KR102736892B1 - Backlight unit and display device - Google Patents

Abstract

Embodiments of the present invention relate to a backlight unit and a display device, wherein by arranging an optical pattern that scatters, reflects or diffracts light in a path along which light is emitted in a vertical direction from a light source arranged in a direct-type backlight unit, the brightness uniformity and image quality of the backlight unit can be improved. In addition, by allowing light to be totally reflected within a transparent film through a diffraction pattern having a higher refractive index than a transparent film arranged on the light source, and controlling the emission path of the light through a light emission pattern arranged on the transparent film, the light efficiency can be increased while improving the image quality of the backlight unit.

Description

BACKLIGHT UNIT AND DISPLAY DEVICE

Embodiments of the present invention relate to a backlight unit and a display device.

As the information society develops, the demand for display devices that display images is increasing, and various types of display devices such as liquid crystal display devices and organic light-emitting display devices are being utilized.

Among these display devices, a liquid crystal display device may include a display panel and a light source device such as a backlight unit that supplies light to the display panel.

Therefore, the thickness of the display device may increase due to the backlight unit, and if the thickness of the backlight unit is reduced, there is a problem that the optical gap between the light source and the display panel may not be sufficiently secured, resulting in a deterioration in image quality.

An object of embodiments of the present invention is to provide a backlight unit and a display device capable of preventing hot spots while reducing the thickness of the display device.

An object of embodiments of the present invention is to provide a backlight unit and a display device capable of reducing power consumption by increasing light efficiency while improving image uniformity.

In one aspect, embodiments of the present invention provide a display device including a display panel, and a backlight unit supplying light to the display panel, wherein the backlight unit includes a plurality of light sources arranged on a printed circuit, a reflector arranged in at least a portion of an area excluding an area on the printed circuit where the plurality of light sources are arranged, a light source protection member arranged on the plurality of light sources and the reflector, a transparent film arranged on the light source protection member, and a plurality of optical patterns arranged on a lower surface of the transparent film and arranged at positions corresponding to each of the plurality of light sources.

In such display devices, the plurality of optical patterns may be light conversion patterns, and an air gap may exist between the optical patterns and the light source protection member.

Alternatively, the plurality of optical patterns may be diffraction patterns having a refractive index higher than the refractive index of the transparent film. In this case, a plurality of light-emitting patterns having a refractive index higher than the refractive index of the transparent film may be arranged on the upper surface of the transparent film.

In another aspect, embodiments of the present invention provide a backlight unit including a plurality of light sources arranged on a printed circuit, a reflector arranged in at least a portion of an area excluding an area on the printed circuit where the plurality of light sources are arranged, a light source protection member arranged on the plurality of light sources and the reflector, a transparent film arranged on the light source protection member, and a plurality of light conversion patterns arranged on a lower surface of the transparent film and arranged at positions corresponding to each of the plurality of light sources, wherein an air gap exists between the plurality of light conversion patterns and the light source protection member.

In another aspect, embodiments of the present invention provide a backlight unit including a plurality of light sources arranged on a printed circuit, a reflector arranged in at least a portion of an area excluding an area on the printed circuit where the plurality of light sources are arranged, a light source protection member arranged on the plurality of light sources and the reflector, a transparent film arranged on the light source protection member, a plurality of diffraction patterns arranged on a lower surface of the transparent film and arranged at positions corresponding to each of the plurality of light sources and having a refractive index higher than a refractive index of the transparent film, and a plurality of light emission patterns arranged on an upper surface of the transparent film and having a refractive index higher than a refractive index of the transparent film.

In various embodiments, a display device includes a display panel and a backlight unit. The backlight unit includes a transparent film including a printed circuit, a light source on the printed circuit, and a holographic film on a lower surface of the transparent film facing the printed circuit. The holographic film includes at least one optical pattern that overlaps the light source and changes an angle of a portion of light emitted by the light source. The backlight unit further includes an outgoing pattern on an upper surface of the transparent film, wherein a portion of light having the changed angle passes through the outgoing pattern toward the display panel. The outgoing pattern has a refractive index greater than a refractive index of the transparent film such that a refractive angle of a portion of light emitted from the outgoing pattern is less than an incident angle of a portion of light incident on the outgoing pattern.

In an embodiment, the display device further includes a coating layer on the transparent film, wherein the coating layer has a refractive index lower than a refractive index of the transparent film.

In an embodiment, the optical pattern changes the angle of different portions of light emitted by the light source, and the coating layer reflects different portions of the light having the changed angle toward the bottom surface of the transparent film.

In an embodiment, the coating layer overlaps the emission pattern.

In an embodiment, a portion of light having a changed angle passing through the emission pattern passes further through the coating layer.

In an embodiment, the upper surface of the coating layer is flat.

In an embodiment, the holographic film further includes a substrate film between the lower surface of the transparent film and the optical pattern, wherein the substrate film has a refractive index less than a refractive index of the optical pattern.

In an embodiment, a plurality of optical patterns are arranged in a grid shape on the lower surface of the substrate film.

In an embodiment, the refractive index of the substrate film is equal to or less than the refractive index of the transparent film.

In an embodiment, the optical pattern is a diffraction pattern, and the refractive index of the optical pattern is greater than the refractive index of the transparent film.

In an embodiment, the light emission pattern has an elliptical shape. The major radius of the elliptical shape may be equal to the minor radius of the elliptical shape. In another embodiment, the major radius of the elliptical shape is greater than the minor radius of the elliptical shape.

In an embodiment, the upper surface of the light emission pattern is parallel to the lower surface of the light emission pattern. The light emission pattern may have a trapezoidal shape.

In an embodiment, the display device further includes a cover bottom beneath the printed circuit, and an adhesive tape bonding the printed circuit to the cover bottom.

In an embodiment, the holographic film includes a plurality of first optical patterns in a region overlapping with the light source and a plurality of second optical patterns in another region overlapping with the space between the light sources, wherein the first optical patterns have a greater density than the density of the second optical patterns.

In an embodiment, the display device further includes a reflective film that receives and exposes a light source, the reflective film having a height greater than a height of the light source and reflecting light emitted from the light source.

In various embodiments, the backlight unit includes a transparent film including a printed circuit, a light source on the printed circuit, and an optical pattern on a lower surface of the transparent film facing the printed circuit, the optical pattern overlapping the light source and changing an angle of a portion of light emitted by the light source. The backlight unit further includes a diffusion film on the transparent film, the light emission pattern being on an upper surface of the transparent film and beneath the diffusion film, the portion of light having the changed angle passing through the light emission pattern toward the diffusion film, the light emission pattern having a refractive index greater than a refractive index of the transparent film such that a refractive angle of a portion of light emitted from the light emission pattern is less than an incident angle of a portion of light incident on the light emission pattern.

