KR20080076546A - Display device - Google Patents

Abstract

A display device is provided to block ultraviolet rays incident on an organic layer by forming an ultraviolet blocking film corresponding to the entire organic layer. A display device(1) includes an insulating substrate(11), a first electrode(71), an organic layer(90), a second electrode(95), and an ultraviolet blocking film(97). The first electrode is formed on the insulating substrate. The organic layer is formed on the first electrode. The second electrode is formed on the organic layer. The ultraviolet blocking film is formed on a path of external light incident on the organic layer to block ultraviolet rays. The ultraviolet blocking film is formed between the first electrode and the organic layer. The second electrode has a reflective metal layer. The ultraviolet blocking film corresponds to the entire organic layer.

Description

Display {DISPLAY DEVICE}

1 is an equivalent circuit diagram of a display device according to a first embodiment of the present invention.

2 is a layout view of a display device according to a first exemplary embodiment of the present invention.

3 is a cross-sectional view taken along line III-III of FIG. 2.

4 is an enlarged view of a portion A of FIG. 3.

5 is a partially enlarged view of a display device according to a second exemplary embodiment of the present invention.

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

11: first insulating board 12: second insulating board

15: buffer layer 41: first insulating layer

42: color filter 43: second insulating layer

71: anode 80: partition

81: Opening part 90: Organic layer

95: negative electrode 97: ultraviolet ray shielding film

The present invention relates to a display device. More specifically, the present invention is to provide a display device that can improve the life.

Recently, many flat panel display devices such as organic light emitting diodes (OLEDs), liquid crystal display devices (LCDs), and plasma display panels (PDPs) have been developed in place of conventional CRTs. It is becoming.

Among them, the organic light emitting display device is in the spotlight due to its advantages such as low voltage driving, light weight, wide viewing angle, and high speed response.

The organic light emitting device includes an organic layer having a light emitting layer for emitting light. Electrons and holes are supplied to the light emitting layer, and light is generated by recombining the supplied electrons and holes in the light emitting layer.

However, since the light emitting layer included in the organic layer absorbs external light and emits light, the light emitting layer may react sensitively to a small amount of ultraviolet light, thereby deforming and decomposing the light, thereby shortening the life of the display device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a display device capable of extending the life of the light emitting layer by blocking ultraviolet rays flowing into the organic layer.

According to a preferred embodiment of the present invention for achieving the above object of the present invention, a display device includes an insulating substrate, a first electrode located on the insulating substrate, an organic layer located on the first electrode, on the organic layer It includes a second electrode positioned on the path of the external light flowing into the organic layer, and a UV blocking film for blocking ultraviolet rays.

The ultraviolet blocking film is preferably located between the first electrode and the organic layer.

The second electrode may comprise a reflective metal layer.

The ultraviolet blocking film is preferably provided so as to correspond to the entire organic layer.

The UV blocking film contains at least one of silver (Ag) and aluminum (Al), and is preferably formed of a thin film of several to several tens of nanometers.

The UV blocking film may be formed through sputtering or may be formed by depositing.

The UV blocking film may include blocking points spaced apart from each other, and the interval between the blocking points is preferably shorter than the wavelength of the ultraviolet light.

Hereinafter, an equivalent circuit diagram of a pixel of the display device 1 according to the first embodiment of the present invention will be described with reference to FIG. 1.

As shown in FIG. 1, a plurality of signal lines are provided in one pixel. The signal line includes a gate line for transmitting a scan signal, a data line for transmitting a data signal, and a driving voltage line for transmitting a driving voltage. The data line and the driving voltage line are adjacent to each other and disposed side by side, and the gate line extends perpendicular to the data line and the driving voltage line.

Each pixel includes an organic light emitting element LD, a switching thin film transistor Tsw, a driving thin film transistor Tdr, and a capacitor C.

The driving thin film transistor Tdr has a control terminal, an input terminal, and an output terminal. The control terminal is connected to the switching thin film transistor Tsw, the input terminal is connected to a driving voltage line, and the output terminal is an organic light emitting diode ( LD).

The organic light emitting element LD has an anode connected to the output terminal of the driving thin film transistor Tdr and a cathode connected to the common voltage Vcom. The organic light emitting element LD displays an image by emitting light having a different intensity according to the output current of the driving thin film transistor Tdr. The current of the driving thin film transistor Tdr varies in magnitude depending on the voltage applied between the control terminal and the output terminal.

The switching thin film transistor Tsw also has a control terminal, an input terminal and an output terminal, the control terminal is connected to the gate line, the input terminal is connected to the data line, and the output terminal of the driving thin film transistor Tdr. It is connected to the control terminal. The switching thin film transistor Tsw transfers a data signal applied to the data line to the driving thin film transistor Tdr according to a scan signal applied to the gate line.

