Planar lighting device and display device

Abstract

The present application can be applied to the technical field of display devices, for example, to a planar illumination device and a display device using a light emitting element package. The planar illumination device of the present application can include a wiring substrate, a light source including a plurality of first light emitting element packages and a plurality of second light emitting element packages arranged on the wiring substrate, and a light diffusion layer on the light source.

Description

Technical Field

[0001] This invention is applicable to the field of display device technology, for example, it relates to a planar lighting device and a display device using a light-emitting element package. Background Technology

[0002] Recently, display devices with excellent characteristics such as thinness and flexibility have been developed in the field of display technology. Currently, the main commercially available displays are liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs).

[0003] In the realm of displays, liquid crystal displays (LCDs) are used in various devices such as televisions, laptops, desktop computer monitors, and mobile phones.

[0004] Since such LCDs cannot emit light on their own, a light-emitting device is needed to illuminate the LCD panel in order to display image information.

[0005] Since the light-emitting device of an LCD is integrated into the back of the liquid crystal panel, it is called a planar illumination device or backlight unit. The backlight unit can be described as a device that forms a uniform surface light source to provide light to the liquid crystal panel.

[0006] Since such a backlight unit provides a planar light source towards the LCD panel, it can be considered an example of a planar lighting device. Such a planar lighting device is considered to be a light source that can uniformly illuminate a flat surface and is relatively thin.

[0007] As the light source for such backlight units, light-emitting diodes (LEDs) and other light-emitting elements are being used. To achieve a white light source, a combination of a blue LED and a phosphor can be used. For example, a white light source can be achieved by combining a blue LED and a yellow phosphor. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a planar lighting device and a display device that can improve color reproduction.

[0009] The technical problem to be solved by the present invention is to provide a planar lighting device and a display device that can improve light efficiency while achieving high color reproduction.

[0010] The technical problem to be solved by the present invention is to provide a planar lighting device and a display device that can achieve constant color reproduction in panels with different characteristics.

[0011] The planar lighting device of the present invention, for achieving the above-mentioned objectives, includes: a wiring substrate; a light source including a plurality of first light-emitting element packages and a plurality of second light-emitting element packages arranged on the wiring substrate; and a light diffusion layer located on the light source; the first light-emitting element packages include: a first light-emitting element including a first light-emitting layer and a second light-emitting layer stacked on top of each other, the first light-emitting layer emitting light of a first color having a first emission wavelength, and the second light-emitting layer emitting light of a second color having a second emission wavelength; and a first phosphor that is converted from the light emitted by the first light-emitting element to emit light of a third color having a third emission wavelength; the second light-emitting element packages include: a second light-emitting element including a third light-emitting layer having a fourth emission wavelength and emitting light of the first color; a second phosphor that is converted from the light emitted by the second light-emitting element to emit light of the second color having a fifth emission wavelength; and a third phosphor that is converted from the light emitted by the second light-emitting element to emit light of the third color having a sixth emission wavelength.

[0012] In an exemplary embodiment, the full width at half maximum (FWHM) of the spectrum of the first emission band may be narrower than the full WHM of the spectrum of the fourth emission band.

[0013] In an exemplary embodiment, the intensity of the spectrum of the first emission band may be less than the intensity of the spectrum of the fourth emission band.

[0014] In an exemplary embodiment, the full width at half maximum (FWHM) of the spectrum of the fifth emission band may be smaller than the full WHM of the spectrum of the second emission band.

[0015] In an exemplary embodiment, the intensity of the spectrum of the fifth emission band may be less than the intensity of the spectrum of the second emission band.

[0016] In an exemplary embodiment, the first light-emitting element package and the second light-emitting element package may have different color coordinate settings.

[0017] In an exemplary embodiment, the first light-emitting element package and the second light-emitting element package may be arranged adjacent to each other.

[0018] In an exemplary embodiment, the shift of the color coordinates of the second light-emitting element package as a function of current can be less than the shift of the color coordinates of the first light-emitting element package as a function of current.

[0019] In an exemplary embodiment, the first light-emitting element package may include a first-1 light-emitting element and a first-2 light-emitting element that are adjacent to each other.

[0020] In the first-1 light-emitting element and the first-2 light-emitting element, the stacking order of the first light-emitting layer and the second light-emitting layer can be different from each other.

[0021] A display device according to an aspect of the present invention for achieving the above-mentioned objective may include: a planar illumination device for emitting white light; and a liquid crystal display panel located on the planar illumination device, having a color conversion filter for converting the white light of the planar illumination device. The planar illumination device includes: a light source including a plurality of first light-emitting element packages and a plurality of second light-emitting element packages constituting the white light source; and a light diffusion layer located on the light source. The first light-emitting element packages include: a first light-emitting element including a first light-emitting layer and a second light-emitting layer stacked on top of each other, the first light-emitting layer emitting light of a first color having a first emission wavelength, and the second light-emitting layer emitting light of a second color having a second emission wavelength; and a first phosphor that is converted from the light emitted by the first light-emitting element to emit light of a third color having a third emission wavelength. The second light-emitting element packages include: a second light-emitting element including a third light-emitting layer emitting the first color having a fourth emission wavelength; a second phosphor that is converted from the light emitted by the second light-emitting element to emit light of the second color having a fifth emission wavelength; and a third phosphor that is converted from the light emitted by the second light-emitting element to emit light of the third color having a sixth emission wavelength.

[0022] In an exemplary embodiment, the content of at least one of the second phosphor and the third phosphor encapsulated in the second light-emitting element can be adjusted according to the transmission spectrum of the color conversion filter.

[0023] In an exemplary embodiment, the second phosphor may have a first content to have the target color coordinate values ​​of the liquid crystal display panel.

[0024] In an exemplary embodiment, the third phosphor may have a second content to have the target color coordinate values ​​of the liquid crystal display panel.

[0025] According to another aspect of the present invention for achieving the above-mentioned objective, a display device may include: a planar illumination device for emitting white light; and a liquid crystal display panel located on the planar illumination device, having a color conversion filter for converting the white light from the planar illumination device; the planar illumination device includes: a light source including a plurality of light-emitting element packages constituting a white light source; and a light diffusion layer located on the light source; the light-emitting element package includes: a light-emitting element including a first light-emitting layer and a second light-emitting layer stacked on top of each other, the first light-emitting layer emitting light of a first color having a first emission wavelength, and the second light-emitting layer emitting light of a second color having a second emission wavelength; and a phosphor that is converted from the light emitted from the light-emitting element to emit light of a third color having a third emission wavelength.

[0026] According to embodiments of the present invention, the color reproduction of the display device can be improved.

[0027] According to embodiments of the present invention, it is possible to improve the light efficiency while achieving color reproduction of the display device.

[0028] According to embodiments of the present invention, constant color reproduction can be achieved in panels with different characteristics.

[0029] According to embodiments of the present invention, the color reproduction of a display device utilizing a planar illumination device (backlight unit) can be improved to the level of a self-emissive display device, and the target color coordinates of each display device can be achieved. Simultaneously, the luminance of the display device can be maintained or increased.

[0030] Furthermore, according to another embodiment of the present invention, additional technical effects not mentioned herein are also present. Those skilled in the art will understand this from the full spirit of the specification and drawings. Attached Figure Description

[0031] Figure 1 This is a conceptual diagram of a planar lighting device according to the first embodiment of the present invention.

