KR102245505B1 - Dual display device and method for fabricating the same - Google Patents

Abstract

The present invention provides a double-sided display device including a plurality of first pixel portions that emit light in one direction, and a plurality of second pixel portions that emit light in another direction opposite to one direction, the plurality of first and Each of the second pixel units is disposed adjacent to the switching element on the upper side of the lower substrate and the upper substrate to be bonded to each other, the switch element provided on the upper side of the lower substrate, and the lower substrate disposed on the second pixel part An organic light emitting diode that is disposed above the switching device and emits light based on a driving voltage selectively applied from the switching device, and the upper portion corresponding to the organic light emitting diode of the second pixel unit. A reflective plate on the substrate, a black matrix disposed on an outer portion of the first and second pixel portions of the upper substrate, and an upper color filter disposed on an upper substrate corresponding to the organic light emitting diode of the first pixel portion. It provides a double-sided display device.

Description

DUAL DISPLAY DEVICE AND METHOD FOR FABRICATING THE SAME}

The present invention relates to a double-sided display device capable of displaying different images on both sides, and more particularly, to a double-sided display device capable of increasing luminance by improving rear luminous efficiency and a method of manufacturing the same.

As the information age enters in earnest, the field of displays that visually displays electrical information signals is rapidly developing. Accordingly, research has been continued to develop performances such as thinner, lighter, and low power consumption for various flat display devices.

Typical examples of such flat panel display devices include Liquid Crsytal Display device (LCD), Plasma Display Panel device (PDP), Field Emission Display device (FED), and electroluminescent display device. (Electro Luminescence Display device: ELD), Electro-Wetting Display device (EWD), and Organic Emitting Display device (OLED) can be seen.

Among them, an organic light emitting display device (hereinafter referred to as "OLED") is a device that displays an image using a self-luminous device (Organic Light Emitting Diode).

Accordingly, the organic light emitting display device (OLED) includes two or more organic light emitting devices that emit light of different colors, so that a color image can be realized without a separate color filter. In addition, since there is no need to provide a separate light source, there are advantages in miniaturization, thickness reduction, and weight reduction than liquid crystal display devices, a wide viewing angle, and a reaction speed that is 1000 times faster than that of a liquid crystal display device, thereby reducing an afterimage.

On the other hand, the organic light emitting display device (OLED) can be implemented in any one of a front emission type, a rear emission type, and a double-sided emission type (i.e., a double-sided display device) according to the relative position between the emission layer, the reflective layer, and the black matrix of the organic light emitting device. I can.

That is, when all of the plurality of pixels include an emission layer formed on the reflective layer, the organic light emitting display device OLED is a top emission type in which light is emitted to an upper side of a substrate on which a cell array is formed on an upper surface.

In addition, after applying the light-emitting structure of the transmissive part to the rear light-emitting part (the anode electrode is extended to the transmissive part and then applied as the light-emitting part), a black matrix is formed on the upper substrate to block the light emitted to the front and to emit light only to the rear side. It becomes light emitting type.

In addition, when some of the plurality of pixels are of the top emission type and the remainder of the plurality of pixels are of the bottom emission type, the organic light emitting display device OLED is a double-sided emission type (hereinafter, referred to as "double-sided display device").

However, in the double-sided light emitting display device, in the case of the rear light emitting part, only some of the light emitted from the organic light emitting diode is extracted out of the lower substrate, and some of the light emitted from the organic light emitting diode is absorbed by the black matrix formed on the upper substrate. The luminance of is lower than that of the front.

An object of the present invention is to provide a double-sided display device capable of increasing luminance by improving the rear luminous efficiency of the double-sided display device and a method of manufacturing the same.

In order to solve the above-described problem, the double-sided display device according to the present invention includes a plurality of first pixel portions that emit light in one direction, and a plurality of second pixels that emit light in the other direction opposite to one direction. In the double-sided display device including a portion, each of the plurality of first and second pixel portions is a lower substrate and an upper substrate that are bonded to each other to face each other, a switch element provided on the upper side of the lower substrate, and the second pixel portion A lower color filter disposed above the lower substrate adjacent to the switching element, an organic light emitting diode disposed above the switching element and emitting light based on a driving voltage selectively applied from the switching element, the second A reflector on the upper substrate corresponding to the organic light emitting diode of the pixel unit, a black matrix disposed on the outer portion of the first and second pixel units of the upper substrate, and on the upper substrate corresponding to the organic light emitting diode of the first pixel unit It includes an upper color filter disposed on.

In the double-sided display device according to the present invention, the reflective plate overlaps the organic light emitting diode of the second pixel portion and the lower color filter.

In the double-sided display device according to the present invention, a reflection reduction plate is interposed between the reflection plate and the upper substrate.

The method of manufacturing a double-sided display device according to the present invention includes a plurality of first pixel portions that emit light in one direction, and a plurality of second pixel portions that emit light in the other direction opposite to one direction. A method of manufacturing a device, the method comprising: forming a switching element for each of a plurality of first and second pixel units on an upper side of a lower substrate, and a lower color filter adjacent to the switching element on an upper side of a lower substrate of the second pixel Forming an organic light emitting diode of each of the plurality of first and second pixel units on the upper side of the switching element among the lower substrate, the upper side of the upper substrate facing the organic light emitting diode of the second pixel unit Forming a reflector on the upper substrate, forming a black matrix to shield light above the first and second pixel portions of the upper substrate, forming an upper color filter above the first pixel portion of the upper substrate, And forming and bonding an adhesive layer between the lower substrate and the upper substrate.