The capacitor C is connected between the control terminal and the input terminal of the driving thin film transistor Tdr. The capacitor C charges and maintains a data signal input to the control terminal of the driving thin film transistor Tdr.

Hereinafter, the display device 1 according to the first exemplary embodiment of the present invention will be described with reference to FIGS. 2 to 4.

2 to 4, a buffer layer 15 is formed on the first insulating substrate 11. The buffer layer 15 may be formed of silicon oxide, and prevents impurities of the first insulating substrate 11 from flowing into the amorphous silicon layer during the crystallization of the amorphous silicon layer.

The driving semiconductor layer 21 and the driving resistance contact layer 22 are formed on the buffer layer 15. The driving semiconductor layer 21 and the driving resistance contact layer 22 are made of polysilicon.

The driving semiconductor layer 21 and the driving ohmic contact layer 22 are manufactured by forming an amorphous silicon layer and an amorphous ohmic contact layer on the buffer layer 15 and then crystallizing and patterning the amorphous semiconductor layer. In the crystallization process, a solid phase crystallization method may be used.

The first metal layer is formed on the buffer layer 15, the driving semiconductor layer 21, and the driving resistance contact layer 22.

The first metal layer includes a gate line 31, a switching gate electrode 32, a driving source electrode 33, and a driving drain electrode 34. The gate line 31 and the switching gate electrode 32 are integrally formed.

The first insulating layer 41 is formed on the first metal layer. The first insulating layer 41 may be made of silicon nitride.

The switching semiconductor layer 51 and the switching resistance contact layer 52 are formed on the first insulating layer 41. The switching semiconductor layer 51 and the switching ohmic contact layer 52 correspond to the switching gate electrode 32 and may be made of amorphous silicon.

A second metal layer is formed on the first insulating layer 41, the switching semiconductor layer 51, and the switching ohmic contact layer 52. In addition, a color filter 42 is formed on the first insulating layer 41 corresponding to the anode 71.

The second metal layer includes a data line 61, a switching source electrode 62, a switching drain electrode 63, a driving gate electrode 64, a storage capacitor line 65, and a driving voltage line 66.

The data line 61 and the switching source electrode 62 are integral. The switching drain electrode 63, the driving gate electrode 64, and the storage capacitor line 65 are also integrally formed.

The second insulating layer 43 is formed on the second metal layer. The second insulating layer 43 may also be referred to as a planarization layer and may include an organic material. As the organic material, any one of a benzocyclobutene (BCB) series, an olefin series, an acrylic resin series, a polyimide series, and a fluororesin may be used.

The first contact hole 44, the second contact hole 45, and the third contact hole 46 are formed in the second insulating layer 43. The first contact hole 44 exposes the driving drain electrode 34, the second contact hole 45 exposes the driving source electrode 33, and the third contact hole 46 opens the driving voltage line 66. Expose In the first contact hole 44, the first insulating layer 41 is also removed.

The transparent conductive layer is formed on the second insulating layer 43. The transparent conductive layer includes an anode 71 and a bridge electrode 72, and may be made of indium tin oxide (ITO) or indium zinc oxide (IZO).

The anode 71 is electrically connected to the driving drain electrode 34 through the contact hole 44. The bridge electrode 72 electrically connects the driving source electrode 33 and the driving voltage line 66 through the second contact hole 45 and the third contact hole 46. The storage capacitor line 65 extends below the bridge electrode 72 to form the storage capacitor Cst.

The partition wall 80 is formed on the second insulating layer 43.

The partition wall 80 is formed of an acryl-based or imide-based polymer, and distinguishes between the anodes 71.

A portion of the partition wall 80 is removed to form an opening 81 that exposes a portion of the anode 71.

The organic layer 90 is formed on the anode 71 exposed by the partition wall 80 and the opening 81. The organic layer 90 includes a light emitting layer that emits white light.

The region where the anode 71 and the organic layer 90 directly contact is called a pixel region. In this embodiment, the pixel region is substantially coincident with the region of the opening 81, and light is mainly generated in the pixel region.

Cathode 95 includes a reflective metal layer comprising aluminum.

The ultraviolet blocking film 97 is provided so as to correspond to the entire organic layer 90. Therefore, ultraviolet rays flowing into the organic layer 90 from the outside may be blocked.

The UV blocking layer 97 may include at least one of silver (Ag) and aluminum (Al), and may be formed of a thin film of several to several tens of nanometers.

In the present embodiment, the thickness d1 of the UV blocking film 97 is formed of an ultra-thin film of 5 to 50 nm.

