KR20090122023A - Transparent organic light emitting diode backlight unit and transparent full color liquid crystal display using thereof - Google Patents

Abstract

PURPOSE: A transparent organic light emitting diode backlight unit and a transparent full color liquid crystal display using thereof are provided to remove a color filter and a transparency full-color liquid crystal display by using a three color light emitted from the transparent OLED backlight unit. CONSTITUTION: A transparent organic light emitting diode backlight unit includes a first transparent electrodes, a red OLED, a green OLED, a blue OLED, and a second transparent electrode. The first transparent electrode(120) is formed on the transparent substrate(110). The red OLED(130) is formed on the first transparent electrodes corresponding to the red sub-pixel location of the display device and emits red wavelength. The green OLED(140) is formed on first transparent electrodes corresponding to the green sub pixel location of the display device and emits green wavelength. The blue OLED(150) is formed on the first transparent electrodes corresponding to the blue subpixel location of the display device and emits blue wavelength. The second transparent electrode(160) is formed on the red OLED, the green OLED, and the blue OLED.

Description

TRANSPARENT ORGANIC LIGHT EMITTING DIODE BACKLIGHT UNIT AND TRANSPARENT FULL COLOR LIQUID CRYSTAL DISPLAY USING THEREOF}

The present invention relates to a transparent organic light emitting diode (OLED) backlight unit (BLU), and more particularly, a see-through transparent pool having good transparency using a transparent OLED BLU emitting tricolor light. A transparent organic light emitting diode backlight unit capable of implementing a color liquid crystal display (LCD) and a transparent full color liquid crystal display panel using the same.

Liquid crystal displays (LCDs) include a backlight unit (BLU) to provide a suitable amount of light or illumination, which is difficult to implement a transparent display due to the main components such as the light guide plate and the color filter of the backlight unit.

LCD pixels are generally illuminated from the back through a BLU using a cold cathode fluorescent lamp (CCFL) or light emitting diode (LED) as the light source.

In addition, LCDs have a wide color range, but require color filters to implement full color displays.

However, the LCD according to the prior art is opaque in the case of the back of the display is difficult to see through the background and the like behind, there are the following two problems in implementing a full-color LCD transparent.

1) The transmittance of the red, green and blue color filters used to achieve natural colors is only about 30%.

2) In case of BLU of LCD using cold cathode tube and LED, it is a factor that hinders the development of transparent display because of its opacity or scattering of light such as diffuser.

In other words, it is difficult to implement a see-through display having good transparency, which is normally visible only when necessary because it is integrated with a window of a home or a windshield of a car using an LCD according to the prior art.

An object according to an embodiment of the present invention, a transparent organic light emitting diode backlight unit and a transparent full-color liquid crystal using the same to remove the color filter by using the three-color light emitted from the transparent OLED backlight unit, and to implement a transparent full-color liquid crystal display To provide a display.

Another object of the present invention is to provide a transparent organic light emitting diode backlight unit capable of implementing a see-through liquid crystal display ranging from small to large, and a transparent full color liquid crystal display using the same.

In order to achieve the above object, a transparent organic light emitting diode backlight unit according to an aspect of the present invention comprises a first transparent electrode formed on a transparent substrate; A red OLED formed on the first transparent electrode corresponding to the red subpixel position of the display device to emit a red wavelength; A green OLED formed on the first transparent electrode corresponding to the green subpixel position of the display element to emit a green wavelength; A blue OLED formed on the first transparent electrode corresponding to the blue subpixel position of the display element to emit a blue wavelength; And a second transparent electrode formed on the red OLED, the green OLED, and the blue OLED.

According to another aspect of the present invention, a transparent organic light emitting diode backlight unit includes: a first transparent electrode formed on an upper portion of a transparent substrate; A blue OLED formed on the first transparent electrode and emitting blue wavelengths; A second transparent electrode formed on the blue OLED; A red light emitter formed on an upper portion of the second transparent electrode corresponding to a red subpixel position of a display element and excited by the blue wavelength to emit a red wavelength; A green light emitter formed on the second transparent electrode corresponding to the green subpixel position of the display element and excited by the blue wavelength to emit a green wavelength; And a passivation layer formed on the second transparent electrode corresponding to a position of the red emitter, the green emitter, and the blue subfill cell of the display device.

