Organic light-emitting diode (OLED) display device

Abstract

This invention relates to an organic light-emitting display device. [Solution] The organic light-emitting display device includes a substrate, a first voltage line and a second voltage line on the substrate, a first scan line and a second scan line arranged sequentially on the substrate in a plan view, a data line that intersects the first scan line and the second scan line, a first thin-film transistor connected to the second scan line and the data line and located around the second scan line, a second thin-film transistor connected to the first thin-film transistor, an OLED connected to the first voltage line and the second thin-film transistor, a third thin-film transistor connected to the second thin-film transistor, the OLED and the second scan line and located around the second scan line, a fourth thin-film transistor connected to the second thin-film transistor and the third thin-film transistor and located around the first scan line, and a storage capacitor element connected to the second thin-film transistor and located on the opposite side of the first scan line from the second scan line.

Description

Technical Field

[0001] The present invention relates to an organic light emitting display device.

Background Art

[0002] An organic light emitting display device includes two electrodes and an organic light emitting layer positioned therebetween. Electrons injected from one electrode and holes injected from the other electrode combine in the organic light emitting layer to form excitons, and the excitons emit light while releasing energy.

[0003] Such an organic light emitting display device includes a plurality of pixels each including an organic light emitting diode which is a self-emitting element, and a plurality of thin film transistors and capacitors for driving the organic light emitting diode are formed in each pixel. The plurality of thin film transistors basically include a switching thin film transistor and a driving thin film transistor.

[0004] For the switching thin film transistor, a thin gate insulating film is formed between the gate electrode and the semiconductor layer for a rapid switching operation. At this time, since the thickness of the gate insulating film of the driving thin film transistor formed in the same layer as the switching thin film transistor also becomes thin, the driving range of the gate voltage applied to the gate electrode of the driving thin film transistor (driving range) becomes narrow. Therefore, it is difficult to control by adjusting the magnitude of the gate voltage (Vgs) of the driving thin film transistor to have a rich gradation.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been devised to solve the problems of the background art as described above, and relates to an organic light emitting display device capable of expanding the driving range of a driving thin film transistor to express a rich gradation.

Means for Solving the Problems

[0006] An organic light-emitting display device according to one embodiment of the present invention includes a substrate, scan lines formed on the substrate for transmitting scan signals, data lines and drive voltage lines that intersect the scan lines and transmit data signals and drive voltages, respectively, a switching thin-film transistor connected to the scan lines and the data lines, a drive thin-film transistor connected to the switching drain electrode of the switching thin-film transistor, and an organic light-emitting diode connected to the drive drain electrode of the drive thin-film transistor, wherein the drive semiconductor layer of the drive thin-film transistor may be bent.

[0007] The system may further include a first gate insulating film covering the drive semiconductor layer, and a storage capacitor formed on the first gate insulating film and superimposed on the drive semiconductor layer.

[0008] The storage capacitor may include a first storage capacitor formed on the first gate insulating film and superimposed on the drive semiconductor layer, a second gate insulating film covering the first storage capacitor, and a second storage capacitor formed on the second gate insulating film and superimposed on the first storage capacitor.

[0009] The driving semiconductor layer may include a plurality of bent portions.

[0010] The drive semiconductor layer has a plurality of first extensions extending in a first direction and a portion that is different from the first direction. The bending portion includes a plurality of second extensions extending in a second direction, and the bending portion may connect the first extension and the second extensions.

[0011] The system may further include a compensating thin-film transistor that compensates for the threshold voltage of the driving thin-film transistor and is connected to the driving thin-film transistor.

[0012] The present invention further includes a light-emitting control thin-film transistor that turns on in response to a light-emitting control signal transmitted by a light-emitting control line and transmits a drive voltage from the drive thin-film transistor to the organic light-emitting diode, wherein the light-emitting control thin-film transistor may be located between the drive drain electrode of the drive thin-film transistor and the organic light-emitting diode.

[0013] The compensation source electrode of the compensation thin film transistor and the light emission control source electrode of the light emission control thin film transistor are connected through a transistor coupling portion, and the storage capacitor may be extended and superimposed on the transistor coupling portion.

[0014] The drive semiconductor layer may be extended and superimposed on the transistor coupling portion.

[0015] The transistor connection portion may be formed in the same layer as the data line and may be connected to the compensation source electrode and the light emission control source electrode through contact holes formed in the interlayer insulating film.

[0016] The driving semiconductor layer may further include branching portions that branch off from the bending portion.

[0017] The storage capacitor may be extended and superimposed on the branch section.

[0018] The driving semiconductor layer includes a first path semiconductor layer connected to the compensation thin film transistor and a second path semiconductor layer connected to the light emission control thin film transistor, wherein the length of the first path semiconductor layer may be shorter than the length of the second path semiconductor layer.

[0019] The storage capacitor may be extended and superimposed on the first path semiconductor layer and the second path semiconductor layer.

[0020] An interlayer insulating film covering the second storage battery plate, a connecting member formed on the interlayer insulating film and connected to the first storage battery plate through a contact hole formed in the second gate insulating film and the interlayer insulating film, and a protective film covering the interlayer insulating film and the connecting member are further included, and the connecting member may be connected to the compensation drain electrode of the compensation thin film transistor.

[0021] The scan line is formed in the same layer as the first storage battery plate, and the data line and the drive voltage line may be formed in the same layer as the connecting member.

[0022] The drive voltage line may be connected to the second storage battery plate through a contact hole formed in the interlayer insulating film.

[0023] An operation control thin film transistor that is turned on by a light emission control signal transmitted by the light emission control line and transmits the drive voltage to the drive thin film transistor is further included, and the operation control thin film transistor may be located between the drive voltage line and the drive source electrode of the drive thin film transistor.

[0024] An initialization thin film transistor that is turned on by a previous scan signal transmitted through the scan line before and transmits an initialization voltage transmitted through the initialization voltage line to the drive gate electrode of the drive thin film transistor is further included, and the initialization thin film transistor may be located between the initialization voltage line and the drive gate electrode of the drive thin film transistor.

[0025] A bypass thin film transistor that bypasses a part of the drive current transmitted by the drive thin film transistor by a bypass control signal transmitted by the bypass control line is further included, and the bypass thin film transistor may be located between the initialization voltage line and the light emission control drain electrode of the light emission control thin film transistor.

[0026] An organic light-emitting display device according to another embodiment of the present invention includes a substrate, a scan line and an initialization voltage line formed on the substrate and transmitting a scan signal and an initialization voltage respectively, a data line and a drive voltage line intersecting the scan line and transmitting a data signal and a drive voltage respectively, a switching thin film transistor connected to the scan line and the data line, a drive thin film transistor connected to a switching drain electrode of the switching thin film transistor, an organic light-emitting diode connected to a drive drain electrode of the drive thin film transistor, a light-emitting control thin film transistor positioned between the drive drain electrode of the drive thin film transistor and the organic light-emitting diode, and a bypass thin film transistor positioned between the initialization voltage line and a light-emitting control drain electrode of the light-emitting control thin film transistor. The bypass thin film transistor may bypass a part of a drive current transmitted by the drive thin film transistor by a bypass control signal transmitted by a bypass control line.

[0027] The drive semiconductor layer of the drive thin film transistor may be bent.

[0028] It may further include a first gate insulating film covering the drive semiconductor layer and a storage capacitor formed on the first gate insulating film and overlapping the drive semiconductor layer.

[0029] The storage capacitor may include a first storage capacitor plate formed on the first gate insulating film and overlapping the drive semiconductor layer, a second gate insulating film covering the first storage capacitor plate, and a second storage capacitor plate formed on the second gate insulating film and overlapping the first storage capacitor plate.

[0030] The drive semiconductor layer may include a plurality of bent portions, the drive semiconductor layer may include a plurality of first extension portions extending in a first direction and a plurality of second extension portions extending in a second direction different from the first direction, and the bent portions may connect the first extension portions and the second extension portions.

[0031] The system may further include a compensating thin-film transistor that compensates for the threshold voltage of the driving thin-film transistor and is connected to the driving thin-film transistor.