In an embodiment, the backlight unit further includes a coating layer between the transparent film and the diffusion film, wherein the coating layer has a refractive index lower than a refractive index of the transparent film.

In an embodiment, the backlight unit further includes a color conversion sheet on the diffusion film and one or more optical sheets on the color conversion sheet.

In various embodiments, the backlight unit includes a plurality of light sources arranged on a printed circuit. The backlight unit further includes a reflective film arranged in at least a portion of an area other than an area where the plurality of light sources are arranged on the printed circuit. The backlight unit further includes a light source protection member arranged on the plurality of light sources and the reflective film. The backlight unit further includes a transparent film arranged on the light source protection member. The backlight unit further includes a plurality of light conversion patterns arranged at positions corresponding to the plurality of light sources on a lower surface of the transparent film, and an air gap exists between the plurality of light conversion patterns and the light source protection member.

In an embodiment, the thickness of the central portion of at least one of the plurality of light conversion patterns is greater than the thickness of the peripheral portion.

In an embodiment, the plurality of light conversion patterns include a first light conversion pattern disposed in an outer region of the display panel and a second light conversion pattern disposed in a central region of the display panel, wherein a thickness of the first light conversion pattern is smaller than a thickness of the second light conversion pattern or an area of the first light conversion pattern is smaller than an area of the second light conversion pattern.

In an embodiment, the backlight unit further includes an adhesive layer disposed between the light source protection member and the transparent film, the adhesive layer being disposed in at least a portion of an area other than an area where the plurality of light conversion patterns are disposed, and an edge of each of the plurality of light conversion patterns is spaced apart from the adhesive layer.

According to embodiments of the present invention, by placing a transparent film having a light conversion pattern arranged at a position corresponding to the light source on the light source, the thickness of the backlight unit and the display device can be reduced while preventing the hot spot phenomenon.

According to embodiments of the present invention, by arranging a diffraction pattern on the lower surface of a transparent film at a position corresponding to a light source and arranging a light emission pattern on the upper surface of the transparent film, light incident in a vertical direction can be guided through the transparent film and light can be emitted from a desired area.

This allows the uniformity of light emitted through the backlight unit to be improved, and power consumption to be reduced by increasing light efficiency.

FIG. 1 is a drawing showing a schematic configuration of a display device according to embodiments of the present invention.
FIG. 2 is a drawing showing an example of the structure of a backlight unit included in a display device according to embodiments of the present invention.
FIGS. 3A to 3E are drawings showing examples of specific structures of the backlight unit illustrated in FIG. 2.
FIG. 4 is a drawing showing a first embodiment of the structure of a backlight unit according to embodiments of the present invention.
FIGS. 5A and 5B are drawings showing examples of structures according to the positions of the light conversion patterns included in the backlight unit illustrated in FIG. 4.
FIG. 6 is a drawing showing a second embodiment of the structure of a backlight unit according to embodiments of the present invention.
FIG. 7 is a drawing showing an example of the structure of a transparent film on which a diffraction pattern and an emission pattern included in the backlight unit illustrated in FIG. 6 are arranged.
FIG. 8 is a drawing showing another example of the structure of a transparent film in which the diffraction pattern and the emission pattern included in the backlight unit illustrated in FIG. 6 are arranged.
FIG. 9 is a drawing showing another example of the structure of a transparent film in which a diffraction pattern and an emission pattern included in the backlight unit illustrated in FIG. 6 are arranged.
FIG. 10 is a drawing showing an example of the structure of the light emission pattern included in the backlight unit illustrated in FIG. 6.
FIG. 11 is a drawing showing an example of the arrangement structure of the light emission pattern included in the backlight unit illustrated in FIG. 6.
FIG. 12 is a drawing showing an example of a comparison result between a simulation image and light efficiency of a backlight unit according to embodiments of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. When adding reference numerals to components in each drawing, the same components may have the same numerals as much as possible even if they are shown in different drawings. In addition, when describing the present invention, if it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

In addition, when describing components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and the nature, order, sequence, or number of the components are not limited by the terms. When it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but that other components may be "interposed" between each component, or that each component may be "connected," "coupled," or "connected" through another component.

FIG. 1 is a drawing showing a schematic configuration of a display device (100) according to embodiments of the present invention.

Referring to FIG. 1, a display device (100) according to embodiments of the present invention may include a display panel (110) including an active area (A/A) and a non-active area (N/A), a gate driving circuit (120), a data driving circuit (130), and a controller (140) for driving the display panel (110).

In the display panel (110), a plurality of gate lines (GL) and a plurality of data lines (DL) are arranged, and subpixels (SP) are arranged in areas where the gate lines (GL) and data lines (DL) intersect.

The gate driving circuit (120) is controlled by a controller (140) and sequentially outputs scan signals to a plurality of gate lines (GL) arranged on the display panel (110) to control the driving timing of a plurality of subpixels (SP).

The gate driving circuit (120) may include one or more gate driver integrated circuits (GDICs), and may be located on only one side of the display panel (110) or on both sides depending on the driving method.

Each gate driver integrated circuit (GDIC) may be connected to a bonding pad of a display panel (110) by a tape automated bonding (TAB) method or a chip on glass (COG) method, or may be implemented as a gate in panel (GIP) type and placed directly on the display panel (110), and in some cases, may be integrated and placed on the display panel (110). In addition, each gate driver integrated circuit (GDIC) may be implemented by a chip on film (COF) method mounted on a film connected to the display panel (110).

The data driving circuit (130) receives image data from the controller (140) and converts the image data into an analog data voltage. Then, the data voltage is output to each data line (DL) in accordance with the timing at which a scan signal is applied through the gate line (GL), so that each subpixel (SP) expresses brightness according to the image data.

The data drive circuit (130) may include one or more source driver integrated circuits (SDICs).

Each source driver integrated circuit (SDIC) may include a shift register, a latch circuit, a digital-to-analog converter, an output buffer, etc.

Each source driver integrated circuit (SDIC) may be connected to a bonding pad of the display panel (110) by a tape automated bonding (TAB) method or a chip on glass (COG) method, or may be directly placed on the display panel (110), and in some cases, may be integrated and placed on the display panel (110). In addition, each source driver integrated circuit (SDIC) may be implemented by a chip on film (COF) method, and in this case, each source driver integrated circuit (SDIC) may be mounted on a film connected to the display panel (110) and may be electrically connected to the display panel (110) through wires on the film.

The controller (140) supplies various control signals to the gate driving circuit (120) and the data driving circuit (130), and controls the operation of the gate driving circuit (120) and the data driving circuit (130).