According to another aspect of the present invention, a transparent organic light emitting diode backlight unit includes: a first transparent electrode formed on an upper portion of a transparent substrate; An OLED formed on the first transparent electrode and emitting a predetermined wavelength; A second transparent electrode formed on the OLED; A first light emitter formed on an upper portion of the second transparent electrode corresponding to a first subpixel position of a display element and excited by the predetermined wavelength to emit a first wavelength; A second light emitter formed on the second transparent electrode corresponding to the second subpixel position of the display element and excited by the predetermined wavelength to emit a second wavelength; And a third light emitter formed on an upper portion of the second transparent electrode corresponding to a third subpixel position of the display element and excited by the predetermined wavelength to emit a third wavelength.

The transparent liquid crystal display according to an aspect of the present invention adjusts the transmittance of the red wavelength, the blue wavelength, and the green wavelength emitted from the transparent organic light emitting diode backlight unit by using a liquid crystal, and may not include a color filter.

According to another aspect of the present invention, a transparent liquid crystal display adjusts transmittance of a first wavelength, a second wavelength, and a third wavelength emitted from a transparent organic light emitting diode backlight unit by using a liquid crystal, and does not include a color filter. Sub-pixels may be formed in a region corresponding to a region in which the first, second and third emitters of the transparent organic light emitting diode backlight unit are formed.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, a transparent organic light emitting diode backlight unit and a transparent full color liquid crystal display using the same according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In general, the OLED is composed of an upper electrode, a lower electrode, and a plurality of organic layers formed between the upper electrode and the lower electrode. In the present invention, the OLED is used to refer to a plurality of organic layers except for the upper electrode and the lower electrode.

1 is a cross-sectional view of a transparent organic light emitting diode backlight unit according to an embodiment of the present invention.

Referring to FIG. 1, in the transparent OLED BLU 100, a first transparent electrode 120 is formed on a transparent substrate 110, for example, a glass substrate, and a red OLED 130 is formed on the first transparent electrode 120. ), Green OLED 140 and blue OLED 150 are formed.

Here, OLED refers to a self-luminous organic material that emits light by using an electroluminescence phenomenon that emits a certain wavelength when a current flows in a fluorescent organic compound. It can be driven at low voltage, can be made thin, and has a wide viewing angle And fast response speed. Since such OLEDs will be apparent to those skilled in the art, detailed descriptions thereof will be omitted.

In this case, the red OLED 130, the green OLED 140, and the blue OLED 150 formed on the first transparent electrode 120 are formed in a lattice shape (a) or a line shape as shown in FIG. 2. (b), preferably, corresponding to the position of the sub-pixels formed in the liquid crystal display using the transparent OLED BLU according to the present invention. That is, the red OLED 130 is formed at the red subpixel position of the liquid crystal display, the green OLED 140 is formed at the green subpixel position of the liquid crystal display, and the blue OLED 150 is formed at the blue subpixel position.

A second transparent electrode 160 is formed on the red OLED 130, the green OLED 140, and the blue OLED 150, and a driving voltage applied to the first transparent electrode 120 and the second transparent electrode 160. The red, green and blue wavelengths are emitted from the red OLED 130, the green OLED 140, and the blue OLED 150.

In this case, the first transparent electrode 120 and the second transparent electrode 160 to which the driving voltage is applied may be an indium-tin-oxide (ITO) electrode in the case of a positive electrode, and a metal thin film having a low work function in the case of a negative electrode. It may be a composite multilayer electrode having an ITO or the like formed thereon or on top thereof. In driving, all pixels may have a common cathode and a common anode, or as shown in FIG. 3, a method of enabling separate driving for each line through a stripe-shaped electrode may be performed. Such a driving scheme is obvious to those skilled in the art, and thus a detailed description thereof will be omitted.

A protective layer 170 or a transparent substrate is formed on the second transparent electrode 160 to protect the second transparent electrode 160.

As such, since the transparent OLED BLU according to the present invention emits red wavelengths, green wavelengths, and blue wavelengths through the transparent substrate and the transparent electrode, the liquid crystal display using the transparent OLED BLU does not need to have a color filter. A full color liquid crystal display can be implemented.

In general, liquid crystal displays have RGB subpixels, which are arranged in an array or a similar arrangement, such as a line array, a mosaic array and a delta array, wherein the transparent OLED BLU according to the invention is Red OLEDs, green OLEDs, and blue OLEDs may be arranged in a form of an arrangement of RGB subpixels of a liquid crystal display.

Of course, the arrangement of the RGB OLED of the transparent OLED BLU may vary depending on the driving method. For example, in the case of the driving method having the common cathode and the common anode, all three arrangement types described above are possible, and the electrode in the form of a line In the case of driving separately for each line through the line it is preferable to apply to the line arrangement and mosaic arrangement.

