least one optical layer <NUM>. The optical layer <NUM> may include the light guide plate, diffuser plate, reflective film or other optical films (or plates). The light source LS may be an edge-lit type backlight module, and the light emitting source <NUM> may be disposed near at least one of the sidewalls of the optical layer <NUM> (such as the light guide plate), or the light source LS and the first substrate <NUM> (or the second substrate <NUM>) may be disposed at different sides of the optical layer <NUM>, but not limited thereto. In some embodiments, the light source LS may be a direct-lit type backlight module (not shown), the optical layer <NUM> may be the diffuser plate, reflective film or other optical films, and the optical layers <NUM> (such as diffuser plate) may be disposed between the light emitting source <NUM> and first substrate <NUM>, or the optical layers <NUM> (such as reflective film) may disposed under the light emitting source <NUM>. The light emitting source <NUM> may include light emitting diode (LED), micro-LED, mini-LED, organic light-emitting diode (OLED), quantum dot light emitting diode (QLED; QDLED), quantum dot, fluorescent material, phosphor materials, other suitable light sources, or combinations thereof, but not limited thereto. In some embodiment, the backlight module can emit blue light or UV light, but not limited thereto.

Referring to <FIG>, it is a schematic diagram illustrating a measurement of the transmittance of the second substrate. In some embodiments, the measurement of the transmittance (such as T1, T2, T3, T4 or T5) may be performed to a measuring location Q of the second substrate <NUM> after the lighting device <NUM> is dismantled. For example, the second substrate <NUM> in <FIG> may be dismantled from the lighting device <NUM> in <FIG>, but not limited thereto. In some embodiments, the transmittance of the second substrate <NUM> may be measured without dismantling the lighting device <NUM> when the area of the second substrate <NUM> is larger than the area of the first substrate <NUM>, and the measuring location Q can be chosen from a part of the second substrate <NUM>, and the part of the second substrate <NUM> does not overlap with the first substrate <NUM> in the normal direction V of the second substrate <NUM>, but not limited thereto. As shown in <FIG>, the second substrate <NUM> may include a display region AA and a peripheral region PA, and the shielding structure <NUM> and the light converting units (such as LCU1, LCU2) may be disposed in the display region AA. In some embodiments, the shielding structure <NUM> may extend to a portion of the peripheral region PA, but not limited thereto. Referring to an arrow AT shown in <FIG>, the transmittance of the second substrate <NUM> may be measured from a measuring location Q of the second substrate <NUM> in the peripheral region PA, but not limited thereto. In some embodiments, the transmittance of the second substrate <NUM> may be measured from a measuring location Q of the second substrate <NUM> in the display region AA.

As shown in <FIG>, part of the planarization layer <NUM>, part of the electrode <NUM>, and part of the alignment layer <NUM> may correspond to the measuring location Q of the second substrate <NUM>, but not limited thereto. In some embodiments, the polymer film, Bragg layer, silicon oxide film, silicon nitride film, inorganic material, organic material, or combinations thereof may be disposed on the second substrate <NUM> and correspond to the measuring location Q, but not limited thereto. According to the results from experiments, the above-mentioned materials may not affect or slightly affect the result of transmittance of the second substrate <NUM>, which can be neglected.

It should be noted that, some materials should not be located in the measuring location Q while measuring the transmittance of the second substrate <NUM>, such as the shielding structure <NUM>, the light converting units (such as LCU1, LCU2 and LCU3), the filter (the filter layer FL1 and FL2), the polarizer <NUM> (such as WGP), metallic materials, other reflective materials, shading materials or light absorbing materials, but not limited. These materials should be removed from the measuring location Q by dry etching, wet etching or other methods before the measurement is performed. The wet etching may include drop etching or shower etching, for example, the acid etching solution ST849 or alkali etching solution ST823 may be used, but not limited thereto. The dry etching may include using the fast particle beam, ion beam, or atom beam to perform the bombardment of etching, but not limited thereto. Therefore, in some embodiments, the measurement may be performed to the second substrate <NUM> after other films disposed on the second substrate <NUM> are removed.

