KR100752377B1 - Organic electroluminescent display device - Google Patents

Abstract

An organic electroluminescent display using a tiling technique is disclosed. In the organic electroluminescent display device according to the present invention, a plurality of display panels are joined to form one organic EL display panel. In order to compensate for the deterioration of the luminance of the seam region where the plurality of display panels are bonded, a polarizing film having high transmittance is adhered to the seam region. A polarizing film having low transmittance is attached to a region other than the seam region. The transmittance of each polarizing film is inversely proportional to the luminance value of each region. Accordingly, an organic EL display device is provided in which the joint display of the display panel is minimized and the overall luminance is uniform.

Tiling, seam display minimization, organic electroluminescent display

Description

Organic Electroluminescent Display {ORGANIC ELECTROLUMINESCENT DISPLAY DEVICE}

1 is a block diagram showing a combined organic EL display device using a tiling technique according to an embodiment of the present invention.

FIG. 2 is a block diagram showing in detail the representative small organic EL display device shown in FIG.

3 is a perspective view illustrating organic EL display panels using a polarizing film according to an exemplary embodiment of the present invention.

FIG. 4 is a cross-sectional view cut along the line II ′ of the organic EL display panels shown in FIG. 3.

* Description of main parts of drawing *

10 EL display panel 12 pixel portion

14: scan driver 16: light emission control driver

20: data driver 50: first polarizing film

60: second polarizing film

The present invention relates to an organic electroluminescent display, and more particularly, in a tiling technology in which a plurality of display panels are bonded to realize a single screen, minimizing a seam display phenomenon recognized in a bonding area to which each display panel is bonded. The present invention relates to an organic electroluminescent display using a tiling technique having a uniform brightness.

The flat panel display has been researched and developed due to the advantages of reducing the weight and size of the display device using a cathode ray tube, and as a result, a liquid crystal display (LCD) and a field emission display (Field Emission Display) FED), plasma display panels (PDPs), and organic electroluminescent display devices (hereinafter referred to as organic EL display devices) have been developed and put into practical use. Among them, the PDP is possible to configure a large screen, but has a problem in that power consumption is low due to low luminous efficiency and brightness, and LCD has a problem in that power consumption is large because response speed is slow and light is emitted by a backlight.

In contrast, an organic EL display device emits light using organic materials, and has a wider viewing angle, faster response speed, better contrast, and better visibility as a self-luminous device than an LCD. In addition, since no backlight is required, the thickness and weight can be reduced.

However, the size of the EL display panel per glass substrate is limited due to the limitations in the manufacturing process when the organic EL display device constitutes an enlarged screen. In addition, in the case of a large screen, the fall of the yield at the time of a defect generate | occur | produced in a part of screen is inevitable, and securing in-plane uniformity is also difficult.

A technique developed as one of the solutions to the organic EL display device, which is difficult to form a large screen as described above, is a tiling technique, which is a method of forming a single EL display panel by joining a plurality of EL display panels.

However, such a large screen configuration method using the tiling technique causes a phenomenon in which seams are displayed (called seam phenomenon) at the bonded interface between the plurality of EL display panels, thereby resulting in a uniform luminance. There is a problem that can not display the image and visibility is not good.

Various attempts have been made to solve such a seam display problem, and a method of minimizing seam display using an optical lens has been disclosed. Patent Registration No. 10-0300430 is connected to at least two flat panel display in a state where the screens are in contact with each other, the compensation lens is installed on the periphery of the screen including the seams near the mutual contact of the flat panel display unit, the compensation lens It is disclosed to reduce the area covered by the other area than the other area of the flat panel display, and to form a space between the pixels and the pixels in the reduced area in inverse proportion to the magnification of the compensation lens.

However, the method of compensating the seam display portion using the compensation lens as described above has difficulty in optimizing the magnification of the compensation lens, the cost of using the optical lens, and is insufficient to completely eliminate the display of the seam portion. .

Therefore, a new method other than using an optical lens is required to minimize the seam display in the tiling technology to improve the visibility and to make the luminance uniform.

The technical problem to be solved by the present invention to solve the above problems is to visually compensate by minimizing the seam display (seam phenomenon) at the junctions of the plurality of EL display panel, to have a uniform brightness as a whole and to improve the quality of the screen An organic electroluminescent display including an EL display panel is provided.