In the method of manufacturing a double-sided display device according to the present invention, the method further includes forming a reflection reduction plate between the upper substrate and the reflective plate.

In the method for manufacturing a double-sided display device according to the present invention, a reflecting plate and a reflection reducing plate are formed at the same time.

In the method for manufacturing a double-sided display device according to the present invention, the reflection reduction plate is any of a transparent conductive material including molybdenum (Mo), ITO (Indium-Tin-Oxide) and IZO (Indium-Zinc-Oxide), or an alloy thereof. It is characterized by forming one.

In the method of manufacturing a double-sided display device according to the present invention, the reflector is characterized in that any one of silver alloy, aluminum (Al), molybdenum (Mo), and molybdenum titanium (MoTi) is used.

In the present invention, since a reflective plate with high reflectivity is formed in a pixel portion that emits light on the back side, light emitted from the organic light emitting diode to the front side is reflected to the rear side through the reflector, so that the efficiency of light emitted through the back side of the double-sided display device is improved. Can be improved.

In addition, in the present invention, since the reflector is first formed before the black matrix is formed in the pixel portion emitting the backlight, the reflector can be used as an alignment key when the black matrix is manufactured.

In addition, according to the present invention, by further forming a reflection reduction plate on a reflection plate positioned in a pixel portion emitting rear light, front reflection by the reflection plate from the upper substrate can be reduced.

1 is a plan view illustrating examples of a pixel arrangement structure of a double-sided display device according to an exemplary embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1 and illustrating examples of first and second pixels according to an exemplary embodiment of the present invention.
3 is a flowchart illustrating a method of manufacturing a double-sided display device according to the first embodiment of the present invention.
4A to 4K are cross-sectional views illustrating a method of manufacturing the double-sided display device according to the exemplary embodiment of FIG. 2.
5 is a cross-sectional view taken along line II-II of FIG. 1 and illustrating examples of first and second pixels according to another exemplary embodiment of the present invention.
6A to 6L are cross-sectional views illustrating a method of manufacturing a double-sided display device according to another exemplary embodiment of the present invention of FIG. 5.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and the general knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. The same reference numerals refer to the same elements throughout the specification. In addition, in describing the present invention, when it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When'include','have', and'consist of' mentioned in the present specification are used, other parts may be added unless'only' is used. In the case of expressing the constituent elements in the singular, it includes the case of including the plural unless specifically stated otherwise.

In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description.

In the case of a description of the positional relationship, for example, if the positional relationship of two parts is described as'upper','upper of','lower of','next to','right' Or, unless'direct' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, when a temporal predecessor relationship is described as'after','following','after','before', etc.,'right' or'direct' It may also include cases that are not continuous unless this is used.

First, second, etc. are used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, the first component mentioned below may be a second component within the technical idea of the present invention.

Each of the features of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be independently implemented with respect to each other or can be implemented together in an association relationship. May be.

In addition, in describing the constituent elements of the invention, terms such as first, second, a, and b may be used. These terms are for distinguishing the constituent element from other constituent elements, and the nature, order, or order of the constituent element is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected or connected to that other component, but another component between each component It will be understood that elements may be “connected”, “coupled” or “connected”. In the same context, when it is described that a component is formed "above" or "below" another component, the component is all formed directly on the other component or indirectly through another component. It should be understood as including.

Hereinafter, embodiments of the present invention will be described in detail through exemplary drawings.

1 is a plan view illustrating examples of a pixel arrangement structure of a double-sided display device according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1 and illustrating examples of first and second pixels according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the double-sided display device 100 according to an embodiment of the present invention emits light in one direction to display an image from a first surface, and a second-sided display device 100 displays an image in the other direction. It includes a second pixel portion B that emits light in a direction (that is, in a direction opposite to one direction) to display an image on a second surface facing the first surface.

Here, the first pixel portion A includes a plurality of first pixels emitting light in one direction, and the second pixel portion B includes a plurality of second pixels emitting light in the other direction. .

As shown in FIG. 1, a plurality of first pixel portions A and a plurality of second pixel portions B are arranged in a matrix form in first and second directions (corresponding to horizontal and vertical directions in FIG. 1). do. In addition, the plurality of first and second pixel portions A and B are alternately arranged in at least one of the first and second directions.

For example, the plurality of first and second pixel portions A and B may be alternately arranged in the first and second directions. However, the plurality of first and second pixel portions A and B are not limited to the case where they are alternately arranged in the first and second directions, and the plurality of first and second pixel portions A and B are Like the gate lines, they may be arranged alternately along the second direction (vertical direction in FIG. 1) in units of columns in the first direction (horizontal direction in FIG. 1).

As shown in FIG. 2, the first pixel portion A includes a switching element 120 formed on the lower substrate 101, an organic light emitting diode 140 formed on the switching element 120, and An upper substrate 151 having an adhesive layer 161 formed on the organic light emitting diode 140 and an upper color filter 157 formed on the adhesive layer 161 and facing the organic light emitting diode 140 ).

A black matrix 155 is formed in a region of the upper substrate 151 of the first pixel portion A except for the upper color filter 157.

Meanwhile, the second pixel portion B includes a switching element 120 formed on the lower substrate 101, an organic light emitting diode 140 formed above the switching element 120, and an organic light emitting diode 140. And an upper substrate 151 having an adhesive layer 161 formed on the adhesive layer 161 and a reflective plate 153 formed on the adhesive layer 161 and facing the organic light emitting diode 140.

