Light-emitting indicator device

Abstract

Light-emitting display device, comprising: a scoreboard (110); and Subpixels positioned in a display area of ​​the scoreboard (110), wherein at least one of the subpixels has a color filter arranged between two electrode layers (118, 119), and at least one other of the subpixels has a color filter arranged on a protective layer (124) on the two electrode layers (118, 119), wherein the subpixels have a red, a green and a blue subpixel, wherein the red subpixel has a red color filter (CFR) arranged between the two electrode layers (118, 119), the green subpixel has a green color filter (CFG) arranged between the two electrode layers (118, 119), and the blue subpixel has a blue color filter (CFB) arranged on the protective layer (124) covering a light-emitting diode (OLED), wherein the blue color filter (CFB) contained in the blue subpixel comprises a first blue color filter (CFBa) arranged according to a bank layer (120) defining the emission regions for a red and a green subpixel, and a second blue color filter (CFBb) arranged according to an emission region of the blue subpixel and the bank layer (120) defining the emission region of the blue subpixel.

Description

BACKGROUND OF THE INVENTIONField of the invention

[0001] The present invention relates to a light-emitting display device. State of the art

[0002] With the development of information technology, markets for display devices that serve as a connecting medium between users and information are growing. Accordingly, display devices such as organic light-emitting diodes (OLEDs), liquid crystal displays (LCDs), and plasma display panels (PDPs) are increasingly being used.

[0003] Among the aforementioned display devices, the OLED display device includes a display panel with multiple subpixels, a driver for driving the display panel, and a power supply for powering the display panel. The driver includes a scan driver for providing scan signals (or gate signals) to the display panel and a data driver for providing data signals to the display panel.

[0004] OLED displays display images in such a way that light-emitting diodes of selected subpixels emit light when scan signals and data signals are applied to subpixels arranged in a matrix. OLED displays are classified into a bottom-emitting type, which emits light toward a lower substrate, and a top-emitting type, which emits light toward a top substrate.

[0005] OLED displays have various advantages because they display images based on light generated by LEDs contained in subpixels, and are therefore considered promising display devices. It is an object of the present invention to realize ultra-high-resolution OLED displays.

[0006] US 2017 / 0 025 482 A1 relates to a thin film transistor array substrate and an organic light emitting diode (OLED) display device including the same, in which a color layer is disposed on a first substrate corresponding to a white subpixel and a non-color filter region is included in a second substrate corresponding to the white subpixel.

[0007] US 2016 / 0 079 311 A1 relates to an organic light-emitting display device comprising: an organic light-emitting device including a plurality of subpixels each emitting light of different colors; a color filter formed on the organic light-emitting device in a region corresponding to each of the subpixels; a spacer color filter formed in the color filter between red, green, and blue color filters at locations corresponding to non-emitting regions; and a substrate provided on the color filter to encapsulate the organic light-emitting device. SUMMARY OF THE INVENTION

[0008] This object is achieved by the subject matter of the independent claim. Further advantageous embodiments and developments are described in the corresponding dependent claims. The present disclosure provides a light-emitting display device comprising a display panel and subpixels. The subpixels are positioned in a display region of the display panel. At least one of the subpixels comprises a color filter arranged between two electrode layers, and at least one other of the subpixels comprises a color filter arranged on a protective layer on the two electrode layers.

[0009] The two electrode layers may include a reflective electrode layer positioned on a first substrate of the display panel and may include a first electrode layer positioned on the reflective electrode layer.

[0010] The subpixels may comprise a red, a green, and a blue subpixel, wherein the red subpixel may comprise a red color filter disposed between the two electrode layers, the green subpixel may comprise a green color filter disposed between the two electrode layers, and the blue subpixel may comprise a blue color filter disposed on a protective layer covering a light-emitting diode.

[0011] The red subpixel may have an emission layer that emits red light, the green subpixel may have an emission layer that emits green light, and the blue subpixel may have an emission layer that emits blue light.

[0012] The blue color filter included in the blue subpixel may include a first blue color filter arranged corresponding to the bank layer defining emission layers of the red and green subpixels, and a second blue color filter arranged corresponding to an emission region of the blue subpixel and a bank layer defining the emission region.

[0013] The light-emitting display device may further comprise black matrix layers positioned between the protective layer and the first blue color filter and between the protective layer and the second blue color filter, respectively.

[0014] The first blue color filter can cover the surface of the black matrix layer, and the second blue color filter covers the surface and side of the black matrix layer.

[0015] The red color filter may be arranged corresponding to the emission area of ​​the red subpixel, the green color filter may be arranged corresponding to the emission area of ​​the green subpixel, and the blue color filter may be arranged corresponding to the emission area of ​​the blue subpixel.

[0016] The protective layer may be formed in a single-layer or multi-layer structure covering the subpixels and having a flat surface.

[0017] The light-emitting display device may further comprise a blue color filter, wherein the blue color filter may be arranged on a black matrix layer defining non-emission regions of the red and green subpixels.

[0018] The reflective electrode layer and the first electrode layer may electrically contact each other on one or both of their sides.

[0019] The reflective electrode layer and the first electrode layer can electrically contact each other along their entire edges.

[0020] The color filter arranged between the two electrode layers may have a size equal to or smaller than the first electrode layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are included to provide a further explanation of the invention, are incorporated in and illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Fig. 1 is a schematic block diagram of an organic light emitting display device. Fig. Figure 2 is a schematic diagram of a subpixel. Fig. 3 is a circuit diagram showing part of Fig. 2 shows in detail. Fig. 4 is a cross-sectional view showing a part of a display area of ​​a display panel according to an experimental example. Fig. 5 is a cross-sectional view of an explanatory example showing a part of a display area of ​​a display panel. Fig. Fig. 6 is a plan view of a reflective electrode layer, a color filter layer, and a first electrode layer formed on the display panel of Fig. 5 are laminated. Fig. 7 illustrates a display panel realized according to the first embodiment of the present invention. Fig. 8 is a cross-sectional view of an explanatory example showing a part of a display area of ​​a display panel. Fig. 9 illustrates a display panel realized according to the second embodiment of the present invention. Fig. Figure 10 shows reflectance test results for display panel configurations. Fig. Figure 11 shows simulation results obtained from reflectance tests based on the Fig. 7 to 9 were obtained. The Fig. 12 and Fig. 13 are cross-sectional views of explanatory examples showing a part of a display area of ​​a display panel. DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0022] Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings.

