KR102489587B1 - Optical Source Unit and Display Device Using the Same - Google Patents

Abstract

In particular, the present invention relates to a light source unit to which a band pass filter film is applied, which expands a color gamut, does not deteriorate materially, and solves a light leakage problem, and a display device using the same. The light source unit of the present invention emits light of a specific wavelength. The color gamut is expanded by absorbing the inside and transmitting wavelengths of the remaining gamut, and for this, a reflective holographic optical film having a Bragg mirror function is applied.

Description

Light source unit and display device using the same {Optical Source Unit and Display Device Using the Same}

The present invention relates to a display device, and more particularly, to a light source unit to which a band-pass filter film is applied, in which a color gamut is expanded, there is no material deterioration, and a light leakage problem is solved, and a display device using the same.

Specific examples of the flat panel display device include a liquid crystal display device (LCD), an organic light emitting display device (Organic Emitting Display Device), a plasma display panel device (PDP), and a quantum dot display device (Quantum Dot Display Device). ), field emission display device (FED), electrophoretic display device (EPD), etc., which commonly use a flat panel display panel for realizing an image as an essential component, A flat panel display panel has a structure in which a pair of transparent insulating substrates are bonded face-to-face with an inherent light emitting or polarizing or other optical material layer interposed therebetween.

Among them, a light-receiving display panel such as a liquid crystal display does not emit light by itself and is essentially used by attaching a light source unit to one side. In particular, it is named as a backlight unit in the sense of being located on the lower side of the light-receiving display panel. In this case, light emitted from the backlight passes through transparent electrodes (pixel electrodes, common electrodes) in the display panel to display information, and displays information with high luminance. The video can be provided to viewers.

Meanwhile, a general backlight unit includes a light guide plate having a light source on one side and a plurality of optical sheets on the light guide plate.

However, the color gamut expressed by the backlight unit developed so far remains at a limited color expression that is not enough to express the color of the natural world.

In addition, efforts to expand the color gamut by applying an optical sheet that emits light in a photo luminescence (light emission by light absorption) method using quantum dots, which are semiconductors of several nanometers in size, are applied to the optical sheet. Although this has been proposed, an optical sheet including quantum dots is easily oxidized under conditions in which oxygen, moisture, and heat are applied, and thus, there is a problem in that performance degradation occurs.

In addition, since the optical sheet including quantum dots absorbs the light emitted from the light guide plate and emits secondary light in an omnidirectional angle, there is also a problem in that light leakage occurs, and there is an obstacle in applying this to the backlight unit, and other A solution was required.

The present invention has been made to solve the above-mentioned problems, and provides a light source unit to which a band pass filter film is applied that solves the light leakage problem while expanding the color gamut and without material degradation, and a display device using the same. There is a purpose.

The light source unit of the present invention for achieving the above object absorbs light of a specific wavelength inside and transmits wavelengths of the remaining range to expand the color gamut, and for this purpose, a reflective type having a Bragg mirror function. A hologram optical film is applied.

The light source unit of the present invention, for example, includes a light guide plate, an LED array positioned on one side of the light guide plate, and an LED array positioned on the upper side of the light guide plate, and absorbing at least one of a wavelength between red light and green light and a wavelength between green light and red light. It is made including a band pass filter film to.

And, the band pass filter film preferably has a total reflection property with respect to the wavelength of the absorbed light. To this end, the band pass filter film may be formed by stacking one or more pairs of insulating layers having a refractive index difference. In addition, the band pass filter film may have a repeated refractive index pattern in a horizontal or inclined shape on at least one insulating layer in the pair of insulating layers.

For example, the band pass filter film may absorb a wavelength of 560 nm to 610 nm, or may absorb a wavelength of 450 nm to 500 nm.

