Transparent display device having a minimized bezel

This application claims the priority of Korean Patent Application No. 10-2013-0160755 filed on Dec. 20, 2013 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

The present disclosure relates to a transparent display device and a transparent organic light-emitting display device with reduced width and thickness of their bezels.

An organic light-emitting display (OLED) device is capable of emitting light and thus does not require an additional light source, unlike a liquid crystal display (LCD). Therefore, an OLED device can be made lighter and thinner than a LCD device. Further, an OLED device has advantages in that it consumes less power, realizes better colors and has good response speed, view angle and contrast ratio (CR) than a LCD device. For at least these reasons, an OLED device is considered as the next generation display.

A “transparent display device” means that a viewer can see a background through the display along with images displayed thereon. The pixel area of a transparent OLED device can be divided into a light-emitting area in which organic light-emitting elements emit lights to display images, and a transparent area through which external light passes. Transparency of the transparent OLED device is obtained by the transparent area

Typically, the substrate of a display device comprises a display area and non-display area. Opaque elements such as a battery and a plurality of circuit boards are disposed under the display area of the substrate. Therefore, even when the display area is transparent, it is difficult to make the display device transparent. In order to achieve a transparent display device under the given condition, it can be conceived to place opaque elements on one side of the display device all together, or to divide them into two parts to place one on either side of the display device.

When two circuit boards are separately placed on two sides of the transparent display device, the elements on one circuit board are electrically connected to the elements on the other circuit board via an additional interconnection film, which is a separate element from a substrate. When the additional interconnection film is disposed on the side portions of the substrate, the bezel size of the transparent display device is increased. Also, the thickness of the interconnection film can increase the thickness of the transparent display device. In addition, when a printing process is used to manufacture the interconnection film, it is difficult to form the lines of the interconnection film in a multi-layered structure. Because the lines are spread apart, the width of the interconnection film is increased proportional to the width and/or number of the lines. This can increase the width of the bezel of the transparent display device even further. In view of this, a novel transparent display device and a transparent OLED device with reduced width and thickness of their bezels is described herein.

An object of the present disclosure is to provide a transparent OLED device with reduced width of its bezel by utilizing existing lines formed on a substrate of the transparent OLED device, without an additional interconnection film for electrically connecting elements disposed on separate circuit boards.

Another object of the present disclosure is to provide a transparent display device and a transparent OLED device with reduced width of their bezels by connecting elements disposed on one side of the transparent display device to elements on another side via lines directly formed on a substrate of the transparent display device, instead of a separate interconnection film.

Yet another object of the present disclosure is to provide a transparent display device and a transparent OLED device in which lines for connecting elements on two separate circuit boards are provided on the transparent substrate to reduce the size of the bezel without undesired noise between the lines.

The objects of the disclosure are not limited to the aforementioned objects, and other objects, which are not mentioned above, will be apparent to those skilled in the art from the following description.

According to an aspect of the present disclosure, there is provided a novel transparent organic light-emitting display device. The transparent substrate includes a display area and non-display area adjacent to the display area. An organic light-emitting element is disposed on the display area of the transparent substrate. A first power line is disposed on the display area of the transparent substrate. The first power line supplies power to the organic light-emitting element. A first circuit board comprises a first power supply provided on a first side of the transparent substrate and a second circuit board comprises a second power supply provided on a second side of the transparent substrate. The first power supply is configured to receive power from the second power supply via the first power line.

No additional interconnection film to supply power to the first power supply is required, and thus the width of the bezel can be reduced.

According to another aspect of the present disclosure, there is provided a novel transparent display device. The transparent display device includes a transparent substrate having a display area and a non-display area disposed on the periphery of the display area. A first substrate and a second substrate are respectively connected to a different side of the transparent substrate. A plurality of connecting lines is disposed on the non-display area of the transparent substrate. The plurality of connecting lines electrically connects a first element on the first substrate and a second element on the second substrate. By forming the plurality of connecting lines on the non-display area of the transparent substrate, the width of its bezel can be reduced, compared to when an additional interconnection film is employed.

The detailed aspects of other embodiments are included in the detailed specification and drawings.

The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1A is a simplified plan view of a transparent OLED device according to an exemplary embodiment of the present disclosure;

FIG. 1B is an enlarged view of a portion of the display area and the non-display area of a transparent substrate in the transparent OLED device according to an exemplary embodiment of the present disclosure;

FIG. 1C is a cross-sectional view of the transparent OLED device, taken along line Ic-Ic′ of FIG. 1B ;

FIG. 1D is a cross-sectional view of the transparent OLED device, taken along line Id-Id′ of FIG. 1B ;

FIG. 2A is a simplified plan view for illustrating lines of a transparent display device according to an exemplary embodiment of the present disclosure; and

FIG. 2B is a cross-sectional view of the transparent display device, taken along line IIb-IIb′ of FIG. 2A .

Various advantages and features of the present invention and methods accomplishing thereof will become apparent from the following description of embodiments with reference to the accompanying drawings. However, the present invention is not limited to exemplary embodiment disclosed herein but will be implemented in various forms. The exemplary embodiments are provided by way of example only so that a person of ordinary skilled in the art can fully understand the disclosures of the present invention and the scope of the present invention. Therefore, the present invention will be defined only by the scope of the appended claims.

Indicating that elements or layers are “on” other elements or layers include both a case in which the corresponding elements are just above other elements and a case in which the corresponding elements are intervened with other layers or elements.