[0023] A display device described below is applicable to any spontaneous emission type display device based on spontaneous emission type elements that can emit light. Specifically, the display device described below is applicable to an inorganic light-emitting display device implemented based on an inorganic LED, as well as an organic light-emitting display device implemented based on an OLED. However, in the following description, an organic light-emitting display device is illustrated as an example.

[0024] Fig. 1 is a schematic block diagram of an organic light emitting display device. Fig. 2 a schematic diagram of a subpixel, and Fig. 3 are circuit diagrams that show part of Fig. 2 in detail.

[0025] As in Fig. 1, the organic light emitting display device includes a timing controller 151, a data driver 155, a scan driver 157, a display panel 110, and a power supply 153.

[0026] Timing controller 151 receives drive signals including a data enable signal, a vertical synchronization signal, a horizontal synchronization signal, and a clock signal, along with a data signal DATA from an image processor (not shown). Timing controller 151 outputs a gate timing signal GDC for controlling the operating timing of scan driver 157 and a data timing signal DDC for controlling the operating timing of data driver 155 based on the drive signals. Timing controller 151 may be configured as an integrated circuit (IC).

[0027] The data driver 155 samples and latches the data signal DATA supplied from the timing controller 151 in response to the data timing signal DDC supplied from the timing controller 151, converts the digital data signal into an analog data signal (or data voltage) using a gamma reference voltage, and outputs the analog data signal. The data driver 155 outputs the data signal DATA via the data lines DL1 to DLn. The data driver 155 may be configured as an integrated circuit.

[0028] The scan driver 157 outputs a scan signal in response to the gate timing signal GDC supplied from the timing controller 151. The scan driver 157 outputs the scan signal via the scan lines GL1 to GLm. The scan driver 157 is configured as an IC or formed in the display panel 110 according to a "gate-in-panel" (a method for forming a transistor through a thin-film formation process).

[0029] The power supply 153 outputs a high voltage and a low voltage. The high voltage and low voltage outputs of the power supply 153 are supplied to the display panel 110. The high voltage is supplied to the display panel 110 via a first power line EVDD, and the low voltage is supplied to the display panel via a second power line EVSS. The power supply 153 can be configured as an integrated circuit.

[0030] The display panel 110 displays an image based on the data signal DATA supplied from the data driver 155, the scan signal supplied from the scan driver 157, and the current supplied from the power supply 153. The display panel 110 has pixels, each pixel having subpixels SP that display images and emit light.

[0031] The display panel 110 is divided into a bottom emission type that emits light downward from a transistor array, a top emission type that emits light upward from the transistor array, and a double emission type that emits light upward and downward.

[0032] The subpixels SP comprise a red, green, and blue subpixel, or a white, red, green, and blue pixel. The subpixels SP can comprise one or more emission regions depending on their emission properties.

[0033] As in Fig. 2, a single subpixel has a programming unit SC for setting a gate-source voltage of a driver transistor DR and an organic LED (OLED) positioned at an intersection of a data line DL1 and a scan line GL1.

[0034] The OLED has an anode (ANO), a cathode (CAT), and an organic emission layer located between the anode (ANO) and the cathode (CAT). The anode (ANO) is connected to the driver transistor (DR).

[0035] The programming unit SC can be implemented by a transistor array comprising at least one switching transistor and at least one capacitor. The transistor array is implemented based on a CMOS semiconductor, a PMOS transistor, or an NMOS transistor. Transistors included in the transistor array can be p-type or n-type transistors. Furthermore, semiconductor layers of the transistors included in the transistor array of the subpixel can comprise amorphous silicon, polysilicon, or oxide.

[0036] The switching transistor is turned on in response to a scan signal from the scan line GL1 to apply a data voltage from the data line DL1 to one electrode of the capacitor. The driver transistor DL ​​adjusts the emission amount of the OLED by controlling the current according to the voltage charged into the capacitor. The emission amount of the OLED is proportional to the current supplied by the driver transistor DR. Furthermore, the subpixel is connected to the first power line EVDD and the second power line EVSS and is supplied with the high voltage and the low voltage by them. As shown in Fig. As shown in Figure 3(a), in addition to the aforementioned switching transistor SW, the driver transistor DR, the capacitor, and the OLED, the subpixel may include an internal compensation circuit CC. The internal compensation circuit CC may include one or more transistors connected to a compensation signal line INIT. The internal compensation circuit CC sets a gate-source voltage of the driver transistor DR to a voltage at which the threshold voltage of the driver transistor DR has been reflected, in order to prevent a luminance change due to the threshold voltage of the driver transistor DR when the OLED emits light. In this case, the scan line GL1 includes at least two scan lines GL1a and GL1b for controlling the switching transistor SW and the transistors of the internal compensation circuit CC.

[0037] As in Fig. As shown in Figure 3(b), the subpixel may include a switching transistor SW1, a driver transistor DR, a detection transistor SW2, a capacitor Cst, and an OLED. The detection transistor SW2 may be included in the compensation circuit CC and performs a detection operation for the compensation operation of the subpixel.

[0038] The switching transistor SW1 serves to supply a first voltage value supplied via the data line DL1 to a first node N1 in response to a scan signal supplied via the first scan line GL1a. Additionally, the detection transistor SW2 initializes or detects a second node N2, positioned between the driver transistor DR and the OLED, in response to a detection signal supplied via the second detection line GL1b.

[0039] The subpixel circuit configurations used in Fig. 3 are merely illustrative of the present invention. That is, the subpixel circuit of the present invention is not limited thereto and can be configured in various configurations, such as 2T1C (2 transistors, 1 capacitor), 3T1C, 4T2C, 6T2C, and 7T2C. < Experimental example >

[0040] Fig. 4 is a cross-sectional view showing a part of a display area of ​​a display panel according to an experimental example.