Meanwhile, a lens unit may be further included between the light guide plate and the LED array to transfer light emitted from the LED array to the light guide plate as parallel light, and in this case, the band pass filter film is positioned closest to the light guide plate. can do. In addition, a plurality of stripe-shaped patterns perpendicular to a light propagation direction of the light guide plate may be provided on a surface of the light guide plate.

Alternatively, the light source unit may further include a prism sheet between the light guide plate and the band pass filter film, and a diffusion plate on top of the band pass filter film.

A display device to which the light source unit structure described above is applied may have the following structure. That is, a cover bottom having a reflector on the inner side, a light guide plate on the reflector in the cover bottom, an LED array located on one side of the light guide plate, a prism sheet on the light guide plate, and a prism sheet closest to the prism sheet, between red light and green light. A band pass filter film absorbing at least one wavelength among wavelengths of , green light and red light, a diffusion plate on top of the band pass filter film, and a display panel on top of the diffusion plate.

As an example of another type of display device, in addition to a prism sheet or a diffusion plate, a lens unit may be further included between the light guide plate and the LED array to transmit light emitted from the LED array to the light guide plate as parallel light.

The light source unit and the display device using the light source unit of the present invention have the following effects.

A HOE film that selectively absorbs light of a specific wavelength is applied to the upper side of the light guide plate to shape the wavelength characteristics of the emitted light transmitted to the display panel, thereby making the distinction between primary color light regions stand out. This improves the color gamut to expand the color gamut.

In addition, the light source unit of the present invention can solve the problem of deterioration or environmental pollution caused by the use of a conventional optical sheet by applying an HOE film that does not materially deteriorate due to long-time use as a band pass filter film.

In addition, the light leakage problem caused by the omnidirectional reflective characteristics of the conventional optical sheet can be solved. In particular, when omnidirectional reflection occurs, the bezel area also increases. In the light source unit of the present invention, the absorbed light is totally reflected inside the band pass filter film and is not reflected to the outside, so the required bezel area is extremely small. can

1 is a perspective view showing a light source unit according to a first embodiment of the present invention;
2a and 2b are cross-sectional views showing the structure and function of the band pass filter film of FIG. 1
Figure 3 is a graph showing the transmittance by wavelength according to an example of the band pass filter film of Figure 2
4 is a graph showing the spectrum of incident light and transmitted light when the light source unit of the present invention is applied.
5A and 5B are diagrams showing the refractive index distribution of light explaining the principle of spectral transformation of the light source unit of the present invention.
6 is a view showing color gamut expansion of the light source unit of the present invention
7 is a perspective view illustrating a display device to which a light source unit according to a first embodiment of the present invention is applied;
8 is a perspective view showing a light source unit according to a second embodiment of the present invention;
9 is a cross-sectional view showing a light source unit according to a second embodiment of the present invention.
Figure 10 is a cross-sectional view showing an example of the structure of the band pass filter film of Figure 9
11 is a graph showing the transmittance according to the wavelength of the light source unit according to the second embodiment of the present invention.
12 is a cross-sectional view of a display device to which a light source unit according to a second embodiment of the present invention is applied.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numbers throughout the specification indicate substantially the same elements. In the following description, if it is determined that a detailed description of a known technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, the component names used in the following description are selected in consideration of the ease of writing the specification, and may be different from the part names of the actual product.

* First embodiment

1 is a perspective view showing a light source unit according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the structure and function of the band pass filter film of FIG. 1 . And, FIG. 3 is a graph showing transmittance per wavelength according to an example of the band pass filter film of FIG. 2 .

1 and 2, the light source unit 1000 according to the first embodiment of the present invention includes a light guide plate 100, an LED array 120 located on one side of the light guide plate 100, and an upper side of the light guide plate. , a bandpass filter film 140 absorbing at least one of a wavelength between red light and green light and a wavelength between green light and red light.