The second pixel portion (B) is formed on the lower substrate (101), is located under the organic light emitting diode (140), the lower color filter facing the organic light emitting diode (140) and the reflective plate (153) (125) is further included.

A black matrix 155 is formed in a region of the upper substrate 151 of the second pixel portion B except for the reflective plate 153.

Here, the switching device 120 includes an active layer 105 formed on the lower substrate 101, a gate insulating layer 107 formed on the channel layer 105c of the active layer 105, and the A gate electrode 109 formed on the gate insulating layer 107 and extending from a gate wiring (not shown), and a first layer formed on the lower substrate 101 and covering the active layer 105 and the gate electrode 109. 1 The passivation layer 111 and a source electrode formed on the first passivation layer 111 to be connected to one side region of the active layer 105, that is, the source region 105a, and connected to a data line (not shown) ( 115), and a second region formed to cover the drain electrode 117 connected to the other region of the active layer 105, that is, the drain region 105b, and the source electrode 115 and the drain electrode 117 And a protective film 119.

In addition, a drain contact hole (not shown) exposing a part of the drain electrode 117 is formed in the second passivation layer 119, and the drain electrode (not shown) is formed on the second passivation layer 119 through the drain contact hole. The pixel electrode 123 connected to the 117 is formed.

A first organic insulating layer 127 covering the pixel electrode 123 is formed on the entire surface of the second passivation layer 119, and a pixel electrode contact hole exposing the pixel electrode 123 in the first organic insulating layer 127 (Not shown, see 129 in Fig. 4A) is formed.

An auxiliary electrode 131 connected to the pixel electrode 123 through the pixel electrode contact hole is formed on the first organic insulating layer 127, and the auxiliary electrode 131 is formed on the front surface of the first organic insulating layer 127. ) Is formed to cover the second organic insulating layer 133.

An auxiliary electrode contact hole (not shown, see 135 of FIG. 4C) exposing a part of the auxiliary electrode 131 is formed in the second organic insulating layer 133.

An anode electrode 137 connected to the auxiliary electrode 131 through the auxiliary electrode contact hole 135 is formed on the second organic insulating layer 133.

Meanwhile, the pixel electrode 123, the auxiliary electrode 131, and the second organic insulating layer 133 may not be formed in some cases. That is, the pixel electrode 123, the auxiliary electrode 131, and the second organic insulating layer 133 are omitted, and the anode electrode 137 is connected to the drain electrode 117 through the first organic insulating layer 127. It may be formed to be in direct contact.

The organic light emitting diode 140 includes an anode electrode 137 formed on the second organic insulating layer 133, a cathode electrode 145 formed opposite the anode electrode 137, the anode electrode 137 and a cathode electrode. An organic emission layer 143 formed between 145 and a pixel defining layer 141 formed at a boundary between the organic emission layers 143 are included.

Here, the anode electrode 137 is connected to the drain electrode 117 of the switching device 120, so when a driving voltage is applied to the anode electrode 137 from the drain electrode 117, the organic light-emitting layer 140 is In response to electrons and holes injected through the electrode 137 and the cathode electrode 145, light in a predetermined wavelength region is generated. That is, the emission regions of each of the first and second pixel portions A and B correspond to the regions in which the organic emission layer 143 is formed.

The switching device 120 and the anode electrode 137 are formed to correspond to each of a plurality of pixels including the first and second pixel portions A and B, and the cathode electrode 145 is formed to correspond to the plurality of pixels in common. Can be formed.

As described above, in the double-sided display device according to an embodiment of the present invention, a reflective plate having high reflectivity is formed on the upper substrate of the second pixel portion B that emits rear light, so that light emitted from the organic light emitting diode to the front surface is reflected Since it is reflected toward the back side through the light, the efficiency of light emitted through the back side of the double-sided display device can be improved.

A method of manufacturing a double-sided display device according to an exemplary embodiment of the present invention will be described with reference to FIGS. 3 and 4A to 4K.

3 is a flowchart illustrating a method of manufacturing a double-sided display device according to the first embodiment of the present invention.

4A to 4K are cross-sectional views illustrating a method of manufacturing the double-sided display device according to the exemplary embodiment of FIG. 2.

As shown in FIG. 3, in the method of manufacturing a double-sided display device according to an embodiment of the present invention, the step of preparing a lower substrate (S110), switching of a plurality of first and second pixels on the upper side of the lower substrate, respectively. Forming a device (S112), forming a lower color filter adjacent to the switching device on an upper side of a lower substrate of a second pixel (S114), and each of a plurality of first and second pixels on an upper side of the switching device. Forming an organic light emitting diode (S116), preparing an upper substrate disposed opposite to the lower substrate (S118), forming a reflective plate on the upper side of the upper substrate facing the organic light emitting diode of the second pixel Step S120, forming a black matrix for shielding light above the first and second pixels of the upper substrate (S122), forming an upper color filter above the first pixel of the upper substrate ( S124) and forming and bonding an adhesive layer between the lower substrate and the upper substrate (S126).

In a method of manufacturing a double-sided display device according to an exemplary embodiment of the present invention, as shown in FIG. 4A, a plurality of first and second pixel regions are formed on the lower substrate 101 while the lower substrate 101 is first prepared. A switching element 120 (TFT) corresponding to each is formed.

The step of forming the switching device 120 is performed through the following processes.

First, a buffer insulating layer 103 is formed on the lower substrate 101 using an inorganic insulating material, and then a semiconductor material layer (not shown) made of polycrystalline silicon or an oxide semiconductor is deposited on the entire surface of the buffer insulating layer 103. Then, the active layer 105 is formed by selectively etching the semiconductor material layer through an etching technique.

