KR100747683B1 - Electroluminescence Device and Driving Apparatus With Two Surface Display function - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent element having a double-sided display function capable of displaying on both sides using an electroluminescent element and a driving device thereof.

An electroluminescent device having a double-sided display function according to the present invention includes a first transparent electrode having a first polarity, a second transparent electrode having a second polarity opposite to the first polarity, a first transparent electrode, and a second transparent electrode. It is provided with a light emitting layer for generating light by the first and second polarity which is provided between the electrodes.

With this configuration, the electroluminescent device having a double-sided display function and its driving device according to the present invention can be effectively bidirectional display by using an organic EL and an inorganic EL device having a low work function of one of the two transparent electrodes. Do. In addition, by mounting the reflecting plates on both sides of the bidirectional display, high efficiency can be obtained by concentrating light in one direction. Furthermore, by using two electrodes having different work functions, an electroluminescent device having a thin structure of double-sided display function is provided.

Description

Electroluminescence Device and Driving Apparatus With Two Surface Display function}             

1A and 1B are a perspective view and a cross-sectional view showing a conventional organic light emitting device.

FIG. 2 is a cross-sectional view illustrating a light emitting mechanism of the organic light emitting diode shown in FIGS. 1A and 1B.

3 is a perspective view showing an electroluminescent device having a double-sided display function using the organic light emitting device according to the first embodiment of the present invention.

4 is a cross-sectional view showing an electroluminescence device having a double-sided display function using the organic light emitting device according to the first embodiment of the present invention.

5A to 5D are cross-sectional views showing an electroluminescence device having a double-sided display function with a reflecting plate according to a second embodiment of the present invention.

Fig. 6 is a sectional view showing an electroluminescent element having a double-sided display function according to the present invention.

7 is a block diagram illustrating a data driver according to the present invention.

8 is a diagram illustrating bidirectional scanning by a data driver according to the present invention.

Fig. 9 is a sectional view showing an electroluminescent element having a double-sided display function with a sensing sensor according to a third embodiment of the present invention.

FIG. 10 is a flowchart illustrating an operation of a sensing sensor illustrated in FIG. 9.

11 is a cross-sectional view showing an electroluminescent device having a double-sided display function using an inorganic light emitting device according to a fourth embodiment of the present invention.

12A to 12D are cross-sectional views showing an electroluminescent element having a double-sided display function with a reflecting plate according to a fifth embodiment of the present invention.

Fig. 13 is a sectional view showing an electroluminescent element having a double-sided display function with a sensing sensor according to the present invention.

<Explanation of symbols for main parts of drawing>

2: glass substrate 4: transparent electrode

6, 26: hole injection layer 8, 28: hole transport layer

10, 30: organic light emitting layer 12, 32: electron transport layer

14, 34: electron injection layer 16, 36: cathode electrode

18, 38, 236: light emitting layer 22, 230: lower glass substrate

24, 36, 232, 242: transparent electrodes 42, 44, 244, 246: reflector plates

46,100,200,250: Double-sided display panel 47: Data driver

48: scan driver 49: control unit                 

60: bidirectional shift register 62: data register

64: Latch 66: Level Shifter

68: digital-to-analog converter 70: buffer

202, 204, 252, 254 sensor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display device, and more particularly, to an electroluminescent device having a double-sided display function capable of displaying on both sides by using an electroluminescent device and a driving device thereof.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of a cathode ray tube. Such flat panel displays include liquid crystal displays ("LCD"), field emission displays, plasma display panels, and electroluminescence ("EL"). Display device).

In order to increase the display quality of such a flat panel display device and to attempt to make a large screen, studies are being actively conducted. Among them, the EL device has the advantage that the response speed is as fast as the cathode electrode tube compared to the light receiving device such as LCD, which is currently in the spotlight. Since the low DC driving voltage and ultra thin film are possible, the wall-mounted and portable devices are Application is possible. The EL element is a self-light emitting element which is classified into an inorganic EL and an organic EL according to the material of the light emitting layer and emits light by itself. This EL element displays an image or an image by exciting a fluorescent substance using electric charges such as electrons and holes. The EL element is excellent in luminous efficiency, brightness and viewing angle.

Referring to FIGS. 1 and 2, an organic EL device includes a transparent electrode 4, a hole related layer, an organic light emitting layer 10, an electron related layer, and a cathode electrode 16 sequentially stacked on a transparent substrate 2. do.