Here, as shown in FIG. 3, the band pass filter film 140 has absorption characteristics for a specific wavelength (λc) among light incident from the light guide plate 100, and transmission characteristics for the remaining wavelengths (λa, λb). have And, it has a total internal reflection characteristic with respect to the wavelength (λc) of the absorbed light, and is made of, for example, a holographic optical element (HOE). In particular, the band-pass filter film 140 has a function of shaping the spectrum of emitted light by trapping light of a specific wavelength among emitted light, thereby shaping light of a color adjacent to the absorbed wavelength. It is possible to expand color gamut and color gamut by distinguishing between fields.

For example, when the band pass filter film 140 absorbs light between green light and red light, a wavelength of 560 nm to 610 nm is absorbed, and when light between blue light and green light is absorbed, a wavelength of 450 nm to 500 nm is absorbed. can absorb The band pass filter film 140 may simultaneously absorb light in these two areas, or absorb light in only one area.

In addition, the expansion of the color gamut is performed according to the following principle. That is, as an example, when the band pass filter film 140 absorbs light with a wavelength of 560 nm to 610 nm between green light and red light, when using the same LED light source array, before applying the band pass filter film 140, the LED The light emitted from the light source array of is emitted evenly over the entire range of the visible ray region, and after applying the band pass filter film 140, it absorbs specific wavelengths of 560 nm to 610 nm, and in particular, adjacent color lights that are distinguished from each other. Since it absorbs the wavelength of the mixed light region between the colors, the expression of green light and red light appears prominently, so that it is possible to obtain an improvement in color reproducibility close to the actual color of the natural world.

As shown in FIG. 2A, the band pass filter film 140 is, for example, a stack in which one or more pairs of insulating layers 145a and 145b having different refractive indices (n1 and n2) are stacked on a transparent substrate 141 ( 145) and the protective film 148 on top of the stack 145.

The protective film 148 is a transparent film provided to prevent particles such as dust from affecting optical properties, and may be omitted in some cases.

In addition, the substrate 141 is used as a formation surface of the stack 145, and it is preferable to be as thin and transparent as possible from an optical point of view, but may have a certain thickness to prevent deformation of the stack 145 during formation. there is. Here, when a plurality of pairs of insulating layers 145a and 145b are provided in the stack 145, each pair may have the same configuration, the same refractive index n1 and n2, and the same thickness.

In addition, one of the insulating layers 145a and 145b has a high refractive index (n1) and the other has a low refractive index (n2). For example, assuming that the first insulating layer 145a has a high refractive index n1, the refractive index value may be 1.5 to 2.3, and the refractive index value of the second insulating layer 145b having a low refractive index n2. may be 1.0 to 1.5. However, the range of refractive index is not limited thereto, and as long as the band pass filter film 140 operates as a Bragg mirror with absorption and total reflection functions for a specific wavelength on the light guide plate 100, other refractive index conditions will also be possible. The band pass filter film 140 has total internal reflection characteristics only for a specific wavelength, and total internal reflection occurs for a specific wavelength within the stack 145, and transmits light of the remaining wavelengths as it is.

In addition, a plurality of stacks 145 in the band pass filter film 140 may be provided to have absorption and total reflection characteristics for two or more wavelengths. In this case, at least one of the refractive index values of the first and second insulating layers of different stacks is different, and preferably, the refractive index value of the high refractive index of each stack is different.

Meanwhile, the insulating layers 145a and 145b in the stack 145 of the band-pass filter film 140 have different refractive indices, and each pair of insulating layers in the stack 145 has a first insulating layer 145a and a second insulating layer 145a. Thicknesses of the second insulating layer 145b may be different from each other.

In addition, as shown in FIG. 2B, in another embodiment, the band pass filter film 245 may be formed of a stack 2450 including a plurality of insulating layer pair units, and at least one insulating layer in the insulating layer pair unit ( 245) may have a repeated refractive index pattern 245a in a horizontal or inclined shape. Here, the refractive index pattern 245a may be located long in the y-axis direction when the horizontal direction in the drawing is referred to as the x-axis and the direction penetrating the ground is referred to as the y-axis, has a high refractive index (n1), and has a refractive index pattern 245a includes another low refractive index n3 material 245b interspersed. For convenience, the insulating layer having the refractive index pattern 245a is referred to as the first insulating layer 245 .