Although first, second, and the like are used in order to describe various components, the components are not limited by the terms. The above terms are used only to discriminate one component from the other component. Therefore, a first component mentioned below maybe a second component within the technical spirit of the present invention.

The same reference numerals indicate the same elements throughout the specification.

In the drawings, size and thickness of each element are arbitrarily illustrated for convenience of description, and the present invention is not necessarily limited to those illustrated in the drawings.

In the present specification, “transparent” or “transparency” means a transparent property and enabling a visible ray to pass through. In addition, it means that the entire incident light is not absorbed, and at least a part of the light is penetrated. Therefore, in a case where the element is transparent or has transparency, a viewer can recognize color, contrast, or the like of the things behind the element.

In a transparent display device, a bezel refers to the frame portion of the transparent display device where images are not displayed when a viewer watches images from the transparent display device. The non-display area NDA of the transparent substrate 110 A corresponds to a portion of the bezel of the transparent OLED device 100 A.

The components of various embodiments of the present disclosure can be partially or entirely bonded to or combined with each other and can be interlocked and operated in technically various ways as can be fully understood by an ordinary person skilled in the art, and the embodiments can be carried out independently of or in association with each other.

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

FIG. 1A is a simplified plan view of a transparent OLED device according to an exemplary embodiment of the present disclosure. Referring to FIG. 1A , a transparent OLED device 100 A includes a transparent substrate 110 A, connecting substrates 115 Aa and 115 Ab, a first circuit board 120 A, a second circuit board 130 A, and a battery 170 A. Further, on the transparent substrate 110 A, a first power line 140 A, a plurality of connecting lines 150 A, and a second power line 160 A are formed.

The transparent substrate 110 A supports a variety of elements in the transparent OLED device 100 A and is made of a transparent material. The transparent substrate 110 A includes a display area DA and a non-display area NDA adjacent to the display area DA. The display area DA is where images are displayed. Although not illustrated in FIG. 1A , organic light-emitting elements and thin-film transistors are formed on the display area DA. The non-display area is where no image is displayed.

The connecting substrate 115 Aa is disposed on a side of the transparent substrate 110 A to connect the transparent substrate 110 A to the first circuit board 120 A. The connecting substrate 115 Ab is disposed on another side of the transparent substrate 110 A to connect the transparent substrate 110 A to the second circuit board 130 A. The connecting substrate 115 Aa and 115 Ab may be flexible printed circuit boards made of flexible materials.

The first circuit board 120 A is connected to the transparent substrate 110 A via the connecting substrate 115 Aa disposed on the side of the transparent substrate 110 A. On the first circuit board 120 A, a processor 124 A and a first power supply 122 A are disposed.

The second circuit board 130 A is connected to the transparent substrate 110 A via the connecting substrate 115 Ab disposed on the other side of the transparent substrate 110 A. On the second circuit board 130 A, a universal serial bus (USB) unit 134 A, a second power supply 132 A, a microphone and speaker 136 A are disposed.

The USB unit 134 A includes a USB socket and a charge circuit. The USB unit 134 A charges the battery 170 A via the charge circuit when a charging cable is connected to the USB socket. When an external device, such as a data cable, capable of transmitting and receiving data signals is connected to the USB socket, the USB unit 134 A transmits/receives data signals to/from the processor 124 A.

The microphone and speaker 136 A include a microphone to receive sound and a speaker to output sound and transmits/receives sound signals to/from the processor 124 A.

The first circuit board 120 A and the second circuit board 130 A may be printed circuit boards.

On the transparent substrate 110 A, the first power line 140 A, the second power line 160 A and the plurality of connecting lines 150 A are formed. FIG. 1A illustrates the connective relationships among the elements. In FIG. 1A , the first power line 140 A, the second power line 160 A and the plurality of connecting lines 150 A are drawn as if they were formed across the transparent substrate 110 A, the first circuit board 120 A, the second circuit board 130 A, and the connecting substrate 115 Aa and 115 Ab. However, it should be appreciated that FIG. 1A merely illustrates the electrical connection between them. That is to say, the first power line 140 A, the second power line 160 A and the plurality of connecting lines 150 A merely refer to lines formed on the transparent substrate 110 A. Interconnection between the first power line 140 A, the second power line 160 A and the plurality of connecting lines 150 A to the elements disposed on the first circuit board 120 A and/or the second circuit board 130 A may be provided via other lines or connection interfaces formed on the connecting substrates 115 Aa and 115 Ab.

The first power line 140 A is formed on the display area DA of the transparent substrate 110 A to drive an organic light-emitting element in the display area DA. That is, the first power line 140 A supplies power to the organic light-emitting elements. In addition to driving the organic light-emitting elements, the first power line 140 A also serves as the line for delivering power to the first power supply 122 A so that the first power supply 122 A can provide power to the processor 124 A.

The power on the first power line 140 A is supplied from the battery 170 A via the second power supply 132 A. In other words, the second power supply 132 A receives power from the battery 170 A and provides the power to the organic light-emitting elements of the display area DA as well as to the first power supply 122 A through the first power line 140 A. The first power line 140 A may be a VDD line of the transparent OLED device 100 A.

