KR100744633B1 - Back light unit including organic light-emitting device, liquid crystal display apparatus having the same and method of manufacturing the same - Google Patents

Abstract

The backlight unit according to the present invention includes a base substrate, a first electrode pattern layer formed on the base substrate, an organic light emitting pattern layer formed on the first electrode pattern layer, and a second electrode pattern layer formed on the organic light emitting pattern layer. Include. The organic light emitting pattern layer generates light expressing a plurality of colors when a voltage is applied from the outside. In addition, at least one of the first electrode pattern layer and the second electrode pattern layer has electrode patterns corresponding to the color of the light to be expressed, and electrode patterns corresponding to the different colors are electrically separated from each other. The backlight unit may efficiently replace the color filter of the display panel.

Description

BACK LIGHT UNIT INCLUDING ORGANIC LIGHT-EMITTING DEVICE, LIQUID CRYSTAL DISPLAY APPARATUS HAVING THE SAME AND METHOD OF MANUFACTURING THE SAME}

1 is an exploded perspective view conceptually illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a portion of a portion cut along the line II-II ′ of FIG. 1.

3 is a conceptual diagram conceptually illustrating a light emitting pattern of a display pixel and a backlight unit of a display panel to explain a liquid crystal display according to another exemplary embodiment of the present invention.

FIG. 4 is a conceptual diagram conceptually illustrating a display pixel of a display panel and a light emission pattern of a backlight unit to explain a liquid crystal display according to another exemplary embodiment of the present invention.

5 is an exploded perspective view conceptually illustrating a liquid crystal display according to another exemplary embodiment of the present invention.

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

700, 800: display panel 500, 550: backlight unit

710: color pixel 720: display pixel group

100: unit light emitting region 200: base substrate

320: first electrode pattern layer 330: organic light emitting pattern layer

340: second electrode pattern layer 400: partition wall

The present invention relates to a backlight unit including an organic light emitting device and a liquid crystal display device including the backlight unit, and more particularly, a backlight unit that can efficiently replace a color filter of a liquid crystal display device and has excellent display image quality. And a backlight unit.

In general, a backlight of a liquid crystal display device is provided on a sidewall of a direct light type and a light guide plate where a plurality of light sources directly under the liquid crystal panel irradiate light directly to the liquid crystal panel according to the arrangement of the light sources. The installed light source may classify an edge light type that transmits light to the liquid crystal panel. In addition, a cold cathode fluorescent lamp (CCFL), light emitting diodes (light emitting diodes), a fluorescent surface light source lamp, an organic light emitting diode (OLED), etc. may be used as a light source, and currently, liquid crystal display Most of the backlights for liquid crystal displays (LCDs) have CCFL lamps. When using OLED light source, which is expected to be the main light source of next-generation backlight unit, it can be manufactured as a thin film itself, which can drastically reduce the thickness of the backlight, low temperature rise of the backlight, and low power driving. Furthermore, it is possible to increase the size of the backlight unit using the multi module. Accordingly, various researches for improving the lifespan and luminance of surface light emission using white OLED have been conducted.

The backlight unit using white light supplies white light to the liquid crystal panel while being always turned on as a backlight of a general liquid crystal display device. On the other hand, the time division type liquid crystal display device displays a color image by sequentially lighting the R, G, and B light sources of the R, G, and B backlight units at a predetermined time interval for one frame. For this purpose, R, G, B high-speed sequential driving of the backlight unit should be possible and mainly use LED light source.

The present invention can replace the color filter and provide a backlight unit that is easy to form a pattern.

The present invention also provides a liquid crystal display device including the backlight unit having improved image quality.

The present invention also provides a method of manufacturing a backlight unit using an organic light emitting device excellent in process efficiency.

According to an aspect of the present invention, a backlight unit includes a base substrate, a first electrode pattern layer formed on the base substrate, an organic light emitting pattern layer formed on the first electrode pattern layer, and a second electrode formed on the organic light emitting pattern layer. It includes a pattern layer.

The organic light emitting pattern layer generates light expressing a plurality of colors when a voltage is applied from the outside. In addition, at least one of the first electrode pattern layer and the second electrode pattern layer has electrode patterns corresponding to the color of the light to be expressed, and electrode patterns corresponding to the different colors are electrically separated from each other.

A liquid crystal display according to an aspect of the present invention includes a display panel and a backlight unit. The display panel includes a plurality of pixels arranged in a matrix. The backlight unit may include a plurality of light emission units formed on a base substrate, a first electrode pattern layer formed on the base substrate, and a red light emission pattern, a green light emission pattern, and a blue light emission pattern formed on and adjacent to each other. An organic light emitting pattern layer having a pattern group, and a second electrode pattern layer formed on the organic light emitting pattern layer.