[0032] Figure 2 This is a cross-sectional schematic diagram illustrating an example of a first light-emitting element package suitable for a first embodiment of the planar lighting device of the present invention.

[0033] Figure 3 This is a cross-sectional schematic diagram illustrating another example of a light-emitting element package suitable for a planar lighting device according to a first embodiment of the present invention.

[0034] Figure 4 This is a cross-sectional schematic diagram showing the first light-emitting element of a planar lighting device applicable to the first embodiment of the present invention.

[0035] Figure 5This is a cross-sectional schematic diagram illustrating an example of a second light-emitting element package suitable for a planar lighting device according to a first embodiment of the present invention.

[0036] Figure 6 This is a cross-sectional schematic diagram illustrating an example of a second light-emitting element of a planar lighting device applicable to a first embodiment of the present invention.

[0037] Figure 7 This is a cross-sectional schematic diagram illustrating another example of a second light-emitting element suitable for a planar lighting device according to a first embodiment of the present invention.

[0038] Figure 8 This is a diagram showing the emission spectrum of a first light-emitting element package of a planar lighting device applicable to a first embodiment of the present invention.

[0039] Figure 9 This is a diagram showing the emission spectrum of a second light-emitting element package of a planar lighting device applicable to the first embodiment of the present invention.

[0040] Figure 10 This is a conceptual diagram of a planar lighting device according to a second embodiment of the present invention.

[0041] Figure 11 This is a conceptual diagram of a planar lighting device according to the third embodiment of the present invention.

[0042] Figure 12 This is a schematic diagram illustrating the process of adjusting the target color coordinates of a display device using a planar illumination device according to a second or third embodiment of the present invention.

[0043] Figure 13 This is a schematic diagram illustrating the process of adjusting the target color coordinates of a display device using a planar illumination device according to the first embodiment of the present invention.

[0044] Figures 14 to 19 A cross-sectional schematic diagram of another embodiment of a first light-emitting element package suitable for a planar lighting device according to an embodiment of the present invention is shown.

[0045] Figure 20 and Figure 21 This is a diagram illustrating the differences in the stacking order of the first light-emitting element package according to an embodiment of the present invention.

[0046] Figure 22 This is a diagram illustrating the wavelength variation of the driving current of the first light-emitting element package of a planar lighting device according to an embodiment of the present invention.

[0047] Figure 23 This is a graph showing the emission spectrum of a display device according to an embodiment of the present invention.

[0048] Figure 24 and Figure 25 This is a diagram illustrating a display device according to a first embodiment of the present invention.

[0049] Figure 26 and Figure 27 This is a diagram illustrating a display device according to a second embodiment of the present invention. Detailed Implementation

[0050] The embodiments disclosed in this specification will now be described in detail with reference to the accompanying drawings. Unless otherwise specified in the drawing numbers, the same or similar constituent elements will be assigned the same reference numerals, and repeated descriptions will be omitted. The suffixes "module" and "part" used for constituent elements in the following description are assigned or used interchangeably only for ease of writing and do not inherently distinguish one from another. Furthermore, when describing the embodiments disclosed in this specification, detailed descriptions of related well-known technologies are omitted if it is determined that such detailed descriptions might obscure the main idea of ​​the embodiments disclosed in this specification. It should also be noted that the accompanying drawings are only for aiding understanding of the embodiments disclosed in this specification and should not be construed as limiting the technical concepts disclosed in this specification.

[0051] Furthermore, although the various figures are described for ease of explanation, those skilled in the art can also implement another embodiment by combining at least two figures, which is also within the scope of protection of this invention.

[0052] In addition, when it is mentioned that elements such as layers, regions or substrates exist "on" another constituent element, it can be understood as existing directly on another element or that there may be intermediate elements between them.

[0053] The display device described in this specification is a concept encompassing all display devices that display information on a unit pixel or a set of unit pixels. Therefore, it is not limited to finished products but can also apply to components. For example, a panel that is equivalent to a component of a digital TV is also equivalent to the display device described in this specification. Finished products may include mobile phones, smartphones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation devices, Slate PCs, tablet PCs, Ultrabooks, digital TVs, desktop computers, etc.

[0054] However, those skilled in the art will readily understand that the configuration of the embodiments described in this specification can be applied to display devices even in new product forms developed in the future.

[0055] In addition, the semiconductor light-emitting devices mentioned in this specification include concepts such as LED, Mini LED, and Micro LED, and these can be used interchangeably.

[0056] Figure 1 This is a conceptual diagram of a planar lighting device according to the first embodiment of the present invention.

[0057] Reference Figure 1 The planar lighting device 200 of the first embodiment of the present invention is described.

[0058] Here, the planar illumination device 200 can be used as a backlight unit, or it can be the same device as a backlight unit. Since the backlight unit faces the LCD panels 300, 301 (see reference...) Figure 25 , Figure 27 Since a planar light source is provided on the side, it can be considered an example of a planar lighting device. Such a planar lighting device can uniformly illuminate light through a flat surface and can represent a light source with relatively thin thickness. Hereinafter, the planar lighting device 200 and the backlight unit 200 are referred to and described together using the same reference numerals.

[0059] The planar lighting device 200 of the first embodiment may include a wiring substrate 210, a light source including a plurality of first light-emitting element packages 100 and a plurality of second light-emitting element packages 101 arranged on the wiring substrate 210, and a light diffusion layer 220 (221) located on the light source.

[0060] Here, the light diffusion layer 220 (221) can be implemented as a light diffuser plate 220 or a light guide plate 221 depending on the shape of the backlight unit 200.

[0061] As an exemplary embodiment, an optical sheet 230 may be present on one side of the light diffusion layer 220 (221). As an example, the light diffusion layer 220 (221) may be present between the wiring substrate 210 and the optical sheet 230. As an example, such an optical sheet 230 may include a plurality of layers having optical functions.

[0062] The first light-emitting element package 100 and the second light-emitting element package 101 can be arranged on the wiring substrate 210. Such a plurality of light-emitting element packages 100, 101 can emit white light. The plurality of light-emitting element packages 100, 101 can be arranged at constant intervals on the wiring substrate 210.

[0063] Although not shown separately, the wiring substrate 210 may be provided with connection wiring that is electrically connected to a plurality of first light-emitting element packages 100 and a plurality of second light-emitting element packages 101. As an example, at least a portion of the plurality of first light-emitting element packages 100 and the plurality of second light-emitting element packages 101 can be driven individually through such connection wiring. As an example, the light sources can be driven together or driven differently in different areas. Thus, the configuration in which the light sources are driven differently in different areas can be referred to as local dimming. Detailed explanation of this is omitted here.

[0064] Here, the first light-emitting element package 100 may include having two light-emitting layers 124, 125 (see reference). Figure 4 The stacked light-emitting element 120 (first light-emitting element; reference) Figure 2 Such a first light-emitting element package 100 includes such a first light-emitting element 120 and a phosphor 140 (first phosphor; see reference) excited by light emitted from the first light-emitting element 120. Figure 2 It can emit white light with first color coordinates. This will be explained in detail later.