The first power supply 122 A and the second power supply 132 A receive power from the external power source (e.g., battery 170 A) in the form of voltage at a specific level and transform the received voltage into a voltage of a level as required by the elements connected thereto. Specifically, the second power supply 132 A transforms the voltage supplied from the battery 170 A into a drive voltage for the organic light-emitting elements arranged on the display area DA, which is supplied to the organic light-emitting elements via the first power line 140 A. The first power supply 122 A and the second power supply 132 A are electrically connected by the first power line 140 A, and thus the first power supply 122 A receives the same drive voltage supplied to the organic light-emitting elements. The first power supply 122 A transforms the received voltage into a voltage required by the processor 124 A. For example, the second power supply 132 A may receive a first voltage (e.g., 3.8 V) from the battery 170 A, and the second power supply 132 A may supply a second voltage (e.g., 10 V) to the organic light-emitting elements in the display area DA and to the first power supply 122 A via the first power line 140 A. The first power supply 122 A transforms the second voltage into a third voltage (e.g., 1.8 V), which is provided to an element connected to the first power supply 122 A (e.g., the processor 124 A).

The second power line 160 A is formed on the non-display area NDA. Like the first power line 140 A, the second power line 160 A is also used to drive the organic light-emitting elements. In particular, the second power line 160 A connects the first power supply 122 A to the second power supply 132 A and is referenced to the ground potential GND. The second power line 160 A may be a VSS line of the transparent OLED device 100 A.

According to the exemplary embodiment of the present disclosure, the first power line 140 A formed on the display area DA of the transparent substrate 110 A and the second power line 160 A formed on the non-display area NDA of the transparent substrate 110 A connect the first power supply 122 A and the second power supply 132 A to supply power from the second power supply 132 A to the first power supply 122 A. As mentioned above, the first power line 140 A and the second power line 160 A also serve as the power lines for driving the organic light-emitting elements arranged on the display area DA. In this configuration, no additional interconnection film is required on a side of the substrate to provide connection between the first power supply 122 A and the second power supply 132 A. Therefore, the width of the bezel of the transparent OLED device 100 A can be reduced. By eliminating the needs for the separate interconnection film, the thickness of the transparent OLED device 100 A can be decreased.

The plurality of connecting lines 150 A formed on the non-display area NDA of the transparent substrate 110 A electrically connects the first circuit board 120 A to the second circuit board 130 A. That is, the plurality of connecting lines 150 A formed on the non-display area NDA of the transparent substrate 110 A electrically connects the elements disposed on the first circuit board 120 A to the elements disposed on the second circuit board 130 A. As illustrated in FIG. 1A , the plurality of connecting lines 150 A electrically connects the processor 124 A disposed on the first circuit board 120 A to the USB unit 134 A and to the microphone and speaker 136 A disposed on the second circuit board 130 A.

The processor 124 A disposed on the first circuit board 120 A is configured to receive power from the first power supply 122 A. In operation, the processor 124 A on the first circuit board 120 A transmits/receives data signals and/or other detection signals to and from the elements disposed on the second circuit board 130 A via the plurality of connecting lines 150 A. Using the signals on the plurality of connecting lines 150 A, the processor 124 A can carry out various functionalities such as recognizing and checking status of external devices connected to the USB unit 134 A. When an external device capable of transmitting and receiving data signals is connected to the USB socket, the USB unit 134 A may transmit/receive data signals to and from the processor 124 A via the plurality of connecting lines 150 A. Likewise, the processor 124 A may communicate with the microphone and speaker 136 A via the plurality of connecting lines 150 A.

It should be noted that the plurality of connecting lines 150 A are not associated with driving the thin-film transistors or the organic light-emitting elements on the display area DA. Instead, the plurality of connecting lines 150 A are formed on the non-display area NDA of the transparent substrate 110 A for the communication between the elements on two separate circuit boards 120 A and 130 A without the additional interconnection film.

According to the exemplary embodiment of the present disclosure, however, additional interconnection film to connect between elements formed on two sides of the transparent OLED device 100 A is not required. Although the width of the bezel of the transparent OLED device 100 A is increased by the width of the plurality of connecting lines 150 A formed on the non-display area NDA of the transparent substrate 110 A, the increase in the bezel size by the plurality of connecting lines 150 A is smaller than the increase in the bezel size by using an additional interconnection film. For example, the overall width of the plurality of connecting lines 150 A may be approximately 1,500 μm or less, and the width of an additional interconnection film may be approximately 2.5 mm. As illustrated by this example, the width of the bezel of the transparent OLED device 100 A can be reduced by using the connecting lines 150 A. Moreover, decrease in the thickness of the transparent OLED device 100 A may also be achieved by eliminating the additional interconnection film.

Referring to FIG. 1A , the plurality of connecting lines 150 A are disposed between the second power line 160 A formed on the non-display area NDA, and the display area DA. As mentioned, the second power line 160 A is referenced to the ground potential. Thus, by placing the plurality of connecting lines 150 A on an inner side (i.e., closer to the display area DA) than the second power line 160 A, the second power line 160 A can shield the plurality of connecting lines 150 A from possible electrical noises. Such noises may cause interference between the signals or may distort the signals on the plurality of connecting lines 150 A. Accordingly, distorted signals may be transmitted to the processor 124 A thereby generating errors. According to an exemplary embodiment of the present disclosure, the plurality of connecting lines 150 A are located between the second power line 160 A and the display area DA. By doing so, the transparent OLED device 100 A can reduce influence of noise from outside the device 100 A on signals flowing in the plurality of connecting lines 150 A. If noise from the external environment is negligible, however, the plurality of connecting line 150 A may be located on the outer side than the second power line 160 A.

The battery 170 A supplies power to a variety of elements via the second power supply 132 A. When a charging cable is connected to the USB socket of the USB unit 134 A, a charge circuit, which may be a part of the USB unit 134 A, can charge the battery 170 A.