[0032] The invention further includes an interlayer insulating film covering the second storage energy storage plate, a connecting member formed on the interlayer insulating film and connected to the first storage energy storage plate through contact holes formed in the second gate insulating film and the interlayer insulating film, and a protective film covering the interlayer insulating film and the connecting member, wherein the connecting member may be connected to the compensation drain electrode of the compensation thin film transistor.

[0033] The scan lines may be formed in the same layer as the first storage battery plate, and the data lines and drive voltage lines may be formed in the same layer as the connecting member.

[0034] The drive voltage line may be connected to the second storage energy storage plate through a contact hole formed in the interlayer insulating film. [Effects of the Invention]

[0035] According to the present invention, by forming a driving semiconductor layer that includes multiple bent portions, the driving channel region of the driving semiconductor layer can be made longer, thereby widening the driving range of the gate voltage applied to the driving gate electrode.

[0036] Therefore, because the gate voltage has a wide driving range, the magnitude of the gate voltage can be changed, allowing for more precise control of the gradation of light emitted from the organic light-emitting diode (OLED). As a result, the resolution of the organic light-emitting display device can be increased, improving the display quality.

[0037] Furthermore, by forming a storage capacitor superimposed on the drive semiconductor layer to secure the storage capacitor area reduced by the drive semiconductor layer having a bent portion, sufficient storage capacitance can be secured even at high resolutions.

[0038] Furthermore, by forming the first path semiconductor layer connected to the compensation thin-film transistor to be shorter than the second path semiconductor layer connected to the light emission control thin-film transistor, low-gradation unevenness can be prevented. [Brief explanation of the drawing]

[0039] [Figure 1] This is an equivalent circuit diagram of one pixel of an organic light-emitting display device according to the first embodiment of the present invention. [Figure 2] This diagram schematically shows the positions of multiple thin-film transistors and capacitors in an organic light-emitting display device according to the first embodiment of the present invention. [Figure 3] This is a specific arrangement diagram of one pixel of an organic light-emitting display device according to the first embodiment of the present invention. [Figure 4] Figure 3 is a cross-sectional view of the organic light-emitting device taken along line IV-IV. [Figure 5] Figure 3 is a cross-sectional view of the organic light-emitting device cut along the VV line. [Figure 6] This is an enlarged arrangement diagram of the driving thin-film transistors of an organic light-emitting display device according to a second embodiment of the present invention. [Figure 7] This is a layout diagram of an organic light-emitting display device according to a third embodiment of the present invention. [Figure 8] This is an enlarged arrangement diagram of the driving thin-film transistors of the organic light-emitting display device according to the fourth embodiment of the present invention. [Figure 9] This is an enlarged arrangement diagram of the driving thin-film transistor of the organic light-emitting display device according to the fifth embodiment of the present invention. [Figure 10] This is an equivalent circuit diagram of one pixel of an organic light-emitting display device according to the sixth embodiment of the present invention. [Figure 11] This is a layout diagram of an organic light-emitting display device according to the sixth embodiment of the present invention. [Modes for carrying out the invention]

[0040] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings, so that those with ordinary skill in the art to which the present invention pertains can easily implement it. The present invention can be realized in a variety of different forms and is not limited to the embodiments described herein.

[0041] To clearly explain the present invention, unnecessary parts of the description have been omitted, and identical or similar components throughout the specification are given the same reference numerals.

[0042] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrarily indicated for the sake of explanation, and the present invention is not necessarily limited to those shown.

[0043] In the drawings, thicknesses were enlarged to clearly represent the various layers and regions. Additionally, for ease of explanation, the thicknesses of some layers and regions were exaggerated in the drawings. When a layer, film, region, plate, or other part is described as being "on top of" another part, this includes not only cases where it is "immediately above" the other part, but also cases where other parts exist in between.

[0044] Furthermore, throughout the specification, when a part "includes" a certain component, unless otherwise stated, this means that it includes other components, not that it excludes other components. Moreover, throughout the specification, the phrase "on top of" means that it is located above or below the part in question, and does not necessarily mean that it is located above the direction of gravity.

[0045] Hereinafter, an organic light-emitting display device according to the first embodiment of the present invention will be described in detail with reference to Figures 1 to 5.

[0046] Figure 1 is an equivalent circuit diagram of one pixel of an organic light-emitting display device according to a first embodiment of the present invention.

[0047] As shown in Figure 1, one pixel of the organic light-emitting display device according to the first embodiment of the present invention includes a plurality of signal lines 121, 122, 123, 124, 171, 172, a plurality of thin-film transistors (T1, T2, T3, T4, T5, T6) connected to the plurality of signal lines, a storage capacitor (Cst), and an organic light-emitting diode (OLED).

[0048] Thin-film transistors include driving thin-film transistors (T1) and switching thin-film transistors. It includes a thin-film transistor (T2), a compensating thin-film transistor (T3), an initializing thin-film transistor (T4), an operation control thin-film transistor (T5), and an emission control thin-film transistor (T6).

[0049] The signal lines include a scan line 121 that transmits a scan signal (Sn), a previous scan line 122 that transmits a previous scan signal (Sn-1) to an initialization thin-film transistor (T4), a light emission control line 123 that transmits a light emission control signal (En) to an operation control thin-film transistor (T5) and a light emission control thin-film transistor (T6), a data line 171 that crosses the scan line 121 and transmits a data signal (Dm), a drive voltage line 172 that transmits a drive voltage (ELVDD) and is formed almost parallel to the data line 171, and an initialization voltage line 124 that transmits an initialization voltage (Vint) to initialize the drive thin-film transistor (T1).

[0050] The gate electrode (G1) of the drive thin-film transistor (T1) is connected to one end (Cst1) of the storage capacitor (Cst), the source electrode (S1) of the drive thin-film transistor (T1) is connected to the drive voltage line 172 via the operation control thin-film transistor (T5), and the drain electrode (D1) of the drive thin-film transistor (T1) is electrically connected to the anode (anode) of the organic light-emitting diode (OLED) via the light emission control thin-film transistor (T6). The drive thin-film transistor (T1) receives a data signal (Dm) through the switching operation of the switching thin-film transistor (T2) and supplies a drive current (Id) to the organic light-emitting diode (OLED).

[0051] The gate electrode (G2) of the switching thin-film transistor (T2) is connected to scan line 121, the source electrode (S2) of the switching thin-film transistor (T2) is connected to data line 171, and the drain electrode (D2) of the switching thin-film transistor (T2) is The drive thin-film transistor (T2) is connected to the source electrode (S1) of the drive thin-film transistor (T1) and also connected to the drive voltage line 172 via the operation control thin-film transistor (T5). This switching thin-film transistor (T2) is turned on by the scan signal (Sn) transmitted through the scan line 121 and performs a switching operation to transmit the data signal (Dm) transmitted on the data line 171 to the source electrode of the drive thin-film transistor (T1).

[0052] The gate electrode (G3) of the compensating thin-film transistor (T3) is connected to the scan line 121, and the source electrode (S3) of the compensating thin-film transistor (T3) is connected to the drain electrode (D1) of the driving thin-film transistor (T1), and also to the anode of the organic light-emitting diode (OLED) via the light-emitting control thin-film transistor (T6). The drain electrode (D3) of the compensating thin-film transistor (T3) is connected to one end (Cst1) of the storage capacitor (Cst), the drain electrode (D4) of the initialization thin-film transistor (T4), and the gate electrode (G1) of the driving thin-film transistor (T1). The compensating thin-film transistor (T3) is turned on by the scan signal (Sn) transmitted through the scan line 121, connecting the gate electrode (G1) and drain electrode (D1) of the driving thin-film transistor (T1) to each other, thereby diode-connecting the driving thin-film transistor (T1).

[0053] The gate electrode (G4) of the initializing thin-film transistor (T4) is connected to the previous scan line 122, the source electrode (S4) of the initializing thin-film transistor (T4) is connected to the initializing voltage line 124, and the drain electrode (D4) of the initializing thin-film transistor (T4) is connected to one end (Cst1) of the storage capacitor (Cst), the drain electrode (D3) of the compensation thin-film transistor (T3), and the gate electrode (G1) of the driving thin-film transistor (T1). Such an initializing thin-film transistor (T4) is turned on by the previous scan signal (Sn-1) transmitted through the previous scan line 122 and transmits an initializing voltage (Vint) to the gate electrode (G1) of the driving thin-film transistor (T1), performing an initialization operation that initializes the voltage of the gate electrode (G1) of the driving thin-film transistor (T1).