[0065] The second light-emitting element package 101 may include a light-emitting element 130 (second light-emitting element; see reference) that emits light of one color (first color). Figure 5 Such a second light-emitting element package 101 may include a phosphor 150 (second phosphor; see reference 130) that emits light of a second color when excited by light emitted from the second light-emitting element 130. Figure 5 ) and a phosphor 140 (third phosphor; reference) that emits light of a third color when excited by light emitted from the second light-emitting element 130. Figure 5 This allows it to emit white light with second color coordinates. This will be explained in detail later.

[0066] Thus, the planar lighting device 200 may include a first light-emitting element package 100 and a second light-emitting element package 101 having different color coordinate settings from each other.

[0067] As an example, the color reproduction of the planar lighting device 200 can be improved using the first light-emitting element package 100. The luminance of the planar lighting device 200 can be improved, or its color coordinates can be adjusted, using the second light-emitting element package 101. For example, the first light-emitting element package 100 has high color reproduction, but its color coordinates can be fixed; the second light-emitting element package 101 has high luminance, or its color coordinates can be changed.

[0068] The first light-emitting element package 100 can be used to improve the color reproduction of the planar lighting device 200. On the other hand, the second light-emitting element package 101 can be used to improve the luminance of the planar lighting device 200. In addition, the second light-emitting element package 101 can be used to change the color coordinates of the planar lighting device 200 according to the target color coordinates.

[0069] By utilizing a first light-emitting element package 100 and a second light-emitting element package 101 with different color coordinate settings, the color coordinates of the white light emitted from the planar illumination device 200 can be adjusted according to the target color coordinates. On the other hand, such a planar illumination device 200 is used in a display device 10 (see reference 10). Figure 25 and Figure 27 This enables the display device 10 to realize the target color coordinates. This will be described in detail later.

[0070] Figure 2 This is a cross-sectional schematic diagram illustrating an example of a first light-emitting element package suitable for a first embodiment of the planar lighting device of the present invention. Figure 3 This is a cross-sectional schematic diagram illustrating another example of a light-emitting element package suitable for a planar lighting device according to a first embodiment of the present invention. Figure 4 This is a cross-sectional schematic diagram showing the first light-emitting element of a planar lighting device applicable to the first embodiment of the present invention.

[0071] The first light-emitting element package 100 may include a first light-emitting element 120 and a first phosphor 140. The first light-emitting element 120 includes a first light-emitting layer 124 and a second light-emitting layer 125 stacked on top of each other. The first light-emitting layer 124 emits light of a first color in a first emission band, and the second light-emitting layer 125 emits light of a second color in a second emission band. The first phosphor 140 is converted from the light emitted from the first light-emitting element 120 to emit light of a third color in a third emission band.

[0072] Here, as an example, the first color can be blue light, the second color can be green light, and the third color can be red light. In other words, the first emission wavelength can be equivalent to the wavelength of blue light, the second emission wavelength can be equivalent to the wavelength of green light, and the third wavelength can be equivalent to the wavelength of red light.

[0073] Here, the positions of the first light-emitting layer 124 and the second light-emitting layer 125 may be interchanged with each other. Although in Figures 2 to 4 an example in which the second light-emitting layer 125 is disposed on the first light-emitting layer 124 is shown, conversely, the first light-emitting layer 124 may also be disposed on the second light-emitting layer 125.

[0074] Although in Figure 4 , the first light-emitting layer 124 and the second light-emitting layer 125 are shown as the active layer of the light-emitting element 120 having a multiple quantum well (MQW) structure, but in Figure 2 and Figure 3 , they may represent light-emitting portions having a multilayer structure that respectively emit a first color and a second color.

[0075] Referring together to Figure 2 and Figure 4 , as an example, the first light-emitting element package 100 may be configured in the form of the first light-emitting element package 100a as shown in Figure 2 .

[0076] Such a first light-emitting element package 100a may be configured to include a package main body 110 having a reflective cup shape 111, a first light-emitting element 120 disposed inside the package main body 110, a first molding layer 170 covering the first light-emitting element 120 and disposed inside the reflective cup shape 111, and a first phosphor 140 disposed inside the first molding layer 170.

[0077] Here, the first molding layer 170 may be formed using a resin material such as epoxy resin or silicone. The first phosphor 140 may be in a powder form, and is dispersedly disposed inside the first molding layer 170.

[0078] Although not illustrated, the package main body 110 includes circuit lines, and the first light-emitting element 120 is mounted inside the package main body 110 and may be electrically connected to such circuit lines. The package main body 110 may include pads capable of being electrically connected to the outside. Detailed descriptions of such configurations are omitted.

[0079] Referring to Figure 3 and Figure 4 , as an example, the first light-emitting element package 100 may be configured in the form of the first light-emitting element package 100b shown in Figure 3 .

[0080] Figure 3 An example of the light-emitting element package 100b in a chip scale package (CSP) form is shown, in which the second molding layer 171 in which the first phosphor 140 is dispersed is coated on the light-emitting element 120 to constitute the package.

[0081] Such a first light-emitting element package 100b can be configured to include a second molding layer 171 coated on the outside of the first light-emitting element 120 and a first phosphor 140 dispersed within the second molding layer 171.

[0082] Reference Figure 3 A second molding layer 171 of constant thickness can be provided on the outer surface of the light-emitting element 120, excluding the bottom surface of the light-emitting element 120.

[0083] Reference Figure 4 The diagram schematically shows a cross-section of a first light-emitting element 120a according to one embodiment.

[0084] Such a first light-emitting element 120a can be provided on a substrate 121 in sequence with a first conductivity type (e.g., N-type) semiconductor layer 122, a first light-emitting layer 124, a blocking layer 126, a second light-emitting layer 125, and a second conductivity type (e.g., P-type) semiconductor layer 123.

[0085] Here, the first conductivity semiconductor layer 122, as an example, may include an N-type nitride semiconductor (N-GaN) layer. The second conductivity semiconductor layer 123, as an example, may include a P-type nitride semiconductor (P-GaN) layer.

[0086] The barrier layer 126 is a conductive semiconductor layer, and may also include a nitride-based semiconductor. The barrier layer 126 may include an N-type or P-type conductive semiconductor layer, or may include both N-type and P-type semiconductor layers.

[0087] A first electrode 127 electrically connected to the first conductive semiconductor layer 122 can be disposed on one side of the second conductive semiconductor layer 123. In this case, the first electrode 127 and the second conductive semiconductor layer 123 are insulated from each other, and the first electrode 127 can be connected to the first conductive semiconductor layer 122 through a structure such as a through hole.

[0088] A second electrode 128 electrically connected to the second conductive semiconductor layer 123 may be provided on the other side of the second conductive semiconductor layer 123.

[0089] As described above, the positions of the first light-emitting layer 124 and the second light-emitting layer 125 can be interchanged.

[0090] Thus, the first light-emitting element 120a can emit light of the first color and light of the second color together.

[0091] Figure 5 This is a cross-sectional schematic diagram illustrating an example of a second light-emitting element package suitable for a planar lighting device according to a first embodiment of the present invention. Figure 6This is a cross-sectional schematic diagram illustrating an example of a second light-emitting element of a planar lighting device applicable to a first embodiment of the present invention. Figure 7 This is a cross-sectional schematic diagram illustrating another example of a second light-emitting element suitable for a planar lighting device according to a first embodiment of the present invention.