According to one aspect of the present invention, an organic EL display device includes: an organic EL display panel in which a plurality of display panels having pixels emitting light at a predetermined luminance are bonded in a tile form to display one screen; A first polarizing film formed on the organic EL display panel and transmitting light emitted from a seam region to which the tile type display panels are bonded; And a second polarizing film formed in a region other than the first polarizing film, having a lower transmittance than the first polarizing film, and transmitting light emitted from a region other than the seam region.

Also, an object of the present invention is to provide an organic EL display panel in which at least two display panels are bonded to each other to display a single screen, including: at least two lower substrates; A plurality of pixels formed on the at least two lower substrates at predetermined intervals and emitting predetermined light; A passivation layer formed on the plurality of pixels and protecting the plurality of pixels; At least two upper substrates formed on the protective layer and facing the at least two lower substrates; A first polarizing film formed on a bonding region of the at least two upper substrates and transmitting light emitted from the bonding region; And a second polarizing film formed in a region other than the first polarizing film and transmitting light from outside the bonding region, and having a transmittance lower than that of the first polarizing film. Can be.

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

1 is a block diagram showing a combined organic EL display device using a tiling technique according to an embodiment of the present invention.

Referring to FIG. 1, in a combined organic EL display device using a tiling technique according to an exemplary embodiment of the present invention, a plurality of small organic EL display devices 100 are bonded to each other. In the case of FIG. 1, four small organic EL display devices 100 are joined in rows to form two columns, which can be joined in various sizes according to design.

The small organic EL display device 100 is composed of an EL display panel 10 capable of displaying an image and a data driver 20 for supplying an image data signal to the EL display panel 10.

Each of the EL display panels 10 has basically the same structure, and each edge surface is bonded with an adhesive to form one combined EL display panel. The adhesive uses an ultraviolet curable resin or a thermosetting resin such as an epoxy resin.

Each EL display panel 10 can be produced through the same manufacturing process as that of an EL display panel of a small organic light emitting display device conventionally used. Therefore, several of the same EL display panels produced through the same manufacturing process are attached to form one combination EL display panel.

The thin film transistors of a plurality of pixels formed in such an EL display panel have polysilicon as a channel of the thin film transistors for fast response speed and uniformity. In this case, the polysilicon is formed on the glass substrate, and then crystallized into polysilicon through a low temperature polysilicon (LTPS) process.

Signals for forming a plurality of transistors using polysilicon formed by the LTPS process and selecting red, green, and blue pixel circuits and the respective pixels in the EL display panel using the plurality of transistors and controlling light emission A scan driver and a light emission control driver are formed to generate a. The EL display panel 10 will be described later.

The plurality of data drivers 20 are designed as external integrated circuits (ICs) using CMOS forming technology and are electrically connected to the respective EL display panels 10. Electrical connection between one EL display panel 10 and data driver 20 is achieved through a metal pattern printed on the flexible film. That is, the output terminal of the data driver 20 is electrically connected to one end of the metal pattern, and the data line provided on the EL display panel 10 is electrically connected to the other end of the metal pattern. This is called a tape carrier package (TCP) method. Each data driver 20 supplies a data signal to the pixel portion of the EL display panel 10 through a plurality of conductive lines provided on the flexible film.

FIG. 2 is a block diagram showing in detail the representative small organic EL display device shown in FIG.

Referring to FIG. 2, the small organic EL display device 100 includes an EL display panel 10 and a data driver 20.

The EL display panel 10 is composed of a pixel portion 12, a scan driver 14, and a light emission control driver 16.

The pixel portion 12 includes a plurality of data lines D1 -Dm, a plurality of scan lines S1 -Sn, a plurality of emission control lines E1 -En, and a plurality of pixels P11 formed in areas where these lines cross each other. To Pnm).

The plurality of data lines D1 to Dm are electrically connected to the data driver 20 to extend in the vertical direction, and transmit corresponding data signals to the respective pixels.