The controller (140) is mounted on a printed circuit board, a flexible printed circuit, etc., and can be electrically connected to a gate driving circuit (120) and a data driving circuit (130) through the printed circuit board, the flexible printed circuit, etc.

The controller (140) causes the gate driving circuit (120) to output a scan signal according to the timing implemented in each frame, converts image data received from the outside into a data signal format used by the data driving circuit (130), and outputs the converted image data to the data driving circuit (130).

The controller (140) receives various timing signals including a vertical synchronization signal (VSYNC), a horizontal synchronization signal (HSYNC), an input data enable signal (DE, Data Enable), a clock signal (CLK), etc., from an external source (e.g., a host system) along with image data.

The controller (140) can generate various control signals using various timing signals received from the outside and output them to the gate driving circuit (120) and the data driving circuit (130).

For example, the controller (140) outputs various gate control signals (GCS) including a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal (GOE), etc., to control the gate driving circuit (120).

Here, the gate start pulse (GSP) controls the operation start timing of one or more gate driver integrated circuits (GDICs) constituting the gate driving circuit (120). The gate shift clock (GSC) is a clock signal commonly input to one or more gate driver integrated circuits (GDICs) and controls the shift timing of the scan signal. The gate output enable signal (GOE) specifies timing information of one or more gate driver integrated circuits (GDICs).

In addition, the controller (140) outputs various data control signals (DCS) including a source start pulse (SSP), a source sampling clock (SSC), a source output enable signal (SOE), etc., to control the data driving circuit (130).

Here, the source start pulse (SSP) controls the data sampling start timing of one or more source driver integrated circuits (SDICs) constituting the data driving circuit (130). The source sampling clock (SSC) is a clock signal that controls the sampling timing of data in each of the source driver integrated circuits (SDICs). The source output enable signal (SOE) controls the output timing of the data driving circuit (130).

Such a display device (100) may further include a power management integrated circuit that supplies various voltages or currents to the display panel (110), gate driving circuit (120), data driving circuit (130), etc., or controls various voltages or currents to be supplied.

Each subpixel (SP) is defined by the intersection of a gate line (GL) and a data line (DL), and liquid crystals or light-emitting elements may be arranged depending on the type of display device (100).

For example, if the display device (100) is a liquid crystal display device, it includes a light source device such as a backlight unit that irradiates light to the display panel (110), and liquid crystals are arranged in the subpixels (SP) of the display panel (110). Then, by adjusting the arrangement of the liquid crystals by an electric field formed as a data voltage is applied to each subpixel (SP), an image can be displayed while indicating brightness according to the image data.

FIG. 2 is a drawing showing an example of the structure of a backlight unit included in a display device (100) according to embodiments of the present invention.

Referring to FIG. 2, a display device (100) according to embodiments of the present invention may include a display panel (110) and a backlight unit that is positioned below the display panel (110) and supplies light to the display panel (110).

Various structures may be placed between the backlight unit and the display panel (110). For example, the display panel (110) may be fixed on the backlight unit by a guide panel (400) and a foam pad (500), but the present invention is not limited thereto.

The backlight unit may include a cover bottom (201) that stores optical elements, etc. that constitute the backlight unit.

A printed circuit (202) may be placed on the cover bottom (201), and a plurality of light sources (203) may be placed on the printed circuit (202).

The printed circuit (202) may be in the form of a substrate, and a reflector (204) may be placed in at least some areas of the printed circuit (202) where the light source (203) is not placed.

A light source protection member (205) may be placed on a plurality of light sources (203) and a reflector (204). This light source protection member (205) may protect a plurality of light sources (203) and provide a function of diffusing light emitted from the light sources (203). That is, the light source protection member (205) may be in direct contact with the light sources (203) to protect the light sources (203) and provide a light guide function.

A transparent film (300) is placed on the light source protection member (205), and a plurality of optical patterns (310) can be placed on at least one of the upper and lower surfaces of the transparent film (300).

Here, the plurality of optical patterns (310) may be light control patterns and may be arranged at positions corresponding to each of the plurality of light sources (203) on the lower surface of the transparent film (300). Alternatively, in some cases, the plurality of optical patterns (310) may be arranged at positions corresponding to each of the plurality of light sources (203) on the upper surface of the transparent film (300). For example, each of the plurality of optical patterns (310) may be arranged to correspond to a hole formed in the reflector (204). And, in some cases, the area of the optical pattern (310) may be the same as the area of the hole of the reflector (204). Such an optical pattern (310) may improve the image quality of the backlight unit by scattering, reflecting, or diffracting a portion of the light emitted in the vertical direction from the light source (203). In addition, the optical pattern (310) arranged on the transparent film (300) may transmit a portion of the light irradiated from the light source (203). And, the optical pattern (310) may be a light control pattern that can transmit some of the light.

That is, by placing the optical pattern (310) in the area where the intensity of light emitted from the light source (203) is the strongest, it is possible to reduce the brightness difference between the area where the light source (203) is placed (area with a large amount of light) and the area between the light sources (203) (area with a small amount of light).

A diffusion plate (206) may be placed on the transparent film (300) to diffuse light incident from below.

Additionally, a color conversion sheet (207) or one or more optical sheets (208) may be placed on the diffusion plate (206).

FIGS. 3A to 3E are drawings showing examples of specific structures of the backlight unit illustrated in FIG. 2.

Referring to FIG. 3a, a plurality of light sources (203) are arranged on a printed circuit (202).

The light source (203) may be, for example, a light emitting diode (LED), and may also be a small mini light emitting diode (Mini LED) or an ultra-small micro light emitting diode (μLED). Accordingly, the light source (203) in the form of a chip may be arranged in a form mounted on a printed circuit (202), thereby reducing the thickness of the backlight unit. In addition, the light source (203) may also be in the form of a flip chip.

Additionally, the light source (203) may emit light in a white wavelength band, or in some cases, may emit light in a specific wavelength band (e.g., a blue wavelength band).

Referring to FIG. 3b, a reflector (204) may be placed in at least a portion of an area excluding an area where a light source (203) is placed on a printed circuit (202).

This reflector (204) can be manufactured in a form in which an area corresponding to the light source (203) is opened and placed on the printed circuit (202). In addition, the reflector (204) can reflect light emitted from the light source (203) toward the front of the backlight unit, thereby increasing the light efficiency of the backlight unit.

Here, when the light source (203) is arranged in a chip form, the size of the light source (203) is small, so the height of the reflector (204) may be greater than the height of the light source (203).

Accordingly, light emitted laterally from the light source (203) can be reflected from the side of the reflector (204) and emitted to the front of the backlight unit, thereby further increasing the light efficiency of the backlight unit.

Additionally, in some cases, a reflective film coated on the printed circuit (202) may be placed.