[0092] The second light-emitting element package 101 may include second light-emitting elements 130 and 130a, a second phosphor 150, and a third phosphor 140. The second light-emitting elements 130 and 130a include third light-emitting layers 134 and 138 that emit light of a first color having a fourth emission band. The second phosphor 150 is converted from the light emitted by the second light-emitting elements 130 and 130a to emit light of a second color having a fifth emission band. The third phosphor 140 is converted from the light emitted by the second light-emitting elements to emit light of a third color having a sixth emission band.

[0093] Here, as an example, the first color can be blue light, the second color can be green light, and the third color can be red light. In other words, the first emission wavelength can be equivalent to the wavelength of blue light, the second emission wavelength can be equivalent to the wavelength of green light, and the third wavelength can be equivalent to the wavelength of red light.

[0094] The first phosphor 140 and the third phosphor 140 may comprise the same phosphor material. Therefore, they are described using the same reference numerals. However, the first phosphor 140 and the third phosphor 140 may also comprise phosphors of different materials that emit light of the same color. In this case, the emission peak of the spectrum of the first phosphor 140 and the emission peak of the spectrum of the second phosphor 140 may at least partially overlap.

[0095] Reference Figure 5 As an example, the second light-emitting element package 101 may include: a package body 110, including a reflective cup shape 111; a second light-emitting element 130, located within the package body 110; a first molding layer 170, covering the second light-emitting element 130, located within the reflective cup shape 111; and a second phosphor 150 and a third phosphor 140, located within the first molding layer 170.

[0096] Here, the first molding layer 170 can be formed using resin materials such as epoxy resin or silicone. The first phosphor 140 can be dispersed in the first molding layer 170 in powder form.

[0097] Although not shown, the package body 110 includes circuitry, and a first light-emitting element 120 can be mounted within the package body 110 and electrically connected to such circuitry. The package body 110 may include pads capable of external electrical connection. Detailed description of this configuration is omitted.

[0098] On the other hand, the second light-emitting element package 101 can of course also adopt such... Figure 3 The chip-scale package (CSP) configuration described herein is implemented by coating a second molding layer 171 in which a second phosphor 150 and a third phosphor 140 are dispersed to form the package.

[0099] The second light-emitting element used in the second light-emitting element package 101 may include, for example: Figure 6 The horizontal light-emitting element 130 shown or as... Figure 7 The light-emitting element 130a is shown in the form of a flip-chip.

[0100] Reference Figure 6 As an example of the second light-emitting element package 101, the second light-emitting element 130 can be a light-emitting element that emits blue light. Such a second light-emitting element 130 can have a first conductivity type (e.g., N-type) semiconductor layer 132, a light-emitting layer 134, and a second conductivity type (e.g., P-type) semiconductor layer 133 sequentially disposed on a substrate 131.

[0101] Here, the first conductivity semiconductor layer 132, as an example, may include an N-type nitride semiconductor (N-GaN) layer. The second conductivity semiconductor layer 133, as an example, may include a P-type nitride semiconductor (P-GaN) layer.

[0102] The first conductive semiconductor layer 132 may have a partial opening, and the first electrode 135 is located on the opening surface. A second electrode 136 electrically connected to the second conductive semiconductor layer 133 may be disposed on the second conductive semiconductor layer 133.

[0103] Reference Figure 7 As another example of its use in the second light-emitting element package 101, the second light-emitting element 130a can be a light-emitting element that emits blue light. Such a second light-emitting element 130a can have a first conductivity type (e.g., N-type) semiconductor layer 132, a light-emitting layer 138, and a second conductivity type (e.g., P-type) semiconductor layer 137 sequentially disposed on a substrate 131.

[0104] On one side of the second conductive semiconductor layer 137, a first electrode 139 electrically connected to the first conductive semiconductor layer 132 can be provided. At this time, the first electrode 139 and the second conductive semiconductor layer 137 are insulated from each other, and the first electrode 139 can be connected to the first conductive semiconductor layer 132 through a structure such as a through-hole.

[0105] A second electrode 136 electrically connected to the second conductive semiconductor layer 137 may be provided on the other side of the second conductive semiconductor layer 137.

[0106] Figure 8 This is a diagram showing the emission spectrum of a first light-emitting element package of a planar lighting device applicable to a first embodiment of the present invention. Figure 9 This is a diagram showing the emission spectrum of a second light-emitting element package of a planar lighting device applicable to the first embodiment of the present invention.

[0107] As described above, the planar lighting device 200 may include a first light-emitting element package 100 and a second light-emitting element package 101 having different color coordinate settings from each other.

[0108] As an example, the first light-emitting element package 100 and the second light-emitting element package 101 can be arranged adjacent to each other on the wiring substrate 210.

[0109] As an example, the first light-emitting element package 100 and the second light-emitting element package 101 can be arranged alternately on the wiring substrate 210.

[0110] Reference Figure 8 The image shows the emission spectrum of a first light-emitting element package 100 that emits light from a first light-emitting element 120 and a first phosphor 140. In the first light-emitting element 120, a first light-emitting layer 124 and a second light-emitting layer 125 emit light of a first color and light of a second color, respectively.

[0111] Reference Figure 9 The image shows the emission spectrum of a second light-emitting element package 101, which emits light from a third light-emitting layer 134, 138, a second phosphor 150, and a third phosphor 140. The third light-emitting layer 134, 138 emits light of a first color, the second phosphor 150 emits light of a second color, and the third phosphor 140 emits light of a third color.

[0112] The following description uses an example where the first color is blue, the second color is green, and the third color is red. However, the present invention is not limited thereto.

[0113] The first and fourth emission bands described above include a main peak value, and the bands of the main peak values ​​in the first and fourth emission bands can at least partially overlap with each other. As an example, the first emission band of light emitted from the first light-emitting element package 100 and the fourth emission band of light emitted from the second light-emitting element package 101 can correspond to blue light.

[0114] The second and fifth emission bands described above include a main peak value, and the bands of the main peak values ​​in such second and fifth emission bands may at least partially overlap with each other. As an example, the second emission band of light emitted from the first light-emitting element package 100 and the fifth emission band of light emitted from the second light-emitting element package 101 may correspond to blue light.

[0115] The third and sixth emission bands described above include a main peak value, and the bands of the main peak values ​​in such third and sixth emission bands may at least partially overlap with each other. As an example, the third emission band of light emitted from the first light-emitting element package 100 and the sixth emission band of light emitted from the second light-emitting element package 101 may correspond to blue light.

[0116] Reference Figure 8 and Figure 9 It can be seen that the full width at half maximum (FWHM) of the first color light B and the second color light G emitted from the first light-emitting element package 100 is different from that of the first color light B and the second color light G emitted from the second light-emitting element package 101.

[0117] As an example, the full width at half maximum (FWHM) of light B of the first color emitted from the first light-emitting element package 100 may be smaller than the full WHM of light B of the first color emitted from the second light-emitting element package 101, and the full WHM of light G of the second color emitted from the first light-emitting element package 100 may be smaller than the full WHM of light G of the second color emitted from the second light-emitting element package 101.

[0118] On the other hand, the third color light R emitted from the first light-emitting element package 100 and the third color light R emitted from the second light-emitting element package 101 may not have a significant difference in terms of full width at half maximum (FWHM).

