JP4596582B2 - Display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device, and more particularly, to an electroluminescence display device including an electroluminescence element and a thin film transistor.
[0002]
[Prior art]
In recent years, a display device using an electroluminescence (hereinafter referred to as “EL”) element has attracted attention as a display device that replaces a CRT or an LCD. For example, a thin film transistor is used as a switching element for driving the EL element. Research and development of a display device equipped with (Thin Film Transistor: hereinafter referred to as “TFT”) is also underway.
[0003]
As a display pixel arrangement method of the display device, there are so-called stripe arrangement and delta arrangement in which display pixels of the same color are arranged in the column direction. The stripe arrangement is effective, for example, as a display for a personal computer, and the delta arrangement is effective as a display for displaying a moving image with high resolution.
[0004]
FIG. 5 is a plan view of the vicinity of a display pixel of an EL display device in which the conventional display pixel is a stripe arrangement, FIG. 6A is a cross-sectional view taken along line AA in FIG. FIG. 6B is a cross-sectional view taken along line B-B in FIG. 5, and FIG. 6C is a cross-sectional view taken along line C-c in FIG.
[0005]
As shown in FIG. 5, a plurality of gate signal lines 51a and 51b extend in the row direction (left and right direction in the figure), and a plurality of drive signal lines 53a and 53b extend in the column direction (up and down direction in the figure). The display pixel region 110 is an area surrounded by both signal lines. Each display pixel area 110 includes an EL display element 60, a switching TFT 30, a storage capacitor 50, and An EL element driving TFT 40 is disposed.
[0006]
The EL display element 60, the switching TFT 30, the storage capacitor 50, and the EL element driving TFT 40 in the display pixel region 110 surrounded by the gate signal lines 51a and 51b and the driving signal lines 53a and 53b will be described with reference to FIGS.
[0007]
The switching TFT 30 is connected to the gate signal line 51a, to which the gate signal is supplied, the drain electrode 16 connected to the drive signal line 52a to which the drive signal is supplied, and the EL element driving TFT 40. The source electrode 13s is connected to the gate electrode 41. A polycrystalline silicon film (hereinafter referred to as “p-Si film”) which is an active layer is formed on the insulating substrate 10, and a gate electrode 11 is formed thereon via a gate insulating film 12. .
[0008]
A storage capacitor electrode line 54 is arranged in parallel with the gate signal line 51a. The storage capacitor electrode line 54 accumulates electric charges with the capacitor electrode 55 formed in the lower layer through the gate insulating film 12 to form a capacitor. The storage capacitor 50 extends from a part of the source 13 s and is provided to hold a voltage applied to the gate electrode 41 of the EL element driving TFT 40.
[0009]
The EL element driving TFT 40 is supplied to the gate element 41 connected to the source 13 s of the switching TFT 30, the source electrode 44 connected to the anode 61 of the EL element 60 and connected to the source 43 s, and the EL element 60. The drain 43d is connected to the drive power line 53b.
[0010]
The EL element 60 includes an anode 61 connected to the source electrode 43 s, a cathode 67 as a common electrode, and a light emitting element layer 66 sandwiched between the anode 61 and the cathode 67.
[0011]
When the gate signal from the gate signal line 51a is applied to the gate electrode 11, the switching TFT 30 is turned on. Therefore, a drive signal is supplied from the drive signal line 52a to the gate electrode 41 of the EL element driving TFT 40, and the potential of the gate electrode 41 becomes the same as the potential of the drain signal line 52a. Then, a current corresponding to the current value supplied to the gate electrode 41 is supplied to the EL element 60 from the drive power supply line 53b connected to the drive power supply. As a result, the EL element 60 emits light.
[0012]
The EL element 60 includes an anode 61 made of a transparent electrode such as ITO (Indium Thin Oxide), a first hole transport layer 62 made of MTDATA (4,4′-bis (3-methylphenylphenylamino) biphenyl), a TPD (4, Second hole transport layer 63 made of 4 ', 4 "-tris (3-methylphenylphenylamino) triphenylanine), light-emitting layer 64 made of Bebq2 (10-benzo [h] quinolinol-beryllium complex) containing quinacridone derivative, and Bebq2 In this structure, a light emitting element layer 66 composed of an electron transport layer 65 composed of the above, a laminated body of lithium fluoride (LiF) and aluminum (Al), or a cathode 67 composed of a magnesium-indium alloy is laminated in this order.