Although the first circuit board 120 A and the second circuit board 130 A illustrated in FIG. 1A are positioned on opposing sides of the transparent substrate 110 A, it is merely illustrative. In an alternative embodiment of the transparent OLED device 100 A, the first circuit board 120 A and the second circuit board 130 A may be located on one side and any other side of the transparent OLED device 100 A than shown in FIG. 1A .

It should be noted that the elements disposed on the first and the second circuit boards are not particularly limited as depicted in FIG. 1A . Although the microphone and the speaker are illustrated as being disposed together in the microphone and speaker 136 A on the second circuit board 130 A in FIG. 1A , in some other embodiments, they can be disposed separately, one on the first circuit board 120 A and the other on the second circuit board 130 A.

In addition to the microphone and the speaker 136 A illustrated in FIG. 1A , various types of sensors and camera modules can be disposed in the transparent OLED device 100 A. Various types of sensors may include, for example, an illuminance sensor, an acceleration sensor, a proximity sensor, a gyroscope sensor, a magnetic sensor, and a temperature sensor. Similar to the microphone and speaker 136 A, any of the aforementioned additional components disposed on the second circuit board 130 A may communicate with the processor 124 A on the first circuit board 120 A via the plurality of connecting lines 150 A. The number and thickness of the plurality of connecting lines 150 A may be modified depending on the number and the type of the various types of sensors and camera modules connected thereto, and on the voltage level of signals flowing therein.

The transparent OLED device 100 A may further include a memory (for example, a RAM), a communication module or the like. The size of the first circuit board 120 A may be larger than the size of the second circuit board 130 A to provide sufficient room for the elements disposed on the first circuit board 120 A. In some embodiments, such components may be disposed on the same circuit board on which the processor 124 A and the first power supply 122 A are disposed. Some of the components may need to be positioned closer to processor 124 A than others to reduce undesirable noises. As such, such components, for instance the memory, may be disposed as close to the processor 124 A. The first power supply 122 A may supply power of approximately 2.5 V to the memory.

In FIG. 1A , for the convenience of illustration, the transparent OLED device 100 A receives power from the battery 170 A. However, in case of a large, transparent OLED device such as a large-scale television, the transparent OLED device 100 A may be directly connected to an external power source without the battery 170 A or the USB unit 134 A.

In FIG. 1A , the first power line 140 A is formed on the display area DA of the transparent substrate 110 A while the second power line 160 A is formed on the non-display area NDA. However, it should be appreciated that a part of the first power line 140 A may be formed on the non-display area NDA, and a part of the second power line 160 A may be formed on the display area DA.

In some embodiments of the transparent OLED device 100 A, the second power line 160 A is not referenced to the GND but may be supplied with a voltage lower than a voltage loaded on the first power line 140 A for operating the organic light-emitting elements arranged on the display area DA. In this case, an additional ground potential line may be provided on the transparent substrate 110 A and connected to the first power supply 122 A and the second power supply 132 A.

FIG. 1B is an enlarged view of a portion of a display area DA and a non-display area NDA of transparent substrate 110 A in a transparent OLED device 100 A according to an exemplary embodiment of the present disclosure. FIG. 1C is a cross-sectional view of the transparent OLED device, taken along line Ic-Ic′ of FIG. 1B . FIG. 1D is a cross-sectional view of the transparent OLED device, taken along line Id-Id′ of FIG. 1B . Referring to FIG. 1B , a transparent substrate 110 A includes a display area DA and non-display area NDA. On the non-display area NDA, a first power line 140 A, a plurality of connecting lines 150 A (e.g., 150 Aa, 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag, 150 Ah), a second power line 160 A and a pad unit 180 A are formed.

The first power line 140 A, the plurality of connecting lines 150 A and the second power line 160 A are connected to the pad unit 180 A formed on the non-display area NDA of the transparent substrate 110 A. The pad unit 180 A serves to electrically connect the lines on the transparent substrate 110 A to the lines on the connecting substrate 115 Aa or 115 Ab illustrated in FIG. 1A and/or the circuit board 120 A or 130 A. The pad unit 180 A is made of a conductive material. In FIG. 1B , the symbols of lines connected to the pad unit 180 A are illustrated on the pad unit 180 A.

Referring to FIGS. 1B, 1C and 1D , the plurality of connecting lines 150 A includes a plurality of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah, and a detection signal line 150 Aa. The plurality of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah serve to connect various elements to a processor.

A USB_ID line 150 Ab recognizes whether a USB device is connected to the USB unit 134 A. Also, the USB_ID line 150 Ab may be referenced to a floating potential or to the ground potential depending on whether a USB device is connected. A USB DP line 150 Ac and a USB DN 150 Ad in pair transmit/receive data to/from the processor. A SPK_N line 150 Ae and a SPK_P 150 Af in pair transmit/receive a speaker output signal to/from the processor 124 A. A MIC_N line 150 Ag and a MIC_P 150 Ah in pair transmit/receive a microphone input signal to/from the processor 124 A.

The detection signal line 150 Aa, which is a USB_VBUS line, is connected to the processor 124 A and may be supplied with a voltage or a current higher than voltages or currents supplied to the plurality of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag, 150 Ah. For example, the detection signal line 150 Aa may be supplied with, but is not limited to, a voltage of approximately 5 V, or a current of approximately 500 mA. Further, the detection signal line 150 Aa may allow the processor 124 A to recognize whether charging is being carried out.