[0119] Thus, the full width at half maximum (FWHM) of the main peak of the emission spectrum emitted from the first light-emitting element package 100 can be relatively small. This improves color purity through the emission spectrum emitted from the first light-emitting element package 100. Consequently, the color purity of white light emitted from the first light-emitting element package 100 can be improved. The color reproducibility of the planar lighting device 200 including such a light-emitting element package 100 can be further improved.

[0120] The emission peak of the spectrum of the first emission band of the light emitted from the first light-emitting element package 100 can be located within the emission peak of the spectrum of the fourth emission band of the light emitted from the second light-emitting element package 101 (refer to...). Figure 23 ).

[0121] The intensity of the spectrum of the first emission band of light emitted from the first light-emitting element package 100 may be less than the intensity of the spectrum of the fourth emission band of light emitted from the second light-emitting element package 101 (see reference). Figure 23 ).

[0122] The emission peak of the second emission band of the light emitted from the first light-emitting element package 100 can be located within the emission peak of the fifth emission band of the light emitted from the second light-emitting element package 101 (see reference). Figure 23 ).

[0123] The intensity of the spectrum of the second emission band of light emitted from the first light-emitting element package 100 may be less than the intensity of the spectrum of the fifth emission band of light emitted from the second light-emitting element package 101 (see reference). Figure 23 ).

[0124] Figure 10 This is a conceptual diagram of a planar lighting device according to a second embodiment of the present invention.

[0125] Reference Figure 10 The planar lighting device 202 of the second embodiment may include a wiring substrate 210, a light source including a plurality of first light-emitting element packages 100 located on the wiring substrate 210, and a light diffusion layer 220 (221) located on the light source.

[0126] Here, the light diffusion layer 220 (221) can be implemented as a light diffuser plate 220 or a light guide plate 221 depending on the shape of the backlight unit 200.

[0127] As an exemplary embodiment, an optical sheet 230 may be disposed on one side of the light diffusion layer 220 (221). As an example, the light diffusion layer 220 (221) may be disposed between the wiring substrate 210 and the optical sheet 230. As an example, such an optical sheet 230 may include a plurality of layers having optical functions.

[0128] The first light-emitting element package 100 can be arranged on the wiring substrate 210. Such a plurality of light-emitting element packages 100 can emit white light. The plurality of light-emitting element packages 100 can be arranged at constant intervals on the wiring substrate 210.

[0129] Although not shown separately, the wiring substrate 210 may be provided with connection wiring that is electrically connected to a plurality of first light-emitting element packages 100. As an example, at least a portion of the plurality of first light-emitting element packages 100 can be driven individually through such connection wiring. As an example, the light sources can be driven together or driven differently according to different areas. Thus, the configuration in which the light sources are driven differently according to different areas is called local dimming. A detailed description of this is omitted here.

[0130] Here, the first light-emitting element package 100 may include having two light-emitting layers 124, 125 (see reference). Figure 4 The stacked light-emitting element 120 (first light-emitting element; reference) Figure 2 Such a first light-emitting element package 100 may include such a first light-emitting element 120 and a phosphor 140 (first phosphor; see reference 120) excited by light emitted from the first light-emitting element 120. Figure 2 It emits white light with the first color coordinate.

[0131] As an example, the color reproduction of the planar lighting device 200 can be improved by using the first light-emitting element package 100. Such a planar lighting device 200 is used in the display device 10 (see reference). Figure 25 and Figure 27 This allows the display device 10 to display the target color coordinates.

[0132] This second embodiment can utilize a plurality of first light-emitting element packages 100 to realize the planar lighting device 202. This improves the color purity of white light emitted from the first light-emitting element packages 100. Furthermore, it enhances the color reproduction of the planar lighting device 202 including such light-emitting element packages 100.

[0133] Apart from this, the undescribed parts are equally applicable to the matters described in the first embodiment above. Therefore, repeated descriptions are omitted.

[0134] Figure 11 This is a conceptual diagram of a planar lighting device according to the third embodiment of the present invention.

[0135] Reference Figure 11 The planar lighting device 203 of the third embodiment may include a wiring substrate 210, a light source including a plurality of first light-emitting element packages 100 arranged on the wiring substrate 210, and a light diffusion layer 220 (221) located on the light source.

[0136] As an exemplary embodiment, an optical sheet 230 may be disposed on one side of the light diffusion layer 220 (221). As an example, the light diffusion layer 220 (221) may be disposed between the wiring substrate 210 and the optical sheet 230. As an example, such an optical sheet 230 may include a plurality of layers having optical functions.

[0137] On one side of the light diffusion layer 220 (221) or on one side of the optical sheet 230, a high color filter 260 capable of adjusting the color coordinates of the light emitted from the first light-emitting element package 100 may also be provided. As an example, the light emitted from the first light-emitting element package 100 may have fixed color coordinates, such fixed color coordinates can be adjusted by the high color filter 260.

[0138] As an example, the high-chroma filter 260 can be located between the light diffusion layer 220 (221) and the optical filter 230.

[0139] In addition, the matters not described herein are equally applicable to those described above in the first or second embodiment. Therefore, repeated descriptions are omitted.

[0140] Figure 12 This is a schematic diagram illustrating the process of adjusting the target color coordinates of a display device using the planar illumination apparatus of the second and third embodiments of the present invention. Figure 13 This is a schematic diagram illustrating the process of adjusting the target color coordinates of a display device using a planar illumination device according to the first embodiment of the present invention.

[0141] As described above, display devices 10 and 11 can be fabricated using planar lighting devices 200, 202, and 203 (see reference). Figure 25 and Figure 27 ).

[0142] First, refer to Figure 12 This describes the process of adjusting the target color coordinates of a display device using the planar illumination device of the second or third embodiment.

[0143] One embodiment of the display devices 10 and 11 may be configured to include a planar illumination device 202 and 203 that emits white light and a liquid crystal display panel 300, wherein the liquid crystal display panel 300 is located on the planar illumination device 202 and 203 and is provided with a color conversion filter 310 for converting the white light from the planar illumination device 200 (see reference). Figure 25 and Figure 27 At this time, the planar lighting device 200 may include a light source, which includes a plurality of first light-emitting element packages 100 constituting a white light source. Using the first light-emitting element packages 100 to implement the planar lighting devices 202 and 203 improves color reproduction compared to using light-emitting element packages containing blue light-emitting elements and green and red phosphors.

[0144] The first light-emitting element package 100 can be used to adjust the color coordinates of the white light emitted from the planar illumination device 200 according to the target color coordinates. On the other hand, such a planar illumination device 200 can be used in the display device 10 (see reference). Figure 25 and Figure 27 This allows display devices 10 and 11 to display the target color coordinates.

[0145] First, refer to Figure 12As an example, in (a), the target color coordinates (CIE) of the display module combining the planar lighting device 200 and the display panel 300 can be set. Display devices 10 and 11 including such a display module may be required to have uniform color coordinates. As an example, the target color coordinates (Cx, Cy) can be (0.281, 0.288)(Cx, Cy: 0.281, 0.288).

[0146] At this point, as an example, the color coordinates of different panels may differ. For example, refer to... Figure 12 (a) may have different color coordinates: the color coordinates of panel A 301 are (Cx, Cy: 0.269, 0.278), the color coordinates of panel B 302 are (Cx, Cy: 0.281, 0.288), and the color coordinates of panel C 303 are (Cx, Cy: 0.291, 0.274).