As the transparent substrate 2, an organic substrate and a plastic substrate are mainly used. The transparent electrode 4 is made of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide (Indium-Tin). -Zinc-Oxide (ITZO) or the like is formed by vacuum deposition or sputtering to be used as a data electrode.

In the hole related layer, a hole injection layer (HIL) 6 and a hole transfer layer (HTL) 8 are sequentially formed on the transparent electrode 4. The organic light emitting layer (Emitting Layer) (EMI) (10) is a function of emitting light, but mostly also to the function of transporting electrons or holes. In the electron related layer, an electron transfer layer (ETL) 12 and an electron injection layer 14 are sequentially stacked on the organic light emitting layer 10. The light emitting layer 18 including the hole related layer, the organic light emitting layer 10 and the electron related layer is formed by vacuum deposition in the case of a low molecular weight compound, and is formed by spin coating or printing in the case of a polymer compound. do.                         

The cathode electrode 16 may be made of Al, Ag, MgAg, LiAl, LiF-Al, etc., which are materials having a low work function, but are mostly used as scan electrodes with a metal such as aluminum (Al). The work function of the cathode electrode 16 is about 4.2 eV, and the work function of the transparent electrode 4 is about 4.7 eV to 5.0 eV.

In the organic EL device, electrons generated from the cathode electrode 16 having a low work function move toward the transparent electrode 4 having a high work function, and holes generated from the transparent electrode 4 are transferred to the cathode electrode 16. To the side. Thus, electrons and holes collide in the organic light emitting layer 10 during the movement due to the difference in the size of the work function to emit light. In other words, when a driving voltage is applied to the transparent electrode 4, the holes in the hole injection layer 6 and the electrons in the electron injection layer 12 respectively advance toward the organic light emitting layer 10 to be recombined to form excitons. Then, display is performed by using a phenomenon in which visible light of a specific wavelength is generated by energy from the excitons formed. The visible light generated in the organic light emitting layer 10 is blocked by the metal of the cathode electrode 16 and is emitted only through the transparent electrode 4 and the glass substrate 2.

As such, the organic EL device cannot be used for a double-sided display (a display where viewers can watch a video from the front and back of the display) because only one of the two electrodes can be displayed on one side because the electrode is metal.

In addition, two flat panel displays must be superimposed to implement a double-sided display. In particular, in the case of LCD which is a non-light emitting device, a double-sided display sharing a backlight unit has been proposed. However, in the case of LCD, two LCD cells are required with a backlight unit interposed therebetween, which causes a problem that the luminance, viewing angle, and response speed are very low while being expensive.

Accordingly, it is an object of the present invention to provide an electroluminescence element having a double-sided display function and a driving apparatus thereof, which are capable of displaying on both sides using an electroluminescence element.

In order to achieve the above object, an electroluminescent device having a double-sided display function according to the present invention comprises a first transparent electrode having a first polarity, a second transparent electrode having a second polarity opposite to the first polarity, A light emitting layer is disposed between the first transparent electrode and the second transparent electrode to generate light by the first and second polarities.

The first and second transparent electrodes of the electroluminescent device having a double-sided display function according to the present invention are positioned between the upper substrate and the lower substrate.

The light emitting layer of the electroluminescent device having a double-sided display function according to the present invention is characterized in that it is an organic compound or an inorganic compound.

An electroluminescent device having a double-sided display function according to the present invention includes support means for supporting a double-sided display element, and light corresponding to the front and back display surfaces of the double-sided display element, the front display surface and the rear display surface. It further comprises at least one reflector for reflecting toward any one of the display surface.

In the electroluminescent device having a double-sided display function according to the present invention, each of the reflecting plates is slid toward the front display surface and the front rear surface of the double-sided display device.

An electroluminescent drive device having a double-sided display function according to the present invention includes a first transparent electrode having a first polarity, a second transparent electrode having a second polarity opposite to the first polarity, and a first transparent electrode and a second polarity. An electroluminescent device including a light emitting layer that emits light by the first and second polarities which are disposed between the transparent electrodes and a data driver for supplying a data signal to any one of the first and second transparent electrodes And a scan driver which supplies a scan signal to the remaining electrodes of the first and second transparent electrodes, and a controller which supplies a control signal and a data signal to the data driver and supplies a control signal to the scan driver.