That is, a reflective film may be coated on an area other than the front surface of the printed circuit (202) or the area where the light source (203) is placed to increase light efficiency.

In this case, a reflective film coated on the printed circuit (202) may replace the function of the reflector (204), or the reflector (204) may be placed together to provide a reflective function.

Referring to FIG. 3c, a light source protection member (205) may be placed on a plurality of light sources (203) and reflectors (204).

The light source protection unit (205) may be made of, for example, resin.

When the light source protection unit (205) is composed of resin, the light source protection unit (205) can be formed by arranging a partition wall on the outside of the printed circuit (202) or an outer area of an area where a plurality of light sources (203) are arranged on the printed circuit (202) and applying resin to the inside of the partition wall.

This light source protection unit (205) has the function of protecting a plurality of light sources (203) arranged on a printed circuit (202), and can also provide the function of a light guide plate by diffusing light emitted from the light sources (203).

That is, the light emitted from the light source (203) is spread as evenly as possible to the upper surface of the light source protection unit (205) by the light source protection unit (205).

Embodiments of the present invention enable the uniformity of an image to be further improved while reducing the thickness of a backlight unit by arranging an optical pattern (310) having optical characteristics at a position corresponding to a light source (203) on a light source protection member (205).

Referring to FIG. 3d, a transparent film (300) may be placed on a light source protection member (205), and a plurality of optical patterns (310) may be placed on a lower surface of the transparent film (300), but is not limited thereto, and a plurality of optical patterns (310) may be placed on an upper surface of the transparent film (300). In addition, the transparent film (300) may be adhered to the light source protection member (205) through an adhesive layer (209). The adhesive layer (209) may be an OCA (Optical Clear Adhesive). The transparent film (300) may be composed of, for example, PET, but is not limited thereto.

Each of a plurality of optical patterns (310) arranged on the lower surface of the transparent film (300) can be arranged to correspond to each of a plurality of light sources (203) arranged on the printed circuit (202).

That is, the optical pattern (310) can be arranged so that at least a portion overlaps with the light source (203), and when considering the diffusion characteristics of light, it can be arranged so as to overlap with an area including an area where the light source (203) is arranged.

These optical patterns (310) have a constant reflectivity and can scatter, reflect, diffract, or transmit a portion of the light emitted from the light source (203).

For example, the optical pattern (310) may scatter light emitted from a light source (203) so that light is emitted in vertical and diagonal directions. Alternatively, the optical pattern may reflect light emitted from a light source (203) and cause it to be reflected again by a reflector (204) so that light is emitted into an area between the light sources (203).

In this way, by controlling the direction of light emitted from the light source (203) by the optical pattern (310), the image quality of the backlight unit can be improved. That is, the light emitted from the light source (203) can be scattered, reflected, diffracted, or transmitted by the optical pattern (310), thereby improving the brightness uniformity of the backlight unit.

Referring to FIG. 3e, a diffuser plate (206) may be placed on a transparent film (300), and a color conversion sheet (207) may be placed on the diffuser plate (206). In addition, one or more optical sheets (208) may be placed on the color conversion sheet (207).

Here, the positions where the diffusion plate (206) and the color conversion sheet (207) are placed may be swapped.

The diffusion plate (206) diffuses the light emitted through the transparent film (300).

The color conversion sheet (207) can emit light of a specific wavelength band in response to incident light.

For example, when the light source (203) emits light of a first wavelength band (e.g., blue light), the color conversion sheet (207) can emit light of a second wavelength band (e.g., green light) and light of a third wavelength band (e.g., red light) in response to the incident light.

In some cases, the color conversion sheet (207) may be placed only on some areas on the diffusion plate (206).

For example, when the light source (203) emits light in the blue wavelength band, the color conversion sheet (207) may be placed only in an area excluding an area corresponding to an area where blue subpixels (SPs) are placed in the display panel (110). In other words, light that does not pass through the color conversion sheet (207) can be allowed to reach the blue subpixels (SPs) of the display panel (110).

These color conversion sheets (207) may not be arranged depending on the light source (203).

For example, in a case where the light source (203) emits light in a white wavelength band or a light source (203) emitting light in a blue wavelength band is coated with a color conversion film that emits light in a green wavelength band and light in a red wavelength band, the color conversion sheet (207) may not be arranged.

In this way, embodiments of the present invention include a transparent film (300) including an optical pattern (310) positioned corresponding to a light source (203) and several optical elements, thereby reducing the thickness of the backlight unit while improving the image quality displayed by the backlight unit.

Below, embodiments of the present invention are described with specific examples of optical patterns (310) arranged on a transparent film (300).

FIG. 4 is a drawing showing a first embodiment of the structure of a backlight unit according to embodiments of the present invention.

Referring to FIG. 4, a printed circuit (202) is placed on a cover bottom (201), and the printed circuit (202) can be adhered by an adhesive tape (210) placed between the cover bottom (201) and the printed circuit (202).

A plurality of light sources (203) may be arranged on a printed circuit (202), and a reflector (204) may be arranged in at least some area excluding the area where the light sources (203) are arranged.

Here, the light source (203) may be, for example, a light-emitting diode (LED), and may include a light-emitting portion (203a) including an n-type semiconductor layer, an activation layer, and a p-type semiconductor layer, and an electrode portion (203b).

A light source protection unit (205) is placed on a plurality of light sources (203) and reflectors (204).

A transparent film (300) having an optical pattern (310) arranged at a position corresponding to a light source (203) is placed on a light source protection member (205). Here, the optical pattern (310) arranged on the lower surface of the transparent film (300) may be a light conversion pattern (311).

Additionally, a diffusion plate (206), a color conversion sheet (207), and an optical sheet (208) may be placed on a transparent film (300).

The light conversion pattern (311) arranged on the lower surface of the transparent film (300) can be implemented by printing a material having light conversion properties on the transparent film (300). For example, the light conversion pattern (311) can be arranged by printing TiO2 ink on the transparent film (300). When the light conversion pattern (311) uses TiO2 and is a single layer, the reflectivity can be 60 to 70%. In addition, the absorption/transmittance can be 30 to 40%.

In addition, the light conversion pattern (311) arranged on the lower surface of the transparent film (300) may be arranged in a single layer or may be arranged in a multi-layer structure. For example, the light conversion pattern (311) may be arranged in two layers, and when the light conversion pattern (311) has two layers, the reflectivity may be 70 to 80%. In addition, the absorption/transmittance may be 20 to 30%. However, the reflectivity of the light conversion pattern (311) is not limited thereto, and when the content of titanium dioxide (TiO2) included in the light conversion pattern (311) or the thickness of the layer of the light conversion pattern (311) becomes thicker, the reflectivity of the light conversion pattern (311) increases and the transmittance decreases.