And, the other second insulating layer 244 in the insulating layer pair unit is made of a material having a refractive index n2 lower than the high refractive index n1, and in this case, the refractive index n2 is the refractive index of the first insulating layer 245. The refractive index n3 of the material 245b filled between the patterns 245a may be the same.

On the other hand, the stack including the insulating layer pair unit may include a plurality of identical insulating layer pair units and have absorption characteristics of the same wavelength and have a stack structure, or may have a plurality of stacks of different types of insulating layer pair units, The band pass filter film 240 may be configured to have absorption characteristics of different wavelengths.

On the upper side of the light guide plate 100, in addition to the band pass filter film 140 or 240, optical sheets 130 and 150 provided to condense and diffuse light are further provided. The optical sheets include a prism sheet 130 that enhances the condensing property of the light emitted from the lower light guide plate 100 and emits it, and a diffusion plate 150 that diffuses the emitted light upward and emits the emitted light.

Here, the band-pass filter film 140 is preferably located directly above the prism sheet 130 emitting the most condensed light upward from the light guide plate 100 .

Here, the LED array 120 is a plurality of regularly arranged LEDs, has a rectangular shape in plan view, is located on one side of the light guide plate 100 having a constant thickness, and supplies light to the light guide plate 100 on the side. . Further, the LED is a light source that supplies white light to the light guide plate 100, and supplies light over the RGB spectrum to the light guide plate 100 based on a specific phosphor.

Meanwhile, the light guide plate 100 includes a reflector (see 170 in FIG. 7 ) on the lower side, and is accommodated together with the LED array 120 in a cover bottom (see 160 in FIG. 7 ).

In this case, the light guide plate 100 horizontally propagates the light incident from the LED array 120 in plan view, and transmits the light transmitted laterally in the vertical direction by the reflecting plate (170 in FIG. 7) provided on the lower side. It functions to transfer to the upper optical sheets 130 and 150 and the band pass filter film 140 .

Also, the reason why the band pass filter film 140 is closest to the prism sheet 130 is that it has the best light condensing property on the prism sheet 130 among the provided optical sheets. Among the light emitted from the light guide plate 100 , light having some divergence characteristics does not normally have Bragg mirror characteristics within the band pass filter film 140 .

4 is a graph showing spectra of incident light and transmitted light when the light source unit of the present invention is applied.

Figure 4 shows the spectrum of incident light and transmitted light when the light source unit of the present invention is applied. For example, the LED light source used in the LED array 120 is based on the KSF phosphor, and the first peak characteristic of the blue light region In the case where the second peak characteristic is uniformly displayed in the green light and red light regions, the transmitted light spectrum is shown when the band pass filter film is applied and when the band pass filter film is not applied.

That is, when the band pass filter film is not applied, the transmitted light spectrum shows a spectrum in a state where the intensity is slightly weaker than that of the light source directly emitted from the LED light source, but no change in the second peak characteristic is shown. However, when the band pass filter film of the present invention was applied, it was confirmed that clear light absorption characteristics appeared in a region between green light and red light, that is, in a wavelength range of 575 nm to 600 nm.

That is, the light source unit of the present invention can improve the expression of primary color light adjacent to the wavelength of the mixed color through the absorption of the mixed color light region, thereby improving the color reproducibility.

5A and 5B are diagrams illustrating the refractive index distribution of light explaining the principle of spectral transformation of the light source unit of the present invention, and FIG. 6 is a diagram showing color gamut expansion of the light source unit of the present invention.

5A and 5B are diagrams showing the periodic refractive index distribution before and after passing through the band pass filter film, and it can be seen that a gap of a specific wavelength occurs when passing through the band pass filter film. Here, the forbidden wavelength range of light is referred to as a photonic band gap.