The data driver of the electroluminescence driving apparatus having a double-sided display function according to the present invention is provided at one side of the double-sided display element to detect the position of the audience and the detection signal detected by the detection means. Determining means for determining a scanning direction of data, a bidirectional shift resist for shifting data in accordance with the scanning direction of the determining means, a data register for storing data by shifting the bidirectional shift resist, and temporarily storing the shifted data A latch for the display, a level shift for raising the level of data simultaneously supplied from the latch, a digital-analog converter for converting the data supplied from the level shift into an analog signal, and a function for simultaneously supplying an analog data signal to a double-sided display device. Additional buffer Compared.

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 13.

3 and 4, an EL device having a double-sided display function using an organic EL according to a first embodiment of the present invention includes a first transparent electrode between an upper glass substrate 40 and a lower glass substrate 22. 24), the hole related layer, the organic light emitting layer 30, the electron related layer, and the second transparent electrode 36 are sequentially stacked.

The first transparent electrode 24, which is an anode, includes indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide. Any one of materials such as (Indium-Tin-Zinc-Oxide; ITZO) is formed on the lower glass substrate 22 by vacuum deposition or sputtering and used as a data electrode.

In the hole related layer, a hole injection layer (HIL) 26 and a hole transfer layer (HTL) 28 are sequentially formed on the first transparent electrode 24. The organic light emitting layer (Emitting Layer) (EMI) 30 is a function of emitting light, but mostly also to function to transport electrons or holes. In the electron related layer, an electron transfer layer (ETL) 32 and an electron injection layer (EIL) 34 are sequentially stacked on the organic light emitting layer 30. The light emitting layer 38 including the hole related layer, the organic light emitting layer, and the electron related layer is formed by vacuum deposition in the case of a low molecular weight compound, and is formed by spin coating or printing in the case of a polymer compound.

The second transparent electrode 36, which is a cathode, vacuums any one of materials such as indium-tin-oxide (ITO), indium-zinc-oxide (IZO), and indium-tin-zinc-oxide (ITZO). It is formed on the light emitting layer 38 by vapor deposition or sputtering.

As described above, the first transparent electrode 24 and the second transparent electrode 36 have different work functions in the range of 4.7 eV to 5.3 eV by the composition ratio of oxide and O ₂ plasma treatment. Can be set. Accordingly, the work function of the first transparent electrode 24 and the second transparent electrode 36 is set such that any one of the two electrodes 24 and 36 is low so that electrons and holes can move. Accordingly, the light emitting layer 38 emits light using holes and electrons supplied from the first transparent electrode 24 and the second transparent electrode 36 due to the difference in work function by the light emitting mechanism as shown in FIG. 2. do.

The passivation layer 23 is formed on the lower glass substrate 22 on the entire surface except for the portions of the first and second transparent electrodes 24 and 36. In addition, the edges of the upper and lower glass substrates 22 and 40 are closed between the upper and lower glass substrates 22 and 40 by treating the seal 25.

In such an EL device having a double-sided display function using an organic EL device, electrons generated from the second transparent electrode 36 having a low work function move toward the first transparent electrode 24 having a high work function, and the first transparent electrode. Holes generated from the electrode 24 are moved toward the second transparent electrode 36. In this case, materials of the organic light emitting layer, the electron related layer, and the hole related layer in the light emitting layer 38 form an energy band in which holes and electrons are easily moved from the first and second transparent electrodes 24 and 36 to the induced light layer 30. Have

As a result, electrons and holes collide in the organic light emitting layer 30 due to the difference in size of the work function, thereby emitting light. In other words, when a driving voltage is applied to the first transparent electrode 24, holes in the hole injection layer 26 and electrons in the electron injection layer 32 proceed toward the organic light emitting layer 30 to be recombined to excit (Exction). Is formed and displayed using a phenomenon in which visible light of a specific wavelength is generated by energy from the excitons formed.

The visible light generated in the organic light emitting layer 30 is emitted in both directions through the first transparent electrode 24 and the second transparent electrode 36 and the upper and lower glass substrates 22 and 40. Accordingly, the EL element having a double-sided display function using the organic EL element is installed in a place such as a public place to display images from the front and the rear.

5A to 5C, the double-sided display device 100 using the organic EL device according to the second exemplary embodiment of the present invention may include first and second reflecting plates for concentrating visible light in one of front and rear directions. 42, 44).