Referring to FIG. 1C , a thin-film transistor and an organic light-emitting element on the display area DA of the transparent substrate 110 A are illustrated.

A buffer layer 181 A is formed on the transparent substrate 110 A. On the buffer layer 181 A, a coplanar thin-film transistor is formed that includes an active layer 182 A, a gate electrode 184 A, a source electrode 186 A and a drain electrode 187 A. The source electrode 186 A and the drain electrode 187 A are connected to the active layer 182 A via contact holes formed in a gate insulation layer 183 A and in an inter-layer insulation layer 185 A. Although a coplanar thin-film transistor is illustrated in FIG. 1C , the type of the thin-film transistor is not limited thereto but the thin-film transistor may be formed in other structures. Further, although the gate insulation layer 183 A is formed over the surface of the transparent substrate 110 A in FIG. 1C , the gate insulation layer 183 A may be formed only on the active layer 182 A.

On the thin-film transistor, an over coat layer 188 A to flatten the portion over the thin-film transistor is formed. On the over coat layer 188 A, an anode 192 A, an organic light-emitting layer 194 A and a cathode 195 A are formed to implement an organic light-emitting element. A reflective layer 191 A may be formed under the anode 192 A, which may be in contact with the source electrode 186 A via a contact hole in the over coat layer 188 A. A bank 193 A is formed on the edge portion of the anode 192 A that separates adjacent pixels. An encapsulation layer 196 A for protecting the organic light-emitting element is formed over the cathode 195 A. 100 A of a top emission type is illustrated in which light from the organic light-emitting layer 194 A passes through the cathode 195 A. However, an OLED device 100 A of a bottom emission type maybe used in which light from the organic light-emitting layer 194 A passes through the anode 192 A. Even in the bottom emission type, the reflective layer 191 A may also be used if desired. In addition, although the anode 192 A is connected to the source electrode 186 A in FIG. 1C , the anode 192 A may be connected to the drain electrode 187 A depending on the type of the thin-film transistor.

The plurality of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah maybe formed on a same layer and spaced apart from one another. Alternatively, some of the plurality of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah may be formed on two or more of different layers without being overlapped by one another. For instance, the SPK_N line 150 Ae and the MIC_N line 150 Ag can be formed on the inter-layer insulation layer 185 A, and the SPK_P line 150 Af and the MIC_P line 150 Ah may be formed on the gate insulation layer 183 A as shown in FIG. 1C . The lines on each of the insulation layers are spaced apart from other lines on the respective insulation layer. Also, the SPK_N line 150 Ae and the MIC_N line 150 Ag on the inter-layer insulation layer 185 A do not overlap with the SPK_P line 150 Af and the MIC_P line 150 Ah on the gate insulation layer 183 A.

The plurality of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah serve to connect various elements to a processor in order to transmit/receive signals. The width of each of the signal lines may be equal to or less than 100 μm. Although the signal lines 150 Ae, 150 Ag, 150 Af and 150 Ah have the same width W 1 in FIG. 1 , it is merely illustrative. The width of each of the signal lines may be differently designed based on the voltage level of signals and/or the type of signals to be transmitted on the signal line.

Signals flowing in the plurality of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah have low voltage levels and thus are sensitive to noise. Accordingly, interference among the signals may occur. Therefore, the signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah should be spaced apart from one another by a predetermined distance. For example, the distance between signal lines may be approximately 4 μm or more. However, the distance is not limited thereto but may be modified in view of the voltage levels of signals flowing in the signal lines, for example.

On the outer side of the connecting lines 150 A, the second power line 160 A is formed so as to shield the connecting lines 150 A from the noise generated the outside of the transparent OLED device 100 A.

The signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah are formed on the non-display area NDA of the transparent substrate 110 A so as to connect various elements to the processor. Therefore, an additional interconnection film to connect the elements formed on both sides of the transparent OLED device 100 A is not required, thereby reducing the width of bezel of the transparent OLED device 100 A.

The plurality of connecting lines 150 A may include the detection signal line 150 Aa in addition to the plurality of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah. The detection signal line 150 Aa and some of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah may be formed on two or more different layers. In this case, a part of the detection signal line 150 Aa may be arranged to overlap some of the signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah disposed on the different layer as depicted in the embodiment of FIG. 1D . In one embodiment shown in FIG. 1D , signal lines 150 Ab, 150 Ac and 150 Ad are formed on the gate insulation layer 183 A spaced part from one another while the detection signal line 150 Aa is formed on the inter-layer insulation layer 185 A. Here, the detection signal line 150 Aa overlaps with the signal lines 150 Ab, 150 Ac and 150 Ad.

In FIG. 1D , the detection signal line 150 Aa overlaps all of signal lines 150 Ab, 150 Ac and 150 Ad. However, the signal lines 150 Ab, 150 Ac and 150 Ad may be partially overlapped by the detection signal line 150 Aa. Further, in FIG. 1D , the signal lines 150 Ab, 150 Ac and 150 Ad are formed on a same layer and spaced apart from one another. However, they may be formed on two or more different layers such that they do not overlap one another.

Signals applied to the detection signal line 150 Aa may have a higher voltage level than signals applied to the plurality of signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah. Therefore, the width W 2 of the detection signal line 150 Aa may be larger than each width of the signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah so that the detection signal line 150 Aa has lower resistance. For example, the width W 2 of the detection signal line 150 Aa may be 1,000 μm or less.