The light emitting pattern is formed to integrally face a series of pixels formed in the display panel. In addition, the red, green, and blue light emitting patterns in the light emitting pattern group are sequentially lighted or differently lighted simultaneously according to an external input signal.

In order to manufacture the backlight unit according to an aspect of the present invention, first, an electrode material is deposited on a substrate to form a first electrode pattern layer. A barrier rib may be formed on the first electrode pattern layer in parallel with one side of the substrate to facilitate formation of a subsequent pattern layer. An organic light emitting material is deposited between the partitions to form an organic light emitting pattern layer. An electrode material is deposited on the organic light emitting pattern layer to correspond to the organic light emitting pattern layer to form a second electrode pattern layer.

According to the above, the light source supply and the color filter function can be simultaneously performed using only the backlight. Furthermore, the manufacturing efficiency of the backlight employing the organic light emitting device can be maximized.

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

1 is an exploded perspective view conceptually illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the liquid crystal display includes a display panel 700 and a backlight unit 500.

The display panel 700 includes a plurality of pixels 701, 702, and 703 having a lattice shape or a matrix shape. The display panel 700 receives light having a plurality of colors from the backlight unit 500 to display a color image. The display panel 700 includes a red display pixel 701, a green display pixel 702, and a blue display pixel 703 to represent a color image. The display pixels 701, 702, and 703 of each color are arranged in a line parallel to one side of the display panel 700 according to the color type to form the display pixel group 720. The display pixel group 720 includes a red display group, a green display group, and a blue display group, and the display pixel groups 720 are periodically and repeatedly arranged.

The red pixels (R; 701), the green pixels (G; 702), and the blue pixels (B; 703) that are sequentially disposed adjacent to each other function as a kind of subpixels (701, 702, and 703), and one color pixel as a whole. It functions as 710. The color pixels 710 may implement a myriad of colors by appropriately adjusting the grayscale values of the respective subpixels 701, 702, and 703, and thus the liquid crystal display may display an image having a color close to natural colors.

The backlight unit 500 includes a unit light emitting region 100 which is periodically repeated. The unit light emitting area 100 includes a red light emitting area 110, a green light emitting area 120, a blue light emitting area 130, and a non-light emitting area between the light emitting areas 100, 110, and 120. For ease of processing, preferably, the non-light emitting area is constituted by the partition wall portion 103. The red, green, and blue light emitting regions 110, 120, and 130 generate red, green, and blue light, respectively. The backlight unit 500 provides color light to the display panel 700 by simultaneously generating lights having different colors in all the light emitting regions 110, 120, and 130 when the liquid crystal display is operated.

The partition 103 may be formed between adjacent light emitting regions 110, 120, and 130. When the light is emitted to the opposite side (upper side) of the substrate, the barrier rib portion 103 may be opaque to prevent generation of mixed light generated by mixing light having heterogeneous colors with each other, thereby providing a clear display panel 700. It is possible to provide light of three primary colors.

FIG. 2 is a cross-sectional view illustrating a portion of a portion cut along the line II-II ′ of FIG. 1.

The backlight unit 500 includes a base substrate 200, a first electrode pattern layer 320, an organic emission pattern layer 330, a second electrode pattern layer 340, and a partition 400.

The base substrate 200 may include glass or polymer resin.

The first electrode pattern layer 320 is formed by depositing or applying a positive electrode material or a negative electrode material. The electrode material includes, for example, indium tin oxide (ITO) having a high work function (for positive electrode), magnesium (magnesium) or lithium (for negative electrode) having a low work function. The magnesium is deposited at the same time as the silver (Ag) to improve the adhesion with the organic light emitting pattern layer 330, the lithium is preferably deposited with aluminum (Al) at a concentration of about 0.5 ~ 1.0%. Do.

In the present embodiment, the first electrode pattern layer 320 is entirely deposited. Alternatively, the barrier layer 400 may be first formed on the base substrate 200, and then the first electrode pattern layer 320 and the subsequent pattern layer may be formed.

The partition walls 400 are disposed on the first electrode pattern layer 320 at a predetermined interval from each other. The partition 400 is made of an insulating material. The barrier 400 may reduce the number of times the mask is used to form the pattern in a subsequent process, thereby increasing the efficiency of the manufacturing process. Preventing a short circuit between electrodes that may occur between the light emitting regions 110 and 120. Therefore, generation of defective pixels can be prevented in advance, and further, due to the partition wall 400, inkjet printing can be formed in a subsequent process.