Here, as shown in FIG. 3, in the case of an arrangement used in a separate driving method for each line, each column is driven independently, thereby further reducing the effect on the whole when partial defects occur in the liquid crystal display. There are advantages to it. In addition, each of the RGB OLEDs may exhibit different electro-optic characteristics, and the method of using independent line-by-line driving in the form of line pixel arrays is particularly preferred in the present invention because it can selectively compensate for such characteristic differences.

In addition, as shown in FIG. 4, the common electrode driving method and the driving method for each line may be divided into several regions of the entire liquid crystal display, and in this case, the power consumption may be reduced by using a local dimming method. Can be.

5 is a cross-sectional view of a transparent organic light emitting diode backlight unit according to another exemplary embodiment of the present invention.

1 illustrates a transparent OLED BLU using tri-color OLEDs, FIG. 5 illustrates a transparent OLED BLU 500 implemented using a blue OLED, a red emitter, and a green emitter.

That is, after the first transparent electrode 520 is formed on the transparent substrate 510, the blue OLED 530 emitting blue wavelengths is formed on the first transparent electrode 520, and the top of the formed blue OLED 520 is formed. The second transparent electrode 540 is formed on the substrate.

A red emitter 550 and a green emitter 560 are formed on the second transparent electrode 540 to emit red and green wavelengths. The red emitter 550 is a subpixel of a liquid crystal display using a transparent OLED BLU. Among them, the red subpixel is formed at a position where the green light emitter 560 is preferably formed at the position where the green subpixel is formed among the subpixels of the liquid crystal display.

Of course, the red emitter 550 is excited by the blue wavelength emitted from the blue OLED 530 to emit the red wavelength, and the green emitter 560 is excited by the blue wavelength emitted from the blue OLED 530 to the green wavelength. Emits.

The passivation layer 570 is formed on the red emitter 550, the green emitter 560, and a part of the second transparent electrode 540, and the passivation layer 570 formed on the second transparent electrode 540 is a liquid crystal. It may correspond to an area where a blue subpixel is formed among the subpixels of the display.

That is, the blue wavelength emitted from the transparent OLED BLU of FIG. 5 is the blue wavelength of the blue OLED 530 emitted through the second transparent electrode 540 and the protective layer 570.

In this case, since the thickness of the red light emitter 550 and the green light emitter 560 is thin, the protective layer 570 may be uniformly formed on the red light emitter 550, the green light emitter 560, and the second transparent electrode 540. uniformity can be maintained.

FIG. 6 is a cross-sectional view of a transparent organic light emitting diode backlight unit according to another embodiment of the present invention, and uses a white wavelength emitted by a white OLED to emit red, green, and blue wavelengths. 600 is shown.

That is, a white OLED 630 emitting white wavelengths is formed on the transparent substrate 610 and the first transparent electrode 620 sequentially formed, and the second transparent electrode 640 is formed on the white OLED 630. The red light emitter 650, the green light emitter 660, and the blue light emitter 670 are formed on the second transparent electrode 640 by being excited by a white wavelength to emit red, green, and blue wavelengths, respectively. .

As in FIG. 5, the red light emitter 650, the green light emitter 660, and the blue light emitter 670 may include a second transparent electrode corresponding to a region where the red subpixel, the green subpixel, and the blue subpixel are formed in the transparent liquid crystal display. 640 is preferably formed in the upper region.

The protective layer 680 is formed on the red light emitter 650, the green light emitter 660, and the blue light emitter 670 to protect the light emitter.

Since the transparent OLED BLU of FIGS. 5 and 6 is configured by using a single color OLED, driving or manufacturing is more simple than in FIG. 1.

7 is a cross-sectional view of a transparent full color liquid crystal display using a transparent OLED BLU according to an embodiment of the present invention.

Here, the transparent OLED BLU shown in FIG. 7 takes the transparent OLED BLU shown in FIG. 1 as an example.

Of course, the transparent OLED BLU used in the transparent full color liquid crystal display is not limited to the transparent OLED BLU shown in FIG. 1, and any transparent OLED BLU to be claimed in the claims of the present invention may be used.

Referring to FIG. 7, the transparent full-color liquid crystal display includes a lower polarizer for outputting light sources emitted from the transparent OLED BLU 100 on the transparent OLED BLU 100, that is, red wavelength, green wavelength, and blue wavelength in one direction. 710 is formed, and a transparent substrate 720 is formed thereon.