Then, an inorganic insulating material layer (not shown) and a gate metal layer (not shown) covering the active layer 105 are sequentially stacked on the entire surface of the buffer insulating layer 103, and these layers are selectively etched through an etching technique. Thus, the gate insulating film 107 and the gate electrode 109 are formed on the channel region 105c of the active layer 105.

Subsequently, a first protective layer 111 covering the gate electrode 109, the gate insulating layer 107 and the active layer 105 is formed on the entire surface of the lower substrate 101.

Then, by selectively etching the first passivation layer 111 through an etching technique, contact holes (not shown) exposing each of the source region 105a and the drain region 105b of the active layer 105 are formed. To form.

Then, a source electrode 115 and a drain connected to the source region 105a and the drain region 105b of the active layer 105 through the contact holes (not shown) on the first passivation layer 111, respectively. An electrode 117 is formed.

Then, a second passivation layer 119 is formed on the first passivation layer 111 to cover the active layer 105, the source electrode 115 and the drain electrode 117.

Through these processes, the switching device 120 is formed on the lower substrate 101.

Then, although not shown in the drawing, a drain contact hole (not shown) exposing a portion of the drain electrode 117 is formed by selectively etching the second passivation layer 119 through an etching technique.

Subsequently, a pixel electrode 123 connected to the drain electrode 117 through the drain contact hole (not shown) is formed on the second passivation layer 119.

Then, a lower color filter 125 is formed on the second passivation layer 119 of the second pixel portion B adjacent to the pixel electrode 123.

Subsequently, after depositing a first organic insulating layer 127 covering the pixel electrode 123 on the entire surface of the second passivation layer 119, the first organic insulating layer 127 is selectively etched through an etching technique. A pixel electrode contact hole 129 exposing a portion of the electrode 123 is formed.

Then, as shown in FIG. 4B, after depositing a conductive layer for an auxiliary electrode (not shown) on the first organic insulating layer 127, the conductive layer for the auxiliary electrode (not shown) is formed through an etching technique. By selectively etching, an auxiliary electrode 131 connected to the pixel electrode 123 through the pixel electrode contact hole 129 is formed.

Subsequently, as shown in FIG. 4C, after depositing a second organic insulating layer 133 covering the auxiliary electrode 131 on the entire surface of the first organic insulating layer 127, the second organic insulating layer ( By selectively etching the 133, an auxiliary electrode contact hole 135 exposing a portion of the auxiliary electrode 131 is formed.

Then, as shown in FIG. 4D, after depositing a transparent conductive material layer (not shown) on the entire surface of the second organic insulating layer 133, the transparent conductive material layer (not shown) is selectively selected through an etching technique. By etching to form an anode electrode 137 corresponding to each of the first and second pixel portions A and B. In this case, since the plurality of first pixel portions A do not emit light through the optical path including the lower substrate 101, the anode electrode 137 may be disposed at a position overlapping the switching element 120. However, since the plurality of second pixel portions B emit light through an optical path including the lower substrate 101, the anode electrode 137 is disposed at a position overlapping the lower color filter 125.

Accordingly, the anode electrode 137 is connected to the drain electrode 117 of the switching device 120 through the auxiliary electrode 131 and the pixel electrode 123, so that each pixel portion A , A driving signal corresponding to B) is selectively supplied.

Subsequently, as shown in FIG. 4E, a pixel defining layer 141 corresponding to an outer periphery of each of the plurality of first and second pixel portions A and B is formed on the second organic insulating layer 133. . In this case, the pixel defining layer 141 may be formed to overlap at least a portion of the anode electrode 137 at the edges of each of the first and second pixel portions A and B.

Then, as shown in FIG. 4F, on the anode electrode 137 including the pixel defining layer 141, an organic emission layer 143 corresponding to each of the plurality of first and second pixel portions A and B is formed. ) To form. In this case, the organic light-emitting layer 143 may be formed of any self-luminous material such as a light-emitting organic material.

Subsequently, as shown in FIG. 4G, on the pixel defining layer 141 including the organic emission layer 143 of the plurality of first and second pixel portions A and B, the cathode electrode 145 is formed of a transparent conductive material. To form. In this case, the cathode electrode 145 is formed to be interconnected to each of the plurality of first and second pixel portions A and B. That is, the cathode electrodes 145 of each of the plurality of first and second pixel portions A and B are integrally formed.

Accordingly, the anode electrode 137 and the cathode electrode 145 of each of the plurality of first and second pixel portions A and B, and the organic light emitting layer 143 between the electrodes 137 and 145 are organic light emitting diodes. Form 140.

Then, as shown in FIG. 4H, after forming a reflective material layer (not shown) with high reflectivity on the upper substrate 151 that is bonded to face the lower substrate 101, the reflective material The reflective plate 153 is formed on the plurality of second pixel portions B among the upper substrate 151 by selectively etching a layer (not shown). As the reflective material layer (not shown), silver alloy, aluminum (Al), molybdenum (Mo), or molybdenum titanium (MoTi) is used.

At this time, when the upper substrate 151 faces the lower substrate 101 and is bonded together, the reflective plate 153 overlaps the organic emission layer 140 and the lower color filter 125. In addition, the reflector 153 may serve as an allign key when manufacturing a reverse type black matrix.

Subsequently, a black matrix film (not shown) covering the reflective plate 153 is applied on the front surface of the upper substrate 151. At this time, the black matrix film (not shown) may be made of chromium (Cr) or black resin.