[0041] As in Fig. 4, the display panel according to the experimental example includes a first substrate 110a, a transistor array TFTA, organic light-emitting diodes (OLEDs), a resin layer 125, a second substrate 110b, and a polarizing film 127.

[0042] The transistor array TFTA is positioned on the first substrate 110a. The transistor array TFTA includes switching transistors, capacitors, and driver transistors. The OLEDs are positioned on the transistor array TFTA. The OLEDs include a first electrode layer 119 connected to the source or drain electrodes of the driver transistors, an emission layer 121, and a second electrode layer 122. The resin layer 125 is positioned on the first substrate 110a and covers the OLEDs and the transistor array TFTA. The second substrate 110b is positioned on the resin layer 125.

[0043] First to third subpixels SP1 to SP3 included in the display panel are defined by a bank layer 120. The first to third subpixels SP1 to SP3 include elements included in the transistor array TFTA and the OLEDs.

[0044] The experimental example is a top-emission type display panel that emits light generated by OLEDs upward from the transistor array TFTA, that is, it emits light through the second substrate 110b. In the experimental example, the polarizing film 127 is disposed on the second substrate 110b to reduce the reflectance of the display panel caused by external light. The polarizing film 127 can be provided by being attached or laminated on the surface of the second substrate 110b. < First embodiment >

[0045] Fig. 5 is a cross-sectional view of an explanatory example showing a part of the display area of ​​the display panel. Fig. Fig. 6 is a plan view of a reflective electrode layer, a color filter layer, and a first electrode layer formed on the display panel of Fig. 5 are laminated, and Fig. 7 illustrates a display panel realized according to the first embodiment of the present invention.

[0046] As in Fig. As shown in Fig. 5, the display panel according to the first embodiment of the present invention includes a first substrate 110a, a transistor array TFTA, OLEDs, a protective layer 124, black matrix layers BM, color filters CF1, CF2 and CF3, and a second substrate 110b.

[0047] At least one of the first substrate 110a and the second substrate 110b may be formed from a material through which light can pass, such as glass, silicon, plastic, or resin. The transistor array TFTA is positioned on the first substrate 110a. The transistor array TFTA includes switching transistors, capacitors, and driver transistors.

[0048] The OLEDs are positioned on the transistor arrays TFTA. The OLEDs have a reflective electrode layer 118, a first electrode layer 119, an emission layer 121, and a second electrode layer 122. One of the reflective electrode layer 118 and the first electrode layer is directly connected to the source or drain electrodes of the driver transistors contained in the transistor array TFTA.

[0049] The reflective electrode layer 118 may be formed of a metallic material with a reflectance, such as Ag or Al. The first electrode layer 119 and the second electrode layer 122 serve as the anode and cathode (or vice versa). The emission layer 121 includes at least one emission layer. The emission layer 121 can generate white light, red light, green light, or blue light. The emission layer 121 can generate light of a specific color according to a combination of different colors generated by the first and second emission layers.

[0050] The protective layer 124 is positioned on the OLEDs. The protective layer 124 serves to protect the OLEDs and the transistor array TFTA from moisture or oxygen. The protective layer 124 is positioned on the first substrate 110a and covers the OLEDs and the transistor array TFTA. The protective layer 124 is formed in a monolayer or multilayer structure. The protective layer 124 has a flat surface. When the protective layer 124 is formed in a multilayer structure, the protective layer 124 may have a structure in which an organic material and an inorganic material are alternately laminated. The protective layer 124 may be defined as an encapsulation layer formed on the first substrate 110a to encapsulate the OLEDs and the transistor array TFTA.

[0051] The first to third subpixels SP1 to SP3 included in the display panel are defined by a bank layer 120. The bank layer 120 is positioned on the transistor array TFTA and has openings that selectively expose the first electrode layer 119. The openings of the bank layer 120 define the subpixel regions and emission areas. The first to third subpixels SP1 to SP3 include elements included in the transistor array TFTA and the OLEDs and are defined by the bank layer 120.

[0052] The black matrix layers BM are positioned on the protective layer 124. The black matrix layers BM include a black pigment to block the penetration of light. The black matrix layers BM are separated according to the bank layer 120 on the first substrate 110a. Regions where the black matrix layers BM are positioned are defined as non-emission regions, where no light is emitted, and regions where the black matrix layers BM are not positioned are defined as emission regions, where light is emitted.

[0053] In the first embodiment, color filters CF1, CF2, and CF3 are used to eliminate a polarizing film positioned on the display panel, and at least two of the color filters CF1, CF2, and CF3 are arranged at different levels. A structure for achieving this is described below.

[0054] The first subpixel SP1 includes the first color filter CF1 disposed between the reflective electrode layer 118 and the first electrode layer 119. That is, the first subpixel SP1 includes a layer that causes color change under the emission layer 121. A color change occurs in the first subpixel SP1 based on the first color filter CF1 disposed between the two electrode layers 118 and 119. Light generated by the emission layer 121 of the first subpixel SP1 is emitted through a path described below and changed into a first color.

[0055] A portion of the light generated by the emission layer 121 (light emitted from the upper part of the emission layer) passes through the second electrode layer 122, the protective layer 124, and the second substrate 110b to be projected into the air. The remaining portion of the light generated by the emission layer 121 (light emitted from the lower part of the emission layer) passes through the first electrode layer 119 and the first color filter CF1, is then reflected by the reflective electrode layer 118, passes through the first color filter CF1 again, and sequentially passes through all layers of the first color filter CF1 to be projected into the air. That is, a portion of the light generated by the emission layer 121 of the first subpixel SP1 passes through the first color filter CF1 at least twice.

[0056] The second subpixel SP2 includes the second color filter CF2 disposed between the reflective electrode layer 118 and the first electrode layer 119. That is, the second subpixel SP1 includes a layer that causes color change under the emission layer 121. A color change occurs in the second subpixel SP2 based on the second color filter CF2 disposed between the two electrode layers 118 and 119. Light generated by the emission layer 121 of the second subpixel SP2 is emitted through a path described below and changed into a second color.