[0054] The gate electrode (G5) of the operation control thin-film transistor (T5) is connected to the light emission control line 123, the source electrode (S5) of the operation control thin-film transistor (T5) is connected to the drive voltage line 172, and the drain electrode (D5) of the operation control thin-film transistor (T5) is connected to the source electrode (S1) of the drive thin-film transistor (T1) and the drain electrode (S2) of the switching thin-film transistor (T2).

[0055] The gate electrode (G6) of the light emission control thin-film transistor (T6) is connected to the light emission control line 123, the source electrode (S6) of the light emission control thin-film transistor (T6) is connected to the drain electrode (D1) of the drive thin-film transistor (T1) and the source electrode (S3) of the compensation thin-film transistor (T3), and the drain electrode (D6) of the light emission control thin-film transistor (T6) is electrically connected to the anode of the organic light-emitting diode (OLED). The operation control thin-film transistor (T5) and the light emission control thin-film transistor (T6) are simultaneously turned on by the light emission control signal (En) transmitted through the light emission control line 123, so that the drive voltage (ELVDD) is transmitted to the organic light-emitting diode (OLED) and a drive current (Id) flows through the organic light-emitting diode (OLED).

[0056] The other end (Cst2) of the storage capacitor (Cst) is connected to the drive voltage line 172, and the cathode of the organic light-emitting diode (OLED) is connected to the common voltage (ELVSS). As a result, the organic light-emitting diode (OLED) displays an image by emitting light when a drive current (Id) is transmitted from the drive thin-film transistor (T1).

[0057] The following describes the specific operation process of one pixel of the organic light-emitting display device according to the first embodiment of the present invention. I will explain in detail.

[0058] First, during the initialization period, a low-level previous scan signal (Sn-1) is supplied through the previous scan line 122. Subsequently, the initialization thin-film transistor (T4) turns on in response to the low-level previous scan signal (Sn-1), and the initialization voltage (Vint) is connected from the initialization voltage line 124 to the gate electrode of the driving thin-film transistor (T1) through the initialization thin-film transistor (T4), thereby initializing the driving thin-film transistor (T1).

[0059] Subsequently, during the data programming period, a low-level scan signal (Sn) is supplied through scan line 121. This causes the switching thin-film transistor (T2) and the compensating thin-film transistor (T3) to turn on in response to the low-level scan signal (Sn).

[0060] At this time, the driving thin-film transistor (T1) is diode-coupled by the turned-on compensating thin-film transistor (T3) and is forward-biased.

[0061] Then, a compensation voltage (Dm + Vth, where Vth is the negative value) is applied to the gate electrode of the driving thin-film transistor (T1), which is reduced by the threshold voltage (Vth) of the driving thin-film transistor (T1) by the data signal (Dm) supplied from data line 171.

[0062] A drive voltage (ELVDD) and a compensation voltage (Dm+Vth) are applied across the storage capacitor (Cst), and a charge corresponding to the voltage difference across the storage capacitor (Cst) is stored in the storage capacitor (Cst). Subsequently, during the light emission period, the light emission control signal (En) supplied from the light emission control line 123 is changed from a high level to a low level. As a result, during the light emission period, the low-level light emission control signal (En) turns on the operation control thin-film transistor (T5) and the light emission control thin-film transistor (T6).

[0063] Subsequently, a drive current (Id) is generated by the voltage difference between the gate electrode voltage of the drive thin-film transistor (T1) and the drive voltage (ELVDD), and this drive current (Id) is supplied to the organic light-emitting diode (OLED) through the light-emitting control thin-film transistor (T6). During the light emission period, the gate-source voltage (Vgs) of the drive thin-film transistor (T1) is maintained at "(Dm + Vth) - ELVDD" by the storage capacitor (Cst), and according to the current-voltage relationship of the drive thin-film transistor (T1), the drive current (Id) is proportional to the square of the value obtained by subtracting the threshold voltage from the source-gate voltage "(Dm - ELVDD)²". Therefore, the drive current (Id) is determined independently of the threshold voltage (Vth) of the drive thin-film transistor (T1).

[0064] Now, let's explain in detail the pixel structure of the organic light-emitting display device shown in Figure 1, referring to Figures 2 to 5 along with Figure 1.

[0065] Figure 2 is a schematic diagram showing the positions of multiple thin-film transistors and capacitors in an organic light-emitting display device according to the first embodiment of the present invention. Figure 3 is a specific arrangement diagram of one pixel in the organic light-emitting display device according to the first embodiment of the present invention. Figure 4 is a cross-sectional view of the organic light-emitting display device of Figure 3 taken along the line IV-IV. Figure 5 is a cross-sectional view of the organic light-emitting display device of Figure 3 taken along the line VV.

[0066] As shown in Figures 2 to 5, the pixels of the organic light-emitting display device according to the first embodiment of the present invention are subjected to a scan signal (Sn), a previous scan signal (Sn-1), a light emission control signal (En), and an initialization voltage (Vint), respectively, and a scan line 12 is formed along the row direction. 1. It includes a scan line 122, a light emission control line 123, and an initialization voltage line 124, and includes a data line 171 and a drive voltage line 172 that intersect with all of the scan line 121, the scan line 122, the light emission control line 123, and the initialization voltage line 124, and apply a data signal (Dm) and a drive voltage (ELVDD) to the pixel, respectively.

[0067] Furthermore, each pixel has a drive thin-film transistor (T1), a switching thin-film transistor (T2), a compensation thin-film transistor (T3), an initialization thin-film transistor (T4), an operation control thin-film transistor (T5), a light emission control thin-film transistor (T6), a storage capacitor (Cst), or an organic light-emitting diode (OLED) 70 formed on it.

[0068] The drive thin-film transistor (T1), switching thin-film transistor (T2), compensation thin-film transistor (T3), initialization thin-film transistor (T4), operation control thin-film transistor (T5), and light emission control thin-film transistor (T6) are formed along the semiconductor layer 131, which is formed by bending into various shapes. Such a semiconductor layer 131 is made of polysilicon and includes a channel region that is not doped with impurities, and a source region and a drain region formed by doping impurities on both sides of the channel region. Here, such impurities vary depending on the type of thin-film transistor, but can be N-type or P-type impurities. Such semiconductor layers include a driving semiconductor layer 131a formed on a driving thin-film transistor (T1), a switching semiconductor layer 131b formed on a switching thin-film transistor (T2), a compensation semiconductor layer 131c formed on a compensation thin-film transistor (T3), an initialization semiconductor layer 131d formed on an initialization thin-film transistor (T4), an operation control semiconductor layer 131e formed on an operation control thin-film transistor (T5), and an emission control semiconductor layer 131f formed on an emission control thin-film transistor (T6).

[0069] The driving thin film transistor (T1) includes a driving semiconductor layer 131a, a driving gate electrode 125a, a driving source electrode 176a, and a driving drain electrode 177a. The driving semiconductor layer 131a is bent. The driving semiconductor layer 131a includes a plurality of first extension portions 31 extending in a first direction, a plurality of second extension portions 32 extending in a second direction different from the first direction, and a plurality of bending portions 33 connecting the first extension portions 31 and the second extension portions 32. Therefore, the driving semiconductor layer 131a may be arranged in a zigzag shape. The driving semiconductor layer 131a shown in FIGS. 2 and 3 includes three first extension portions 31, two second extension portions 32, and four bending portions 33. Therefore, the driving semiconductor layer 131a is arranged in a long shape like the Chinese character 'ji'.

[0070] Thus, by forming the driving semiconductor layer 131a including a plurality of bending portions 33, the driving semiconductor layer 131a can be formed long in a narrow space. Therefore, since the driving channel region 131a1 of the driving semiconductor layer 131a can be formed long, the driving range of the gate voltage applied to the driving gate electrode 125a becomes wide. Therefore, since the driving range of the gate voltage is wide, the magnitude of the gate voltage can be changed, and the gradation of the light emitted from the organic light emitting diode (OLED) can be more precisely controlled. As a result, the resolution of the organic light emitting display device can be increased and the display quality can be improved.

[0071] Such a driving semiconductor layer 131a can have various embodiments such as 'S','M', 'W' by arranging the first extension portion 31, the second extension portion 32, and the bending portion 33 in various ways.