Then, the black matrix layer (not shown) is blocked with a mask (not shown) in which a non-transmissive region for light is selectively formed.

Subsequently, the black matrix film (not shown) is irradiated with ultraviolet rays, and then the black matrix film (not shown) irradiated with ultraviolet rays is developed to form a black matrix 155 as shown in FIG. 4I. At this time, since the region not irradiated with ultraviolet rays is removed by the developer, the black matrix 155 is formed in the region irradiated with ultraviolet rays. In addition, the black matrix 155 is formed on the outer edges of the plurality of first and second pixel portions A and B. That is, the black matrix 155 is disposed at a position that does not overlap with the organic emission layer 140 of the plurality of first and second pixel portions A and B, the reflective plate 153 and the lower color filter 125.

In addition, a portion of the black matrix 155 positioned in the plurality of second pixel portions B may cover an edge portion of the reflective plate 153.

Then, as shown in FIG. 4J, after applying a color pigment covering the reflective plate 153 and the black matrix 155 on the front surface of the upper substrate 151, the upper substrate 151 is selectively etched through an etching technique. The upper color filter 157 is formed in the first pixel portion A of ), that is, in the region between the black matrix 155. In this case, a part of the upper color filter 157 may cover the edge of the black matrix 155.

Subsequently, as shown in FIG. 4K, by forming an adhesive layer 161 between the upper substrate 151 and the lower substrate 101 and bonding them together, the double-sided light emitting display device 100 according to an embodiment of the present invention. To complete the manufacturing process. In this case, the color filters 157 of the plurality of first pixel portions A are disposed to overlap with the organic light emitting diode 140 on the upper side of the lower substrate 101, and the reflective plate 153 of the plurality of second pixel portions B ) Is disposed to overlap the organic light emitting diode 140 and the lower color filter 125 on the upper side of the lower substrate 101.

In this way, the light emitted from the organic light-emitting diodes 140 disposed in the plurality of first pixel portions (A) passes through the upper color filter 157 to emit light in the entire surface, and The light emitted from the disposed organic light emitting diode 140 passes through the lower color filter 125 to emit light on the rear surface, thereby implementing a double-sided light emitting display device. At this time, a part of the light emitted from the organic light emitting diode 140 of the second pixel portion B is reflected through the reflective plate 153 formed on the upper substrate 151 of the second pixel portion B, and thus the lower color It passes through the filter 125 to emit light from the back side.

Accordingly, the present invention reflects light emitted from the organic light emitting diode toward the upper side through the reflective plate in the second pixel (B) so as to emit light toward the lower substrate toward the rear side, thereby improving the efficiency of light emitted toward the rear side.

In addition, in the present invention, since the reflector is first formed before the black matrix is formed in the pixel portion emitting the backlight, the reflector can be used as an alignment key when the black matrix is manufactured.

Meanwhile, a double-sided display device according to another embodiment of the present invention will be described with reference to FIG. 5.

5 is a cross-sectional view taken along line II-II of FIG. 1 and illustrating examples of first and second pixels according to another exemplary embodiment of the present invention.

As shown in FIG. 5, in the double-sided display device 200 according to an embodiment of the present invention, a first pixel portion A that emits light in one direction to display an image from a first surface, and another direction It includes a second pixel portion B that emits light in a direction (that is, in a direction opposite to one direction) to display an image on a second surface facing the first surface.

Here, the first pixel portion A includes a plurality of first pixels emitting light in one direction, and the second pixel portion B includes a plurality of second pixels emitting light in the other direction. .

Although not shown in the drawings, as in the exemplary embodiment of the present invention, the plurality of first pixel portions A and the plurality of second pixel portions B are in the first and second directions (in the horizontal and vertical directions in FIG. 1 ). It is arranged in a matrix form. In addition, the plurality of first and second pixel portions A and B are alternately arranged in at least one of the first and second directions.

For example, the plurality of first and second pixel portions A and B may be alternately arranged in the first and second directions. However, the plurality of first and second pixel portions A and B are not limited to the case where they are alternately arranged in the first and second directions, and the plurality of first and second pixel portions A and B are Like the gate lines, they may be arranged alternately along the second direction (vertical direction in FIG. 1) in units of columns in the first direction (horizontal direction in FIG. 1).

As shown in FIG. 5, the first pixel portion A includes a switching element 220 formed on the lower substrate 201, an organic light emitting diode 240 formed on the switching element 220, and An upper substrate 251 having an adhesive layer 261 formed on the organic light emitting diode 240 and an upper color filter 259 formed on the adhesive layer 261 and facing the organic light emitting diode 240 ).

A black matrix 257 is formed in a region of the upper substrate 251 of the first pixel portion A except for the upper color filter 259.

Meanwhile, the second pixel portion B includes a switching element 220 formed on the lower substrate 201, an organic light emitting diode 240 formed above the switching element 220, and an organic light emitting diode 240. An upper substrate 251 having an adhesive layer 261 formed on the top of the adhesive layer 261 and a reflection reduction plate 253a and a reflection plate 255a formed on the adhesive layer 261 and facing the organic light emitting diode 240 ).

The second pixel portion B is formed on the lower substrate 201 and is positioned under the organic light emitting diode 240 to provide the organic light emitting diode 240, the reflection reduction plate 253a, and the reflection plate 255a. It further includes a lower color filter 225 facing the ).

A black matrix 257 is formed in a region of the upper substrate 251 of the second pixel portion B except for the reflection reduction plate 253a and the reflection plate 255a.