On the other hand, FIG. 6 also shows the color gamut defined by the CIE in 1931, as shown in FIG. 6, and the area within the boundary appearing in the shape of a horseshoe is the range of the natural world that can be recognized by humans. The range that can be expressed in the actual display device is limited to the triangular shape therein, and when the above-described band pass filter film is applied, an effect of increasing the area of the triangular shape can be obtained by improving the color reproduction rate.

7 is a perspective view and a cross-sectional view illustrating a display device to which a light source unit according to a first embodiment of the present invention is applied.

7 shows a display device 2000 to which the above-described light source unit of the present invention is applied. Looking in order from the bottom, the cover bottom 160 and the reflector 170 provided on the inner surface of the cover bottom 160 are shown in FIG. ), the light guide plate 100 located on the reflector 170 and accommodated in the cover bottom 160, and located on one side of the light guide plate 100 and accommodated in the cover bottom 160 together with the light guide plate The LED array 120, the optical sheets 130 and 150 including the band pass filter 140 located above the light guide plate 100, and the display panel 200 located above the periphery of the light guide plate 100 are supported. It includes a guide panel 180 having a function of performing a function, a display panel 200 placed on the guide panel 180, and a case top 190 having upper edges and side portions of the display panel 200.

Here, the case top 190 and the guide panel 180 have a frame shape with at least an open area (display area) of the display panel 200 .

Also, the LED array 120 may be replaced with other types of light sources such as fluorescent lamps in some cases. However, in this case, the absorption wavelength region may be shifted and adjusted according to the wavelength spectrum of the light source.

The LED array 120 has a plurality of LEDs 120a mounted on a PCB substrate 120b, and the incident part of the LEDs 120a is disposed to face the side of the light guide plate 100.

In addition, it may be considered that the LED array 120 is arranged on the lower side of the light guide plate 100 rather than on the side depending on the case.

The cover bottom 160 has a rectangular inner surface and side surfaces vertically connected to four sides of the inner surface, and has a storage space therein between the inner surface and the side surface. In addition, the thickness of the side surface of the cover bottom 160 is equal to or greater than the sum of the light guide plate 100 and the reflector 170, and the light guide plate 100 and the reflector 170 are inside the cover bottom 160. ) is stored.

In addition, the display panel 200 is a panel that displays an image by receiving light coming from the lower side, and may be, for example, a liquid crystal display panel. In the case of a liquid crystal display panel, the TFT array substrate 210 facing each other; It consists of a color filter substrate 220 and a liquid crystal layer therebetween. In addition, polarizers 230a and 230b having transmissive axes crossing each other may be included in the upper and lower portions of the display panel. Here, the TFT array substrate and the color filter substrate include a plurality of pixels in a matrix form corresponding to the active area (display area), and the TFT array substrate includes a gate line and a data line for crossing and dividing pixels; Each of the pixels includes a pixel electrode provided in a region between the gate line and the data line, and a thin film transistor connected to the gate line and the data line. The color filter substrate includes a black matrix layer covering gate lines and data lines, thin film transistors, and color filter layers corresponding to respective pixels. In addition, a common electrode may be formed over the entire active region of the color filter substrate or may be provided in the TFT array substrate in a form alternating with the pixel electrode for each pixel.

Meanwhile, the above-described liquid crystal display panel is only an example, and each component may be formed on a substrate different from the presented example, and further includes components such as an inorganic insulating film or an organic insulating film between lines. can do.

* Second embodiment

8 is a perspective view showing a light source unit according to a second embodiment of the present invention, and FIG. 9 is a cross-sectional view showing a light source unit according to a second embodiment of the present invention. 10 is a cross-sectional view showing an example of the structure of the band pass filter film of FIG. 9 .

A light source unit according to a second embodiment of the present invention represents a backlight unit that emits light with directivity.