[0057] A portion of the light generated by the emission layer 121 passes through the second electrode layer 122, the protective layer 124, and the second substrate 110b to be projected into the air. The remaining portion of the light generated by the emission layer 121 passes through the first electrode layer 119 and the second color filter CF2, is then reflected by the reflective electrode layer 118, passes through the second color filter CF2 again, and sequentially passes through all layers on the second color filter CF2 to be projected into the air. That is, a portion of the light generated by the emission layer 121 of the second subpixel SP2 passes through the second color filter CF2 at least twice.

[0058] The third subpixel SP3 includes the third color filter CF3 disposed on the protective layer 124. That is, the third subpixel SP3 does not include a layer that causes a color change under the emission layer 121. The third color filter CF3 includes a third first color filter CF3a and a third second color filter CF3b.

[0059] The third-first color filter CF3a may cover all or part of the surface of the black matrix layer BM disposed on the protective layer 124 of adjacent subpixels. The third and second color filters CF3b cover gaps between the black matrix layers BM disposed on the protective layer 124 of the third subpixel SP3. The third and second color filters CF3b may cover the sides and surfaces of the black matrix layers BM separated on both sides of the protective layer 124 of the third subpixel SP3. In such a case, the area CFA occupied by the third-second color filter CF3b is larger than the area occupied by the third subpixel SP. This is merely an example, and the third color filter CF3 may be positioned between the black matrix layers BM disposed on the protective layer 124 of the third subpixel SP3.

[0060] A color change occurs in the third subpixel SP3 based on the third color filter CF3 disposed on the protective layer 124. Light generated by the emission layer 121 of the third subpixel SP3 is emitted through a path described below and changed into a third color.

[0061] A portion of the light generated by the emission layer 121 passes through the second electrode layer 122, the protective layer 124, the third color filter CF3, and the second substrate 110b to be projected into the air. The remaining portion of the light generated by the emission layer 121 passes through the first electrode layer 119 and is then reflected by the reflective electrode layer 118, passes through the first electrode layer 119 again, and sequentially passes through all layers on the first electrode layer 119 to be projected into the air. That is, a portion of the light generated by the emission layer 121 of the third subpixel SP3 passes through the third color filter CF3 at least once.

[0062] As described above, in the first and second sub-pixels SP1 and SP2, light generated by the emission layer 121 passes through the first and second color filters CF1 and CF2 at least twice to be changed into the first color and the second color according to the reflective electrode layer 118. In contrast, in the third sub-pixel SP3, light generated by the emission layer 121 passes through the third color filter CF3 at least once to be changed into the third color, even if it is reflected by the reflective electrode layer 118.

[0063] A drive current (or drive voltage) for driving the OLEDs is applied through the reflective electrode layer 118 or the first electrode layer 119, which is connected to the source or drain electrodes of the driver transistors. The first and second color filters CF1 and CF2 may be formed from a material that exhibits conductivity and can cause a color change. However, if the color filter layer is formed from a non-conductive or non-metallic material, the first and second color filters CF1 and CF2 may be formed from a material that creates resistance between the two electrode layers 118 and 119.

[0064] On the other hand, when both the reflective electrode layer 118 and the first electrode layer 119 are connected to the source or drain electrodes of the driver transistors, even if the first and second color filters CF1 and CF2 are disposed between the reflective electrode layer 118 and the first electrode layer 119, problems such as an increase in contact resistance do not occur. However, when one of the reflective electrode layer 118 and the first electrode layer 119 is connected to the source or drain electrodes of the driver transistors (particularly when the first electrode layer is connected to the source or drain electrodes via the reflective electrode layer), it is desirable to provide the first and second color filters CF1 and CF2 as shown in Fig. 6 shown.

[0065] Although the following description is based on the first subpixel SP1, the same applies to the second subpixel SP2. Although the reflective electrode layer 118 and the first electrode layer 119 are assumed to have the same size, this is still exemplary, and they may have different sizes.

[0066] As in Fig. As shown in Figure 6(a), the first color filter CF1 can be arranged between the reflective electrode layer 118 and the first electrode layer 119, which have a contact area CNTA where the reflective electrode layer 118 and the first electrode layer 119 contact each other on their sides. The first electrode layer 119 covers the first color filter CF1 and contacts one side of the reflective electrode layer 118.

[0067] As in Fig. As shown in Figure 6(b), the first color filter CF1 may be disposed between the reflective electrode layer 118 and the first electrode layer 119, which have a contact area CNTA where the reflective electrode layer 118 and the first electrode layer 119 contact each other across their entire edges. The first electrode layer 119 covers the first color filter CF1 and contacts the entire edges of the reflective electrode layer 118. That is, the first color filter CF1 is encapsulated by the reflective electrode layer 118 and the first electrode layer 119.

[0068] As in Fig. As shown in Figure 6(c), the first color filter CF1 may be arranged between the reflective electrode layer 118 and the first electrode layer 119, which have a contact area CNTA where the reflective electrode layer 118 and the first electrode layer 119 contact each other on both sides. The first electrode layer 119 covers the first color filter CF1 and contacts both sides of the reflective electrode layer 118.

[0069] As in the examples of Fig. 6, since the first color filter CF1 is disposed between the reflective electrode layer 118 and the first electrode layer 119, it is desirable that the first color filter CF1 be smaller than the two electrode layers 118 and 119. However, when both the reflective electrode layer 118 and the first electrode layer 119 are electrically connected, the size of the first color filter CF1 may be equal to or larger than the two electrode layers 118 and 119.

[0070] Hereinafter, a display panel structure realized taking into account the characteristics of the emission layer and the color filter layer based on the first embodiment of the present invention will be described with focus on specific parts with reference to Fig. 6 described.

[0071] As in Fig. As shown in Figure 7, a red subpixel SPR and a green subpixel SPG have the same structure, while a blue subpixel SPB has a different structure than the red subpixel SPR and the green subpixel SPG.