Additionally, in some cases, as in the example illustrated in FIG. 4, the light conversion pattern (311) arranged on the lower surface of the transparent film (300) may be composed of three layers.

This light conversion pattern (311) can be implemented by printing a light conversion material three times on a transparent film (300), and the area of the printed light conversion material can become increasingly narrow. Then, by flipping the transparent film (300) on which the light conversion pattern (311) is arranged and placing it on a light source protection member (205), the light conversion pattern (311) can be arranged on a light source (203).

Accordingly, the area of the light conversion pattern (311) may become narrower as it goes downward from the transparent film (300), and the thickness of the central portion of the light conversion pattern (311) may be greater than the thickness of the outer portion.

That is, since the intensity of light emitted in the vertical direction from the light source (203) is the greatest, the central portion of the light conversion pattern (311) can be arranged thicker.

In this way, by arranging the light conversion pattern (311) on the light source (203), the path of light emitted vertically from the light source (203) can be changed or a portion of the light can be blocked, thereby preventing or reducing the appearance of hot spots in the area where the light source (203) is arranged.

A transparent film (300) on which such a light conversion pattern (311) is arranged can be adhered to a light source protection member (205) by an adhesive layer (209).

At this time, the adhesive layer (209) may be placed on at least a portion of the area excluding the area where the light conversion pattern (311) is placed on the lower surface of the transparent film (300).

Accordingly, the adhesive layer (209) may not be placed in the area where the light conversion pattern (311) is placed, and an air gap may exist between the light conversion pattern (311) and the light source protection part (205).

Additionally, the side of the light conversion pattern (311) and the adhesive layer (209) may be structured to be spaced apart from each other.

Since an air gap exists between the light conversion pattern (311) and the light source protection unit (205), light emitted in the lateral direction of the light conversion pattern (311) can be reflected by the air gap.

That is, light emitted in the lateral direction of the light conversion pattern (311) can be emitted at a large refractive angle by the air layer with a low refractive index, or can be reflected from the air layer. In addition, light reflected from the air layer can be reflected again by the reflection plate (204) and emitted, thereby assisting the light conversion function of the light conversion pattern (311) and increasing light efficiency.

In this way, the light efficiency of the backlight unit can be increased while preventing hot spots through a structure in which the light conversion pattern (311) and the air gap are arranged at positions corresponding to the light source (203).

At this time, the light conversion pattern (311) placed on the lower part of the transparent film (300) may be placed in a different structure depending on the position at which it is placed.

FIG. 5a and FIG. 5b are drawings showing examples of structures according to the position of the light conversion pattern (311) included in the backlight unit illustrated in FIG. 4.

Referring to FIG. 5a, examples of brightness displayed through a backlight unit according to the structure of a light conversion pattern (311) are shown. <EX1> shows an example of brightness measured when the light conversion pattern (311) is arranged in a certain structure, and <EX2> shows an example of brightness measured when the light conversion pattern (311) is arranged in a different structure depending on the position.

As shown in <EX1> of Fig. 5a, when the structure of the light conversion pattern (311a) arranged in the outer area of the backlight unit and the light conversion pattern (311d) arranged in the central area are the same, the brightness of the outer area of the backlight unit may appear low.

That is, since the outer area of the backlight unit has a relatively small number of light sources (203) that supply light to the area, when a light conversion pattern (311) having the same level of light conversion characteristics is arranged, the brightness may be lowered compared to the central area of the backlight unit.

Accordingly, as illustrated in <EX2> of FIG. 5, by differently arranging the structures of the light conversion pattern (311a) arranged in the outer area of the backlight unit and the light conversion pattern (311d) arranged in the central area, it is possible to prevent a decrease in brightness in the outer area of the backlight unit and make the overall brightness uniform.

For example, the light conversion pattern (311) may be arranged so that the thickness (T1) of the light conversion pattern (311a) arranged in the outer area of the backlight unit is smaller than the thickness (T2) of the light conversion pattern (311d) arranged in the central area.

Alternatively, the light conversion pattern (311) may be arranged so that the area (W1) of the thickest part of the light conversion pattern (311b) arranged adjacent to the outer area of the backlight unit is smaller than the area (W2) of the thickest part of the light conversion pattern (311d). In other words, the area of the part with high blocking characteristics in the light conversion pattern (311a, 311b) arranged in the outer area of the backlight unit or an area adjacent to the outer area can be made small.

Additionally, the light conversion pattern (311) may be arranged so that the thickness of the light conversion pattern (311) gradually decreases from the central area of the backlight unit to the outer area, or so that the area of the thickest part of the light conversion pattern (311) gradually decreases.

Additionally, in some cases, the number of light sources (203) or the spacing between the light sources (203) may be arranged differently in the central and peripheral areas of the backlight unit, and the light conversion patterns (311) may be arranged differently.

Referring to FIG. 5b, another example of a structure in which a light conversion pattern (311) is arranged on the lower surface of a transparent film (300) is shown.

Here, the spacing between the light sources (203) arranged in the outer region of the backlight unit may be narrower than the spacing between the light sources (203) arranged in the central region of the backlight unit. That is, the light sources (203) may be arranged in a more dense structure in the outer region of the backlight unit so that the brightness of the central region and the outer region of the backlight unit becomes uniform.

In addition, since the light conversion patterns (311) arranged on the lower surface of the transparent film (300) are arranged to correspond to the light source (203), the spacing between the light conversion patterns (311) arranged in the outer area of the backlight unit may be different from the spacing between the light conversion patterns (311) arranged in the central area.

For example, the spacing (D1) of the light conversion patterns (311) arranged in the outer region of the backlight unit in the first direction may be smaller than the spacing (D2) of the light conversion patterns (311) arranged in the central region in the first direction. In addition, the spacing (D3) of the light conversion patterns (311) arranged in the outer region of the backlight unit in the second direction may be smaller than the spacing (D4) of the light conversion patterns (311) arranged in the central region in the second direction.

At this time, the size, thickness, etc. of the light conversion pattern (311) arranged in the outer area of the backlight unit may be different from the size, thickness, etc. of the light conversion pattern (311) arranged in the central area of the backlight unit.

For example, as in the example illustrated in FIG. 5b, the size (S1) of the light conversion pattern (311e, 311f) arranged in the outer area of the backlight unit may be smaller than the size (S2) of the light conversion pattern (311g) arranged in the central area of the backlight unit.

Alternatively, the light conversion pattern (311) may have a multilayer structure as described above, in which case the thickness or the area of the thickest part of the light conversion pattern (311e, 311f) arranged in the outer region of the backlight unit may be smaller than the thickness or the area of the thickest part of the light conversion pattern (311g) arranged in the central region of the backlight unit.