[0147] As described above, excellent color reproduction can be achieved using the first light-emitting element package 100. In this case, the color coordinates of the light emitted from the first light-emitting element package 100 can be fixed according to the first light-emitting element 120. Since light of a first color (e.g., blue) and light of a second color (e.g., green) are emitted from the light-emitting layer of the first light-emitting element 120 in the first light-emitting element package 100, a constant emission wavelength can be achieved.

[0148] Therefore, in order to achieve the target color coordinates by combining with panels 301, 302, and 303 that have different color coordinates from each other, a first light-emitting element package 100 that emits light with different color coordinates from each other can be used.

[0149] Reference Figure 12 (b) can utilize at least a portion of different first light-emitting element packages 100 that emit light with different color coordinates. As an example, in the first planar lighting device 200a, the light emitted from the first light-emitting element package 100 can have color coordinates (Cx, Cy: 0.287, 0.245), in the second planar lighting device 200b, the light emitted from the first light-emitting element package 100 can have color coordinates (Cx, Cy: 0.275, 0.235), and in the third planar lighting device 200c, the light emitted from the first light-emitting element package 100 can have color coordinates (Cx, Cy: 0.265, 0.249).

[0150] In this way, each panel 301, 302, 303 can be modified (adjusted) by using at least a portion of the different first light-emitting element packages 100 that emit light with different color coordinates.

[0151] Therefore, referring to Figure 12(c) In each display device that combines each panel 301, 302, 303 and the planar lighting devices 200a, 200b, 200c, a constant target color coordinate (Cx, Cy; 0.281, 0.288) can be achieved.

[0152] In this way, the color reproduction of the display device 10 using the planar illumination device (backlight unit) 200 can be improved to the level of a self-emissive display device, and the target color coordinates of each display device 10, 11 can be achieved. Furthermore, the brightness of the display device 10 can be maintained or improved.

[0153] Next, refer to Figure 13 This describes the process of adjusting the target color coordinates of the display device using the planar illumination device of the first embodiment.

[0154] One embodiment of the display devices 10 and 11 may be configured to include a planar illumination device 200 that emits white light and a liquid crystal display panel 300, wherein the liquid crystal display panel 300 is located on the planar illumination device 200 and is provided with a color conversion filter 310 for converting the white light from the planar illumination device 200 (see reference). Figure 25 and Figure 27 At this time, the planar lighting device 200 may include a plurality of first light-emitting element packages 100 constituting a white light source and a light source including a plurality of second light-emitting element packages 101.

[0155] As described above, the first light-emitting element package 100 can be used to improve the color reproduction of the planar lighting device 200 or the display devices 10, 11. On the other hand, the second light-emitting element package 101 can be used to improve the luminance of the planar lighting device 200 or the display devices 10, 11. In addition, the second light-emitting element package 101 can be used to change the color coordinates of the planar lighting device 200 or the display devices 10, 11 according to the target color coordinates.

[0156] By utilizing a first light-emitting element package 100 and a second light-emitting element package 101 with different color coordinate settings, the color coordinates of the white light emitted from the planar illumination device 200 can be adjusted according to the target color coordinates. On the other hand, such a planar illumination device 200 can be used in display devices 10, 11 (see reference 10). Figure 25 and Figure 27 This causes display devices 10 and 11 to display the target color coordinates.

[0157] First, refer to Figure 13As an example, in (a), the target color coordinates (CIE) of the display module combining the planar lighting device 200 and the display panel 300 can be set. Display devices 10 and 11 including such a display module may be required to have uniform color coordinates. As an example, the target color coordinates (Cx, Cy) can be (0.281, 0.288)(Cx, Cy: 0.281, 0.288).

[0158] At this point, as an example, the color coordinates of different panels may differ. For example, refer to... Figure 13 (a) may have different color coordinates: the color coordinates of panel A 301 are (Cx, Cy: 0.269, 0.278), the color coordinates of panel B 302 are (Cx, Cy: 0.281, 0.288), and the color coordinates of panel C 303 are (Cx, Cy: 0.291, 0.274).

[0159] As described above, although excellent color reproduction can be achieved using the first light-emitting element package 100, the first light-emitting element package 100 can be in a fixed state. Since light of a first color (e.g., blue) and light of a second color (e.g., green) are emitted from the light-emitting layer of the first light-emitting element 120 in the first light-emitting element package 100, a constant emission wavelength can be achieved.

[0160] On the other hand, the second light-emitting element package 101 can realize the change (adjustment) of color coordinates. Since the second color light emitted from the second light-emitting element package 101 is emitted by the second phosphor 150, the color coordinates of the light can be changed by using the second light-emitting element package 101.

[0161] Reference Figure 13 In (b), the color coordinates of the white light emitted from the first light-emitting element package 100, represented by BG, can be fixed at (Cx, Cy: 0.275, 0.235). However, the light emitted from the second light-emitting element package 101, represented by B, can have different values ​​in each panel to achieve the target color coordinates. As an example, in the first planar lighting device 200d, the light emitted from the second light-emitting element package 101 can have color coordinates of (Cx, Cy: 0.299, 0.255); in the second planar lighting device 200e, the light emitted from the second light-emitting element package 101 can have color coordinates of (Cx, Cy: 0.275, 0.235); and in the third planar lighting device 200f, the light emitted from the second light-emitting element package 101 can have color coordinates of (Cx, Cy: 0.255, 0.263).

[0162] Thus, the color coordinates of the light emitted from the second light-emitting element package 101 can be changed (adjusted) according to each panel 301, 302, 303. Although the light emitted from the light-emitting elements 120 and 130 has fixed color coordinates, the phosphors 140 and 150 that emit converted light by being excited by the light emitted from such light-emitting elements 120 and 130 can be changed according to their content, substances, etc.

[0163] As an example, the content of at least one of the second phosphor 150 and the third phosphor 140 in the second light-emitting element package 101 can be adjusted according to the transmission spectrum of the color conversion filter 310 of the display devices 10 and 11. As an example, the second phosphor 150 may have a first content to have the target color coordinate value of the liquid crystal display panel 300. As an example, the third phosphor 140 may have a second content to have the target color coordinate value of the liquid crystal display panel 300.

[0164] Therefore, referring to Figure 13 (c) In each display device that combines each panel 301, 302, 303 and each planar lighting device 200d, 200e, 200f, a constant target color coordinate (Cx, Cy; 0.281, 0.288) can be achieved.

[0165] In this way, the color reproduction of the display devices 10 and 11 using the planar illumination device 200 (backlight unit) can be improved to the level of self-emissive display devices, and the target color coordinates of each display device 10 and 11 can be achieved. Furthermore, the luminance of the display devices 10 and 11 can be maintained or improved.

[0166] On the other hand, since the color coordinate shift of the second light-emitting element package 101 with the change of current tends to be smaller than that of the first light-emitting element package 100 with the change of current, by providing the first light-emitting element package 100 and the second light-emitting element package 101 together in the planar lighting device 200, the color change rate according to the driving current can be reduced.

[0167] Figures 14 to 19 This is a cross-sectional schematic diagram illustrating another embodiment of a first light-emitting element package suitable for an embodiment of the present invention. Figure 14 , Figure 16 as well as Figure 18 Another embodiment of the first light-emitting element package is shown. Figure 15 , Figure 17 as well as Figure 19 An implementation example of a first light-emitting element applied to these first light-emitting element packages is shown.