In some experiment, the measurement of the transmittance may be performed to thirty-six measuring locations of the second substrate <NUM> uniformly distributed in the display region AA and/or the peripheral region PA, but not limited thereto. The thirty-six measuring locations should be chosen according to criteria of the measuring location Q mentioned above.

The transmittance of the second substrate <NUM> may be measured by some instruments such as the spectroradiometer or color analyzer, but not limited thereto. The instruments may include CA-<NUM>, CS 1000T, CS <NUM>, BM5A or other suitable instruments, but not limited thereto. In addition, the spectrum of the first light OL1 or the second light OL2 may be measured by the spectroradiometer. The instrument may be disposed at a side of the emitting surface of the lighting device <NUM>, and the emitting surface may be away from the light source LS while measuring. The lighting device <NUM> may turn on at least one of the lighting units LU1 (or at least one of the lighting units LU2), and the lighting device <NUM> may emit the first light OL1 (or the second light OL2). The lighting unit(s) LU1 or LU2 may be operated in the condition of maximum gray level while measuring, but not limited thereto.

Referring to <FIG>, it is a schematic diagram illustrating a cross-sectional view of a lighting device according to a third embodiment. Different from the second embodiment, the second substrate <NUM> is disposed between a display panel <NUM> (such as liquid crystal display panel) and the light source LS. The lighting device <NUM> may include a quantum dot (QD) cell <NUM> disposed between the display panel <NUM> and the light source LS. The QD cell <NUM> includes a bottom substrate <NUM>, the second substrate <NUM>, the first light converting units LCU1, the second light converting units LCU2, and an adhesive layer <NUM>. In some embodiments, the adhesive layer <NUM> may be a black adhesive layer, but not limited thereto. The first light converting units LCU1, the second light converting units LCU2, and the adhesive layer <NUM> may be disposed between the bottom substrate <NUM> and the second substrate <NUM>, and the second substrate <NUM> is disposed on the first light converting units LCU1 and the second light converting units LCU2. In some embodiments, the adhesive layer <NUM> may be disposed at the periphery of the bottom substrate <NUM> (or the periphery of the second substrate <NUM>), and the bottom substrate <NUM> and the second substrate <NUM> may be adhered through the adhesive layer <NUM>. In some embodiments, the adhesive layer <NUM> may be adjacent to (or surrounds) the first light converting units LCU1 and the second light converting units LCU2. In some embodiment, the light source LS may be the edge-lit type backlight module, and the optical layer <NUM> may be a light guide, but not limited thereto. In some embodiments, the light source LS may be a direct-lit type backlight module (not shown), and the optical layer <NUM> may be a diffusing film or a reflective film, but not limited thereto. For example, the diffusing film may be disposed on the light source LS, or the reflective film may be disposed under the light source LS, but not limited thereto.

The light (e.g. blue light) provided by the light source LS may pass through the first light converting units LCU1 and the second light converting units LCU2, and the lights (e.g. red and green lights) emitted by the first light converting units LCU1 and the second light converting units LCU2 may pass through the second substrate <NUM>. The lights emitted by the first light converting units LCU1 and the second light converting units LCU2 may be mixed to form white light, and portions of blue lights can be reduced by the second substrate <NUM>. Additionally, the white light provided by the QD cell <NUM> may be converted into different colors (or wavelengths) by color filters of different sub-pixels disposed in the liquid crystal display panel <NUM>, but not limited thereto. In some embodiment, the quantum dots of the first light converting units LCU1 and the quantum dots of the second light converting units LCU2 may be separated (or be patterned), the quantum dots of the first light converting units LCU1 does not overlap with the quantum dots of the second light converting units LCU2 in the normal direction V of the second substrate <NUM>, but not limited thereto. In some embodiments, the quantum dots of the first light converting units LCU1 and the quantum dots of the second light converting units LCU2 may be mixed in a same layer, and the wavelength (or color) emitted from <NUM> could be modulated. In some embodiments, the substrates of the display panel <NUM> may be substrates that does not include the metal ions, the nanoparticles or the yellowing polymer, but not limited thereto. In some embodiments, at least one of the substrates of the display panel <NUM> may be replaced by the second substrate <NUM>, in this situation, the substrate of the QD cell <NUM> may not include the metal ions, the nanoparticles or the yellowing polymer, but not limited thereto. The above alternative designs may be applied to the fourth embodiment or the fifth embodiment.