[0072] The emission layer 121 of the red subpixel SPR emits red light, the emission layer 121 of the green subpixel SPG emits green light, and the emission layer 121 of the blue subpixel SPB emits blue light.

[0073] The red subpixel SPR and the green subpixel SPG have a red color filter CFR and a green color filter CFG, respectively, arranged between the two electrode layers 118 and 119, while the blue subpixel SPB has a blue protection filter CFB arranged on the protection layer 124 instead of being arranged between the two electrode layers 118 and 119.

[0074] Light emitted directly through the emission layer 121 by the red subpixel SPR, the green subpixel SPG, and the blue subpixel SPB, and light reflected and projected by the reflective electrode layer 118 are combined. Accordingly, the light generated by the emission layer of each subpixel must have the same color as the color of the color filter disposed in each subpixel. Furthermore, the red subpixel SPR, the green subpixel SPG, and the blue subpixel SPB must be arranged according to the emission regions, even though they are located at different positions.

[0075] The blue color filter CFB includes a first blue color filter CFBa covering the surface of the black matrix layer BM positioned corresponding to the bank layer defining the red subpixel SPR and the green subpixel SPG, and a second blue color filter CFBb covering the surfaces and sides of the black matrix layers BM positioned corresponding to the bank layer defining the blue subpixel SPB and its emission region.

[0076] The first blue color filter CFBa is positioned on the surface of the black matrix layer BM, which is positioned corresponding to the bank layer defining the red subpixel SPR and the green subpixel SPG. The reflectance of the black matrix layer BM is further reduced according to the first blue color filter CFBa covering the black matrix layer BM, because the first blue color filter CFBa has a lower reflectance than the black matrix layer BM. Furthermore, in the red subpixel SPR and the green subpixel SPG, non-emission regions are covered by the blue color filter instead of the red color filter and the green color filter included in the red subpixel SPR and the green subpixel SPG, thus also reducing the possibility of color mixing between subpixels.

[0077] Based on the test results described below, the red, green and blue color filters CFR, CFG and CFB are arranged separately between the electrode layers 118 and 119 and on the protective layer 124 positioned in the emission regions, while the emission layers 121 included in the red, green and blue subpixels SPR, SPG and SPB, respectively, emit red light, green light and blue light, as shown in the diagram in Fig. Structure shown in Figure 7.

[0078] The penetration and reflection properties of the red, green, and blue color filters CFR, CFG, and CFB were tested using the red, green, and blue color filters CFR, CFG, and CFB. According to the test results, the red, green, and blue color filters CFR, CFG, and CFB have reflectance as low as that of a polarizing film, while exhibiting penetration properties superior to that of a polarizing film. Namely, the implementation example of the first embodiment relies on the reflectivity of the red, green, and blue color filters CFR, CFG, and CFB, in addition to their color-changing capability.

[0079] According to an implementation of the first embodiment, it is possible to reduce the reflectance of the display panel to a level obtained when a polarizing film is attached to the display panel using a structure in which the color filters are separately arranged in the subpixels that emit red light, green light, and blue light. Furthermore, according to an implementation of the first embodiment, the reflectance can be reduced by using color filters instead of a polarizing film, and therefore, the luminance can be increased, and the manufacturing cost can be reduced because the polarizing film can be eliminated. Furthermore, according to an implementation of the first embodiment, it is possible to realize a flexible organic light-emitting display device because a thin display panel can be achieved due to the elimination of the polarizing film.Furthermore, according to an implementation of the first embodiment, the blue color filter covers non-emission areas instead of the red and green color filters, and therefore the possibility of color mixing occurring between subpixels can be reduced.

[0080] Simulation results and effects obtained when the red subpixel SPR and the green subpixel SPF are realized in the same structure and the blue subpixel SPB is realized in a different structure as in the implementation example of the first embodiment are shown in the Fig. 10 and Fig. 11 can be seen. <Zweite Ausführungsform>

[0081] Fig. 8 is a cross-sectional view of an explanatory example showing a part of the display area of ​​the display panel. Fig. 9 illustrates a display panel realized according to the second embodiment of the present invention.

[0082] As in Fig. As shown in Fig. 8, the display panel according to the second embodiment of the present invention includes a first substrate 110a, a transistor array TFTA, OLEDs, a protective layer 124, color filters CF1, CF2 and CF3, and a second substrate 110b.

[0083] At least one of the first substrate 110a and the second substrate 110b may be formed of a material through which light can pass, such as glass, silicon, plastic, or resin. The transistor array TFTA is positioned on the first substrate 110a. The transistor array TFTA includes switching transistors, capacitors, and driver transistors.

[0084] The OLEDs are positioned on the transistor arrays TFTA. The OLEDs have a reflective electrode layer 118, a first electrode layer 119, an emission layer 121, and a second electrode layer 122. One of the reflective electrode layer 118 and the first electrode layer is directly connected to the source or drain electrodes of the driver transistors contained in the transistor array TFTA.

[0085] The reflective electrode layer 118 may be formed of a metallic material with a reflectance, such as Ag or Al. The first electrode layer 119 and the second electrode layer 122 serve as the anode and cathode (or vice versa). The emission layer 121 includes at least one emission layer. The emission layer 121 can generate white light, red light, green light, or blue light. The emission layer 121 can generate light of a specific color according to a combination of different colors generated by the first and second emission layers.

[0086] The protective layer 124 is positioned on the OLEDs. The protective layer 124 has a flat surface. The protective layer 124 serves to protect the OLEDs and the transistor array TFTA from moisture or oxygen. The protective layer 124 is positioned on the first substrate 110a and covers the OLEDs and the transistor array TFTA. The protective layer 124 is formed in a monolayer or multilayer structure. When the protective layer 124 is formed in a multilayer structure, the protective layer 124 may have a structure in which an organic material and an inorganic material are alternately laminated. The protective layer 124 may be defined as an encapsulation layer formed on the first substrate 110a to encapsulate the OLEDs and the transistor array TFTA.