[0072] FIG. 6 is an enlarged layout view of the driving thin film transistor of the organic light emitting display device according to the second embodiment of the present invention.

[0073] As shown in FIG. 6, the driving semiconductor layer 131a may be arranged in an 'S' shape.

[0074] On the other hand, the driving source electrode 176a is doped with impurities in the driving semiconductor layer 131a The drive source region 176a corresponds to the drive drain electrode 177a, which is doped with impurities in the drive semiconductor layer 131a. A storage capacitor (Cst) is formed on top of the drive gate electrode 125a, superimposed on it.

[0075] The storage capacitor (Cst) includes a first storage plate 125a and a second storage plate 127, separated by a second gate insulating film 142. Here, the drive gate electrode 125a also functions as the first storage plate 125a, and the second gate insulating film 142 acts as a dielectric. The storage capacitance is determined by the charge stored in the storage capacitor (Cst) and the voltage between the two storage plates 125a and 127.

[0076] The first storage energy plate 125a is formed in a rectangular shape, separated from adjacent pixels, and is made of the same material and in the same layer as the scan line 121, previous scan line 122, light emission control line 123, switching gate electrode 125b, compensating gate electrode 125c, operation control gate electrode 125e, and light emission control gate electrode 125f.

[0077] The second storage energy storage plate 127 is connected to adjacent pixels and is formed in the same layer and made of the same material as the initialization voltage line 124.

[0078] Thus, in order to secure the storage capacitor region reduced by the bent portion of the drive semiconductor layer 131a, a storage capacitor is formed by superimposing it with the drive semiconductor layer 131a, making it possible to secure storage capacitance even at high resolutions.

[0079] The switching thin-film transistor (T2) includes a switching semiconductor layer 131b, a switching gate electrode 125b, a switching source electrode 176b, and a switching drain electrode 177b. The switching source electrode 176b is a portion protruding from the data line 171, and the switching drain electrode 177b corresponds to the switching drain region 177b in the switching semiconductor layer 131b, which is doped with impurities.

[0080] The compensating thin-film transistor (T3) includes a compensating semiconductor layer 131c, a compensating gate electrode 125c, a compensating source electrode 176c, and a compensating drain electrode 177c. The compensating source electrode 176c corresponds to the compensating source region 176c of the compensating semiconductor layer 131c, which is doped with impurities, and the compensating drain electrode 177c corresponds to the compensating drain region 177c of the compensating semiconductor layer 131c, which is doped with impurities. The compensating gate electrode 125c forms a separate dual gate electrode 25 to prevent leakage current.

[0081] The initialized thin-film transistor (T4) includes an initialized semiconductor layer 131d, an initialized gate electrode 125d, an initialized source electrode 176d, and an initialized drain electrode 177d. The initialized drain electrode 177d corresponds to an initialized drain region 177d in the initialized semiconductor layer 131d that is doped with impurities. The initialized source electrode 176d is connected to the initialized voltage line 124 through an initialized connection line 78. One end of the initialized connection line 78 is connected to the initialized voltage line 124 through a contact hole 161 formed in the second gate insulating film 142 and the interlayer insulating film 160, and the other end of the initialized connection line 78 is connected to the initialized source electrode 176d through a contact hole 161 formed in the gate insulating film 141, the second gate insulating film 142, and the interlayer insulating film 160.

[0082] The motion-controlled thin-film transistor (T5) includes a motion-controlled semiconductor layer 131e, a motion-controlled gate electrode 125e, a motion-controlled source electrode 176e, and a motion-controlled drain electrode 177e. The motion-controlled source electrode 176e is part of the drive voltage line 172, and the motion-controlled drain electrode 177e is an impurity-doped motion-controlled drain region in the motion-controlled semiconductor layer 131e. This corresponds to region 177e.

[0083] The light emission controlled thin-film transistor (T6) includes a light emission controlled semiconductor layer 131f, a light emission controlled gate electrode 125f, a light emission controlled source electrode 176f, and a light emission controlled drain electrode 177f. The light emission controlled source electrode 176f corresponds to the light emission controlled source region 176f in the light emission controlled semiconductor layer 131f, which is doped with impurities.

[0084] One end of the drive semiconductor layer 131a of the drive thin-film transistor (T1) is connected to the switching semiconductor layer 131b and the compensation semiconductor layer 131c, and the other end of the drive semiconductor layer 131a is connected to the operation control semiconductor layer 131e and the light emission control semiconductor layer 131f. Therefore, the drive source electrode 176a is connected to the switching drain electrode 177b and the operation control drain electrode 177e, and the drive drain electrode 177a is connected to the compensation source electrode 176c and the light emission control source electrode 176f.

[0085] The first storage capacitor plate 125a of the storage capacitor (Cst) is connected to the compensation drain electrode 177c and the initialization drain electrode 177d through a connecting member 174. This connecting member 174 is formed in the same layer as the data line 171. One end of the connecting member 174 is connected to the compensation drain electrode 177c and the initialization drain electrode 177d through contact holes 166 formed in the first gate insulating film 141, the second gate insulating film 142, and the interlayer insulating film 160. The other end of the connecting member 174 is connected to the first storage capacitor plate 125a through contact holes 167 formed in the second gate insulating film 142 and the interlayer insulating film 160. At this time, the other end of the connecting member 174 is connected to the first storage capacitor plate 125a through a storage opening 27 formed in the second storage capacitor plate 127.

[0086] The second storage capacitor plate 127 of the storage capacitor (Cst) is connected to the common voltage line 172 through a contact hole 168 formed in the interlayer insulating film 160.

[0087] On the other hand, the switching thin-film transistor (T2) is used as a switching element to select the pixel to be made to emit light. The switching gate electrode 125b is connected to the scan line 121, the switching source electrode 176b is connected to the data line 171, and the switching drain electrode 177b is connected to the driving thin-film transistor (T1) and the operation control thin-film transistor (T5). In addition, the light emission control drain electrode 177f of the light emission control thin-film transistor (T6) is directly connected to the pixel electrode 191 of the organic light-emitting diode 70 through a contact hole 181 formed in the protective film 180.

[0088] The structure of the organic light-emitting display device according to the first embodiment of the present invention will be described in detail below with reference to Figures 4 and 5, in accordance with the stacking order.

[0089] At this time, the structure of the thin-film transistors will be described centering on the driving thin-film transistor (T1), the switching thin-film transistor (T2), and the light emission control thin-film transistor (T6). Also, since the remaining thin-film transistors (T3, T4, T5) have substantially the same laminated structure as the driving thin-film transistor (T1), the switching thin-film transistor (T2), and the light emission control thin-film transistor (T6), detailed description thereof will be omitted.

[0090] A buffer layer 111 is formed on a substrate 110, and the substrate 110 is formed of an insulating substrate made of glass, quartz, ceramic, plastic, or the like.

[0091] A driving semiconductor layer 131a, a switching semiconductor layer 131b, and a light emission control semiconductor layer 131f are formed on the buffer layer 111. The driving semiconductor layer 131a includes a driving channel region 131a1 and a driving source region 176a and a driving drain region 177a that face each other with the driving channel region 131a1 therebetween. The switching semiconductor layer 131b includes a switching channel region 131b1 and a switching source region 132b and a switching drain region 177b that face each other with the switching channel region 131b1 therebetween. The light emission control thin-film transistor (T6) includes a light emission control channel region 131f1, a light emission control source region 176f, and a light emission control drain region 133f.

[0092] The driving semiconductor layer 131a includes a plurality of bent portions 33 and is formed in a zigzag shape, specifically, a shape like the Chinese character 'ji'. Therefore, it can be formed long within a narrow space. Accordingly, since the driving channel region 131a1 of the driving semiconductor 131a can be formed long, the driving range of the gate voltage applied to the driving gate electrode 125a becomes wide.

[0093] A first gate insulating film 141, made of silicon nitride (SiNx) or silicon oxide (SiO2), is formed on the switching semiconductor layer 131a, the driving semiconductor layer 131b, and the light emission control semiconductor layer 131f.