A first transparent pixel electrode 730 and a second transparent pixel electrode 750 are formed to apply a driving voltage of the liquid crystal display, and the first transparent pixel electrode 730 is formed on the transparent substrate 720. The transparent pixel electrode 750 is formed on the liquid crystal layer 740.

The liquid crystal layer 740 is formed on the first transparent pixel electrode 730, and the angle of the liquid crystal is adjusted by a voltage applied to the first transparent pixel electrode 730 and the second transparent pixel electrode 750, thereby making it transparent. Control the transmittance of light emitted from the OLED BLU. That is, when the screen is displayed on the liquid crystal display by adjusting the light transmittance, the color of the screen may be adjusted. For example, black may be displayed on the screen of the liquid crystal display by blocking all light emitted from the transparent OLED BLU, and red By controlling the transmittance of the green and blue light, respectively, various colors can be displayed. Thus, by adjusting the transmittance of the light emitted from the transparent OLED BLU, a full color liquid crystal display can be realized.

The transparent substrate 760 and the upper polarizer 770 are sequentially formed on the second transparent pixel electrode 750.

As can be seen in Figure 7, the transparent full-color liquid crystal display according to an embodiment of the present invention can realize full color by adjusting the light transmittance of the red, green and blue wavelengths emitted from the transparent OLED BLU, the see-through operation is possible Liquid crystal displays ranging from small to large can be implemented.

In addition, since light of red, green, and blue wavelengths is emitted from the transparent OLED BLU, a color filter having a low transmittance can be removed from the liquid crystal display, thereby realizing a full color transparent liquid crystal display.

Such a transparent full color liquid crystal display according to an exemplary embodiment of the present invention may include both a liquid crystal display operating in an active driving method and a passive driving method.

That is, the present invention can be applied not only to the passive liquid crystal display liquid crystal display of FIG. 7 but also to the active liquid crystal display liquid crystal display having a thin film transistor.

Referring to FIG. 7, the transparent liquid crystal display of the active driving method is described. In order to apply the active driving method, the transparent liquid crystal display must form a plurality of thin film transistor subpixels. Here, the plurality of thin film transistor subpixels are formed on the transparent substrate 720 in parallel with the first transparent pixel electrode 730. The red OLED, the green wavelength, and the blue wavelength of the transparent OLED BLU are emitted. The region, here, may be formed inside the region corresponding to the formation region of the red OLED, the green OLED, and the blue OLED, or may be formed entirely in some region of the liquid crystal display panel.

In this case, the thin film transistor subpixels may include a circuit unit including a signal line, and the like, and in order to ensure high transparency throughout the liquid crystal display, the thin film transistor or the conductive lines for transmitting signals and power may also be formed as transparent. The transparent thin film transistor may be made of ZnO or a similar oxide compound as a transport layer.

The transparent full-color liquid crystal display according to the present invention has transparency while using existing liquid crystal device technology and can be enlarged at the same time, so that when implemented as a new concept display or TV (TV), a window integrated TV, a special functional type It is possible to realize a TV with various functions and types such as a see-through monitor. Of course, the applicable field is not limited thereto, and may be broadly applied to automotive, advertising and military fields.

As described above, the present invention can improve the light transmittance by using the spatially divided and patterned transparent OLED BLU, and can remove the color filter which greatly reduces the transmittance by emitting red, green and blue wavelengths of light from the transparent OLED BLU itself. By using such a transparent OLED BLU, it is possible to realize a liquid crystal display ranging from small to large, which can be transparent and realize full color.

The transparent organic light emitting diode backlight unit and the transparent full color liquid crystal display using the same according to the present invention can be modified and applied in various forms within the scope of the technical idea of the present invention, and are not limited to the above embodiments. In addition, the embodiments and drawings are merely for the purpose of describing the contents of the invention in detail, not intended to limit the scope of the technical idea of the invention, the present invention described above is common knowledge in the technical field to which the present invention belongs As those skilled in the art can have various substitutions, modifications, and changes without departing from the spirit of the present invention, it is not limited to the embodiments and the accompanying drawings. And should be judged to include equality.

1 is a cross-sectional view of a transparent organic light emitting diode backlight unit according to an embodiment of the present invention.

2 is an exemplary view of an OLED array of a transparent organic light emitting diode backlight according to the present invention.

3 is a diagram illustrating an arrangement of a transparent electrode of a transparent organic light emitting diode backlight according to the present invention.