[0087] First to third subpixels SP1 to SP3 included in the display panel are defined by a bank layer 120. The bank layer 120 is positioned on the transistor array TFTA and has openings that selectively expose the first electrode layer 119. The openings of the bank layer 120 define the subpixel regions and emission areas. The first to third subpixels SP1 to SP3 comprise elements included in the transistor array TFTA and the OLEDs and are defined by the bank layer 120.

[0088] The third color filter CF3 is positioned on the protective layer 124. The third color filter CF3 includes a third first color filter CF3a and a third second color filter CF3b. The third first color filter CF3a is isolated and arranged corresponding to the bank layer 120 on the first substrate 110a. The third and second color filters CF3b are arranged corresponding to the emission region of the third subpixel SP3. The third and second color filters CF3b may extend to both sides of the protective layer 124 to cover the bank layer 120, which is arranged on both sides of the third subpixel SP3. In such a case, the area CFA occupied by the third second color filter CF3b is larger than the area occupied by the third subpixel SP3. However, this is exemplary, and the third color filter CF3 may be arranged on the protective layer 124 to correspond only to the emission region of the third subpixel SP3.

[0089] In the second embodiment, color filters CF1, CF2, and CF3 are used to eliminate a polarizing film positioned on the display panel, and at least two of the color filters CF1, CF2, and CF3 are arranged at different levels. A structure for achieving this is described below.

[0090] The first subpixel SP1 includes the first color filter CF1 disposed between the reflective electrode layer 118 and the first electrode layer 119. That is, the first subpixel SP1 includes a layer that causes color change under the emission layer 121. A color change occurs in the first subpixel SP1 based on the first color filter CF1 disposed between the two electrode layers 118 and 119. Light generated by the emission layer 121 of the first subpixel SP1 is emitted through a path described below and changed into a first color.

[0091] A portion of the light generated by the emission layer 121 (light emitted from the upper part of the emission layer) passes through the second electrode layer 122, the protective layer 124, and the second substrate 110b to be projected into the air. The remaining portion of the light generated by the emission layer 121 (light emitted from the lower part of the emission layer) passes through the first electrode layer 119 and the first color filter CF1, is then reflected by the reflective electrode layer 118, passes through the first color filter CF1 again, and sequentially passes through all layers of the first color filter CF1 to be projected into the air. That is, a portion of the light generated by the emission layer 121 of the first subpixel SP1 passes through the first color filter CF1 at least twice.

[0092] The second subpixel SP2 includes the second color filter CF2 disposed between the reflective electrode layer 118 and the first electrode layer 119. That is, the second subpixel SP1 includes a layer that causes color change under the emission layer 121. A color change occurs in the second subpixel SP2 based on the second color filter CF2 disposed between the two electrode layers 118 and 119. Light generated by the emission layer 121 of the second subpixel SP2 is emitted through a path described below and changed into a second color.

[0093] A portion of the light generated by the emission layer 121 passes through the second electrode layer 122, the protective layer 124, and the second substrate 110b to be projected into the air. The remaining portion of the light generated by the emission layer 121 passes through the first electrode layer 119 and the second color filter CF2, is then reflected by the reflective electrode layer 118, passes through the second color filter CF2 again, and sequentially passes through all layers on the second color filter CF2 to be projected into the air. That is, a portion of the light generated by the emission layer 121 of the second subpixel SP2 passes through the second color filter CF2 at least twice.

[0094] The third subpixel SP3 includes the third color filter CF3 disposed on the protective layer 124. That is, the third subpixel SP3 does not include a layer that causes color change under the emission layer 121. A color change occurs in the third subpixel SP3 based on the third color filter CF3 disposed on the protective layer 124. Light generated by the emission layer 121 of the third subpixel SP3 is emitted through a path described below and changed into a third color.

[0095] A portion of the light generated by the emission layer 121 passes through the second electrode layer 122, the protective layer 124, the third color filter CF3, and the second substrate 110b to be projected into the air. The remaining portion of the light generated by the emission layer 121 passes through the first electrode layer 119 and is then reflected by the reflective electrode layer 118, passes through the first electrode layer 119 again, and sequentially passes through all layers on the first electrode layer 119 to be projected into the air. That is, a portion of the light generated by the emission layer 121 of the third subpixel SP3 passes through the third color filter CF3 at least once.

[0096] As described above, in the first and second sub-pixels SP1 and SP2, light generated by the emission layer 121 passes through the first and second color filters CF1 and CF2 at least twice to be changed into the first color and the second color according to the reflective electrode layer 118. In contrast, in the third sub-pixel SP3, light generated by the emission layer 121 passes through the third color filter CF3 at least once to be changed into the third color, even if it is reflected by the reflective electrode layer 118.

[0097] A drive current (or drive voltage) for driving the OLEDs is applied through the reflective electrode layer 118 or the first electrode layer 119, which is connected to the source or drain electrodes of the driver transistors. The first and second color filters CF1 and CF2 may be formed from a material that exhibits conductivity and can cause a color change. However, if the color filter layer is formed from a non-conductive or non-metallic material, the first and second color filters CF1 and CF2 may be formed from a material that creates resistance between the two electrode layers 118 and 119.

[0098] On the other hand, when both the reflective electrode layer 118 and the first electrode layer 119 are connected to the source or drain electrodes of the driver transistors, even if the first and second color filters CF1 and CF2 are disposed between the reflective electrode layer 118 and the first electrode layer 119, problems such as an increase in contact resistance do not occur. However, when one of the reflective electrode layer 118 and the first electrode layer 119 is connected to the source or drain electrodes of the driver transistors (especially when the first electrode layer is connected to the source or drain electrodes via the reflective electrode layer), it is desirable to provide the first and second color filters CF1 and CF2 according to the structure of Fig. 6 described in the first embodiment. However, the present invention is not limited thereto.

[0099] Hereinafter, a display panel structure realized taking into account the characteristics of the emission layer and the color filter layer based on the second embodiment of the present invention will be described with focus on specific parts with reference to Fig. 8 described.