The detection signal line 150 Aa may be a line provided for the processor to check whether charging is being carried out (e.g., USB_VBUS line). Since a constant level of voltage is applied to the detection signal line 150 Aa, it can be arranged to overlap the signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah without significant increase in noise between the lines. In this arrangement, the area occupied by the plurality of connecting lines 150 A on the non-display area NDA of the transparent substrate 110 A can be reduced as compared to the configuration where the detection signal line 150 Aa does not overlap of the signal lines 150 Ab, 150 Ac, 150 Ad, 150 Ae, 150 Af, 150 Ag and 150 Ah. Accordingly, the width of the bezel of the transparent OLED device 100 A can be further reduced.

Some of the plurality of connecting lines 150 A are made of the same material as the material for the gate electrode 184 A of the thin-film transistor formed on the display area DA of the transparent substrate 110 A. The others plurality of connecting lines 150 A are made of the same material as the material for the source electrode 186 A and the drain electrode 187 A of the thin-film transistor. As illustrated in FIG. 1C , the SPK_P line 150 Af and the MIC_P 150 Ah are made of the same material as the material for the gate electrode 184 A of the thin-film transistor. The SPK_N line 150 Ae and the MIC_N line 150 Ag are made of the same material as the material for the source electrode 186 A and the drain electrode 187 A. In addition, as illustrated in FIG. 1D , the USB_ID line 150 Ab, the USB DP line 150 Ac and USB DN line 150 Ad are made of the same material as the material for the gate electrode 184 A of the thin-film transistor. The detection signal line 150 Aa, which is a USB_VBUS line for example, is made of the same material as the material for the source electrode 186 A and the drain electrode 187 A. As used herein, the expression that two elements are made of the same material means that one element includes a layer made of the same material as the material for the other element, and that one element is produced together with the other elements. Forming two elements with the same material can simplify the process and design.

The configuration of the pad unit 180 A illustrated in FIG. 1B and the configuration of the plurality of connecting lines 150 A illustrated in FIGS. 1C and 1D are merely illustrative. The configuration of the pad unit 180 A illustrated in FIG. 1B and the configuration of the plurality of connecting lines 150 A can be modified depending on the elements formed on the both sides of the transparent substrate 110 A. For example, when a camera module is disposed on a side of the transparent substrate 110 A, the plurality of connecting lines 150 A connects the processor to the camera module and may include lines to transmit/receive image or video signals. Further, the lines to transmit/receive image or video signals may be connected to the pad unit 180 A. Although the embodiments in the present disclosure are described in reference to the USB standard, it should be appreciated that the transparent OLED device 100 A may employ various other types of interface standards. Accordingly, the configuration of the pad unit 180 A and the connecting lines 150 A connected thereto may be changed according to the interface standards used in the transparent OLED device 100 A.

In FIG. 1D , the detection signal line 150 Aa overlaps the signal lines 150 Ab, 150 Ac and 150 Ad. However, the detection signal line 150 Aa and the signal lines 150 Ab, 150 Ac and 150 Ad may be formed on a same layer spaced apart from one another, or may be formed on two or more different layers so that the former dose not overlap the latter, depending on the level or type of voltage applied to the detection signal line 150 Aa and on the available area of the non-display area NDA of the transparent substrate 110 A.

In FIGS. 1C and 1D , some of the plurality of connecting lines 150 A are made of the same material as the material for the gate electrode 184 A of the thin-film transistor. The others plurality of connecting lines 150 A are made of the same material as the material for the source electrode 186 A and the drain electrode 187 A. However, some of the plurality of connecting lines 150 A may be made of the same material as the material for the reflective layer 191 A or the cathode 195 A. In this instance, the plurality of connecting lines 150 A may be formed on three or more different layers to overlap one another, depending on design choices. By doing so, the width of the bezel of the transparent OLED device 100 A can be further reduced.

FIG. 2A is a simplified plane view of a transparent display device according to an exemplary embodiment of the present disclosure. FIG. 2B is a cross-sectional view of the transparent display device, taken along line IIb-IIb′ of FIG. 2A . A transparent display device 200 may include various types of transparent display devices. For example, the transparent display device 200 may include a transparent OLED device or a transparent liquid crystal display device.

Referring to FIG. 2A , the transparent display device 200 includes a transparent substrate 210 , a first substrate 220 , a second substrate 230 , and a third substrate 215 a and 215 b . The transparent substrate 210 includes a display area DA and a non-display area NDA disposed on the periphery of the display area DA. The first substrate 220 is connected to a side of the transparent substrate 210 while the second substrate 230 is connected to another side of the transparent substrate 210 . On the first substrate 220 , a first power supply 222 and a first element 224 are disposed. On the second substrate 230 , a second power supply 232 and a second element 234 are disposed. A third substrate 215 a connects the transparent substrate 210 to the first substrate 220 . A third substrate 215 b connects the transparent substrate 210 to the second substrate 230 .

On the transparent substrate 210 , an auxiliary power line 240 , a plurality of connecting lines 250 and a ground (GND) line 260 are formed. FIG. 2A illustrates the connective relationships among the elements. In FIG. 2A , the auxiliary power line 240 , the plurality of connecting lines 250 and the ground line 260 are drawn as if they were formed across the transparent substrate 210 , the first substrate 220 , the second substrate 230 , and the third substrates 215 a and 215 b . However, FIG. 2A merely illustrates electrically connected relationships among them. That is to say, the auxiliary power line 240 , the plurality of connecting lines 250 and the ground line 260 are actually formed only on the transparent substrate 210 and are electrically connected to elements disposed on the first substrate 220 or the second substrate 230 via other lines formed on the third substrates 215 a and 215 b.