[0094] A first gate wiring is formed on the first gate insulating film 141, including a scan line 121 containing a drive gate electrode 125a, a switching gate electrode 125b, and a compensating gate electrode 125c, a previous scan line 122 containing an initialization gate electrode 125d, and a light emission control line 123 containing an operation control gate electrode 125e and a light emission control gate electrode 125f.

[0095] The drive gate electrode 125a is isolated from the scan line 121, and the floating gate electrode 25 is superimposed on the drive channel region 131a1 of the drive semiconductor layer 131a. The switching gate electrode 125a is connected to the scan line 121, and the switching gate electrode 125b is superimposed on the switching channel region 131b1 of the switching semiconductor layer 131b. The light emission control gate electrode 125f is superimposed on the light emission control channel region 131f1 of the light emission control semiconductor layer 131f.

[0096] In this case, the switching thin-film transistor (T2) is able to perform rapid switching operations because only the first gate insulating film 141 is formed between the switching gate electrode 125b and the switching semiconductor layer 131b. In the driving thin-film transistor (T1), although only the first gate insulating film 141 is formed between the driving gate electrode 125a and the driving semiconductor layer 131a, the driving channel region 131a1 of the driving semiconductor layer 131a is long, so the driving range of the gate voltage applied to the driving gate electrode 125a is widened, and the gradation of the light emitted from the organic light-emitting diode (OLED) can be controlled more precisely.

[0097] The first gate wirings 125a, 125b, 125c, 125d, 125e, 125f, 121, 122, 123 and the first gate insulating film 141 are covered by the second gate insulating film 142. The second gate insulating film 142 is formed of silicon nitride (SiNx) or silicon oxide (SiO2), etc.

[0098] A second gate wiring, including a second storage capacitor plate 127 and an initialization voltage line 124, is formed on the second gate insulating film 142. The second storage capacitor plate 127 is superimposed on the first storage capacitor plate 125a to form a storage capacitor (Cst), and the first storage capacitor plate 125a is superimposed on the drive semiconductor layer 131a. By forming a storage capacitor (Cst) in this manner, superimposed on the drive semiconductor layer 131a, the area of ​​the storage capacitor (Cst) that is reduced by the drive semiconductor layer 131a having a bent portion 33 is secured, making it possible to secure storage capacitance even at high resolutions where the pixel size is reduced.

[0099] Meanwhile, an interlayer insulating film 160 is formed on the second gate insulating film 142, the second storage energy storage plate 127, and the initialization voltage line 124. The first gate insulating film 141, the second gate insulating film 142, and the interlayer insulating film 160 all have contact holes 163 that expose the light emission control drain region 131f1 of the light emission control semiconductor layer 131f. The interlayer insulating film 160, like the first gate insulating film 141 and the second gate insulating film 142, is produced using a ceramic series material such as silicon nitride (SiNx) or silicon oxide (SiO2).

[0100] On the interlayer insulating film 160, data wiring is formed, including a data line 171 containing a switching source electrode 176b, a drive voltage line 172, a connecting member 174, and a light emission control drain electrode 177f.

[0101] Furthermore, the switching source electrode 176b and the light emission control drain electrode 177f are connected to the switching source region 131b1 of the switching semiconductor layer 131b and the light emission control drain region 131f1 of the light emission control semiconductor layer 131f, respectively, through contact holes 162 and 163 formed in the interlayer insulating film 160, the first gate insulating film 141, and the second gate insulating film 142.

[0102] A protective film 180 is formed on the interlayer insulating film 160, covering the data wirings 171, 172, 174, and 177f, and a pixel electrode 191 is formed on the protective film 180. The pixel electrode 191 is connected to the light emission control drain electrode 177f through contact holes 181 formed in the protective film 180.

[0103] A partition wall 350 is formed on the periphery of the pixel electrode 191 and on the protective film 180, and the partition wall 350 has a partition wall opening 351 that exposes the pixel electrode 191. The partition wall 350 may be made of a resin such as polyacrylic resin or polyimide, or an inorganic material of the silica series.

[0104] An organic light-emitting layer 370 is formed on the pixel electrode 191 exposed to the partition opening 351, and a common electrode 270 is formed on the organic light-emitting layer 370. In this way, an organic light-emitting diode 70 is formed, including the pixel electrode 191, the organic light-emitting layer 370, and the common electrode 270.

[0105] Here, the pixel electrode 191 is the anode of the hole injection electrode, and the common electrode 270 is the cathode of the electron injection electrode. However, one embodiment of the present invention is not necessarily limited to this, and depending on the driving method of the organic light-emitting display device, the pixel electrode 191 may be the cathode and the common electrode 270 may be the anode. Holes and electrons are injected into the organic light-emitting layer 370 from the pixel electrode 191 and the common electrode 270, respectively, and light emission occurs when the exciton formed by the coupling of the injected holes and electrons falls from the excited state to the ground state.

[0106] The organic light-emitting layer 370 is composed of a low-molecular-weight organic substance or a high-molecular-weight organic substance such as PEDOT (Poly 3,4-ethylenedioxythiophene). Alternatively, the organic light-emitting layer 370 may be formed as a multilayer film containing a light-emitting layer and one or more of the following: a hole injection layer (HIL), a hole transporting layer (HTL), an electron transporting layer (ETL), and an electron injection layer (EIL). If all of these are included, the hole injection layer is placed on the positive electrode pixel electrode 710, and the hole transporting layer, light-emitting layer, electron transporting layer, and electron injection layer are stacked sequentially on top of it. Since the common electrode 270 is formed of a reflective conductive material, it becomes a back-emitting type organic light-emitting display device. Examples of reflective materials include lithium (Li), calcium (Ca), and phosphate. Substances such as lithium fluoride / calcium (LiF / Ca), lithium fluoride / aluminum (LiF / Al), aluminum (Al), silver (Ag), magnesium (Mg), or gold (Au) may be used.

[0107] On the other hand, while the first storage capacitor 125a was rectangular in the first embodiment, a third embodiment is also possible in which a part of the first storage capacitor 125a is expanded to increase the storage capacitance.

[0108] Hereinafter, with reference to Figure 7, an organic light-emitting display device according to the third embodiment of the present invention will be described in detail.

[0109] Figure 7 is a layout diagram of an organic light-emitting display device according to a third embodiment of the present invention.

[0110] The third embodiment is substantially the same as the first embodiment shown in Figures 1 to 5, except for the drive semiconductor layer and storage capacitor, so repeated explanations will be omitted.

[0111] As shown in Figure 7, the driving thin-film transistor (T1) of the organic light-emitting display device according to the third embodiment of the present invention includes a driving semiconductor layer 131a, a driving gate electrode 125a, a driving source electrode 176a, and a driving drain electrode 177a. The driving semiconductor layer 131a is bent. The driving semiconductor layer 131a includes a plurality of first extensions 31 extending in a first direction, a plurality of second extensions 32 extending in a second direction different from the first direction, and a plurality of bent portions 33 connecting the first extensions 31 and the second extensions 32.

[0112] Such a drive semiconductor layer 131a may extend to the side and be adjacent to the data line 171. Therefore, since the length of the drive semiconductor layer 131a is increased, the driving range of the gate voltage applied to the drive gate electrode 125a can be further widened.

[0113] In this case, the compensation source electrode 176c of the compensation thin-film transistor (T3) and the light emission control source electrode 176f of the light emission control thin-film transistor (T6) are formed in the same layer, but the compensation source electrode 176c and the light emission control source electrode 176f are separated from each other by a separation portion (d) so as not to overlap with the driving semiconductor layer 131a.

[0114] The drive gate electrode 125a, i.e., the first storage capacitor 125a, is extended to the side so as to overlap with the extended drive semiconductor layer 131a, and the first storage capacitor 125a partially overlaps with the separation portion (d). In addition, the second storage capacitor 127 is also extended so as to overlap with the first storage capacitor 125a, and the second storage capacitor 127 partially overlaps with the separation portion (d).

[0115] The compensation source electrode 176c and the light emission control source electrode 176f, which are separated from each other, are connected through a transistor connector 71 formed in the same layer as the data line 171. One end of the transistor connector 71 is connected to the compensation source electrode 176c through contact holes 61 formed in the first gate insulating film 141, the second gate insulating film 142, and the interlayer insulating film 160, and the other end of the transistor connector 71 is connected to the light emission control source electrode 176f through contact holes 62 formed in the first gate insulating film 141, the second gate insulating film 142, and the interlayer insulating film 160. Therefore, the storage capacitor (Cct) is extended and superimposed on the transistor connector 71, and the drive semiconductor layer 131a is extended and superimposed on the transistor connector 71.