Here, the switching device 220 includes an active layer 205 formed on the lower substrate 201, a gate insulating layer 207 formed on the channel layer 205c of the active layer 205, and the A gate electrode 209 formed on the gate insulating layer 207 and extending from a gate wiring (not shown), and a first formed on the lower substrate 201 and covering the active layer 205 and the gate electrode 209. 1 The passivation layer 211 and a source electrode (not shown) formed on one side of the active layer 205 on the first passivation layer 211 to be connected to the source area 205a and connected to a data line (not shown). 215, and a second region formed to cover the drain electrode 217 connected to the other region of the active layer 205, that is, the drain region 205b, and the source electrode 215 and the drain electrode 217 It includes a protective film 219.

In addition, a drain contact hole (not shown) exposing a part of the drain electrode 217 is formed in the second passivation layer 219, and the drain electrode ( A pixel electrode 223 connected to 217 is formed.

A first organic insulating layer 227 covering the pixel electrode 223 is formed on the front surface of the second passivation layer 219, and a pixel electrode contact hole exposing the pixel electrode 223 to the first organic insulating layer 227 (Not shown, see 229 in Fig. 6A) is formed.

An auxiliary electrode 231 connected to the pixel electrode 223 through the pixel electrode contact hole is formed on the first organic insulating layer 227, and the auxiliary electrode 231 is formed on the front surface of the first organic insulating layer 227. A second organic insulating layer 233 covering) is formed.

An auxiliary electrode contact hole (not shown, see 235 of FIG. 6C) exposing a part of the auxiliary electrode 231 is formed in the second organic insulating layer 233.

An anode electrode 237 connected to the auxiliary electrode 231 through the auxiliary electrode contact hole 235 is formed on the second organic insulating layer 233.

Meanwhile, the pixel electrode 223, the auxiliary electrode 231, and the second organic insulating layer 233 may not be formed in some cases. That is, the pixel electrode 223, the auxiliary electrode 231, and the second organic insulating layer 233 are omitted, and the anode electrode 237 is connected to the drain electrode 217 through the first organic insulating layer 227. It may be formed to be in direct contact.

The organic light emitting diode 240 includes an anode electrode 237 formed on the second organic insulating layer 233, a cathode electrode 245 formed opposite the anode electrode 237, the anode electrode 237 and a cathode electrode. An organic emission layer 243 formed between the 245 and a pixel definition layer 241 formed at a boundary between the organic emission layers 243 are included.

Here, the anode electrode 237 is connected to the drain electrode 217 of the switching device 220, so when a driving voltage is applied to the anode electrode 237 from the drain electrode 217, the organic light emitting layer 240 is In response to electrons and holes injected through the electrode 237 and the cathode electrode 245, light in a predetermined wavelength region is generated. That is, the emission regions of each of the first and second pixel portions A and B correspond to the organic emission layer 243.

The switching element 220 and the anode electrode 237 are formed to correspond to each of a plurality of pixels including the first and second pixel portions A and B, and the cathode electrode 245 corresponds to the plurality of pixels in common. Can be formed.

As described above, in the double-sided display device according to another embodiment of the present invention, a reflection reduction plate is additionally formed under the reflection plate provided on the upper substrate of the second pixel portion B, which emits rear light, so that the front surface by the reflection plate from the upper substrate. Can reduce reflection.

A method of manufacturing a double-sided display device according to an exemplary embodiment of the present invention will be described with reference to FIGS. 6A to 6L.

6A to 6L are cross-sectional views illustrating a method of manufacturing a double-sided display device according to another exemplary embodiment of the present invention of FIG. 5.

As shown in FIG. 6A, a switching element 220 (TFT) corresponding to each of the plurality of first and second pixel regions is formed on the prepared lower substrate 101.

The step of forming the switching device 220 is performed through the following processes.

First, a buffer insulating layer 203 is formed on the lower substrate 201 using an inorganic insulating material, and then a semiconductor material layer (not shown) made of polycrystalline silicon or an oxide semiconductor is deposited on the entire surface of the buffer insulating layer 203. Then, the active layer 205 is formed by selectively etching the semiconductor material layer through an etching technique.

Then, an inorganic insulating material layer (not shown) and a gate metal layer (not shown) covering the active layer 205 are sequentially stacked on the entire surface of the buffer insulating layer 203, and these layers are selectively etched through an etching technique. Thus, a gate insulating film 207 and a gate electrode 209 are formed on the channel region 205c of the active layer 205.

Subsequently, a first protective layer 211 covering the gate electrode 209, the gate insulating layer 207 and the active layer 205 is formed on the entire surface of the lower substrate 201.

Then, by selectively etching the first passivation layer 211 through an etching technique, contact holes (not shown) exposing each of the source region 205a and the drain region 205b of the active layer 205 are formed. To form.

Then, a source electrode 215 and a drain connected to the source region 205a and the drain region 205b of the active layer 205 through the contact holes (not shown) on the first passivation layer 211, respectively. An electrode 217 is formed.

Then, a second passivation layer 219 is formed on the first passivation layer 211 to cover the active layer 205, the source electrode 215, and the drain electrode 217.

Through these processes, the switching element 220 is formed on the lower substrate 201.

Then, although not shown in the drawing, a drain contact hole (not shown) exposing a portion of the drain electrode 217 is formed by selectively etching the second passivation layer 219 through an etching technique.

Subsequently, a pixel electrode 223 connected to the drain electrode 217 through the drain contact hole (not shown) is formed on the second passivation layer 219.