The plurality of connecting lines 250 formed on the non-display area NDA of the transparent substrate 210 electrically connect the elements formed on the first substrate 220 and the elements formed on the second substrate 230 . Referring to FIGS. 2A and 2B , the plurality of connecting lines 250 electrically connect the first element 224 formed on the first substrate 220 and the second element 234 formed on the second substrate 230 . The first element 224 and the second element 234 maybe one of a processor, a USB unit, a microphone, a speaker, a camera module, various types of sensors and the like.

The plurality of connecting lines 250 may be formed on a same layer spaced apart from one another. Although the plurality of connecting lines 250 includes four lines 250 a , 250 b , 250 c and 250 d in FIG. 2B , the number and width of the lines may be changed depending on the types of the first element 224 and the second element 234 . Further, the plurality of connecting lines 250 maybe formed on two or more different layers depending on the design of the display area DA and the non-display area NDA of the transparent display device 200 . When the plurality of the connecting lines 250 are formed on two or more different layers, they do not overlap one another or they partially overlap one another. That is to say, when the plurality of connecting lines 250 are separately formed on two or more different layers, some of the connecting lines 250 formed on a layer may overlap the other connecting lines 250 formed on another layer, or some of the connecting lines 250 may not overlap one another.

Referring to FIG. 2A , in the non-display area NDA of the transparent substrate 210 , the auxiliary power line 240 and the ground line 260 are formed. The auxiliary power line 240 is configured to supply power to the first power supply 222 disposed on the first substrate 220 . That is to say, power from an external power source is supplied to the second power supply 232 disposed on the second substrate 230 , and is supplied to the first power supply 222 disposed on the first substrate 220 from the second power supply 232 via the auxiliary power line 240 .

The external power source supplying power to the second power supply may be a battery.

The first power supply 222 and the second power supply 232 receive power in the form of voltage at a specific level from the external power source and transform the received power into a voltage of a level as required by each of the elements to supply it. An example is described with reference to FIG. 2A . If the first element 224 is a processor, the second power supply 232 receives power from the external power source to output a voltage as required by the first power supply 222 . The first power source 222 receives power via the auxiliary power line 240 to output a voltage as required by the processor.

The first power supply 222 and the second power supply 232 are connected to each other via the ground line 260 . The ground line 260 may be one of the lines to drive the elements of the display area DA. For example, the elements of the display area DA may be organic light-emitting elements or liquid crystal elements.

The auxiliary power line 240 and the plurality of the connecting lines 250 are not associated with driving the elements of the display area DA of the transparent display device 200 and are additionally formed on the non-display area NDA of the transparent substrate 210 . The transparent display device 200 does not employ an additional interconnection film to electrically connect elements formed on two sides of the transparent display device 200 . Therefore, it is necessary to additionally form the auxiliary power line 240 and the plurality of the connecting lines 250 on the transparent substrate 210 . Unlike the embodiment described in reference to FIG. 1A , the auxiliary power line 240 in FIG. 2A is dedicated for connecting the elements formed on two sides of the transparent display device 200 , independently of existing lines in the display area DA. In other words, the auxiliary power line 240 is not used in providing power to the elements of the display area DA. Accordingly, it is not necessary to take into account the level of a voltage or the amplitude of a current supplied to the elements formed on the display area DA, thereby allowing for various design choices.

When the transparent display device 200 is an OLED device, elements formed on two sides of the transparent substrate 210 can be more stably connected by introducing the auxiliary power line 240 . If the power for driving the elements of the display area DA of the transparent OLED device is different from the power to be supplied to the first power supply 222 , the auxiliary power line 240 formed on the non-display area NDA is added in addition to the power lines to drive the elements of the display area DA, so that the first power supply 222 can receive power more stably. In addition, the ground line 250 can be utilized as a VSS line for the transparent OLED device.

When the transparent display device 200 is a liquid crystal display device, a liquid crystal element is formed on the display area DA of the transparent substrate 210 . The elements formed on two sides of the transparent substrate 210 can be electrically connected via the auxiliary power line 240 and the plurality of the connecting lines 250 formed on the non-display area of the transparent substrate 210 . In addition, the ground line 260 can be utilized as a common electrode line for the transparent liquid crystal display device.

As the auxiliary power line 240 and the plurality of connecting lines 250 are formed on the non-display area NDA of the transparent substrate 210 , the width of the bezel of the transparent display device 200 may be increased by the sum of the width of the auxiliary power line 240 and the width of the plurality of connecting lines 250 . However, the width of the bezel of the transparent display device 200 according to the exemplary embodiment of the present disclosure can be reduced eventually, because the sum of the width of the auxiliary power line 240 and the width of the connecting lines 250 is less than the width of an additional interconnection film to connect elements formed on two sides of the transparent display device 200 .

A part of the auxiliary power line 240 and some of the connecting lines 250 may be formed on two or more different layers, and a part of the auxiliary power line 240 maybe arranged to overlap with some of the connecting lines 250 . Referring to FIG. 2B , the auxiliary power line 240 formed on the second insulation layer 285 overlaps some of the connecting lines 250 formed on the first insulation layer 283 . In FIG. 2B , the auxiliary power line 240 overlaps some of the connecting lines 250 b , 250 c and 250 d.