[0100] As in Fig. As shown in Figure 9, a red subpixel SPR and a green subpixel SPG have the same structure, while a blue subpixel SPB has a different structure than the red subpixel SPR and the green subpixel SPG.

[0101] The emission layer 121 of the red subpixel SPR emits red light, the emission layer 121 of the green subpixel SPG emits green light, and the emission layer 121 of the blue subpixel SPB emits blue light.

[0102] The red subpixel SPR and the green subpixel SPG have a red color filter CFR and a green color filter CFG, respectively, arranged between the two electrode layers 118 and 119, while the blue subpixel SPB has a blue protection filter CFB arranged on the protection layer 124 instead of being arranged between the two electrode layers 118 and 119.

[0103] The blue color filter CFB includes a first blue color filter CFBa positioned corresponding to the bank layer defining the red subpixel SPR and the green subpixel SPG, and a second blue color filter CFBb positioned corresponding to the bank layer defining the blue subpixel SPB and its emission region.

[0104] Light emitted directly through the emission layer 121 by the red subpixel SPR, the green subpixel SPG, and the blue subpixel SPB, and light reflected and projected by the reflective electrode layer 118 are combined. Accordingly, the light generated by the emission layer of each subpixel must have the same color as the color of the color filter disposed in each subpixel. Furthermore, the red subpixel SPR, the green subpixel SPG, and the blue subpixel SPB must be arranged according to the emission regions, even though they are located at different positions.

[0105] Based on the test results described below, the red, green and blue color filters CFR, CFG and CFB are arranged separately between the electrode layers 118 and 119 and on the protective layer 124, which are positioned in the emission regions, while the emission layers 121 included in the red, green and blue subpixels SPR, SPG and SPB, respectively, emit red light, green light and blue light, as shown in the diagram in Fig. Structure shown in Figure 9.

[0106] The penetration and reflection properties of the red, green, and blue color filters CFR, CFG, and CFB were tested using the red, green, and blue color filters CFR, CFG, and CFB. According to the test results, the red, green, and blue color filters CFR, CFG, and CFB have reflectance as low as that of a polarizing film, while exhibiting penetration properties superior to that of a polarizing film. The implementation example of the second embodiment is based on the reflectivity of the red, green, and blue color filters CFR, CFG, and CFB, in addition to their color-changing capability.

[0107] According to an implementation of the second embodiment, it is possible to reduce the reflectance of the display panel to a level obtained when a polarizing film is attached to the display panel using a structure in which the color filters are separately arranged in the subpixels that emit red light, green light, and blue light. Furthermore, according to an implementation of the second embodiment, the reflectance can be reduced by using color filters instead of a polarizing film, and therefore, the luminance can be increased, and the manufacturing cost can be reduced because the polarizing film can be eliminated. Furthermore, according to an implementation of the second embodiment, it is possible to realize a flexible organic light-emitting display device because a thin display panel can be achieved due to the elimination of the polarizing film.

[0108] Simulation results and effects obtained when the red subpixel SPR and the green subpixel SPF are realized in the same structure and the blue subpixel SPB is realized in a different structure as in the implementation example of the second embodiment are shown in the Fig. 10 and Fig. 11 can be seen.

[0109] Fig. 10 shows reflectance test results for display panel configurations, and Fig. Figure 11 shows simulation results obtained from reflectance tests based on the Fig. 7 and Fig. 9 were received.

[0110] Referring to Fig. 10, a glass substrate GLS has a reflectance (%) of 8.93, a polarizing film POL has a reflectance (%) of 5.43, a structure in which a black matrix layer BM and a glass substrate GLS are sequentially laminated has a reflectance (%) of 7.25, and a structure in which a glass substrate GLS and a black matrix layer BM are sequentially laminated has a reflectance (%) of 10.79.

[0111] In addition, a structure in which a red color filter CFR and a glass substrate GLS are sequentially laminated has a reflectance (%) of 7.37, a structure in which a green color filter CFG and a glass substrate GLS are sequentially laminated has a reflectance (%) of 7.75, a structure in which a blue color filter CFB and a glass substrate GLS are sequentially laminated has a reflectance (%) of 6.49, and the average reflectance (%) thereof is 7.2.

[0112] According to the reflectance test results for display board configurations, the blue color filter CFB has the lowest reflectance among the red, green, and blue color filters CFR, CFG, and CFB.

[0113] As in Fig. 11, the Fig. 7 and Fig. 9 according to the first and second embodiments of the present invention, examples of structures applied to a display panel based on the fact that the blue color filter CFB has the lowest reflectance from the test results of Fig. 10. Fig. Figure 11 shows results of simulations of the reflectance properties of the Fig. 7 and Fig. 9 according to the first and second embodiments compared to the experimental example of Fig. 4, to the structures of the Fig. 7 and Fig. 9 to be evaluated.

[0114] Regarding the experimental example, a simulation result was obtained when the display panel had a transmittance of 43% and a luminance of 100 nits due to the polarizing film attached to it. According to the simulation result, the display panel of the experimental result had a reflectivity (%) of 5.43.

[0115] With respect to the first embodiment, a simulation result was obtained when a display panel arranged in the manner shown in Fig. 7, has a transmittance of 90%, which is the average of the transmittances of a red, green, and blue color filter, and a luminance of 90.3 nits. Regarding the second embodiment, a simulation result was obtained when a display panel formed in the structure shown in Fig. 9, has a transmittance of 90%, which is the average of the transmittances of a red, green, and blue color filter, and a luminance of 90.3 nits. According to the simulation results, the display panels of both the first and second embodiments have a reflectance (%) of 5.8.

[0116] As can be seen from the simulation results, the first and second embodiments achieve more than twice the luminance improvement compared to the experimental example due to an increase in transmittance due to the elimination of the polarizing film, while achieving a reflectance equivalent to that of a structure including the polarizing film, such as the experimental example. That is, the first and second embodiments can minimize the loss of light generated by the emission layer.

[0117] As described above, the first and second embodiments can achieve a reflectance equivalent to that obtained using a polarizing film without a polarizing film and minimize light loss, and therefore, an organic light-emitting display device with high efficiency and low reflectance can be provided.