In addition, although the plurality of scan lines S1 -Sn and the plurality of emission control lines E1 -En extend in the vertical direction like the data driver 20 unlike the conventional art, the same scans are performed on the pixels arranged in the horizontal direction. And a contact hole for each scan and emission control line S1 -Sn and E1 -En to transmit the emission control signal. Accordingly, the metal wiring connected through the contact hole extends in the horizontal direction to transmit scan and light emission control signals to the pixels in the horizontal direction.

Each of the pixels P11 to Pnm has three red, green, and blue pixels arranged in rows and columns repeatedly. Each of the red, green, and blue pixels differs only from the organic material of the organic light emitting layer that actually emits light, and the wiring layout and the circuit connection relationship of the driving circuit unit are the same. Therefore, red, green, and blue light are emitted at luminance corresponding to the data signal applied to each pixel, and one color is expressed by a combination of these three colors.

The scan driver 14 is formed between the data driver 20 and the pixel unit 12. This is because a plurality of EL display panels 10 are joined to form one large panel, so that each scan driver 14 must be formed on the same side as the data driver 20 (this is called 'uniaxial drive'). . The scan driver 14 is connected to a plurality of scan lines S1 -Sn, and sequentially selects the pixels P11 -Pnm by sequentially applying a scan signal to the pixel unit 12.

The emission control driver 16 is formed between the scan driver 14 and the pixel unit 12, and is connected to the plurality of emission control lines E1 -En to sequentially emit light control signals to the pixel unit 12. Is applied to control the emission time of each pixel P11-Pnm.

As described above, the data driver 20 supplies a data signal to the pixel portion 12 of the EL display panel 10 through a plurality of conductive lines provided on the flexible film.

In the organic EL display device using the tiling technique having the above-described configuration, the EL display panels bonded in the form of tiles by receiving the divided image data output from the plurality of data drivers 20 display the respective images and combine them. Will display one normal screen.

In the organic EL display device using the tiling technique, since a plurality of display panels are bonded, each bonding surface, that is, a seam region, is inevitably formed. Therefore, the luminance of light emitted from the seam region is smaller than the luminance emitted from other areas. As a result, the seam area is more clearly seen, resulting in a tile-like shape as a whole, and poor visibility and poor quality and reliability.

In order to solve this problem, the present invention proposes to use a polarizing film on the display panel as shown in FIG. 3 without using the conventional optical lens.

3 is a perspective view illustrating organic EL display panels using a polarizing film according to an exemplary embodiment of the present invention.

Referring to Fig. 3, in the organic EL display panel, the display panel 1 and the display panel 2 are joined to each other, and a joint region A including a joining surface portion is formed. The luminance B1 coming out of the seam area A is smaller than the luminance B2 coming out of the area B other than the seam area A. FIG. Here, the unit of brightness is [cd / m ^ 2].

In addition, a first polarizing film 50 is formed on the seam area A where the display panel 1 and the display panel 2 are bonded to each other, and a region other than the seam area in each of the display panel 1 and the display panel 2 is formed. The second polarizing film 60 is formed on B).

The transmittance T1 of the first polarizing film 50 is determined in consideration of the brightness B1 of the light emitted from the seam area A.

In addition, the transmittance T2 of the second polarizing film 60 is determined in consideration of the brightness B2 of the light emitted from the region B other than the seam region A.

That is, the relationship between the transmittance T1 of the first polarizing film 50 and the transmittance T2 of the second polarizing film 60 may be represented by Equation 1 below.

[Equation 1]

B1 × T1 = B2 × T2

Here, B1 is the brightness of the light passing through the first polarizing film, B2 is the brightness of the light passing through the second polarizing film, T1 is the transmittance of the first polarizing film and T2 is the second polarizing film Is the transmittance of.

For convenience of explanation below, the luminance B1 of the seam area A is referred to as 80 [cd / m ^ 2], and the luminance B2 of the other area B is set to 100 [cd / m ^ 2]. Will be described. Each of the luminances B1 and B2 may experimentally obtain the light emitted when the same image data signal is applied.

Accordingly, when the ratios of the transmittance of the first polarizing film and the transmittance of the second polarizing film are obtained with the respective luminances B1 and B2 and Equation 1, Equation 2 below.