Figure 4 is another exemplary view of a transparent electrode arrangement of the transparent organic light emitting diode backlight according to the present invention.

5 is a cross-sectional view of a transparent organic light emitting diode backlight unit according to another exemplary embodiment of the present invention.

6 is a cross-sectional view of a transparent organic light emitting diode backlight unit according to another embodiment of the present invention.

7 is a cross-sectional view of a transparent full color liquid crystal display using a transparent OLED BLU according to an embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

110,720,760: transparent substrate

120: first transparent electrode

130: red OLED

140: green OLED

150: blue OLED

160: second transparent electrode

170: protective layer

710: lower polarizer

730: first transparent pixel electrode

740: liquid crystal layer

750: second transparent pixel electrode

770: upper polarizer

Claims (9)

A first transparent electrode formed on the transparent substrate; A red OLED formed on the first transparent electrode corresponding to the red subpixel position of the display device to emit a red wavelength; A green OLED formed on the first transparent electrode corresponding to the green subpixel position of the display element to emit a green wavelength; A blue OLED formed on the first transparent electrode corresponding to the blue subpixel position of the display element to emit a blue wavelength; And A second transparent electrode formed on the red OLED, the green OLED, and the blue OLED Transparent organic light emitting diode backlight unit comprising a. The method of claim 1, The red OLED, the green OLED and the blue OLED A transparent organic light emitting diode backlight unit formed in a stripe form or in a lattice form. A first transparent electrode formed on the transparent substrate; A blue OLED formed on the first transparent electrode and emitting blue wavelengths; A second transparent electrode formed on the blue OLED; A red emitter formed on the second transparent electrode corresponding to the red subpixel position of the display element and excited by the blue wavelength to emit a red wavelength; A green light emitter formed on the second transparent electrode corresponding to the green subpixel position of the display element and excited by the blue wavelength to emit a green wavelength; And A passivation layer formed on the second transparent electrode corresponding to the position of the red light emitter, the green light emitter, and the blue subfill cell of the display device. Transparent organic light emitting diode backlight unit comprising a. A first transparent electrode formed on the transparent substrate; An OLED formed on the first transparent electrode and emitting a predetermined wavelength; A second transparent electrode formed on the OLED; A first light emitter formed on an upper portion of the second transparent electrode corresponding to a first subpixel position of a display element and excited by the predetermined wavelength to emit a first wavelength; A second light emitter formed on the second transparent electrode corresponding to the second subpixel position of the display element and excited by the predetermined wavelength to emit a second wavelength; And A third light emitter formed on the second transparent electrode corresponding to the third subpixel position of the display element and excited by the predetermined wavelength to emit a third wavelength Transparent organic light emitting diode backlight unit comprising a rule. The method of claim 4, wherein The OLED White OLED, The first light emitter, the second light emitter and the third light emitter A transparent organic light emitting diode backlight unit which is a red light emitter, a green light emitter, and a blue light emitter. The transparent liquid crystal display which does not contain a color filter by adjusting the transmittance | permeability of red wavelength, blue wavelength, and green wavelength emitted from the transparent organic light emitting diode backlight unit of any one of Claims 1 and 3 using a liquid crystal. The method of claim 6, The transparent liquid crystal display A first transparent pixel electrode; A second transparent pixel electrode; A liquid crystal is formed between the first transparent pixel electrode and the second transparent pixel electrode, and the liquid crystal is controlled by a voltage applied to the first transparent pixel electrode and the second transparent pixel electrode. A liquid crystal layer for controlling transmittance of light emitted from the backlight unit; And A transparent substrate formed on the transparent organic light emitting diode backlight unit and the second transparent pixel electrode. Transparent liquid crystal display comprising a. The method of claim 7, wherein The transparent liquid crystal display An inner portion of the transparent substrate formed in parallel with the first transparent pixel electrode and corresponding to a region in which a red wavelength, a green wavelength, and a blue wavelength are emitted of the transparent organic light emitting diode backlight unit A plurality of thin film transistor subpixels formed in or formed in a portion of the liquid crystal display panel Transparent liquid crystal display further comprising. The transmittance of the first wavelength, the second wavelength, and the third wavelength emitted from the transparent organic light emitting diode backlight unit of claim 4 is adjusted using a liquid crystal, does not include a color filter, and is formed of the transparent organic light emitting diode backlight unit. A transparent liquid crystal display in which subpixels are formed in a region corresponding to a region where a first luminous body, a second luminous body, and a third luminous body are formed.

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