[0116] In this way, by connecting the compensation source electrode 176c and the light emission control source electrode 176f through the transistor coupling portion 71, the drive semiconductor layer 131a, the first storage capacitor plate 125a, and the second storage capacitor plate 127 can be extended to the separation portion (d) between the compensation source electrode 176c and the light emission control source electrode 176f, thereby further expanding the storage capacitor (Cst).

[0117] On the other hand, in the first embodiment, the driving semiconductor layer is not directly connected to the compensation source electrode at the bent portion, but a fourth embodiment is also possible which further includes a branching portion that branches directly to the compensation source electrode at the bent portion.

[0118] The organic light-emitting display device according to the fourth embodiment of the present invention will be described in detail below with reference to Figure 8.

[0119] Figure 8 is an enlarged arrangement diagram of the driving thin-film transistors of the organic light-emitting display device according to the fourth embodiment of the present invention.

[0120] The fourth embodiment is substantially the same as the first embodiment shown in Figures 1 to 5, except for the drive semiconductor layer and the storage capacitor; therefore, repeated explanations will be omitted.

[0121] As shown in Figure 8, the driving thin-film transistor (T1) of the organic light-emitting display device according to the fourth embodiment of the present invention includes a driving semiconductor layer 131a, a driving gate electrode 125a, a driving source electrode 176a, and a driving drain electrode 177a. The driving semiconductor layer 131a is bent. The driving semiconductor layer 131a includes a first extension 31 extending in a first direction, a second extension 32 extending in a second direction different from the first direction, a bent portion 33 connecting the first extension 31 and the second extension 32, and a branch portion 34 that branches directly to the compensation source electrode 176c at the bent portion. Such a driving semiconductor layer 131a has an overall "┤" shape (the opposite shape of the "T" character). Therefore, since the length of the driving semiconductor layer 131a is increased, the driving range of the gate voltage applied to the driving gate electrode 125a can be further widened.

[0122] The branching portion 34 corresponds to the first path semiconductor layer (CH1) connected to the compensation thin-film transistor (T3), and the second extension portion 32 corresponds to the second path semiconductor layer (CH2) connected to the light emission control thin-film transistor (T6). Furthermore, the drive gate electrode, i.e., the first storage capacitor plate 125a, is superimposed on the first path semiconductor layer (CH1) and the second path semiconductor layer (CH2) of the drive semiconductor layer 131a, and the second storage capacitor plate 127 is superimposed on the first storage capacitor plate 125a. Therefore, the area of ​​the storage capacitor (Cst) is increased, making it easy to secure storage capacitance even at high resolutions.

[0123] On the other hand, in the fourth embodiment, the lengths of the first path semiconductor layer (CH1) and the second path semiconductor layer (CH2) were the same, but a fifth embodiment is also possible in which the lengths of the first path semiconductor layer (CH1) and the second path semiconductor layer (CH2) are different.

[0124] The organic light-emitting display device according to the fifth embodiment of the present invention will be described in detail below with reference to Figure 9.

[0125] Figure 9 is an enlarged arrangement diagram of the driving thin-film transistors of an organic light-emitting display device according to the fifth embodiment of the present invention.

[0126] The fifth embodiment, compared to the fourth embodiment shown in Figure 8, has a drive semiconductor layer and stray Since they are essentially the same except for the dicapacitor, repeated explanations will be omitted.

[0127] As shown in Figure 9, the driving thin-film transistor (T1) of the organic light-emitting display device according to the fifth embodiment of the present invention includes a driving semiconductor layer 131a, a driving gate electrode 125a, a driving source electrode 176a, and a driving drain electrode 177a. The driving semiconductor layer 131a is bent. The driving semiconductor layer 131a includes a first extension 31 extending in a first direction, a second extension 32 extending in a second direction different from the first direction, a bent portion 33 connecting the first extension 31 and the second extension 32, and a branch portion 34 that branches directly to the compensation source electrode 176c at the bent portion. Therefore, since the length of the driving semiconductor layer 131a is increased, the driving range of the gate voltage applied to the driving gate electrode 125a can be further widened.

[0128] The branching portion 34 corresponds to the first path semiconductor layer (CH1) connected to the compensation thin-film transistor (T3), and the zigzag portion 30, including the first extension portion 31, the second extension portion 32, and the bent portion 33, corresponds to the second path semiconductor layer (CH2) connected to the light emission control thin-film transistor (T6). Furthermore, the drive gate electrode, i.e., the first storage capacitor plate 125a, is superimposed on the first path semiconductor layer (CH1) and the second path semiconductor layer (CH2) of the drive semiconductor layer 131a, and the second storage capacitor plate 127 is superimposed on the first storage capacitor plate 125a. Therefore, the area of ​​the storage capacitor (Cst) is increased, making it easy to secure storage capacitance even at high resolutions.

[0129] Furthermore, the length of the first path semiconductor layer (CH1) is shorter than the length of the second path semiconductor layer (CH2). This structure is called a short-pass diode structure, and because the lengths of the first path semiconductor layer (CH1) and the second path semiconductor layer (CH2) are different, currents of different magnitudes flow simultaneously. Since the length of the first path semiconductor layer (CH1) is short, a relatively large current flows through it, and since the length of the second path semiconductor layer (CH2) is long, a relatively small current flows through it simultaneously. By utilizing this characteristic of being able to simultaneously supply currents of different magnitudes to a single driving thin-film transistor, it is possible to rapidly compensate the threshold voltage and at the same time supply a constant current to the organic light-emitting diode, thereby reducing the current deviation between driving thin-film transistors with characteristic deviations and preventing unevenness due to differences in current magnitude. This driving operation will be explained in detail below.

[0130] The driving thin-film transistor (T1) charges the storage capacitor (Cst) with a voltage corresponding to the data signal (Dm) based on the scan signal (Sn), and provides a current corresponding to the voltage charged in the storage capacitor (Cst) to the organic light-emitting diode (OLED). At this time, since the threshold voltage of the driving thin-film transistor (T1) may change over time, the compensating thin-film transistor (T3) compensates for the threshold voltage (Vth) of the driving thin-film transistor (T1) by diode-connecting the driving thin-film transistor (T1) based on the scan signal (Sn).

[0131] Therefore, while the data signal (Dm) is transmitted, the relatively large current flowing through the first path semiconductor layer (CH1) can rapidly charge the storage capacitor (Cst) to a predetermined voltage (compensation voltage) through the compensation thin-film transistor (T3), thus enabling rapid and easy threshold voltage (Vth) compensation.

[0132] Furthermore, because a relatively small current flows through the second path semiconductor layer (CH2) and is supplied to the organic light-emitting diode (OLED) through the light-emitting control thin-film transistor (T6), unevenness can be prevented. In other words, because the rate of change of current due to the change in voltage applied to the drive gate electrode of the drive thin-film transistor (T1) is small, the current control voltage width (data swi The grange can be increased, thereby increasing the range of data voltages that represent gamma, and the current deviation between driving thin-film transistors having characteristic deviations (scatter) can be reduced, thus preventing unevenness due to differences in current magnitude.

[0133] Conventional drive thin-film transistors are designed to allow only one magnitude of current to flow through the drive semiconductor layer 131a, thus supplying the same magnitude of current to the compensation thin-film transistor (T3) and the light emission control thin-film transistor (T6). In this case, if the length of the drive semiconductor layer 131a of the drive thin-film transistor (T1) is shortened to quickly compensate the threshold voltage (Vth) of the drive thin-film transistor (T1), the s-factor of the transistor characteristic curve (transfer curve) decreases, and the rate of change of current due to changes in the voltage applied to the drive gate electrode becomes larger. As a result, a large current is supplied to the organic light-emitting diode (OLED), causing unevenness.

[0134] Conversely, if the length of the driving semiconductor layer 131a of the driving thin-film transistor (T1) is made longer to prevent unevenness, the compensation of the threshold voltage (Vth) of the driving thin-film transistor is delayed due to the small current, resulting in unevenness because low-gradation compensation is not performed. This problem becomes more serious as the resolution increases. In other words, as the resolution increases, the time during which the data signal (Dm) is applied decreases, so current flows to the organic light-emitting diode (OLED) before the threshold voltage (Vth) is fully compensated, which induces current deviation and causes unevenness.

