KR101158904B1 - Display device - Google Patents

Abstract

Disclosed is a display device having improved display quality of an image. The display device includes a display panel and a light generating unit. The display panel is interposed between a first substrate on which switching elements are formed, a second substrate on which first, second, and third color filters are formed at a predetermined area ratio to implement color in a unit pixel, and between the first and second substrates. A liquid crystal layer. The light generating unit generates first, second and third light having a color concentration ratio inversely proportional to the area ratio of the color filters, and implements white light by mixing the first, second and third light, and generates white light with the display panel. to provide. As such, as white light is generated by mixing light having a color concentration corresponding to the area ratio of the color filters, color reproducibility may be improved, and as a result, display quality of an image of the display device may be further improved.

Light Emitting Diode, Color Filter

Description

Display device {DISPLAY DEVICE}

1 is an exploded perspective view illustrating a display device according to a first embodiment of the present invention.

2 is a cross-sectional view conceptually illustrating the display device of FIG. 1.

3 is a plan view illustrating the color filter substrate of FIG. 1.

4 is a graph illustrating color concentration of the light emitting diode of FIG. 1.

5 is a cross-sectional view conceptually illustrating a display device according to a second exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: storage container 200: light generating unit

210: light emitting diode 220: driving substrate

RL: Red light emitting diode GL: Green generating diode

BL: blue light emitting diode WL: white generating diode

300: light guide plate 400: reflector

500: optical member 600: display panel

700: display device

The present invention relates to a display device, and more particularly, to a display device with improved display quality of an image.

Recently, an information processing device has various forms and various functions, and processes information at a higher speed. The information processed in the information processing apparatus has an electrical signal format. Therefore, in order for the user to visually check the information processed by the information processing apparatus, display apparatuses displaying the information as an image are required.

One of the display devices, a liquid crystal display, displays an image using liquid crystals. The liquid crystal display device has advantages of thinner, lighter weight, lower power consumption, and lower driving voltage than other display devices.

The liquid crystal display generally includes a liquid crystal display panel displaying an image using light transmittance of a liquid crystal, and a backlight assembly disposed under the liquid crystal display panel to provide light to the liquid crystal display panel. back-light assembly).

The backlight assembly includes a light generating unit for generating light, and the light generating unit generally includes a cold cathode fluorescent lamp (CCFL), a flat fluorescent lamp (FFL), and a light emitting diode (Light). Emitting Diode, LED) is a typical example. Among the light generating units, the light emitting diodes may be manufactured in a chip form, have high luminance and low power consumption, and thus are recently used as light sources of the backlight assembly.

The liquid crystal display panel includes an array substrate on which switching elements are formed, a color filter substrate on which color filters are formed, and a liquid crystal layer interposed between the array substrate and the color filter.

In general, color filters having three colors, such as red, green, and blue, are formed in a pixel of a conventional color filter substrate. However, recently developed color filter substrates have high brightness and low power. In three color filters, four color filters in which a white color filter is added are formed.

However, when the white color filter is added on the color filter substrate, the brightness of the liquid crystal display is improved, but instead, the color density is reduced and the color reproducibility of the liquid crystal display is reduced.

Therefore, the technical problem of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a display device that improves the display quality of an image by adjusting the color density of a light emitting diode to improve color reproducibility.

A display device according to an embodiment for achieving the above object of the present invention includes a display panel and a light generating unit.

The display panel includes a first substrate on which switching elements are formed, a second substrate on which first, second, and third color filters are formed at a predetermined area ratio to realize color in a unit pixel, and between the first and second substrates. It includes a liquid crystal layer interposed therein.

The light generating unit generates first, second, and third lights having a color concentration ratio inversely proportional to the area ratio, and implements white light by mixing the first, second, and third lights. Provide white light.

According to such a display device, as light having a color concentration corresponding to the area ratio of the color filters is mixed to form white light, color reproducibility may be improved, and as a result, display quality of an image of the display device may be further improved. .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First Embodiment of Display Device>

1 is an exploded perspective view illustrating a display device according to a first exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view conceptually illustrating the display device of FIG. 1.

1 and 2, the display device 700 according to the present embodiment includes a storage container 100, a light generating unit 200, a light guide plate 300, a reflector plate 400, an optical member 500, and a display. Panel 600.

The storage container 100 includes a bottom portion 110 and side portions 120 extending from an edge of the bottom portion 110. The storage container 100 forms a storage space by the bottom portion 110 and the side portions 120, and the light storage unit 200, the light guide plate 300, the reflective plate 400, and the optical member 500 are formed in the storage space. ) And the display panel 600 are housed.

The light generating unit 200 is disposed to face one side of the light guide plate 300 to generate light. Alternatively, a pair of light generating units 200 may be disposed to face both sides of the light guide plate 300. The light generating unit 200 includes, for example, a light emitting diode 210 for generating a point light source and a driving substrate 220 for supplying power to the light emitting diode 210.