That is, by reducing the size of the light conversion pattern (311e, 311f) arranged in the outer area of the backlight unit, it is possible to arrange it so as to correspond to the light sources (203) arranged at a narrow interval. Accordingly, it is possible to prevent a hot spot from occurring at a location corresponding to the light sources (203) in the outer area of the backlight unit.

In addition, by lowering the level at which light emitted from a light source (203) is blocked in the outer area of the backlight unit, the amount of light emitted is increased, and a decrease in brightness in the outer area of the backlight unit is prevented, so that uniform brightness can be displayed in the entire area of the backlight unit.

In this way, by arranging the structure of the light conversion pattern (311) differently for each area of the backlight unit, it is possible to prevent brightness from decreasing in the outer area of the backlight unit and improve brightness uniformity.

In addition, through the structure in which the aforementioned light conversion pattern (311) is arranged, hot spots of the backlight unit can be prevented and brightness uniformity can be improved.

In addition, embodiments of the present invention provide a method for improving the image quality of a backlight unit and increasing light efficiency by diffracting light emitted in a vertical direction from a light source (203).

FIG. 6 is a drawing showing a second embodiment of the structure of a backlight unit according to embodiments of the present invention.

Referring to FIG. 6, a printed circuit (202) adhered by an adhesive tape (210) is placed on a cover bottom (201), and a plurality of light sources (203) are placed on the printed circuit (202). In addition, a reflector (204) may be placed on at least a portion of an area excluding an area where the light sources (203) are placed on the printed circuit (202).

A light source protection member (205) may be placed on a plurality of light sources (203) and reflectors (204), and a transparent film (300) having an optical pattern (310) placed at a position corresponding to the light source (203) may be placed on the light source protection member (205).

The transparent film (300) and the light source protection member (205) can be bonded by an adhesive layer (209). In addition, a diffusion plate (206), a color conversion sheet (207), and an optical sheet (208) can be placed on the transparent film (300).

Here, the optical pattern (310) arranged on the lower surface of the transparent film (300) may be a diffraction pattern (312). And, the diffraction pattern (312) may have a refractive index higher than the refractive index of the transparent film (300).

Accordingly, light emitted in a vertical direction from a light source (203) can be diffracted by the diffraction pattern (312) and incident on the transparent film (300) at a large refractive angle.

That is, since light passing through the diffraction pattern (312) is incident at a refractive angle at which light can be totally reflected within the transparent film (300), light incident on the transparent film (300) can be totally reflected within the transparent film (300) and spread out.

Additionally, a plurality of light-emitting patterns (320) having a refractive index higher than the refractive index of the transparent film (300) may be arranged on the transparent film (300).

Accordingly, when the light that is totally reflected within the transparent film (300) reaches the lower surface of the light emission pattern (320), the angle of refraction becomes smaller than the angle of incidence, so it can be emitted to the outside through the light emission pattern (320).

In this way, light emitted in a vertical direction from a light source (203) is incident on the transparent film (300) with only the path of light adjusted by the diffraction pattern (312), so that almost no light loss occurs.

And, since the light that is totally reflected within the transparent film (300) is emitted from the position where the light emission pattern (320) is arranged, the area or direction from which light is emitted on the transparent film (300) can be controlled through the position where the light emission pattern (320) is arranged.

Accordingly, by minimizing the loss of light emitted from the light source (203) and controlling the light emission position, the image quality of the backlight unit can be improved while increasing light efficiency, thereby reducing the power consumption of the backlight unit.

FIG. 7 is a drawing showing an example of the structure of a transparent film (300) on which a diffraction pattern (312) and a light emission pattern (320) included in the backlight unit illustrated in FIG. 6 are arranged.

Referring to FIG. 7, a plurality of diffraction patterns (312) may be arranged at positions corresponding to the light source (204) on the lower surface of the transparent film (300). In addition, a plurality of light emission patterns (320) may be arranged on the upper surface of the transparent film (300).

Here, a substrate film (330) may be placed between the transparent film (300) and the diffraction pattern (312). Then, the substrate film (330) and the diffraction pattern (312) may be combined and referred to as a hologram film.

That is, the diffraction pattern (312) may be directly arranged on the lower surface of the transparent film (300), but a substrate film (330) may be arranged between the transparent film (300) and the diffraction pattern (312) to facilitate the arrangement of the diffraction pattern (312) or to increase the total reflection effect of light within the transparent film (300).

The refractive index of the substrate film (330) may be lower than the refractive index of the diffraction pattern (312). Accordingly, light incident on the substrate film (330) through the diffraction pattern (312) may be incident at a total reflection angle.

In addition, the refractive index of the substrate film (330) may be the same as or nearly similar to the refractive index of the transparent film (300). In this case, when the refractive index of the substrate film (330) and the refractive index of the transparent film (300) are different, the refractive index of the transparent film (300) may be made slightly larger than the refractive index of the substrate film (330), thereby preventing light from being emitted from the light emission pattern (320) due to excessive total reflection of light incident on the transparent film (300).

The diffraction pattern (312) may be arranged in a form in which a specific structure is repeated on the lower surface of the substrate film (330), and may be arranged in a grid form, for example. In addition, it may be arranged in various forms that can diffract light.

That is, the shape of the diffraction pattern (312) is not limited to a specific shape, and due to the difference in refractive index between the diffraction pattern (312), the base film (330), and the transparent film (300), light emitted from the light source (203) and passing through the diffraction pattern (312) is totally reflected within the transparent film (300).

And, light that reaches the light-emitting pattern (320) that is placed on the transparent film (300) and has a refractive index higher than that of the transparent film (300) is emitted to the outside through the light-emitting pattern (320).

For example, when light incident at an angle of θ1 onto a transparent film (300) reaches an emission pattern (320) having a refractive index higher than the refractive index of the transparent film (300), it is incident at an angle of θ2 that is smaller than θ1 and can be emitted outside the emission pattern (320).

In this way, by controlling the emission path of light incident on the transparent film (300) through the light emission pattern (320) without light loss, the light efficiency can be increased while increasing the overall brightness uniformity.

Additionally, a layer may be additionally placed on the transparent film (300) to enhance the total reflection effect.

FIG. 8 is a drawing showing another example of the structure of a transparent film (300) in which a diffraction pattern (312) and a light emission pattern (320) included in the backlight unit illustrated in FIG. 6 are arranged.

Referring to FIG. 8, a holographic film including a substrate film (330) and a diffraction pattern (312) can be placed at a position corresponding to a light source (203) on the lower surface of a transparent film (300).

Additionally, a light-emitting pattern (320) can be placed on a transparent film (300).