8 and 9 , the light source unit according to the second embodiment of the present invention includes a light guide plate 300, a lens unit 420 on one side of the light guide plate 300, and a constant relative to the lens unit 420. The LED light source 410a having a focal length is positioned above the light guide plate and the light input part 400 including the regularly arranged LED array 410, and at least one of a wavelength between red light and green light and a wavelength between green light and red light. It includes a band pass filter film (bandpass filter) 500 that absorbs the wavelength of.

Here, the lens unit 420 receives light from the LED light source 410a of a point light source and converts the incident light to the light guide plate 300 according to the focal length from the LED light source 410a and the curvature of the incident part of the lens unit 420. It expands to the corresponding width of the lens unit 420 and serves to transmit straight light, and the light guide plate 300 functions to emit the transmitted straight light in parallel.

Meanwhile, the lens unit 420 is not limited to the illustrated example, and functions to transmit straight light by expanding the light of the LED light source to the width of the light guide plate 300 between the LED light source 410a and the light guide plate 300. If so, it can be changed to other forms as well.

In addition, the lens unit 420 may further include a reflective layer on the upper side so that the light is not diverged to the upper side and the light is transmitted to the light guide plate 300 in parallel. Also, the lens unit 420 may have the same thickness as that of the light guide plate 300 .

Meanwhile, a plurality of stripe patterns 310 may be provided on an upper surface of the light guide plate 300 in a shape perpendicular to a traveling direction of parallel light in the light guide plate 300 . With the provision of the stripe pattern 310, it is easy to control the direction of light emitted from the light guide plate 300.

In addition, in the light source unit according to the second embodiment of the present invention, the lens unit 420 is disposed between the light guide plate 300 and the LED array 410 to transmit constant parallel light to the light guide plate 300, and the light guide plate The light transmitted upward from 300 is transmitted to the display panel (not shown) through the band pass filter film 500 and the light tilted in a certain direction. Or a structure useful for directional devices, such as a privacy display panel.

In this case, a display panel may be directly provided on the upper side of the band pass filter film 500 without providing a separate optical film. In addition, the band-pass filter film 500 itself is also disposed closest to the light guide plate 300, so that the band-pass filter film 500 can perform selective absorption and total reflection of the parallel light emitted upward.

Here, the configuration of the band pass filter film 500 is the same as the configuration described in FIG. 2a or 2b described above, or a stack 545 provided with one or more insulating layer pair units to maintain the directivity of outgoing light tilted in a specific direction It may also be in the form of having a surface grating or volume grating with a surface or a certain thickness.

Also, the stack 545 may be formed on a transparent substrate 541 having a predetermined thickness.

Meanwhile, the light source unit of the above-described second embodiment may also have the same wavelength selective characteristic of outgoing light as that of the above-described first embodiment.

11 is a graph showing the transmittance according to the wavelength of the light source unit according to the second embodiment of the present invention.

In FIG. 11, the light source unit of the second embodiment is composed of a band pass filter film 500 having absorption characteristics at a first wavelength (λc) between red light and green light and at a second wavelength (λd) between green light and blue light. It may be formed in the form of stacking two stacks 545 formed by stacking material layers 545a and 545b having different absorption characteristics on a substrate 541 .

In addition, the light source unit of the second embodiment of the present invention may have the following configuration.

12 is a cross-sectional view illustrating a display device to which a light source unit according to a second embodiment of the present invention is applied.

As shown in FIG. 12 , the display device according to the second embodiment of the present invention, when viewed in order from the bottom, includes the cover bottom 160, the reflector 170 provided on the inner surface of the cover bottom 160, and the The light guide plate 300 located on the reflector 170 and accommodated in the cover bottom 160, and the LED located on one side of the light guide plate 300 and accommodated in the cover bottom 160 together with the light guide plate 300. A lens unit 420 having a constant focal length with respect to the array 410, the light guide plate 300, and each LED light source 410a constituting the LED array, and closer to the light guide plate 300 than the LED light source 410a And, the band pass filter 500 located above the light guide plate 300, the guide panel 180 located above the periphery of the light guide plate 300 and supporting the display panel 200, and the guide panel ( 180) and a case top 190 having an upper edge and a side portion of the display panel 200.