A plurality of light emitting diodes 210 are arranged in a row on the driving substrate 220 and generate a point light source by receiving power from the driving substrate 220. The light emitting diode 210 is disposed to face one side of the light guide plate 300 to inject a point light source into one side of the light guide plate 300.

The light emitting diode 210 includes a red light emitting diode RL generating red light, a green light emitting diode GL generating green light, and a blue light emitting diode BL generating blue light. In this case, the red light, the green light, and the blue light are mixed with each other by the light guide plate 300 and the optical member 500 to form white light, and the white light is incident on the display panel 600.

The driving substrate 220 is electrically connected to an external power supply device (not shown) to supply power to the light emitting diode 210. The driving substrate 220 has a plate shape formed along one side of the light guide plate 220.

The driving substrate 220 is made of a metal material having high thermal conductivity, for example, aluminum (Al), to emit heat generated from the light emitting diode 210, and the light emitting diode 210 is formed on or inside the metal material. A power line (not shown) for supplying power to the furnace is formed. In this case, in order to insulate the power line from the metal material, the power line is coated with an insulating material.

The light guide plate 300 is disposed in the storage container 100 such that one side of the light guide plate 300 faces the light generating unit 200. In this case, the light generated by the light generating unit 200 is incident on one side of the light guide plate 300, and is refracted and reflected inside the light guide plate 300 to be emitted to the upper portion of the light guide plate 300. A plurality of reflection patterns (not shown) may be formed on the lower surface of the light guide plate 300 to scatter the light to improve luminance uniformity. Although the light guide plate 300 illustrated in the drawings has a flat rectangular parallelepiped shape, the light guide plate 300 may have a wedge shape.

The reflective plate 400 is disposed in the storage container 100 and is disposed below the light guide plate 300. The reflective plate 400 reflects the light emitted to the lower portion of the light guide plate 300 among the light incident into the light guide plate 300, and re-injects the light into the light guide plate 300.

The optical member 500 is disposed in the accommodation container 100 and is disposed above the light guide plate 300. The optical member 500 improves the optical characteristics of the light emitted to the upper portion of the light guide plate 300. The optical member 500 may include, for example, a diffusion sheet 510 that diffuses light to improve uniformity of brightness, and at least one prism sheet 520 that increases vertical brightness in front through refraction and reflection of light. Include. In this case, the light emitted from the optical member is white light formed by mixing the red light, the green light, and the blue light.

The display panel 600 is disposed above the optical member 500 and displays an image by using the white light emitted from the optical member 500. The display panel 600 includes a first substrate 610, a second substrate 620, a liquid crystal layer 630, a printed circuit board 640, and a flexible printed circuit board 650.

The first substrate 610 includes a plurality of pixel electrodes (not shown) arranged in a matrix form and a thin film transistor (TFT) that applies a driving voltage to each of the pixel electrodes. ) And signal lines (not shown) for operating the thin film transistors (TFTs), respectively. A driving chip electrically connected to the signal line and applying a driving signal to the thin film transistors TFT is disposed at an edge of the first substrate 610.

The pixel electrode includes a transparent and conductive indium tin oxide film (ITO), an indium zinc oxide film (IZO), and an amorphous indium tin oxide film (a-ITO). And the like are patterned and formed by a photo-etch process.

The second substrate 620 is disposed to face the first substrate 610. The second substrate 620 includes a transparent substrate 610, a color filter 624 disposed on the transparent substrate 610 to face the pixel electrodes, and a front surface of the second substrate 620 to cover the color filter 624. And a common electrode (not shown) that is disposed in and is transparent and conductive.

The color filters 624 may include a red color filter RF selectively passing red light of the white light, a green color filter GF selectively passing green light of the white light, and a blue light selectively passing blue light of the white light. It includes a color filter (BF) and a white color filter (WF) for passing the white light as it is. In this case, the white color filter WF may be a transparent organic film that transmits the white light as it is. Alternatively, the white color filter WF may be omitted to transmit the white light as it is.

The liquid crystal layer 630 is interposed between the first substrate 610 and the second substrate 620 and rearranged by an electric field formed between the pixel electrode and the common electrode. The rearranged liquid crystal layer 630 adjusts the light transmittance of the light passing through the optical member 500, and the light having the light transmittance adjusted passes through the color filters 624 to display an image.

The printed circuit board 640 includes a driving circuit unit for processing an image signal, and the driving circuit unit converts an externally input image signal into a control signal for controlling the driving chip.

The flexible circuit board 650 electrically connects the printed circuit board 640 and the first substrate 610, and provides a control signal generated from the printed circuit board 640 to the first substrate 610. The flexible circuit board 650 is bent to arrange the printed circuit board 640 under the display device 700, that is, under the bottom 110 of the storage container 100.