In the present embodiment, the ultraviolet blocking film 97 is provided in direct contact with the anode 71.

Ultraviolet rays are a generic term for electromagnetic waves having a wavelength of about 10 to 397 nm.

Therefore, the visible light region having a wavelength longer than that of ultraviolet light can pass through, and ultraviolet light having a wavelength smaller than the thickness d1 of the ultraviolet light blocking film 97 is filtered out.

The UV blocking layer 97 may be formed through sputtering.

A portion of the cathode 95 is in direct contact with the partition wall 80.

On the cathode 95, a second insulating substrate 12 covering the cathode 95 is positioned.

The second insulating substrate 12 is usually provided with an insulating glass substrate.

In the display device 1 according to the first embodiment, the holes transferred from the anode 71 and the electrons transferred from the cathode 95 are combined in the organic layer 90 to become excitons. In the process of deactivation of excitons, light is emitted. Among the light generated in the organic layer 90, the light directed toward the cathode 95 is reflected back to the anode 71.

Light directed to the anode 71 is given color while passing through the color filter 42, and then is emitted to the outside through the insulating substrate 11. This method is called a bottom-emission method.

The organic layer 90 may react sensitively even with a small amount of ultraviolet rays to undergo degeneration and decomposition, thereby shortening its lifespan.

However, the display device according to the present invention is provided such that the UV blocking film 97 corresponds to the entire organic layer 90. Therefore, ultraviolet rays introduced into the organic layer 90 from the outside can be effectively blocked.

Therefore, the life of the display device 1 may be extended by protecting the organic layer 90, which may easily react with a small amount of ultraviolet light and may undergo denaturation and decomposition.

In the present exemplary embodiment, the UV blocking film 97 is provided between the anode 71 and the organic layer 90, but according to the manufacturer's intention, external light flows in such as the color filter 42 or the first insulating substrate 11. It may be provided where it is located in the path.

In another embodiment, the anode 71 may include a reflective metal, and the cathode 95 may be provided transparently. In this case, the light is emitted to the outside through the cathode (95), this method is called a top-emission (top-emission) method. In this case, the color filter 42 is formed on the cathode 95.

In the case of a top-emission method, the UV blocking film may be provided on a cathode or a color filter positioned in an inflow path of external light.

Hereinafter, a display device according to a second exemplary embodiment of the present invention will be described with reference to FIG. 5.

Hereinafter, only the characteristic parts distinguished from the first embodiment will be described and described, and the descriptions thereof will be omitted according to the first embodiment and known techniques. In addition, in the second embodiment of the present invention, for the convenience of description, the same components will be described using the same reference numerals.

As shown in FIG. 5, the UV blocking film may include blocking points 98 spaced apart from each other, and the interval d2 between the blocking points 98 is shorter than a wavelength of ultraviolet light.

Therefore, visible light regions having a wavelength longer than that of ultraviolet light can pass through, and ultraviolet light having a wavelength longer than the distance d2 between the blocking points 98 is filtered out.

For reference, in the present exemplary embodiment, the blocking point 98 may be formed to be very thin and naturally spaced apart from each other when the UV blocking film is deposited on the anode 71.

In the display device 1 according to the present invention, the ultraviolet blocking film is provided to correspond to the entire organic layer 90, so that ultraviolet rays flowing into the organic layer 90 from the outside can be effectively blocked.

Therefore, the life of the display device 1 may be extended by protecting the organic layer 90, which may easily react with a small amount of ultraviolet light and may undergo denaturation and decomposition.

As described above, although described with reference to the preferred embodiments of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

The display device of the present invention can effectively block ultraviolet rays flowing into the organic layer to protect the organic layer, thereby extending the life of the display device.

Claims (9)

In the display device, An insulating substrate; A first electrode on the insulating substrate; An organic layer on the first electrode; A second electrode on the organic layer; And a UV blocking layer positioned on a path of external light flowing into the organic layer and blocking ultraviolet rays. The method of claim 1, The ultraviolet blocking layer is provided between the first electrode and the organic layer. The method of claim 1, And the second electrode includes a reflective metal layer. The method of claim 1, The ultraviolet blocking layer corresponds to the entire organic layer. The method of claim 1, The ultraviolet blocking layer includes at least one of silver (Ag) and aluminum (Al). The method of claim 1, The ultraviolet blocking layer is formed of a thin film of several tens to several tens of nanometers. The method of claim 6, The UV blocking layer is formed by sputtering. The method of claim 1, The UV blocking layer may include blocking points spaced apart from each other. The method of claim 8, And the interval between the blocking points is shorter than the wavelength of ultraviolet rays.

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