Here, the LED array 410 may be replaced with other types of light sources such as fluorescent lamps depending on circumstances. However, in this case, the region of the absorption wavelength of the band pass filter film 500 may be shifted and adjusted according to the wavelength spectrum of the light source.

On the other hand, since the same functions are performed for the same codes as those in the first embodiment described above, the description thereof is omitted.

A light source unit and a display device using the light source unit of the present invention apply a Holographic Optical Element Film (HOE) film that selectively absorbs light of a specific wavelength to an upper side of a light guide plate to shape the wavelength characteristics of emitted light transmitted to a display panel, thereby shaping primary color light The distinction between areas can be made more pronounced. This improves the color gamut to expand the color gamut.

In addition, the light source unit of the present invention can solve the deterioration problem and environmental pollution problem caused by the use of the conventional optical sheet by applying the band pass filter film to the HOE film, which is not materially deteriorated due to long-term use.

In addition, the light leakage problem caused by the omnidirectional reflective characteristics of the conventional optical sheet can be solved. In particular, when omnidirectional reflection occurs, the bezel area also increases. In the light source unit of the present invention, the absorbed light is totally reflected inside the band pass filter film and is not reflected to the outside, so the required bezel area is extremely small. can

On the other hand, the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be clear to those skilled in the art.

100: light guide plate 120: LED array
130: prism sheet 140: band pass filter film
141: substrate 145: stack
145a: first insulating layer 145b: second insulating layer
148: protective film 150: diffusion plate
160: cover bottom 170: reflector
180: guide panel 190: case top
200: display panel 300: light guide plate
310: stripe pattern 410: LED array
420: lens unit 500: band pass filter film

Claims (11)

light guide plate;
an LED array located on one side of the light guide plate; and
A prism sheet, a band pass filter film, and a diffusion plate sequentially positioned above the light guide plate;
The band pass filter film absorbs at least one wavelength of a wavelength between red light and green light and a wavelength between green light and red light with respect to light incident from the prism sheet, and totally reflects the light of the absorbed wavelength inside,
The light emitted from the LED array is supplied to one side of the light guide plate, is collected by the prism sheet via the light guide plate, and emits through the diffusion plate after excluding the light of the wavelength absorbed by the band pass filter film. . According to claim 1,
The band pass filter film is a light source unit formed by stacking one or more pairs of insulating layers having a refractive index difference. According to claim 2,
The band pass filter film has a repeated refractive index pattern in a horizontal or inclined form on at least one insulating layer in the pair of insulating layers. According to claim 1,
The band pass filter film is a light source unit including a band pass filter film that absorbs wavelengths of 560 nm to 610 nm. According to claim 1,
The band pass filter film is a light source unit that absorbs a wavelength of a wavelength of 450 nm to 500 nm. delete delete delete delete Cover bottom having a reflector on the inner side;
a light guide plate on the reflector in the bottom of the cover;
an LED array located on one side of the light guide plate;
a prism sheet on the light guide plate;
A band that is closest to the prism sheet and absorbs at least one wavelength among wavelengths between red light and green light and wavelengths between green light and red light with respect to light incident from the prism sheet, and internally reflects the light of the absorbed wavelength. pass filter film;
a diffusion plate on top of the band pass filter film; and
a display panel above the diffusion plate;
The light emitted from the LED array is supplied to one side of the light guide plate, is collected by the prism sheet via the light guide plate, and emits through the diffusion plate after excluding the light of the wavelength absorbed by the band pass filter film, and the display A display device delivered to the panel. delete

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