The display device 700 according to the present exemplary embodiment is coupled to the storage container 100 to prevent the display panel 600 from being damaged or damaged by external shock and vibration, and the display panel 600 is stored in the storage container 100. It may include a top chassis (not shown) to prevent the departure from.

Although the light generating unit 200 according to the present exemplary embodiment is illustrated as being disposed on the side surface of the light guide plate 300, the light generating unit 200 may be disposed below the display panel 600, that is, under the optical member 500. Specifically, a plurality of light generating units 200 are disposed below the optical member 500 to generate light, and the generated light may be directly applied to the display panel 600 via the optical member 500. have.

3 is a plan view illustrating the color filter substrate of FIG. 1, and FIG. 4 is a graph showing the color concentration of the light emitting diode of FIG. 1.

Referring to FIG. 3, a plurality of color filters 624 for implementing a plurality of colors are formed on the color filter substrate 620 according to the present embodiment. The color filters 624 include, for example, a red color filter RF, a green color filter GF, and a blue color filter BF.

In this case, one red color filter RF, one green color filter GF, and one blue color filter BF are grouped into one to form one pixel. The unit pixels are arranged in a matrix form.

A white region is formed in the unit pixel to realize the white color by transmitting the white light as it is. The white color filter GF, which is a transparent organic film, may be formed in the white region, but nothing may be formed.

The red color filter RF, the green color filter GF, and the blue color filter BF formed in the unit pixel have a predetermined area ratio. In one example, the red color filter RF, the green color filter GF, and the blue color filter BF have an area ratio of 7: 8: 10.

The red color filter RF, the green color filter GF, and the blue color filter BF shown in the drawing have the area ratio in the unit pixel and form one sub pixel. In this case, each sub-pixel has a different area.

Alternatively, the red color filter RF, the green color filter GF, and the blue color filter BF formed in the unit pixel may be configured with different numbers of subpixels to have the area ratio. In this case, each of the subpixels has the same rectangular shape.

For example, when the red color filter RF, the green color filter GF, and the blue color filter BF in the unit pixel have an area ratio of 7: 8: 10, the red color filter RF is Formed in the number of subpixels corresponding to the ratio of seven, green color filter GF is formed in the number of subpixels corresponding to the ratio of eight, and red color filter BF in the number corresponding to the ratio of ten It is formed in the sub pixel.

Referring to FIG. 4, the light emitting diode 210 according to the present embodiment includes a red light emitting diode RL generating red light, a green light emitting diode GL generating green light, and a blue light emitting diode BL generating blue light. Include.

Each of the red light emitting diode RL, the green light emitting diode GL, and the blue light emitting diode BL generates red light, green light, and blue light having a color density corresponding to the area ratio of the color filters 624. Preferably, each of the red light emitting diode RL, the green light emitting diode GL, and the blue light emitting diode BL generates red light, green light, and blue light having a color concentration inversely proportional to the area ratio of the color filters 624.

Specifically, as the area ratio has 7: 8: 10 according to the red color filter (RF), the green color filter (GF), and the blue color filter (BF), the color concentration ratios of the red light, the green light, and the blue light are inversely reversed. 10: 8: 7.

The red, green and blue light having a color concentration ratio of 10: 8: 7 are mixed with each other by the light guide plate 300 and the optical member 500 to form white light, and the white light is incident on the display panel 600.

In addition, the red light emitting diode RL includes a red fluorescent material for converting internal light into the red light, and the green light emitting diode GL includes a green fluorescent material for converting internal light into the green light. BL) includes a blue phosphor that converts internal light into the blue light.

In order to generate red light, green light and blue light according to the color concentration ratio, the red fluorescent material, the green fluorescent material and the blue fluorescent material are preferably formed in a volume ratio proportional to the color concentration ratio. For example, when the color concentration ratio is 10: 8: 7, the volume ratio of the red phosphor, the green phosphor, and the blue phosphor is also 10: 8: 7.

Specifically, when the color concentration ratio of the red light, the green light, and the blue light is 100: 80: 70, the red light emitting diode RL includes a red fluorescent material having a volume ratio of 100, and the green light emitting diode GL Includes a green fluorescent material having a volume ratio of 80, and the blue light emitting diode BL includes a blue fluorescent material having a volume ratio of 70.

As described above, the color reproducibility of the display apparatus 700 may be further improved by adjusting the color concentration ratios of the red light, the green light, and the blue light in inverse proportion to the area ratio of the color filters 624.