[Equation 2]

T1 / T2 = B2 / B1 = 100/80 = 12.5

Therefore, the transmittance T1 of the first polarizing film 50 is about 12.5 times larger than the transmittance T2 of the second polarizing film 60. For example, if the transmittance T1 of the first polarizing film 50 is 60%, the transmittance T2 of the second polarizing film 60 should have 48%.

As described above, the first and second polarizing films having predetermined transmittances may be formed on the seam region A and the region B other than the seam using Equations 1 and 2, respectively.

FIG. 4 is a cross-sectional view cut along the line II ′ of the organic EL display panels shown in FIG. 3.

Referring to FIG. 4, the organic EL display panel according to the present invention is formed on the lower substrate 31 and the lower substrate 31 at predetermined intervals, and includes a plurality of red (R) and green light emitting light. (G), blue (B) pixels, a protective layer 33 for protecting the plurality of pixels, and an upper substrate 35 on the protective layer 33 facing the lower substrate.

In the organic EL display panel according to the present invention, the display panel 1 and the display panel 2 are bonded to each other to be divided into a seam region A and a region B other than that.

Accordingly, the first polarizing film 50 is formed on the upper substrate 35 of the seam region A, and the second polarizing film 50 is formed on the upper substrate 35 of the other region B. To form. 4 is a cross-sectional view of FIG. 3, so a detailed description of FIG. 4 will be omitted with reference to FIG. 3.

The first polarizing film 50 is formed on the seam area, but may be formed to cover at least one column of pixels formed in the seam portion of the display panel 1 or / and the display panel 2. The area of the first polarizing film 50 may be extended to a region where the luminance of the seam region and the other luminances can be compared numerically.

As described above, the organic EL display device using the tiling technique according to the embodiment of the present invention has a transmittance in the seam region and other regions, respectively, in order to compensate for the decrease in luminance in the seam region of the display panels bonded in the form of tiles. By bonding other polarizing films to minimize the seam display, the overall brightness of the organic EL display panel can be made uniform.

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

As described above, in order to compensate for a decrease in luminance in the seam area of the display panels bonded in the form of tiles, a polarization film having different transmittances is adhered to the seam area and other areas, thereby displaying seam (seam) phenomenon. ), And the organic EL display device having a uniform brightness as a whole.

Claims (6)

An organic EL display panel in which a plurality of display panels having pixels emitting light at a predetermined luminance are bonded in a tile form to display one screen; A first polarizing film formed on the organic EL display panel and transmitting light emitted from a seam region to which the tile type display panels are bonded; And And a second polarizing film formed in a region other than the first polarizing film, having a lower transmittance than the first polarizing film, and transmitting light emitted from a region other than the seam region. The method of claim 1, The relationship between the transmittance of the first polarizing film and the transmittance of the second polarizing film is established by the following Equation. [Equation] B1 × T1 = B2 × T2 Here, B1 is the brightness of light entering the first polarizing film and B2 is the brightness of light entering the second polarizing film, T1 is the transmittance of the first polarizing film and T2 is the transmittance of the second polarizing film to be. The method of claim 1, And the first polarizing film is formed so as to cover at least one column of pixels formed in the seam region portion. An organic EL display panel in which at least two display panels are bonded to display one screen, At least two lower substrates; A plurality of pixels formed on the at least two lower substrates at predetermined intervals and emitting predetermined light; A passivation layer formed on the plurality of pixels and protecting the plurality of pixels; At least two upper substrates formed on the protective layer and facing the at least two lower substrates; A first polarizing film formed on a bonding region of the at least two upper substrates and transmitting light emitted from the bonding region; And An organic EL display panel comprising a second polarizing film formed in a region other than the first polarizing film, transmitting light from the bonding region and having a transmittance lower than that of the first polarizing film. The method of claim 4, wherein The relationship between the transmittance of the first polarizing film and the transmittance of the second polarizing film is established by the following Equation. [Equation] B1 × T1 = B2 × T2 Here, B1 is the brightness of light entering the first polarizing film and B2 is the brightness of light entering the second polarizing film, T1 is the transmittance of the first polarizing film and T2 is the transmittance of the second polarizing film to be. The method of claim 4, wherein And the first polarizing film is formed so as to cover at least one column of pixels formed in the junction region.

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