As the first and second reflecting plates 42 and 44, Al, Ag, MgAg, or the like, which are materials having high reflectance, are used. The first and second reflecting plates 42 and 44 are housed in support means 41 (not shown) for supporting the EL element 100 having a double-sided display function, or are installed in a ceiling or the like. The first and second reflecting plates 42 and 44 are detached from the supporting means 41 and mounted on the front screen A or the rear screen B of the double-sided display element 100 by a driving device (not shown). One screen is hidden.

In addition, the support means 41 of the EL element 100 having a double-sided display function is provided with two reflecting plates 42, 44 provided on both sides as shown in Fig. 5C. Each of the reflecting plates 42 and 44 is formed in multiple stages so that the overlapping portions do not leak light.

When viewers are viewed on both screens A and B of the EL element 100 having a double-sided display function, the first and second reflecting plates 42 and 44 are accommodated in the supporting means 41 as shown in FIG. 5A. The state of being installed on the ceiling is maintained. As a result, the visible light emitted from the EL element 100 having the double-sided display function is displayed on both the front screen A and the rear screen B. FIG.

On the other hand, when the audience sees only one side of the front screen (A) or the rear screen (B), not the two screens (A, B) of the EL element 100 having a double-sided display function, that is, as shown in Figure 5b When viewed from the front screen (A), the second reflector 44 covers the rear screen (B). Accordingly, the visible light emitted to the rear screen B of the EL element 100 having the double-sided display function is reflected by the second reflecting plate 44 and concentrated on the front screen A. FIG.

On the other hand, one reflector plate 43 is installed on the support means 41 of the first and second reflector plates 42 and 44 as shown in FIG. 5D. The reflecting plate 43 is mounted on the opposite screen in which the audience is located in the EL element 100 having the double-sided display function to focus visible light toward the audience. On the other hand, when the visible light is to be concentrated on the other screen, the EL element 100 having a double-sided display function is rotated by a rotating device (not shown) to be mounted on the reflecting plate 43 to concentrate the visible light on the opposite side. In this way, one reflecting plate 43, not two reflecting plates 42 and 44, is provided in the support means 41, and the EL element 100 is rotated to face the reflecting plate 43, thereby allowing any one screen of the screen. To focus visible light.

6 is a block diagram showing a driving device of an EL element having a double-sided display function according to the present invention.

Referring to Fig. 6, an EL element having a double-sided display function scans a double-sided display panel 46, a controller 49 for generating data signals and control signals, and a scan line GL of the double-sided display panel 46. A scan driver 48 for supplying a signal and a data driver 47 for supplying a data signal to the data line DL of the double-sided display panel 46 are provided.

In the double-sided display panel 46, an emission layer (not shown) is formed between the data line DL and the scan line GL. Light emitted from the light emitting layer is emitted to the front and rear surfaces of the double-sided display panel 46.

The controller 49 generates a data signal and a control signal, among which the data signal is supplied to the data driver 47 and the control signal is supplied to the data driver 47 and the scan driver 48, respectively.

The scan driver 48 sequentially supplies a scan signal to the scan line GL in response to a control signal of the controller 49.

The data driver 47 supplies the data signal to the data line DL in response to the control signal of the controller 49.

In this manner, the scan signal is supplied from the scan driver 48 to the scan line GL by the control signal, and the light emitting layer supplied with the data signal from the data driver 47 to the data line DL emits light to generate light. Done.

In this manner, in the EL element having the double-sided display function according to the present invention, when a moving image such as an image is displayed on the double-sided display panel 46, the front screen is normally displayed. On the other hand, on the screen on the back side, a video such as an image is displayed in reverse to the front side. Even if the rear screen is reversely displayed, it does not matter much when the screen of the image and the video is displayed.

However, when text is displayed on the display surface of the double-sided display panel 46, if the text on the front screen is a normal display, information on the rear screen may be displayed in reverse. In order to solve this problem will be described with reference to Figure 7 as follows.

7 and 8, in the driving device of the EL element having the double-sided display function according to the present invention, the data driver includes a bidirectional shift register 60 for determining the order of data, and a data register to which data is supplied. (62), a latch (64) for temporarily storing the data signal supplied from the data resist (62), a level shift (66) for raising the level of the data signal supplied from the latch (64), and a level shift (66). A digital-to-analog converter 68 for converting the digital data signal supplied from the digital signal into an analog data signal, and a buffer 70 for outputting the analog signal to the display element.

The bidirectional shift register 60 includes a clock signal CLK, first and second enable signals ENI01 and ENI02, scan direction selection signals R / L, load signals LOAD, and the like, which are supplied from a controller (not shown). The driving voltages Vdd1 and Vss1 are supplied.