[0168] Reference Figure 14The diagram illustrates an example of a first light-emitting element package 102 comprising a plurality of light-emitting elements (first light-emitting elements) 120a. As an example, the first light-emitting element package 102 may include two light-emitting elements 120 adjacent to each other. These two light-emitting elements 120a may be referred to as the first-1 light-emitting element and the first-2 light-emitting element, respectively.

[0169] As described above, the first light-emitting element 120a may include a first light-emitting layer 124 and a second light-emitting layer 125 stacked on top of each other. The first light-emitting layer 124 emits light of a first color having a first emission wavelength, and the second light-emitting layer 125 emits light of a second color having a second emission wavelength. Here, the positions of the first light-emitting layer 124 and the second light-emitting layer 125 can be interchanged.

[0170] Reference Figure 15 Two light-emitting elements 120a having the same positions of the first light-emitting layer 124 and the second light-emitting layer 125 can be arranged adjacent to each other. Such a light-emitting element 120a may have the second light-emitting layer 125 disposed on the first light-emitting layer 124.

[0171] Such a first light-emitting element package 102 can be configured to include: a package body 110 having a reflective cup shape 111, two first light-emitting elements 120a located within the package body 110 and adjacent to each other, a first molding layer 170 covering the first light-emitting elements 120a and located within the reflective cup shape 111, and a first phosphor 140 located within the first molding layer 170.

[0172] Reference Figure 16 An example of a first light-emitting element package 102a including a plurality of light-emitting elements (first light-emitting elements) 120b is shown.

[0173] Reference Figure 17 Two light-emitting elements 120b having the same positions of the first light-emitting layer 124 and the second light-emitting layer 125 can be arranged adjacent to each other. In such a light-emitting element 120b, the first light-emitting layer 124 can be disposed on the second light-emitting layer 125.

[0174] Reference Figure 18 and Figure 19 In the first light-emitting element package 102b, two light-emitting elements 120a and 120b, which have different positions of the first light-emitting layer 124 and the second light-emitting layer 125, can be located in adjacent positions.

[0175] As an example, the light-emitting element 120a with the second light-emitting layer 125 disposed on the first light-emitting layer 124 and the light-emitting element 120b with the first light-emitting layer 124 disposed on the second light-emitting layer 125 can be disposed adjacent to each other in the first light-emitting element package 102b.

[0176] Figure 20 and Figure 21 This is a diagram illustrating the differences in the stacking order of the first light-emitting element package according to an embodiment of the present invention.

[0177] Figure 20 An example of a light-emitting element package 100a is shown, in which a light-emitting element 120 having a second light-emitting layer 125 disposed on a first light-emitting layer 124 is applied. Figure 21 An example of a light-emitting element package 100c is shown, in which a light-emitting element 120 having a first light-emitting layer 124 disposed on a second light-emitting layer 125 is applied.

[0178] In such light-emitting element packages 100a and 100c, such as Figure 20 As shown in the example, when the first emitting layer 125 emitting light of a first color (e.g., blue) is disposed on the upper side, the amount of light may be relatively reduced because light of a second color (e.g., green) passes through the first emitting layer 125. As a result, the intensity of green light weakens, and color reproducibility may be relatively reduced. Conversely, since blue light is emitted directly, the energy that can excite the first phosphor 140 is relatively large, thus enabling high brightness.

[0179] In such light-emitting element packages 100a and 100c, such as Figure 21 As shown in the example, when the second light-emitting layer 124 emitting light of a second color (e.g., green) is disposed on the upper side, the energy that can excite the first phosphor 140 may be relatively weaker because light of the first color (e.g., blue) passes through the second light-emitting layer 124. Conversely, since green light is emitted directly, color reproducibility can be improved.

[0180] The planar lighting device 200 of this embodiment of the invention can selectively utilize light-emitting element packages 100a and 100c having different configurations of light-emitting layers 124 and 125.

[0181] Figure 22 This is a diagram illustrating the wavelength variation of the driving current of the first light-emitting element package of a planar lighting device according to an embodiment of the present invention.

[0182] As described above, when the planar illumination device 200 is applied to the display devices 10 and 11, the wavelength of light in a certain band may shift due to the change in current according to the screen.

[0183] As an example, in the first light-emitting element package 100, the wavelength offset of the current of the first light-emitting element 120 can be greater than the wavelength offset of the second light-emitting element 130 applicable to the second light-emitting element package 101.

[0184] Thus, since the color coordinate shift of the second light-emitting element package 101 with the change of current tends to be less than that of the first light-emitting element package 100 with the change of current, by providing the first light-emitting element package 100 and the second light-emitting element package 101 together in the planar lighting device 200, the color change rate according to the driving current can be reduced.

[0185] Figure 23 This is a graph showing the emission spectrum of a display device according to an embodiment of the present invention.

[0186] Figure 23 The spectrum of light emitted from display devices 10 and 11 is shown in combination. Figure 23 The upper side of the image shows the transmission area of ​​panel 300. As an example, the transmission bands of the color conversion filter (color filter) 310 through panel 300 are shown. Bp shows the transmission band through the blue filter, Gp shows the transmission band through the green filter, and Rp shows the transmission band through the red filter.

[0187] On the other hand, Figure 23 In the diagram, the spectrum marked with BG shows the emission spectrum of the first light-emitting element package 100, and the spectrum marked with B shows the emission spectrum of the second light-emitting element package 101.

[0188] As is well known, all colors can be represented using the three primary colors: red (R), green (G), and blue (B). If red (R) light, green (G) light, and blue (B) light are all mixed, white light is produced. If the light source passes through a color conversion filter (color filter) 310, the colors can be distinguished.

[0189] Therefore, when a color filter with high extreme values ​​corresponding to the wavelengths of each color meets an input light source, the output light can be the region corresponding to the wavelength of the color filter multiplied by the value of the input light source.

[0190] At this point, the output light is clearly distinguished by color, and the higher the extreme value, the more accurately the colors will not mix. Therefore, color filters are preferably designed to allow light to pass through clearly without mixing with other colors, and light sources with clearly distinguishable output wavelengths of red (R), green (G), and blue (B) light are more advantageous.

[0191] Therefore, as described above, a first light-emitting element package 100 with relatively distinct wavelengths of red (R) light, green (G) light, and blue (B) light can be used to achieve a high-output, high-purity color that matches the color filter.

[0192] On the other hand, by using a second light-emitting element package 101 that has relatively high light intensity, adjustable color coordinates, and relatively small wavelength shift according to current, the target color coordinates of each display device 10, 11 can be easily achieved.

[0193] Figure 24 and Figure 25 This is a diagram illustrating a display device according to a first embodiment of the present invention.

[0194] Reference Figure 24 and Figure 25 This illustrates an example of a display device 10 that includes a direct-lit planar illumination device 200, which uses the first light-emitting element package 100 and the second light-emitting element package 101 of the first embodiment described above as light sources. An example of a display device 10 including the planar illumination device 200 could be a liquid crystal display device 10.