The organic light emitting pattern layer 330 is formed on the first electrode pattern layer 320 between the partitions 400 by a method such as vacuum deposition of an organic light emitting material. The organic light emitting pattern layer 330 may be formed of an organic thin film layer, and the organic thin film layer may include a low molecular weight compound or a high molecular compound. When the organic thin film layer is formed of a low molecular weight compound, the organic light emitting pattern layer 330 further includes an electron transport layer and a hole transport layer.

In the present exemplary embodiment, the organic light emitting pattern layer 330 includes a red light emitting pattern R, a green light emitting pattern G, and a blue light emitting pattern B.

The second electrode pattern layer 340 is formed on the organic light emitting pattern layer 330. The second electrode pattern layer 340 has substantially the same patterns 342 and 344 as the organic light emitting pattern layer 330. The second electrode pattern layer is made of a material different in polarity from the first electrode. The second electrode pattern layer 340 has electrode patterns 342 and 344 corresponding to the red light emission pattern R, the green light emission pattern G, and the blue light emission pattern B. The electrode patterns corresponding to the light emitting patterns 330 of the same color are electrically connected, and the electrode patterns 342 and 344 corresponding to the light emitting patterns 330 of different colors are electrically separated from each other.

Therefore, the magnitude of the voltage can be applied separately for each color, so that the luminous conditions can be efficiently controlled.

After the formation of the second electrode pattern layer 340, a glass cap or a metal can may be encapsulated or a thin film passivation layer may be formed to prevent oxygen and moisture from infiltrating the second electrode pattern. May be formed on layer 340. The thin film passivation layer may have a multilayer structure made of organic and inorganic materials.

The display panel is positioned on the surface layer of the substrate. When the thin film passivation layer is formed, the display panel 700 may be attached onto the surface layer 410 of the partition 400.

In the above, it has been described that the partition wall 400 is formed after the first electrode pattern layer 320 is formed on the base substrate 200. Alternatively, the partition wall 400 is formed with the first electrode pattern layer 320. It may be formed directly on the base substrate 200 before being. In this case, not only the second electrode pattern layer 340 but also the first electrode pattern layer may have the same pattern as the emission pattern of the organic light emitting pattern layer 330.

3 is a conceptual diagram conceptually illustrating a light emitting pattern of a display pixel and a backlight unit of a display panel to explain a liquid crystal display according to another exemplary embodiment of the present invention.

The display panel includes a red display pixel R, a green display pixel G, and a blue display pixel B as the pixel 712. The pixels 712 have the same color display pixels 712 arranged in a diagonal direction rather than in a row (mosaic arrangement).

The emission region of the backlight assembly corresponding thereto is also patterned to correspond to the pixels 712. In the present embodiment, the organic light emitting pattern layer includes light emitting patterns 332 patterned in the same manner as the pixel shape to correspond to each pixel. The first electrode pattern layer or the second electrode pattern layer corresponds to the light emitting patterns having the same color, and is patterned to have the same shape as the light emitting pattern, and the patterns are electrically connected by the electrode pattern connecting unit 342. Therefore, electrode patterns having the same color may receive a common voltage. In addition, electrode patterns having different colors are electrically independent.

FIG. 4 is a conceptual diagram conceptually illustrating a display pixel of a display panel and a light emission pattern of a backlight unit to explain a liquid crystal display according to another exemplary embodiment of the present invention.

The display panel includes a red display pixel R, a green display pixel G, and a blue display pixel B as the pixel 714. The pixels 714 are arranged such that pixels arranged in a row and pixels in adjacent rows have a zigzag positional relationship with each other (delta arrangement).

The light emitting region of the backlight assembly corresponding thereto is also patterned to have the light emitting regions arranged in zigzag corresponding to the pixels 712. In the present embodiment, the organic light emitting pattern layer includes light emitting patterns 344 patterned in the same manner as the pixel shape to correspond to each pixel. The first electrode pattern layer or the second electrode pattern layer corresponds to the light emitting patterns having the same color, and is patterned in the same shape as the light emitting pattern, and the respective patterns are electrically connected by the electrode pattern connecting unit 344. Therefore, electrode patterns having the same color may receive a common voltage. In addition, electrode patterns having different colors are electrically independent.