Here, a coating layer (340) may be disposed on at least a portion of an area excluding an area where a light emission pattern (320) is disposed on a transparent film (300). Some of the light may be refracted by the coating layer (340) and other portions of the light may be reflected by the coating layer (340). In addition, the refractive index of the coating layer (340) may be lower than the refractive index of the transparent film (300).

That is, when light that is totally reflected within the transparent film (300) reaches the coating layer (340) having a lower refractive index than the refractive index of the transparent film (300), it is prevented from being emitted outside the transparent film (300), thereby enhancing the total reflection effect of light within the transparent film (300).

And, when the light that is totally reflected within the transparent film (300) reaches the light emission pattern (320), it can be emitted to the outside through the light emission pattern (320).

Therefore, through the arrangement of the coating layer (340) and the light-emitting pattern (320), the area where light is emitted on the transparent film (300) can be controlled more precisely.

Additionally, this coating layer (340) may be further arranged on the outer surface of the light-emitting pattern (320).

FIG. 9 is a drawing showing another example of the structure of a transparent film (300) in which a diffraction pattern (312) and a light emission pattern (320) included in the backlight unit illustrated in FIG. 6 are arranged.

Referring to FIG. 9, a holographic film may be placed at a position corresponding to a light source (203) on the lower surface of a transparent film (300), and a light emission pattern (320) may be placed on the transparent film (300).

Additionally, a coating layer (340) having a lower refractive index than the refractive index of the transparent film (300) may be placed on the transparent film (300), and the coating layer (340) may also be placed on the light-emitting pattern (320).

That is, since light incident on the light emission pattern (320) is incident at a large angle of incidence, even if a coating layer (340) with a low refractive index is placed on the light emission pattern (320), the light can be emitted to the outside through the light emission pattern (320).

Accordingly, the coating layer (340) can enhance the light-guiding function of the transparent film (300) in an area where the light-emitting pattern (320) is not arranged and protect the light-emitting pattern (320).

And, this coating layer (340) may be arranged on the transparent film (300) and the light-emitting pattern (320) with a constant thickness. In addition, the coating layer (340) may be arranged with a structure having a constant height on the transparent film (300) so that the upper surface of the coating layer (340) on the light-emitting pattern (320) is flat or parallel to the upper surface of the transparent film (300), as in the example illustrated in FIG. 9.

Accordingly, a diffuser plate (206) or the like can be easily placed on a transparent film (300) on which a light emission pattern (320) is placed.

FIG. 10 is a drawing showing an example of the structure of a light emission pattern (320) included in the backlight unit illustrated in FIG. 6.

Referring to FIG. 10, the light emission pattern (320) placed on the transparent film (300) may have various shapes in consideration of the characteristics of the emitted light.

For example, the light emission pattern (320) may be a hemispherical shape with the horizontal radius and the vertical radius being equal. A general viewing angle can be implemented through the hemispherical light emission pattern (320) with the horizontal radius and the vertical radius being equal.

Alternatively, the light emission pattern (320) may be a hemispherical shape (an elliptical shape in which the long radius is longer than the short radius) in which the horizontal radius is larger than the vertical radius. For example, the short radius may be 60% of the long radius. The light emission pattern (320) in a hemispherical shape in which the horizontal radius is larger than the vertical radius may implement the characteristics of a wide viewing angle. Therefore, the brightness in the viewing angle may be increased.

Alternatively, the light-emitting pattern (320) may have a flat upper surface and a narrower upper surface than the lower surface, and the cross-section of the light-emitting pattern (320) may have a trapezoidal shape. That is, the light-emitting pattern (320) may have a structure in which the upper surface is flat (e.g., parallel to the lower surface) to implement the characteristics of a narrow viewing angle, and may also increase the frontal brightness through this structure.

The structure of this light emission pattern (320) can be implemented in various ways depending on the characteristics of the display device (100), and in some cases, light emission patterns (320) having different viewing angle characteristics can be mixed and arranged.

Additionally, the position and density of the light emission pattern (320) can be determined depending on the position of the light source (203).

FIG. 11 is a drawing showing an example of the arrangement structure of the light emission pattern (320) included in the backlight unit illustrated in FIG. 6.

Referring to FIG. 11, a diffraction pattern (312) is placed on a light source (203), and a transparent film (300) is placed on the diffraction pattern (312). Then, a light emission pattern (320) may be placed on the transparent film (300).

Here, the density of the light emission pattern (320) arranged in an area adjacent to the light source (203) (e.g., an area overlapping the light source) may be smaller than the density arranged in an area between and adjacent to the light sources (203) (e.g., an area not overlapping the light source).

That is, the number of light emission patterns (320) arranged in the first area (Area1) adjacent to the light source (203) may be smaller than the number of light emission patterns (320) arranged in the second area (Area2) adjacent to and between the light sources (203) and having the same area as the first area (Area1).

In addition, as another example, the density of the light-emitting patterns (320) arranged in the outer area of the backlight unit may be higher than the density of the light-emitting patterns (320) arranged in the central area of the backlight unit. Accordingly, it is possible to prevent the brightness of the outer area of the backlight unit, where the amount of light is relatively small, from appearing low.

In this way, by adjusting the position of the light emission pattern (320) on the transparent film (300) according to the position of the light source (203), the path of light emitted from the light source (203) is effectively controlled, thereby improving the overall brightness uniformity and image quality of the backlight unit.

FIG. 12 is a drawing showing an example of a comparison result between a simulation image and light efficiency of a backlight unit according to embodiments of the present invention.

Referring to FIG. 12, CASE #1 represents a case where an optical pattern (310) positioned corresponding to a light source (203) in a backlight unit is a light conversion pattern (311), and CASE #2 represents a case where an optical pattern (310) positioned in the backlight unit is a diffraction pattern (312).

As shown in the example in Fig. 12, by arranging an optical pattern (310) such as a light conversion pattern (311) or a diffraction pattern (312) at a position corresponding to a light source (203), it can be seen that hot spots are prevented and brightness uniformity is improved.

And, when the diffraction pattern (312) is arranged, it can be seen that the optical efficiency is further improved because the optical loss due to the optical pattern (310) is reduced.

According to the embodiments of the present invention described above, by arranging an optical pattern (310) that scatters, reflects, or diffracts light on the light source (203) of the backlight unit, hot spots of the backlight unit can be prevented and brightness uniformity can be improved.

Therefore, it is possible to provide high image quality while reducing the thickness of the backlight unit.

In addition, by arranging a diffraction pattern (312) having a higher refractive index than the refractive index of the transparent film (300) on the lower surface of the transparent film (300), light passing through the diffraction pattern (312) is totally reflected within the transparent film (300), thereby preventing loss of light emitted from the light source (203).