[0135] Therefore, by forming the length of the first path semiconductor layer (CH1) connected to the compensation thin-film transistor (T3) to be shorter than the length of the second path semiconductor layer (CH2) connected to the light emission control thin-film transistor (T6), low-gradation unevenness can be prevented.

[0136] On the other hand, while the first embodiment has a 6tr 1cap structure consisting of six thin-film transistors and one storage capacitor, in which the driving semiconductor layer of the driving thin-film transistor is bent, a sixth embodiment is also possible, which has a 7tr 1cap structure consisting of seven thin-film transistors and one storage capacitor, in which the driving semiconductor layer of the driving thin-film transistor is bent.

[0137] Hereinafter, an organic light-emitting display device according to the sixth embodiment of the present invention will be described in detail with reference to Figures 10 and 11.

[0138] Figure 10 is an equivalent circuit diagram of one pixel of the organic light-emitting display device according to the sixth embodiment of the present invention. Figure 11 is an arrangement diagram of the organic light-emitting display device according to the sixth embodiment of the present invention.

[0139] The sixth embodiment is substantially the same as the first embodiment shown in Figures 1 to 5, except for the addition of a current-controlled thin-film transistor; therefore, repeated explanations will be omitted.

[0140] As shown in Figures 10 and 11, one pixel of the organic light-emitting display device according to the sixth embodiment of the present invention includes a plurality of signal lines 121, 122, 123, 124, 128, 171, 172, a plurality of thin-film transistors (T1, T2, T3, T4, T5, T6, T7) connected to the plurality of signal lines, a storage capacitor (Cst), and an organic light-emitting diode (OLED).

[0141] Thin-film transistors are driving thin-film transistors. (T1) transistor, switching thin-film transistor It includes a thin-film transistor (T2), a compensating thin-film transistor (T3), an initializing thin-film transistor (T4), an operation control thin-film transistor (T5), an emission control thin-film transistor (T6), and a current control thin-film transistor (T7).

[0142] The signal lines include a scan line 121 that transmits a scan signal (Sn), a previous scan line 122 that transmits a previous scan signal (Sn-1) to an initialization thin-film transistor (T4), a light emission control line 123 that transmits a light emission control signal (En) to an operation control thin-film transistor (T5) and a light emission control thin-film transistor (T6), a data line 171 that crosses the scan line 121 and transmits a data signal (Dm), a drive voltage line 172 that transmits a drive voltage (ELVDD) and is formed substantially parallel to the data line 171, an initialization voltage line 124 that transmits an initialization voltage (Vint) to initialize a drive thin-film transistor (T1), and a bypass control line 128 that transmits a bypass signal (BP) to a bypass thin-film transistor (T7).

[0143] The gate electrode (G1) of the drive thin-film transistor (T1) is connected to one end (Cst1) of the storage capacitor (Cst), the source electrode (S1) of the drive thin-film transistor (T1) is connected to the drive voltage line 172 via the operation control thin-film transistor (T5), and the drain electrode (D1) of the drive thin-film transistor (T1) is electrically connected to the anode (anode) of the organic light-emitting diode (OLED) via the light-emitting control thin-film transistor (T6).

[0144] The gate electrode (G2) of the switching thin-film transistor (T2) is connected to the scan line 121, the source electrode (S2) of the switching thin-film transistor (T2) is connected to the data line 171, and the drain electrode (D2) of the switching thin-film transistor (T2) is connected to the source electrode (S1) of the drive thin-film transistor (T1), while also being connected to the drive voltage line 172 via the operation control thin-film transistor (T5).

[0145] The gate electrode (G4) of the initial thin-film transistor (T4) is previously connected to scan line 122, the source electrode (S4) of the initial thin-film transistor (T4) is connected to the initial voltage line 124, and the drain electrode (D4) of the initial thin-film transistor (T4) is connected together with one end (Cst1) of the storage capacitor (Cst), the drain electrode (D3) of the compensation thin-film transistor (T3), and the gate electrode (G1) of the drive thin-film transistor (T1).

[0146] The gate electrode (G7) of the bypass thin-film transistor (T7) is connected to the bypass control line 128, the source electrode (S7) of the bypass thin-film transistor (T7) is connected to the drain electrode (D6) of the light emission control thin-film transistor (T6) and the anode of the organic light-emitting diode (OLED), and the drain electrode (D7) of the bypass thin-film transistor (T7) is connected to both the initialization voltage line 124 and the source electrode (S4) of the initialization thin-film transistor (T4).

[0147] The specific operation process of the bypass thin-film transistor (T7) of the organic light-emitting display device according to the sixth embodiment of the present invention will be described in detail below.

[0148] The bypass thin-film transistor (T7) receives a bypass signal (BP) from the bypass control line 128. The bypass signal (BP) is a predetermined voltage level that can keep the bypass thin-film transistor (T7) constantly off. The bypass thin-film transistor (T7) is kept constantly off when the transistor-off level voltage is transmitted to the gate electrode (G7), and in the off state, a portion of the drive current (Id) escapes through the bypass transistor (T7) as a bypass current (Ibp). I'll do that.

[0149] Even when the minimum current of the driving thin-film transistor that displays a black image flows as the driving current, if the organic light-emitting diode (OLED) starts to emit light, the black image will not be displayed properly. Therefore, the bypass thin-film transistor (T7) of the organic light-emitting display device according to the sixth embodiment of the present invention distributes a portion of the minimum current of the driving thin-film transistor (T1) as a bypass current (Ibp) to a current path other than the current path on the organic light-emitting diode side. Here, the minimum current of the driving thin-film transistor means the current under the condition that the gate-source voltage (Vgs) of the driving thin-film transistor is smaller than the threshold voltage (Vth) and the driving thin-film transistor is turned off. In this way, the minimum driving current under the condition that turns off the driving thin-film transistor (for example, a current of 10 pA or less) is transmitted to the organic light-emitting diode and is represented as an image with black brightness.

[0150] When the minimum drive current required to display a black image flows, the effect of clockwise transmission of the bypass current (Ibp) is significant. Conversely, when a large drive current flows to display a general image or a white image, the effect of the bypass current (Ibp) is almost negligible. Therefore, when the drive current required to display a black image flows, the light-emitting current (Ioled) of the organic light-emitting diode, which is reduced by the amount of the bypass current (Ibp) that escapes through the bypass thin-film transistor (T7) from the drive current (Id), will have the minimum current required to reliably display a black image.

[0151] Therefore, by utilizing bypass thin-film transistors, accurate black brightness images can be achieved, and the contrast ratio can be improved.

[0152] The detailed structure of the pixels of the organic light-emitting display device shown in Figure 10 will be explained in detail below, with Figure 11 providing a detailed explanation in conjunction with Figures 10 and 3.

[0153] Figure 11 is an arrangement diagram of an organic light-emitting display device according to the sixth embodiment of the present invention.

[0154] As shown in Figures 10 and 11, the pixels of the organic light-emitting display device according to the sixth embodiment of the present invention include scan lines 121, previous scan lines 122, light emission control lines 123, initialization voltage lines 124, and bypass control lines 128 formed along the row direction to which a scan signal (Sn), a previous scan signal (Sn-1), a light emission control signal (En), and an initialization voltage (Vint) are applied, respectively, and also include data lines 171 and drive voltage lines 172 that intersect with all of the scan lines 121, previous scan lines 122, light emission control lines 123, initialization voltage lines 124, and bypass control lines 128 to which a data signal (Dm) and a drive voltage (ELVDD) are applied to the pixels, respectively.

[0155] Furthermore, each pixel has a drive thin-film transistor (T1), a switching thin-film transistor (T2), a compensation thin-film transistor (T3), an initialization thin-film transistor (T4), an operation control thin-film transistor (T5), a light emission control thin-film transistor (T6), a bypass thin-film transistor (T7), a storage capacitor (Cst), or an organic light-emitting diode (OLED) 70 formed on it.