The first enable signal ENI01 is a signal indicating a time when valid data is present, and the second enable signal ENI02 is a signal for transferring a carrier generated from the bidirectional shift register 60.

The scan direction selection signal R / L selects the shift direction of the bidirectional shift register 60. The scan direction selection signal R / L shifts to the right when the signal is in the high state and shifts to the left when the signal is in the low state.

The load signal LOAD is a signal for simultaneously transmitting the shifted signal of the bidirectional shift register 60 to the data register 62.

The data register 62 stores 6-bit data signals D1 to D6 supplied from a control unit (not shown), and supplies the stored data signal to the latch 64 in synchronization with the shift signal of the bidirectional shift register 60.

The latch 64 receives the polarity control signal MPOL and the driving voltages Vdd1 and Vss1 to temporarily store the data signal supplied from the data register 62. At this time, the stored data signal is simultaneously transmitted to the level shift 66 in synchronization with the load signal LOAD.

The level shift 66 increases the level of the data signal supplied from the latch 64 by receiving the voltages of the gamma voltages Vdd2 and Vss2.

The digital-to-analog converter 68 receives the voltage levels in the range of V0 to V9 and the gamma voltages Vdd2 and Vss2 and converts them to analog of the voltage levels in the range of V0 to V9 by the voltage bell shift 66 to buffer 70. To feed.

The buffer 70 receives the voltages of the polarity control signal MPOL and the gamma voltages Vdd2 and Vss2 and simultaneously supplies the analog data signals S1 to S384 to the display device in synchronization with the load signal LOAD.

As described above, when the data driver displays character information on the screen A as shown in FIG. 8, the high state signal of the scan direction selection signal R / L is supplied to the bidirectional shift register 60. As shown in FIG. Accordingly, the data information stored in the data register 62 is shifted in the right direction, and the shifted data information moves the latch 64, the level shifter 66, the digital-to-analog converter 68, and the buffer 70. It is supplied to the display device 100 through.

On the contrary, in the case where the character information is displayed on the B screen, the signal in the low state among the scan direction selection signals R / L is supplied to the bidirectional shift register 60. Accordingly, the data information stored in the data register 62 is shifted to the left direction, and the shifted data information is applied to the latch 64, the level shifter 66, the digital-to-analog converter 68, and the buffer 70. It is supplied to the EL element 100 having the double-sided display function.

In displaying character information of the EL element 100 having such a double-sided display function, the front screen displays data information from left to right, and the rear screen displays data information from right to left. By displaying, accurate character information can be displayed on both surfaces.

Referring to FIG. 9, an EL device having a double-sided display function using an organic EL according to a third embodiment of the present invention is installed on one side of the double-sided display screen 200 and the double-sided display screen 200, and is used by an audience. First and second sensing sensors 202 and 204 for sensing the position of the &lt; RTI ID = 0.0 &gt;

The double-sided display screen 200 is fixedly installed at a specific position when used by an individual.

The first detection sensor 202 detects an audience located on the front screen A side of the double-sided display screen 200. The second detection sensor 204 detects an audience located on the rear screen B side of the double-sided display screen 200.

The first and second detection sensors 202 and 204 are supplied to the bidirectional shift register 220 through the position sensor 210 shown in FIG. 9.

Referring to FIG. 10, the position detecting unit 210 detects the position of the user from the first and second sensing sensors 202 and 204, compares and compares the detected detection signal DET with the detected state. The scan direction selection signal R / L corresponding to the bidirectional shift register 220 may be supplied according to the determined scan direction selection signal R / L.

In this way, the first and second detection sensors 202 and 204 installed on the double-sided display screens A and B detect the position of the user and transmit the scan direction selection signal R / L to the bidirectional shift register 220. Will be supplied. In detail, when the detection code is supplied from the first detection sensor 202, the determination unit 214 supplies the scan direction signal R for scanning from left to right to the bidirectional shift register 220. On the other hand, when the signal detected from the second detection sensor 204 is supplied, the determination unit 214 supplies the scan direction signal L scanning from right to left to the bidirectional shift register 220 through the inverter INV. .

Accordingly, the data driver shown in FIG. 6 detects the position of the user and automatically adjusts the scanning direction of the data information to supply to the A screen or the B screen.

Fig. 11 is a sectional view showing an EL element having a double-sided display function using the inorganic EL according to the fourth embodiment of the present invention.