That is, in response to the blue color filter BF having a high ratio area, blue light having a low ratio color concentration is generated, and corresponding to the green color filter GF having an intermediate ratio area, a low ratio color is generated. Green light having a density is generated, and red light having a high ratio of color concentration is generated in response to the red color filter RF having a low ratio of area. As a result, the white light formed by mixing the red light, the green light, and the blue light improves the movement of the white color coordinate in the CIE (Coordinate Internationale de L'Eclairage) color coordinates, thereby improving the color reproducibility of the display device 700. Can be improved.

Second Embodiment of Display Device

5 is a cross-sectional view conceptually illustrating a display device according to a second exemplary embodiment of the present invention. Except for the light generating unit, the display device according to the present exemplary embodiment has the same configuration as the display device according to the first exemplary embodiment described above, and therefore, duplicated descriptions thereof will be omitted, and like reference numerals refer to like elements. Let's use the name.

3, 4 and 5, the light generating unit 200 according to the present embodiment, for example, a driving substrate for providing power to the light emitting diode 210 and the light emitting diode 210 for generating a point light source 220.

The plurality of light emitting diodes 210 are arranged in a row on the driving substrate 220, and receive power from the driving substrate 220 to generate a point light source. The light emitting diode 210 includes a white light emitting diode WL for generating white light.

The outer wall of the white light emitting diode WL is formed by mixing a plurality of fluorescent materials (not shown). The phosphors include a red phosphor that converts light into red light, a green phosphor that converts light into green light, and a blue phosphor that converts light into blue light. At this time, the red light, green light and blue light are mixed with each other to become the white light.

The red light, green light and blue light preferably have different color concentration ratios. In one example, the red light, green light, and blue light have a color concentration ratio corresponding to the area ratio of the color filters 624 in the unit pixel, and preferably have a color concentration ratio inversely proportional to the area ratio. In this case, each of the color filters 624 in the unit pixel includes one red color filter RF, a green color filter GF, a blue color filter BF, and a white color filter GF.

Specifically, as the area ratio has 7: 8: 10 according to the red color filter (RF), the green color filter (GF), and the blue color filter (BF), the color concentration ratios of the red light, the green light, and the blue light are inversely reversed. 10: 8: 7. The red light, green light, and blue light having a color concentration ratio of 10: 8: 7 are mixed with each other to form white light, and the white light is incident on the display panel 600.

The red fluorescent substance, green fluorescent substance and blue fluorescent substance are preferably mixed with each other in content ratio to adjust the color concentration ratio of the red light, green light and blue light. For example, the red phosphor, the green phosphor, and the blue phosphor are distributed according to the ratio of 10: 8: 7 so that the color concentration ratios of the red light, the green light, and the blue light have a ratio of 10: 8: 7.

As described above, the color reproducibility of the display apparatus 700 may be further improved by adjusting the color concentration ratios of the red light, the green light, and the blue light generated in the white light emitting diode in inverse proportion to the area ratio of the color filters 624.

As described above, according to the present invention, inversely proportional to the area ratio of the color filters in the unit pixel, the white light is formed by adjusting the color concentration ratios of the red light, the green light, and the blue light generated in the light emitting diode, thereby further improving the color reproducibility of the display device. The display quality of the image can be further improved.

Particularly, in a display device having four color filters that realize red, green, blue, and white, the color concentration ratio of red light, green light, and blue light is adjusted in inverse proportion to the area ratio of the color filter. The concentration can be suppressed.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

Claims (11)

A first substrate on which switching elements are formed, a second substrate on which first, second, and third color filters are formed in a predetermined area ratio to implement color in a unit pixel, and a liquid crystal interposed between the first and second substrates A display panel having a layer; And Light generating first, second, and third lights having a color concentration ratio inversely proportional to the area ratio, and implementing white light by mixing the first, second, and third lights, and providing the white light to the display panel. Including a generating unit, The light generating unit includes a white light emitting diode for implementing the white light, The white light emitting diode is formed by mixing a first fluorescent material for generating the first light, a second fluorescent material for generating the second light, and a third fluorescent material for generating the third light, And the first, second and third fluorescent materials are mixed in an amount ratio inversely proportional to the area ratio. The display device of claim 1, wherein the first, second, and third color filters are a red color filter, a green color filter, and a blue color filter, respectively. The display device of claim 1, wherein a white area is formed in the unit pixel to implement white color. The display device of claim 1, wherein the first, second, and third lights are red light, green light, and blue light. The method of claim 1, wherein the light generating unit comprises a first light emitting diode for generating the first light, a second light emitting diode for generating the second light and a third light emitting diode for generating the third light. Display device characterized in that. delete delete delete The display device according to claim 1, wherein the area ratio is 10: 8: 7 and the color concentration ratio is 7: 8: 10. The display device of claim 1, further comprising a light guide plate disposed under the display panel, the light guide plate receiving the white light through a side surface and guiding the white light to the display panel. The display device of claim 10, further comprising an optical member disposed between the display panel and the light guide plate to improve optical characteristics of the white light.

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