Then, a lower color filter 225 is formed on the second passivation layer 219 of the second pixel portion B adjacent to the pixel electrode 223.

Subsequently, after depositing a first organic insulating layer 227 covering the pixel electrode 223 on the entire surface of the second passivation layer 219, the first organic insulating layer 227 is selectively etched through an etching technique to form the pixel. A pixel electrode contact hole 229 exposing a portion of the electrode 223 is formed.

Then, as shown in FIG. 6B, after depositing a conductive layer for an auxiliary electrode (not shown) on the first organic insulating layer 227, the conductive layer for the auxiliary electrode (not shown) is formed through an etching technique. By selectively etching, an auxiliary electrode 231 connected to the pixel electrode 223 through the pixel electrode contact hole 229 is formed.

Subsequently, as shown in FIG. 6C, after depositing a second organic insulating layer 233 covering the auxiliary electrode 231 on the entire surface of the first organic insulating layer 227, the second organic insulating layer ( By selectively etching the 233, an auxiliary electrode contact hole 235 exposing a portion of the auxiliary electrode 231 is formed.

Then, as shown in FIG. 6D, after depositing a transparent conductive material layer (not shown) on the entire surface of the second organic insulating layer 233, the transparent conductive material layer (not shown) is selectively selected through an etching technique. By etching to form an anode electrode 237 corresponding to each of the first and second pixel portions A and B. In this case, since the plurality of first pixel portions A do not emit light through the optical path including the lower substrate 201, the anode electrode 237 may be disposed at a position overlapping the switching element 220. However, since the plurality of second pixel portions B emit light through an optical path including the lower substrate 201, the anode electrode 237 is disposed at a position overlapping the lower color filter 225.

Accordingly, the anode electrode 237 is connected to the drain electrode 217 of the switching device 220 through the auxiliary electrode 231 and the pixel electrode 223, so that each pixel portion A , A driving signal corresponding to B) is selectively supplied.

Subsequently, as shown in FIG. 6E, a pixel defining layer 241 corresponding to an outer periphery of each of the plurality of first and second pixel portions A and B is formed on the second organic insulating layer 233. . In this case, the pixel defining layer 241 may be formed to overlap at least a portion of the anode electrode 237 at the edges of each of the first and second pixel portions A and B.

Then, as shown in FIG. 6F, on the anode electrode 237 including the pixel defining layer 241, an organic emission layer 243 corresponding to each of the plurality of first and second pixel portions A and B is formed. ) To form. In this case, the organic light-emitting layer 243 may be formed of any self-luminous material such as a light-emitting organic material.

Subsequently, as shown in FIG. 6G, on the pixel defining layer 241 including the organic emission layer 243 of the plurality of first and second pixel portions A and B, the cathode electrode 245 is made of a transparent conductive material. To form. At this time, the cathode electrode 245 is formed to be interconnected to each of the plurality of first and second pixel portions A and B. That is, the cathode electrodes 245 of each of the plurality of first and second pixel portions A and B are integrally formed.

Accordingly, the anode electrode 237 and the cathode electrode 245 of each of the plurality of first and second pixel portions A and B, and the organic light emitting layer 243 between the electrodes 237 and 245 are organic light emitting diodes. Form 240.

Then, as shown in FIG. 6H, a reflection reduction material layer 253 and a reflective material layer having high reflectivity to reduce front reflection by the reflector on the upper substrate 251 that is bonded to the lower substrate 201 Laminate (255). At this time, as the reflection reducing material layer 253, a transparent conductive material such as molybdenum (Mo), Indium-Tin-Oxide (ITO), and Indium-Zinc-Oxide (IZO), or an alloy thereof is used. In addition, as the reflective material layer 255, silver alloy, aluminum (Al), molybdenum (Mo), or molybdenum titanium (MoTi) is used.

Subsequently, as shown in FIG. 6I, the reflection reduction layer 253 and the reflective material layer 255 are selectively etched through an etching technique, and the plurality of second pixel portions (B) regions of the upper substrate 251 are selectively etched. A reflection reduction plate 253a and a reflection plate 255a are formed in the. At this time, when the upper substrate 251 faces and bonds to the lower substrate 201, the reflection reduction plate 253a and the reflection plate 255a overlap the organic emission layer 240 and the lower color filter 225. In addition, the reflection reduction plate 253a and the reflection plate 255a may serve as an alignment key when fabricating a reverse type black matrix structure.

Then, a black matrix film (not shown) covering the reflection reduction plate 253a and the reflection plate 255a is applied on the front surface of the upper substrate 251. At this time, the black matrix film (not shown) may be made of chromium (Cr) or black resin.

Subsequently, the black matrix layer (not shown) is blocked with a mask (not shown) in which a non-transmissive region for light is selectively formed.

Then, the black matrix layer (not shown) is irradiated with ultraviolet rays, and then the black matrix layer (not shown) to which the ultraviolet rays are irradiated is developed to form a black matrix 257 as shown in FIG. 6J. At this time, since the region not irradiated with ultraviolet rays is removed by the developer, the black matrix 257 is formed in the region irradiated with ultraviolet rays. In addition, the black matrix 257 is formed on the outer edges of the plurality of first and second pixel portions A and B. That is, the black matrix 257 overlaps the organic emission layer 240 and the reflection reduction plate 253a, the reflection plate 255a, and the lower color filter 225 of the plurality of first and second pixel portions A and B. It is placed in a position that does not work.