5 is an exploded perspective view conceptually illustrating a liquid crystal display according to another exemplary embodiment of the present invention. The liquid crystal display of FIG. 5 is substantially the same as the liquid crystal display of FIG. 1 except for a backlight as compared to the liquid crystal display of FIG. 1. Therefore, in FIG. 5, the same reference numerals are used for components having the same structure and function as in FIG. 1, and detailed description thereof will be omitted.

Referring to FIG. 5, the display panel 800 includes a plurality of pixels 830 having a lattice shape or a matrix shape. The display panel 800 receives light having a plurality of colors from the backlight unit 550 to display a color image.

As shown in FIG. 5, the pixels 840 include one display pixel group 840 arranged in parallel with respect to a horizontal side of the display panel 800.

One pixel 830 of the display panel 800 receives all of the red, green, and blue light from the backlight unit 550. However, the red, green, and blue light are not sequentially supplied but are sequentially supplied. That is, it is supplied in order of red light, green light, and blue light. Each may be time-divided by one third of a frame, or may be time-divided so as not to be equally different.

The pixel 830 does not need to include separate subpixels to represent a color image, and the role of the subpixels may be replaced by three primary colors of light supplied by time division.

The backlight unit 550 includes a unit light emitting region 100 which is periodically repeated. The unit light emitting region 150 includes a red light emitting region 110, a green light emitting region 120, a blue light emitting region 130, and a non-light emitting region (not shown). The red, green, and blue light emitting regions 110, 120, and 130 generate red, green, and blue light, respectively. The red (R), green (G), and blue light emitting regions 112, 114, and 116 are all included within the width of one pixel of the display panel 800 when viewed in plan view. In other words, the unit emission region 150 faces the display pixel group 840 of the display panel 800. The unit light emitting region 150 may be repeatedly divided into three, four, five, six, and the like (eg, R, G, B, R, G, B). In addition, the organic light emitting layer except for the electrode in the light emitting region may be patterned as a pixel type without being fixed as a line type. The unit light emitting region 150 generates time-divided red, green, and blue light sequentially from the red, green, and blue light emitting regions when an operation signal is applied to the unit light emitting region 150 of the backlight unit 550 from the outside. As a result, the unit emission region 150 sequentially supplies all three primary colors of light to the display panel 800. The display panel 800 may express various colors by adjusting gray levels of red, green, and blue lights sequentially supplied corresponding to external signals.

In the above, only the light emitting mechanism for supplying light of the three primary colors is mentioned, but those skilled in the art will fully understand that it is possible to supply a light source having various colors.

The backlight unit of the present invention can effectively replace the color filter layer provided in the display panel by including an organic light emitting pattern layer capable of generating light having a plurality of colors.

In addition, by forming the light emitting patterns integrally corresponding to the display pixels arranged in a line, the pattern forming process may be simplified, and the image quality deterioration of the liquid crystal display may be reduced due to the poor pattern forming process.

In addition, a single pixel may perform a subpixel function corresponding to R, G, and B independently by performing a time division type three-way light supply.

In addition, the electrode pattern corresponding to the light emitting patterns having the same color may be electrically separated from the electrode pattern corresponding to the light emitting patterns of the different colors to solve the light emission failure of the organic light emitting device due to the short circuit of the electrode.

In addition, by forming a barrier rib during the manufacture of a backlight using an organic light emitting device, there is an advantage that the inkjet method can be used after the barrier rib is formed, and further, the mask process for patterning can be reduced, thereby increasing the efficiency of the manufacturing process.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

Claims (11)

delete delete delete A display panel including a plurality of pixels arranged in a matrix; And i) a base substrate; ii) a first electrode pattern layer formed on the base substrate; iii) a plurality of light emitting pattern groups formed on the first electrode pattern layer and formed adjacent to each other, the plurality of light emitting pattern groups comprising a red light emitting pattern, a green light emitting pattern, and a blue light emitting pattern, wherein the light emitting pattern groups are arranged in a line of the display panel; The organic light emitting pattern layer which supplies all the red, green, and blue light to the inside of the pixel by integrally facing the pixels of the pixel, wherein the red, green, and blue light emitting patterns in the light emitting pattern group are sequentially turned on according to an external input signal. ; And iv) a backlight unit including a second electrode pattern layer formed on the organic light emitting pattern layer. delete delete delete The electrode pattern layer of claim 4, wherein at least one of the first electrode pattern layer and the second electrode pattern layer comprises electrode patterns corresponding to the emission patterns, and electrode patterns corresponding to different colors are electrically connected to each other. Liquid crystal display, characterized in that separated from each other. delete delete delete

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