[0195] The liquid crystal display device 10 may have a planar illumination device 200 disposed on the lower cover 340. Such a planar illumination device 200 may include a first light-emitting element package 100 and a second light-emitting element package 101 according to embodiments of the present invention. Figure 24 and Figure 25 The diagram exemplarily illustrates a planar lighting device 200 in which the first light-emitting element package 100 and the second light-emitting element package 101 of the first embodiment are used as light sources. Alternatively, the planar lighting device 200 may also be implemented using the first light-emitting element package 100 as a light source.

[0196] A light diffuser plate 220 can be disposed on the light source. An optical sheet 230 can be disposed on such a light diffuser plate 220. Here, the optical sheet 230 may include a plurality of functional thin films 231, 232, and 233.

[0197] A reflector 250 may be provided between the planar lighting device 200 and the lower cover 340.

[0198] A liquid crystal display panel 300 can be mounted on the planar lighting device 200. Furthermore, this liquid crystal display panel 300 can be supported by a molding frame 330. A top cover 320 can be mounted on the molding frame 330.

[0199] Although not shown separately, the liquid crystal display panel 300 may include a liquid crystal layer, a color conversion filter (color filter) 310, a polarizer, etc.

[0200] Figure 26 and Figure 27 This is a diagram illustrating a display device according to a second embodiment of the present invention.

[0201] Reference Figure 26 and Figure 27The illustration shows an example of a display device 11 that includes a side-mounted planar illumination device 201, which uses the first light-emitting element package 100 and the second light-emitting element package 101 of the first embodiment described above as light sources. An example of a display device 11 including the planar illumination device 201 could be a liquid crystal display device 10.

[0202] The side-mounted planar lighting device 201 can diffuse light using a light guide plate 221. Optical sheets 230 can be disposed on such a light guide plate 221. Here, the optical sheets 230 may include a plurality of functional thin films 231, 232, and 233.

[0203] In the liquid crystal display device 11, a planar illumination device 201 can be provided on the lower cover 340. Such a planar illumination device 201 may include the first light-emitting element package 100 and the second light-emitting element package 101 according to embodiments of the present invention. Figure 26 and Figure 27 The diagram exemplarily illustrates a planar lighting device 201 in which the first light-emitting element package 100 and the second light-emitting element package 101 of the first embodiment are used as light sources. Alternatively, the planar lighting device 201 may also be implemented using the first light-emitting element package 100 as a light source.

[0204] A reflector 250 may be provided between the planar lighting device 201 and the lower cover 340.

[0205] A liquid crystal display panel 300 can be mounted on the planar lighting device 201. Furthermore, this liquid crystal display panel 300 can be supported by a molding frame 330. A top cover 320 can be mounted on the molding frame 330.

[0206] A heat-conducting strip 270 can be provided on one side of the molding frame 330, and a wiring substrate 211 can be provided on the heat-conducting strip 270. Light can be irradiated from the light source toward the light guide plate 221.

[0207] Although not shown separately, the liquid crystal display panel 300 may include a liquid crystal layer, a color conversion filter 310 (color filter), a polarizer, etc.

[0208] The features, structures, effects, etc., described in the above embodiments are included in at least one embodiment of the present invention, but are not necessarily limited to one embodiment. Furthermore, the features, structures, and effects exemplified in the various embodiments can be combined or modified and implemented by those skilled in the art to which the embodiments pertain. Therefore, it should be understood that content related to such combinations and modifications is included within the scope of the present invention.

[0209] Furthermore, although the foregoing has focused on embodiments, these are merely examples and do not limit the invention. It is understood that those skilled in the art can modify and apply the embodiments not illustrated above without departing from their essential characteristics. For example, various structural elements specifically shown in the embodiments can be modified and implemented. Moreover, differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

1. A planar lighting device, wherein, include: Wiring substrate; The light source includes a plurality of first light-emitting element packages and a plurality of second light-emitting element packages arranged on the wiring substrate; as well as A light diffusion layer is located on the light source; The first light-emitting element package includes: A first light-emitting element includes a first light-emitting layer and a second light-emitting layer stacked on top of each other. The first light-emitting layer emits light of a first color having a first emission wavelength, and the second light-emitting layer emits light of a second color having a second emission wavelength. The first phosphor is converted from the light emitted by the first light-emitting element to emit light of a third color with a third emission wavelength; The second light-emitting element package includes: The second light-emitting element includes a third light-emitting layer that emits light of the first color having a fourth light-emitting band; The second phosphor is converted by light emitted from the second light-emitting element to emit light of the second color with a fifth emission wavelength; and The third phosphor is converted from the light emitted by the second light-emitting element to emit light of the third color having a sixth emission band.

2. The planar lighting device according to claim 1, wherein, The full width at half maximum (FWHM) of the spectrum of the first emission band is narrower than that of the spectrum of the fourth emission band.

3. The planar lighting device according to claim 1, wherein, The intensity of the spectrum of the first emission band is less than the intensity of the spectrum of the fourth emission band.

4. The planar lighting device according to claim 1, wherein, The full width at half maximum (FWHM) of the spectrum of the fifth emission band is narrower than that of the spectrum of the second emission band.

5. The planar lighting device according to claim 1, wherein, The intensity of the spectrum of the fifth emission band is less than the intensity of the spectrum of the second emission band.

6. The planar lighting device according to claim 1, wherein, The first light-emitting element package and the second light-emitting element package have different color coordinate settings.

7. The planar lighting device according to claim 1, wherein, The first light-emitting element package and the second light-emitting element package are arranged adjacent to each other.

8. The planar lighting device according to claim 1, wherein, The shift of the color coordinates of the second light-emitting element package with changing current is smaller than that of the first light-emitting element package with changing current.

9. A display device, wherein, include: A planar lighting device that emits white light; as well as A liquid crystal display panel, located on the planar lighting device, is provided with a color conversion filter for converting the white light from the planar lighting device; The planar lighting device includes: The light source includes a plurality of first light-emitting element packages and a plurality of second light-emitting element packages constituting a white light source; and A light diffusion layer is located on the light source; The first light-emitting element package includes: A first light-emitting element includes a first light-emitting layer and a second light-emitting layer stacked on top of each other. The first light-emitting layer emits light of a first color having a first emission wavelength, and the second light-emitting layer emits light of a second color having a second emission wavelength. The first phosphor is converted from the light emitted by the first light-emitting element to emit light of a third color with a third emission wavelength; The second light-emitting element package includes: The second light-emitting element includes a third light-emitting layer that emits light of the first color having a fourth light-emitting band; The second phosphor is converted by the light emitted from the second light-emitting element to emit light of the second color having a fifth emission wavelength; and The third phosphor is converted from the light emitted by the second light-emitting element to emit light of the third color having a sixth emission band.

10. A display device, wherein, include: A planar lighting device that emits white light; as well as A liquid crystal display panel, located on the planar lighting device, is provided with a color conversion filter for converting the white light from the planar lighting device; The planar lighting device includes: Light source, including a plurality of light-emitting element packages constituting a white light source; and A light diffusion layer is located on the light source; The light-emitting element package includes: A light-emitting element includes a first light-emitting layer and a second light-emitting layer stacked on top of each other. The first light-emitting layer emits light of a first color having a first emission wavelength, and the second light-emitting layer emits light of a second color having a second emission wavelength. The phosphor is converted from the light emitted by the light-emitting element to emit light of a third color with a third emission wavelength.

Images