In addition, by controlling the light emission path through a light emission pattern (320) that is placed on a transparent film (300) and has a higher refractive index than that of the transparent film (300), the image quality of the backlight unit is improved, light efficiency is increased, and power consumption is reduced.

The above description is merely an illustrative description of the technical idea of the present invention, and those skilled in the art will appreciate that various modifications and variations may be made without departing from the essential characteristics of the present invention. In addition, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to explain it, and therefore the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

100: Display device 110: Display panel
120: Gate driving circuit 130: Data driving circuit
140: Controller 201: Cover Bottom
202: Printed circuit 203: Light source
203a: Light-emitting part 203b: Electrode part
204: Reflector 205: Light source protection part
206: Diffuser 207: Color conversion sheet
208: Optical sheet 209: Adhesive layer
210: Adhesive tape 300: Transparent film
310: Optical pattern 311: Optical conversion pattern
312: Diffraction pattern 320: Emission pattern
330: Base film 340: Coating layer
400: Guide Panel 500: Foam Pad

Claims (18)

display panel; and
Includes a backlight unit that supplies light to the display panel,
The above backlight unit,
A plurality of light sources arranged on a printed circuit;
A reflector disposed in at least a portion of an area excluding an area where the plurality of light sources are disposed on the printed circuit;
A light source protection unit disposed on the above plurality of light sources and the reflector;
A transparent film placed on the above light source protection part; and
A plurality of optical patterns are disposed on the lower surface of the transparent film and are disposed at positions corresponding to each of the plurality of light sources,
The above multiple optical patterns are optical conversion patterns,
A display device wherein at least one of the plurality of optical patterns has a central portion having a thickness greater than an outer portion thereof.
delete In the first paragraph,
The above multiple optical patterns are,
It includes a first optical pattern arranged in an area corresponding to an outer area of the display panel, and a second optical pattern arranged in an area corresponding to a central area of the display panel.
A display device wherein the thickness of the first optical pattern is smaller than the thickness of the second optical pattern, or the area of the thickest part of the first optical pattern is smaller than the area of the thickest part of the second optical pattern.
In clause 1,
A display device further comprising an adhesive layer disposed between the light source protection part and the transparent film.
In paragraph 4,
The above adhesive layer is,
At least a portion of an area other than an area where the above plurality of optical patterns are arranged is arranged,
A display device in which an air gap exists between the light source protection unit and the plurality of optical patterns.
In paragraph 5,
A display device in which each side of the plurality of optical patterns and the adhesive layer are spaced apart.
display panel; and
Includes a backlight unit that supplies light to the display panel,
The above backlight unit,
A plurality of light sources arranged on a printed circuit;
A reflector disposed in at least a portion of an area excluding an area where the plurality of light sources are disposed on the printed circuit;
A light source protection unit disposed on the above plurality of light sources and the reflector;
A transparent film placed on the above light source protection part; and
A plurality of optical patterns are disposed on the lower surface of the transparent film and are disposed at positions corresponding to each of the plurality of light sources,
The above plurality of optical patterns are diffraction patterns having a refractive index higher than the refractive index of the transparent film,
A display device further comprising a plurality of light-emitting patterns arranged on an upper surface of the transparent film and having a refractive index higher than a refractive index of the transparent film.
In Article 7
Further comprising a plurality of substrate films arranged between each of the plurality of optical patterns and the transparent film,
The above optical pattern is,
A display device arranged in a grid shape on the lower surface of the above-described film.
In Article 8,
A display device wherein the refractive index of the plurality of substrate films is the same as or lower than the refractive index of the transparent film.
In Article 7,
A display device further comprising a coating layer disposed on at least a portion of an area excluding an area where the plurality of light-emitting patterns are disposed on the upper surface of the transparent film, the coating layer having a refractive index lower than the refractive index of the transparent film.
In Article 10,
The above coating layer is,
A display device further arranged on the outer surface of the above plurality of light-emitting patterns.
In Article 7,
At least one of the above multiple emission patterns,
A display device that is a hemispherical shape with the horizontal and vertical radii equal, or a hemispherical shape with the horizontal radius greater than the vertical radius.
In Article 7,
At least one of the above multiple emission patterns,
A display device having a flat upper surface and an area of the upper surface smaller than the area of the lower surface.
In Article 7,
A display device wherein the number of the light-emitting patterns arranged in the first region adjacent to the light source is smaller than the number of the light-emitting patterns arranged in the second region adjacent between the light sources and having the same area as the first region.
In the first paragraph,
A diffuser plate placed on the transparent film; and
Further comprising a color conversion sheet arranged on the above diffusion plate,
A display device in which the plurality of light sources emit light of a first wavelength band, and the color conversion sheet emits light of a second wavelength band and light of a third wavelength band in response to incident light.
display panel; and
Includes a backlight unit that supplies light to the display panel,
The above backlight unit,
A plurality of light sources arranged on a printed circuit;
A reflector disposed in at least a portion of an area excluding an area where the plurality of light sources are disposed on the printed circuit;
A light source protection unit disposed on the above plurality of light sources and the reflector;
A transparent film placed on the above light source protection part; and
A plurality of optical patterns are disposed on the lower surface of the transparent film and are disposed at positions corresponding to each of the plurality of light sources,
Further comprising a color conversion film arranged on the outer surface of each of the above plurality of light sources,
A display device in which the plurality of light sources emit light of a first wavelength band, and the color conversion film reacts to incident light to emit light of a second wavelength band and light of a third wavelength band.
A plurality of light sources arranged on a printed circuit;
A reflector disposed in at least a portion of an area excluding an area where the plurality of light sources are disposed on the printed circuit;
A light source protection unit disposed on the above plurality of light sources and the reflector;
A transparent film placed on the above light source protection part; and
A plurality of light conversion patterns are disposed on the lower surface of the transparent film and are disposed at positions corresponding to each of the plurality of light sources,
An air gap exists between the above-described plurality of light conversion patterns and the light source protection unit,
A backlight unit in which at least one of the plurality of light conversion patterns has a thickness of a central portion greater than a thickness of an outer portion.
A plurality of light sources arranged on a printed circuit;
A reflector disposed in at least a portion of an area excluding an area where the plurality of light sources are disposed on the printed circuit;
A light source protection unit disposed on the above plurality of light sources and the reflector;
A transparent film placed on the above light source protection member;
A plurality of diffraction patterns arranged on the lower surface of the transparent film, each of which is arranged at a position corresponding to each of the plurality of light sources, and having a refractive index higher than the refractive index of the transparent film; and
A plurality of light-emitting patterns arranged on the upper surface of the transparent film and having a refractive index higher than the refractive index of the transparent film
A backlight unit including:

Images