Referring to FIG. 11, the inorganic EL includes a first transparent electrode 232, a lower insulating layer 234, a light emitting layer 236, and an upper insulating layer 238 between the upper glass substrate 242 and the lower glass substrate 230. The second transparent electrodes 240 are sequentially stacked.

The first transparent electrode 232, which is an anode, includes indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide, and the like. One of materials such as (Indium-Tin-Zinc-Oxide; ITZO) is a data electrode formed on the lower glass substrate 22 by vacuum deposition or sputtering.

The upper and lower insulating layers 234 and 238 are made of a dielectric material and have a predetermined capacitance value. The light emitting layer 236 is made of ZnS, Mn, and the like, and is excited by electrons to emit light to serve to generate visible light.

The second transparent electrode 240, which is a cathode, may vacuum any one of materials such as indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin oxide (ITZO). It is formed on the light emitting layer 236 by vapor deposition or sputtering.

As described above, the first transparent electrode 232 and the second transparent electrode 240 have different work functions in the range of 4.7 eV to 5.3 eV by the composition ratio of oxide and O ₂ plasma treatment. Can be set. Accordingly, the work function of the first transparent electrode 232 and the second transparent electrode 240 is set such that any one of the two electrodes 232 and 240 is low so that electrons and holes can move. Accordingly, the light emitting layer 236 emits light using holes and electrons supplied from the first transparent electrode 232 and the second transparent electrode 240 due to the difference in work function by the light emitting mechanism as shown in FIG. 2. do.

In the double-sided display device using the inorganic EL, when a voltage is applied between the first transparent electrode 232 and the second transparent electrode 240, electrons in the emission layer 236 are accelerated by an electric field. Accelerated electrons collide with holes in the center of the emission layer 236. In this case, visible light is emitted from the light emitting layer 236 in both directions through the first transparent electrode 232 and the second transparent electrode 240.

12A to 12C, an EL element 250 having a double-sided display function using an inorganic EL element according to a fifth embodiment of the present invention is the first for concentrating visible light in either of the front and rear directions. And second reflecting plates 244 and 246.

As the first and second reflecting plates 244 and 246, Al, Ag, MgAg, or the like, which are materials having high reflectance, are used. The first and second reflecting plates 244, 246 are housed in a supporting means 243 (not shown) for supporting the EL element 250 having a double-sided display function, or are installed in a ceiling or the like. The first and second reflecting plates 244 and 246 are detached from the supporting means 243 and mounted on the A surface or the B screen of the EL element 250 having a double-sided display function by a driving device (not shown). Will be hidden.

Incidentally, the reflecting plates 244 and 246 provided on both sides of the supporting means 243, not shown, of the EL element 250 having the double-sided display function as shown in Fig. 12C are divided into upper / lower or left / right and supporting means 243. Is installed on. Each of the reflecting plates 244 and 246 is formed in multiple stages so that the overlapping portions do not leak light.

When viewing viewers from both sides A and B of the EL element 250 having a double-sided display function, the first and second reflecting plates 244 and 246 are accommodated in the supporting means 243 or the ceiling as shown in FIG. 12A. It is maintained in the state installed on the back. Accordingly, the visible light emitted from the EL element 250 having the double-sided display function displays an image on both the A screen and the B screen.

At this time, when the audience sees only on one side of the A screen or the B screen, not the both sides A and B of the EL element 250 having the double-sided display function, that is, when the audience sees on the A screen as shown in FIG. The reflecting plate 246 covers the B screen of the EL element 250 having the double-sided display function. Accordingly, visible light emitted to the B screen of the EL element 250 having the double-sided display function is reflected by the second reflecting plate 246 to be concentrated on the A screen.

On the other hand, one of the first and second reflecting plate 244, 246, one reflecting plate 244 is provided on the support means 243, as shown in FIG. The reflecting plate 244 is mounted on the opposite screen where the audience is located in the EL element 250 having the double-sided display function to focus visible light toward the audience. On the other hand, in the case where the visible light is to be concentrated on the other screen, the EL element 250 having the double-sided display function is rotated by a rotating device (not shown) and mounted on the reflecting plate 244 to concentrate the visible light on the opposite side. As described above, one reflecting plate 244 rather than two reflecting plates 244 and 246 is provided in the supporting means 243, and the EL element 250 is rotated to face the reflecting plate 244, thereby allowing any one screen of the screen. To focus visible light.