[0156] The drive thin-film transistor (T1), switching thin-film transistor (T2), compensation thin-film transistor (T3), initialization thin-film transistor (T4), operation control thin-film transistor (T5), light emission control thin-film transistor (T6), and bypass thin-film transistor (T7) are formed along the semiconductor layer 131, which is formed by bending into various shapes. Such a semiconductor layer 131 is made of polysilicon and consists of a channel region that is not doped with impurities and a source region formed on both sides of the channel region with impurities doped. It includes a source region and a drain region. Here, such impurities vary depending on the type of thin-film transistor, and N-type impurities or P-type impurities are possible. Such a semiconductor layer includes a driving semiconductor layer 131a formed in the driving thin-film transistor (T1), a switching semiconductor layer 131b formed in the switching thin-film transistor (T2), a compensation semiconductor layer 131c formed in the compensation thin-film transistor (T3), an initialization semiconductor layer 131d formed in the initialization thin-film transistor (T4), an operation control semiconductor layer 131e formed in the operation control thin-film transistor (T5), a light emission control semiconductor layer 131f formed in the light emission control thin-film transistor (T6), and a bypass semiconductor layer 131g formed in the bypass thin-film transistor (T7).

[0157] The driving thin-film transistor (T1) includes a driving semiconductor layer 131a, a driving gate electrode 125a, a driving source electrode 176a, and a driving drain electrode 177a. The driving semiconductor layer 131a is bent. The driving semiconductor layer 131a includes a plurality of first extension portions 31 extending in the first direction, a plurality of second extension portions 32 extending in a second direction different from the first direction, and a plurality of bending portions 33 connecting the first extension portions 31 and the second extension portions 32. Therefore, the driving semiconductor layer 131a is arranged in a zigzag shape. The driving semiconductor layer 131a shown in FIGS. 2 and 3 includes three first extension portions 31, two second extension portions 32, and four bending portions 33. Therefore, the driving semiconductor layer 131a is arranged in a long "ji" character shape.

[0158] Thus, by forming the driving semiconductor layer 131a including a plurality of bending portions 33, the driving semiconductor layer 131a can be formed long in a narrow space. Therefore, since the driving channel region 131a1 of the driving semiconductor layer 131a can be formed long, the driving range of the gate voltage applied to the driving gate electrode 125a becomes wide. Therefore, since the driving range of the gate voltage is wide, the magnitude of the gate voltage can be changed, and the gradation of the light emitted from the organic light-emitting diode (OLED) can be controlled more precisely. As a result, the resolution of the organic light-emitting display device can be increased and the display quality can be improved.

[0159] The bypass thin-film transistor (T7) includes a bypass semiconductor layer 131g, a bypass gate electrode 125g, a bypass source electrode 176g, and a bypass drain electrode 177g. The bypass source electrode 176g corresponds to the bypass drain region 177g doped with impurities in the bypass semiconductor layer 131g, and the bypass drain electrode 177g corresponds to the bypass drain region 177g doped with impurities in the bypass semiconductor layer 131g. The bypass source electrode 176g is directly connected to the light emission control drain region 133f.

[0160] The bypass semiconductor layer 131g is formed in the same layer as the drive semiconductor layer 131a, the switching semiconductor layer 131b, the light emission control semiconductor layer 131f, etc., and a first gate insulating film 141 is formed on the bypass semiconductor layer 131g. A bypass gate electrode 125g, which is part of the bypass control line 128, is formed on the first gate insulating film 141, and a second gate insulating film 142 is formed on the bypass gate electrode 125g and the first gate insulating film 141.

[0161] Therefore, the bypass thin-film transistor (T7) is always turned off when a bypass signal (BP) is transmitted from the bypass control line 128, and in the off state, a portion of the drive current (Id) escapes through the bypass transistor (T7) as a bypass current (Ibp). Thus, when a drive current for displaying a black image flows, an accurate black brightness image can be achieved and the contrast ratio can be improved.

[0162] Although the present invention has been described with reference to the preferred embodiments described above, the present invention is not limited thereto, and a wide range of modifications and variations are possible as long as they do not deviate from the concepts and scope of the appended claims, as can be easily understood by those engaged in the art to which the present invention pertains. It can be understood as follows. [Explanation of Symbols]

[0163] 31:1st extension part 32:Second extension part 33: Bending point 110: Circuit board 121: Scan lines 122: Previous scan lines 123: Light control wire 124: Initialization voltage line 125a: Drive gate electrode 125b: Switching gate electrode 131a: Driving semiconductor layer 132b: Switching semiconductor layer 141: First gate insulating film 142: Second gate insulating film 171: Data line 172: Drive voltage line

Claims

1. circuit board and The semiconductor layer on the aforementioned substrate, A switching thin-film transistor, which includes a first portion of the semiconductor layer and is connected to a first scan line and a data line, A drive thin-film transistor including a second portion of the semiconductor layer, wherein the second and first portions of the semiconductor layer connect the drive thin-film transistor to the switching thin-film transistor, and the second portion of the semiconductor layer has a bent portion as the drive thin-film transistor, An operation control thin film transistor including a third portion of the semiconductor layer, wherein the third and second portions of the semiconductor layer connect the operation control thin film transistor to the drive thin film transistor, and the operation control thin film transistor is connected to a first voltage line and an emission control line. A storage capacitor comprising: a first energy storage plate configured to function as the gate electrode of the drive thin-film transistor; a second energy storage plate connected to the first voltage line and superimposed on the first energy storage plate; and a portion of the insulating layer between the first energy storage plate and the second energy storage plate, The second portion of the semiconductor layer is located beneath the first and second energy storage plates. An organic light-emitting diode display device wherein the drive thin-film transistor and the storage capacitor are located between the first scan line and the light-emitting control line in a plan view and are superimposed on each other.

2. A protective layer, It also includes an organic light-emitting diode, The organic light-emitting diode display device according to claim 1, wherein the organic light-emitting diode further includes a pixel electrode on the protective layer, the pixel electrode is superimposed on the second portion of the semiconductor layer and the storage capacitor.

3. A compensating thin-film transistor connected to the gate electrode of the drive thin-film transistor, The system further comprises a connecting member connected to the compensation thin-film transistor and the storage capacitor, The organic light-emitting diode display device according to claim 1, wherein the connecting member is connected to the first energy storage plate through the storage opening of the second energy storage plate.

4. The organic light-emitting diode display device according to claim 3, wherein, in a plan view, the storage opening is located between the first scan line and the light emission control line.

5. A protective layer, The material further includes an organic light-emitting diode, The organic light-emitting diode display device according to claim 4, further comprising a pixel electrode on the protective layer, wherein the pixel electrode is superimposed on the connecting member and the storage opening.

6. The organic light-emitting diode display device according to claim 1, wherein the second portion of the semiconductor layer and the part of the insulating layer are superimposed on each other.

7. circuit board and The semiconductor layer on the aforementioned substrate, A switching thin-film transistor, which includes a first portion of the semiconductor layer and is connected to a first scan line and a data line, A drive thin-film transistor including a second portion of the semiconductor layer, wherein the semiconductor layer connects the drive thin-film transistor to the switching thin-film transistor, and the second portion of the semiconductor layer has a bent portion. A motion control thin film transistor including a third portion of the semiconductor layer, wherein the semiconductor layer connects the motion control thin film transistor to the drive thin film transistor, and the motion control thin film transistor is connected to a first voltage line and a light emission control line. A storage capacitor comprising: a first energy storage plate configured to function as the gate electrode of the drive thin-film transistor; a second energy storage plate connected to the first voltage line and superimposed on the first energy storage plate; and a portion of the insulating layer between the first energy storage plate and the second energy storage plate, The bent portion of the second part of the semiconductor layer overlaps with the part of the insulating layer and is located between the first scan line and the light emission control line in a plan view, in an organic light-emitting diode display device.

8. A compensating thin-film transistor connected to the gate electrode of the drive thin-film transistor, The present invention further includes a connecting member connected to the compensation thin-film transistor and the storage capacitor, The organic light-emitting diode display device according to claim 7, wherein the connecting member is connected to the first energy storage plate through the storage opening of the second energy storage plate.

9. The organic light-emitting diode display device according to claim 8, wherein in the plan view, the storage opening is located between the first scan line and the light emission control line.

10. In a plan view, the connecting member is superimposed on the first scan line, as described in claim 8.

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