Referring to <FIG>, it is a schematic diagram illustrating a cross-sectional view of a lighting device according to a fourth embodiment. Different from the third embodiment, the lighting device <NUM> may include the quantum dot on light guide (QDOG) structure. For example, the second substrate <NUM>, the first light converting units LCU1, and the second light converting units LCU2 may be bonded with (or coated on) the optical layer <NUM>, and the bottom substrate <NUM>.

Referring to <FIG>, it is a schematic diagram illustrating a cross-sectional view of a lighting device according to a fifth embodiment. Different from the fourth embodiment, the lighting device <NUM> may include the quantum dot in light guide (QDIG) structure. For example, the light source LS may be the light emitting source <NUM>, and the quantum dots QD1 of the first light converting units LCU1 and the quantum dots QD2 of the second light converting units LCU2 may be mixed and disposed in the optical layer <NUM>, but not limited thereto. The second substrate <NUM> may be disposed on the optical layer <NUM>. Therefore, the light source LS and the second substrate <NUM> may be disposed at different sides of the optical layer <NUM>, but not limited thereto.

Referring to <FIG>, it is a schematic diagram illustrating a cross-sectional view of a lighting device according to a sixth embodiment. Different from the first embodiment, the lighting device <NUM> may include LED, micro LED, or mini LED but not limited thereto. As shown in <FIG>, the light source LS may include at least one light emitting source <NUM> disposed between the first substrate <NUM> and the second substrate <NUM>, and the transistors Tr of the active matrix layer AM are electrically connected to the light source LS. For example, at least one light emitting source <NUM> may be disposed in the lighting units LU1, LU2, and LU3 respectively. The light emitting source <NUM> may include LED, micro-LED, mini LED, or quantum dots LEDs (QLEDs or QD-LEDs), but not limited thereto. In some embodiment, the active matrix layer AM, the light source LS, the first light converting units LCU1, the second light converting units LCU2, the third light converting units LCU3, or the shielding structure <NUM> may be disposed on (or formed on) the first substrate <NUM>, but not limited thereto. In some embodiments, the thickness of the shielding structure <NUM> may be greater than or equal to the thicknesses of the first light converting units LCU1, the second light converting units LCU2, and/or the third light converting units LCU3. In some embodiments, the filter layer FL1 may be disposed between the first light converting unit LCU1 and the second substrate <NUM>, the filter layer FL2 may be disposed between the second light converting unit LCU2 and the second substrate <NUM>, and an air gap or a transparent layer may be disposed between the third light converting unit LCU3 and the second substrate <NUM>, but not limited thereto. In some embodiments, the filter layer FL1 and the filter layer FL2 can be selectively removed or replaced.

Claim 1:
A lighting device (<NUM>), comprising:
a substrate (<NUM>);
a plurality of first light converting units (LCU1) comprising a plurality of quantum dots having a particle size between <NUM> nanometer and <NUM> nanometers; and
a light source (LS) emitting a light passing through the plurality of first light converting units (LCU1) and the substrate (<NUM>) to generate a first spectrum comprising a main wave (MW11) and a first sub-wave (SW11), wherein the main wave (MW11) has a main peak (PM11) between <NUM> nanometers (nm) to <NUM>, and the first sub-wave (SW11) has a first sub peak (PS11) between <NUM> to <NUM>, and an intensity of the main peak (PM11) is greater than an intensity of the first sub peak (PS11);
wherein the substrate comprises a plurality of metal ions or a plurality of nanoparticles so that a first transmittance (T1) of the substrate (<NUM>) at a wavelength of the main peak (PM11) is greater than a second transmittance (T2) of the substrate (<NUM>) at a wavelength of the first sub peak (PS11).