In addition, a portion of the black matrix 257 positioned in the plurality of second pixel portions B may cover edge portions of the reflection reduction plate 253a and the reflection plate 255a.

Subsequently, as shown in FIG. 6K, after applying a color pigment covering the reflective plate 255a and the black matrix 257 on the front surface of the upper substrate 251, the upper substrate 251 is selectively etched through an etching technique. An upper color filter 259 is formed in the first pixel portion A of ), that is, in a region between the black matrix 257. In this case, a part of the upper color filter 259 may cover a part of the black matrix 257.

Next, as shown in FIG. 6L, by forming and bonding an adhesive layer 261 between the upper substrate 251 and the lower substrate 201, the double-sided light emitting display device 200 according to another embodiment of the present invention is Complete the manufacturing process. At this time, the upper color filters 259 of the plurality of first pixel portions A are disposed to overlap with the organic light emitting diode 240 on the upper side of the lower substrate 201, and reflection of the plurality of second pixel portions B is reduced. The plate 253a and the reflective plate 255a are disposed to overlap the organic light emitting diode 240 and the lower color filter 225 on the upper side of the lower substrate 201.

In this way, the light emitted from the organic light-emitting diodes 240 disposed in the plurality of first pixel portions A passes through the upper color filter 259 to emit full light, and the light is transmitted to the plurality of second pixel portions B. The light emitted from the arranged organic light emitting diode 240 passes through the lower color filter 225 to emit light on the rear surface, thereby implementing a double-sided light-emitting display. At this time, a part of the light emitted from the organic light emitting diode 240 of the second pixel portion B is reflected through the reflecting plate 255a formed on the upper substrate 251 of the second pixel portion B, and the lower color It passes through the filter 225 and emits light at the rear.

In addition, since the reflection reduction plate 253a is formed on the reflection plate 255a, front reflection by the reflection plate 255a can be reduced.

Accordingly, the present invention reflects light emitted from the organic light emitting diode toward the upper side through the reflective plate in the second pixel (B) region to emit light from the bottom side toward the lower substrate, thereby improving the efficiency of the light emitted toward the rear side. , As the reflection reduction plate is formed on the reflection plate, it is possible to reduce front reflection by the reflection plate from the upper substrate.

In addition, in the present invention, since the reflector is first formed before the black matrix is formed in the pixel portion emitting the backlight, the reflector can be used as an alignment key when the black matrix is manufactured.

The embodiments have been described above with reference to the drawings, but the present invention is not limited thereto.

The terms such as "include", "consist of" or "have" described above mean that the corresponding component may be embedded, unless otherwise specified, and thus other components are not excluded. It should be interpreted as being able to further include other components. All terms, including technical or scientific terms, unless otherwise defined, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms generally used, such as terms defined in the dictionary, should be interpreted as being consistent with the meaning of the context of the related technology, and are not interpreted as ideal or excessively formal meanings unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: double-sided light emitting display device 137: anode electrode
140: organic light emitting diode 143: organic light emitting layer
145: cathode electrode 153, 255a: reflector
155: black matrix 253a: reflection reduction plate
A: first pixel portion B: second pixel portion

Claims (8)

In the double-sided display device comprising a plurality of first pixel portions emitting light in one direction, and a plurality of second pixel portions emitting light in another direction opposite to one direction
Each of the plurality of first and second pixel units,
A lower substrate and an upper substrate bonded to each other to face each other;
A switching element provided on the upper side of the lower substrate;
A lower color filter disposed above the lower substrate disposed in the second pixel portion and adjacent to the switching element;
An organic light emitting diode disposed above the switching device and emitting light based on a driving voltage selectively applied from the switching device;
A reflector on the upper substrate corresponding to the organic light emitting diode of the second pixel unit;
A black matrix disposed on an outer portion of the first and second pixel portions of the upper substrate; And
And an upper color filter disposed on an upper substrate corresponding to the organic light emitting diode of the first pixel unit. The double-sided display device according to claim 1, wherein the reflective plate overlaps the organic light emitting diode of the second pixel portion and the lower color filter. The double-sided display device according to claim 1, wherein a reflection reduction plate is interposed between the reflection plate and the upper substrate. In a method of manufacturing a double-sided display device comprising a plurality of first pixel units that emit light in one direction and a plurality of second pixel units that emit light in another direction opposite to one direction,
Forming switching elements of each of the plurality of first and second pixel units on the upper side of the lower substrate;
Forming a lower color filter adjacent to the switching element on a lower substrate of the second pixel;
Forming an organic light-emitting diode of each of the plurality of first and second pixel units on the upper side of the switching element of the lower substrate;
Forming a reflective plate on an upper side of an upper substrate facing the organic light emitting diode of the second pixel portion;
Forming a black matrix for shielding light above the first and second pixel portions of the upper substrate;
Forming an upper color filter on the upper side of the first pixel portion of the upper substrate; And
And forming and bonding an adhesive layer between the lower substrate and the upper substrate. 5. The method of claim 4, further comprising forming a reflection reduction plate between the upper substrate and the reflection plate. 6. The method of claim 5, wherein the reflection plate and the reflection reduction plate are formed at the same time. The method of claim 5, wherein the reflection reduction plate is formed of any one of a transparent conductive material including molybdenum (Mo), ITO (Indium-Tin-Oxide), and IZO (Indium-Zinc-Oxide), or an alloy thereof. Method of manufacturing a double-sided display device. The method of claim 4, wherein the reflector is made of any one of silver alloy, aluminum (Al), molybdenum (Mo), and molybdenum titanium (MoTi).

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