[0118] Meanwhile, the reason why the red and green subpixels R and G in the first and second embodiments have a different luminance from the blue subpixel B will be described below.

[0119] Light generated by the emission layers of the red and green subpixels R and G has the same luminance of 33.3 nits as the light generated by the emission layer of the blue subpixel B. However, light generated by the emission layers of the red and green subpixels R and G is projected downward and upward as described above. Here, the downward projected light passes through the color filter layer at least twice due to the influence of the reflective electrode layer. Light generated by the emission layers of the blue subpixel B is projected downward and upward. Here, the upward and downward projected light passes through the color filter layer only once, even if it is affected by the reflective electrode layer.

[0120] As a result, the red and green subpixels R and G have a luminance of 16.7 nits (amount corresponding to the light emitted from the upper part of the emission layers) + (16.7 nits×0.9×0.9) (amount corresponding to the light emitted from the lower part of the emission layers × amount corresponding to the light that has passed through the color filter layer twice) = 30.2 nits, and the blue subpixel B has a luminance of 33.3 nits (amount corresponding to the light emitted from the upper and lower parts) × 0.9 (amount corresponding to the light that has passed through the color filter layer once).

[0121] According to the test results, the reflectance of the blue color filter CFB was lower than the surface reflectance of the black matrix layer BM. That is, BM > CFB.

[0122] When manufacturing a display panel, the property that the blue color filter CFB has a lower reflectance than the black matrix layer BM can be used. Representative examples are shown in the Fig. 7 and Fig. 9. When the blue color filter CFB covers the surface of the black matrix layer BM, as shown in the Fig. 7 and Fig. As shown in Figure 9, the reflectance of the display panel can be further reduced to obtain the advantage of a low reflectance structure.

[0123] However, the structures according to the first and second embodiments can be modified into a structure according to a third embodiment, which will be described below. In the third embodiment, only parts that are modified from the structures according to the first and second embodiments will be described. <Dritte Ausführungsform>

[0124] The Fig. 12 and Fig. 13 are cross-sectional views of explanatory examples showing a part of a display area of ​​a display panel.

[0125] As in the Fig. 12 and Fig. As shown in Figure 13, the third color filter CF3 may be disposed only on the protective layer 124 corresponding to the third subpixel SP3 according to the third embodiment. The third color filter CF3 may be disposed corresponding to the emission regions or the bank layer 120 and the emission regions.

[0126] When the black matrix layers BM are positioned on the protective layer 124 as shown in Fig. As shown in Figure 12, the third color filter CF3 may cover the sides and surfaces of the black matrix layers BM separated on both sides of the protective layer 124 of the third subpixel SP3. However, the present invention is not limited thereto.

[0127] The first to third embodiments described above are exemplary, and therefore one or more of them may be appropriately combined according to the material properties of a display panel to be modified.

[0128] As described above, the present invention can reduce the reflectance of the display panel to a level equivalent to that obtained when a polarizing film is used while eliminating the polarizing film and minimizing light loss, and therefore can provide an organic light-emitting display device with high efficiency and low reflectance. Furthermore, the present invention can easily realize a flexible organic light-emitting display device by eliminating the polarizing film. Furthermore, the present invention can reduce the manufacturing cost by eliminating the polarizing film. Furthermore, by using the color filter layer, the present invention can prevent color mixing between subpixels.

Claims

[1] A light-emitting display device comprising: a display board (110); and Subpixels positioned in a display area of the display panel (110), wherein at least one of the subpixels comprises a color filter arranged between two electrode layers (118, 119), and at least another of the subpixels comprises a color filter arranged on a protective layer (124) on the two electrode layers (118, 119), wherein the subpixels comprise a red, a green and a blue subpixel, wherein the red subpixel has a red color filter (CFR) arranged between the two electrode layers (118, 119), the green subpixel has a green color filter (CFG) arranged between the two electrode layers (118, 119), and the blue subpixel has a blue color filter (CFB) arranged on the protective layer (124) covering a light-emitting diode (OLED), wherein the blue color filter (CFB) included in the blue subpixel comprises a first blue color filter (CFBa) arranged corresponding to a bank layer (120) defining emission regions for a red and a green subpixel, and a second blue color filter (CFBb) arranged corresponding to an emission region of the blue subpixel and the bank layer (120) defining the emission region of the blue subpixel. [2] The light-emitting display device according to claim 1, further comprising a blue color filter (CFB), wherein the blue color filter (CFB) is disposed on a black matrix layer (BM) defining non-emission regions of the red and green subpixels. [3] The light-emitting display device according to claim 1, further comprising a black matrix layer (BM) positioned between the protective layer (124) and the first blue color filter (CFBa) and between the protective layer (124) and the second blue color filter (CFBb). [4] The light-emitting display device according to claim 3, wherein the first blue color filter (CFBa) covers a surface of the black matrix layer (BM) and the second blue color filter (CFBb) covers the surface and one side of the black matrix layer (BM). [5] The light-emitting display device according to claim 1, wherein the red color filter (CFR) is arranged corresponding to the emission region of the red sub-pixel and the green color filter (CFG) is arranged corresponding to the emission region of the green sub-pixel. [6] A light-emitting display device according to any one of the preceding claims, wherein the two electrode layers (118, 119) comprise a reflective electrode layer (118) positioned on a first substrate (110a) of the display panel (110) and a first electrode layer (119) positioned on the reflective electrode layer (118). [7] The light-emitting display device according to claim 6, wherein the reflective electrode layer (118) and the first electrode layer (119) electrically contact each other at one or both sides thereof, or wherein the reflective electrode layer (118) and the first electrode layer (119) electrically contact each other at the entire edges thereof. [8] A light-emitting display device according to any one of the preceding claims, wherein the color filter disposed between the two electrode layers (118, 119) has a size equal to or smaller than the first electrode layer (119). [9] A light-emitting display device according to any preceding claim, wherein the protective layer (124) is formed in a single-layer or multi-layer structure covering the subpixels and having a flat surface.

Images