Similar to the detection signal line 150 Aa described above, a constant level of voltage may be applied to the auxiliary power line 240 . Accordingly, increase in the noise level between the lines may not be significant even when the auxiliary power line 240 is arranged to overlap with some of the connecting lines 250 . In this configuration, the area occupied by the auxiliary power line 240 and by the plurality of connecting lines 250 on the non-display area NDA of the transparent substrate 210 can be reduced to narrow the bezel of the transparent display device 200 as compared to arranging the auxiliary power line 240 not to overlap with other connecting lines 250 .

In FIG. 2A , the first power supply 222 is disposed on the first substrate 220 while the second power supply 232 is disposed on the second substrate 230 . However, the first power supply 222 and the second power supply 232 both may be disposed on a single substrate. For example, when both of the first power supply 222 and the second power supply 232 are disposed on the second substrate 230 , only the connecting lines 250 to electrically connect the first element 224 disposed on the first substrate 220 to the second element 234 disposed on the second substrate 230 may be formed on the non-display area NDA of the transparent substrate 210 , without an additional power line to connect the first power supply to the second power supply 232 . In this example, the second element 234 may be a processor while the first element 224 may be one of a camera module, a speaker, a microphone and various types of sensors. If the second element 234 disposed on the second substrate 230 is a processor, the processor may receive power from the first power supply 222 or the second power supply 232 and may be connected to the first element disposed on the first substrate 220 via the connecting lines 250 . As will be appreciated, the structure illustrated in FIG. 2A is merely an example and can be modified depending on the size of the transparent display device and applications.

Hereinafter, various characteristics of the transparent OLED device according to the present disclosure will be described.

According to another characteristic of the present disclosure, the device further includes one or more elements disposed on the first circuit board, one or more elements disposed on the second circuit board, and a plurality of connecting lines on the non-display area of the transparent substrate electrically connecting at least one of the elements on the first circuit board and at least one of the elements on the second circuit board.

According to still another characteristic of the present disclosure, said at least one of the elements on the first circuit board connected to said at least one of the elements on the second circuit board via the plurality of the connecting lines is configured to receive power from the first power supply.

According to still another characteristic of the present disclosure, said at least one of the elements that receives power from the first power supply is a processor configured to send a signal to and/or receive the signal from said at least one of the elements on the second circuit board via the plurality of connecting lines.

According to still another characteristic of the present disclosure, the device further includes a second power line formed on the non-display area of the transparent substrate in the non-display area thereof, wherein the plurality of connecting lines is disposed between the second power line and the display area.

According to still another characteristic of the present disclosure, the plurality of connecting lines includes a plurality of signal lines.

According to still another characteristic of the present disclosure, the plurality of the signal lines are disposed on a same layer and spaced apart from one another.

According to still another characteristic of the present disclosure, at least one of the signal lines is disposed on a different layer from another signal line without being overlapped by one another.

According to still another characteristic of the present disclosure, a width of each of the signal lines is equal to or less than 100 μm.

According to still another characteristic of the present disclosure, the plurality of the connecting lines further include at least one detection signal line, wherein the detection signal line is disposed on a different layer from a layer where said one or more signal lines are disposed on.

According to still another characteristic of the present disclosure, the detection signal line and said one or more signal lines are arranged such that at least some part of the detection signal line overlaps with some of the signal lines.

According to still another characteristic of the present disclosure, a width of the detection signal line is equal to or less than 1000 μm.

According to still another characteristic of the present disclosure, the device further includes a thin-film transistor formed on the display area of the transparent substrate in the display area thereof, the thin-film transistor having an active layer, a gate electrode, a source electrode, and a drain electrode, wherein at least one of the connecting lines is made of the same material as the gate electrode, and wherein at least one of the connecting lines is made of the same material as the source electrode or the drain electrode.

Hereinafter, various characteristics of the transparent device according to the present disclosure will be described.

According to another characteristic of the present disclosure, the plurality of the connecting lines are disposed on a same layer and spaced apart from one another.

According to still another characteristic of the present disclosure, the plurality of the connecting lines is disposed on two or more different layers without being overlapped with one another.

According to still another characteristic of the present disclosure, the plurality of the connecting lines are disposed on two or more different layers, and wherein at least one of the connecting lines on one layer at least partially overlaps with another connecting line on another layer.

According to still another characteristic of the present disclosure, the device further includes a first power supply disposed on the first substrate; and an auxiliary power line formed on the non-display area of the transparent substrate in the non-display area thereof providing power to the first power supply.

According to still another characteristic of the present disclosure, the device further includes a second power supply disposed on the second substrate, wherein the second power supply is configured to supply power to the first power supply via the auxiliary power line.

According to still another characteristic of the present disclosure, apart of the auxiliary power line overlaps with at least some of the plurality of connecting lines

The present invention has been described in more detail with reference to the exemplary embodiments, but the present invention is not limited to the exemplary embodiments. It will be apparent to those skilled in the art that various modifications can be made without departing from the technical sprit of the invention. Accordingly, the exemplary embodiments disclosed in the present invention are used not to limit but to describe the technical spirit of the present invention, and the technical spirit of the present invention is not limited to the exemplary embodiments. Therefore, the exemplary embodiments described above are considered in all respects to be illustrative and not restrictive. The protection scope of the present invention must be interpreted by the appended claims and it should be interpreted that all technical spirits within a scope equivalent thereto are included in the appended claims of the present invention.