As described above, in the EL element having the double-sided display function according to the present invention, when the information displayed on the double-sided display includes text, the information on the front screen is correctly displayed. However, in the case of the back screen, there is a problem that the information is displayed in reverse. In order to solve this problem, the shift direction of the bidirectional shift register of the data driver may be shifted as shown in FIG. 8. This displays the character information of the EL element 250 having the double-sided display function. In the front screen, the data direction is displayed from left to right, and in the rear screen, the data direction is displayed from right to left. Thus, accurate character information can be displayed on both sides.

In addition, when an individual uses an EL element 250 having a double-sided display function using an inorganic EL as installed in a specific position, an EL element having a double-sided display function using an inorganic EL has a double-sided display function as shown in FIG. 13. It is provided on one side of the EL element 250 and has first and second detection sensors 252 and 254 for sensing the position of the viewer.

The first detection sensor 252 detects an audience located on the front screen A side of the EL element 250 having a double-sided display function. The second detection sensor 254 detects an audience located on the rear screen B side of the EL element 250 having a double-sided display function.

The first and second detection sensors 252 and 254 automatically determine scan directions of the screens A and B according to the comparatively determined scan direction selection signals R / L of the position detection unit shown in FIG. 10. do. Accordingly, the data information displayed on the screens A and B of the EL element 250 having the double-sided display function determines the scanning direction of the data information according to the position of the user. Can be displayed.

As described above, the EL element having a double-sided display function according to the present invention enables an effective bidirectional display by using an organic EL and an inorganic EL element having a low work function of either of the two transparent electrodes. In addition, by mounting the reflecting plates on both sides of the bidirectional display, high efficiency can be obtained by concentrating light in one direction. Furthermore, by using two electrodes having different work functions, an EL element having a thin-sided double-sided display function is provided.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (12)

A first transparent electrode having a first polarity, A second transparent electrode having a second polarity opposite to the first polarity; And a light emitting layer for generating light by the first polarity and the second polarity, which are provided between the first transparent electrode and the second transparent electrode. 2. The method of claim 1, And the first transparent electrode and the second transparent electrode are positioned between an upper substrate and a lower substrate. The method of claim 1, The work function of the first transparent electrode and the second transparent electrode is an electroluminescent device having a double-sided display function, characterized in that any one of the first transparent electrode and the second transparent electrode is high. The method of claim 1, And the light emitting layer is an organic compound. The method of claim 1, The light emitting layer is an electroluminescent device having a double-sided display function, characterized in that the inorganic compound. The method of claim 1, Support means for supporting the double-sided display element; And at least one reflector for reflecting the light toward one of the front and back display surfaces in correspondence with the front and back display surfaces of the double-sided display element. Electroluminescent element with function. The method of claim 6, And the reflecting plate slides toward the front display surface and the rear display surface of the double-sided display element. The method of claim 7, wherein The reflector is an electroluminescent device having a double-sided display function, characterized in that separated into two facing each other. The method of claim 6, The reflector is an electroluminescent device having a double-sided display function, characterized in that the electroluminescent device is rotated so that any one of the front display surface and the rear display surface to face. A first transparent electrode having a first polarity, a second transparent electrode having a second polarity opposite to the first polarity, and the first and second electrodes positioned and supplied between the first transparent electrode and the second transparent electrode; An electroluminescent element comprising a light emitting layer for generating light by polarity, A data driver supplying a data signal to any one of the first and second transparent electrodes; A scan driver supplying a scan signal to the remaining electrodes of the first and second transparent electrodes; And a control unit for supplying a control signal and a data signal to the data driver and for supplying a control signal to the scan driver. The method of claim 10, The data driver Detection means installed at one side of the double-sided display element to detect a position of an audience; Judging means for judging a detection signal detected by said detecting means to determine a scanning direction of data; A bidirectional shift resist for shifting the data according to the scanning direction of the determining means; A data register for storing the data by shifting the bidirectional shift resist; A latch for temporarily storing the shifted data; A level shift for raising the level of data simultaneously supplied from the latch; A digital-analog converter for converting data supplied from the level shift into an analog signal; And a buffer for simultaneously supplying the analog data signal to the double-sided display element. The method of claim 1, When the light emitting layer is a low molecular weight compound is formed by vacuum deposition, in the case of a high molecular compound electroluminescence device having a double-sided display function, characterized in that formed by spin coating or printing.

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