[0013]
In the EL element, holes injected from the anode and electrons injected from the cathode are recombined inside the light emitting layer, and excitons are generated by exciting organic molecules forming the light emitting layer. Light is emitted from the light emitting layer in the process of radiation deactivation of the excitons, and this light is emitted from the transparent anode through the transparent insulating substrate to emit light.
[0014]
FIG. 7 is a plan view of the vicinity of a display pixel of a conventional delta-array EL display device, FIG. 8A is a cross-sectional view taken along the line AA in FIG. 7, and FIG. FIG. 8 shows a cross-sectional view along the line BB in FIG. 7, and FIG. 8C shows a cross-sectional view along the line CC in FIG.
[0015]
As shown in FIG. 7, in the direction (row direction) in which each gate signal line 51a, 51b, 51c extends, a plurality of display pixels are red (R), green (G), and blue (B) as one cycle. It is arranged repeatedly. The display pixels connected to the adjacent gate signal lines are shifted from each other in the direction in which the gate signal lines extend between the adjacent gate signal lines. This is a so-called delta arrangement.
[0016]
That is, a plurality of display pixels arranged in the row direction and a plurality of display pixels arranged in the same row direction in the next row adjacent to the plurality of display pixels are shifted from each other by a predetermined display pixel in the row direction. It is arranged.
[0017]
The drive power supply line 53a is connected to the drain of the EL element driving TFT of the display pixel 110R corresponding to the gate signal line 51a, and is connected to the drain of the EL element driving TFT of the display pixel 110G corresponding to the gate signal line 51b. It is connected.
[0018]
When connected to each of these TFTs, the drive power supply line 53a is parallel to the drive signal line 52b for supplying a drive signal to the display pixel adjacent to the display pixel 110R, and to the display pixel adjacent to the display pixel 110G. The drive signal line 52a for supplying a drive signal is arranged in parallel.
[0019]
[Problems to be solved by the invention]
By the way, as shown in FIGS. 5 and 7, a so-called stripe arrangement in which display pixels of the same color are arranged in the column direction and a delta arrangement in which a predetermined display pixel is shifted for each row are driven in any arrangement. The signal line and the drive power supply line are formed of the same material at the same time in order to avoid an increase in their manufacturing process.
[0020]
That is, both lines 52c and 53b are made of the same material at the same time by forming Al, which is a material of both lines, on the interlayer insulating film 15 by CVD or the like, forming a resist pattern thereon and etching Al. Formed in layers.
[0021]
However, when forming both lines, if a small dust or foreign matter adheres to the mask or the like that forms the pattern, and the pattern cannot be formed into the shape of the two lines that should originally be formed by the foreign substance. Then, the Al etched based on the pattern leaves a residue so as to straddle the two lines.
[0022]
If it does so, there existed a fault that the drive signal line and drive power source line which were formed in the same layer will be short-circuited.
[0023]
In order to eliminate this drawback, these wirings may be formed in different layers, but this has the disadvantage that the number of steps increases and the cost increases.
[0024]
Therefore, the present invention has been made in view of the above-described conventional drawbacks, and provides a display device capable of obtaining a good display without increasing the number of steps and without short-circuiting the drive signal line and the drive power supply line. For the purpose.
[0025]
[Means for Solving the Problems]
The display device of the present invention includes a self-luminous element having a light emitting layer between a cathode and an anode, a switching thin film transistor that supplies a driving signal for controlling a timing of supplying current to the self-luminous element, and the self-luminous element. Display pixels having a self-luminous element driving thin film transistor for supplying current to the switching thin film transistor are arranged in a matrix, a driving signal line for supplying a driving signal to the switching thin film transistor, and a current according to the driving signal The display device includes a drive power supply line that supplies a self-luminous element, and is arranged so that either the drive signal line or the drive power supply line overlaps the anode.
[0026]
Further, in the display device, either the drive signal line or the drive power supply line is disposed so as to overlap with a lower layer of the anode via an insulating film.
[0027]
In addition, the drive power supply line is a display device that is disposed substantially at the center of the drive signal lines adjacent to each other.
[0028]
By adopting such a configuration, it is possible to prevent a display defect from occurring due to a short circuit between both lines even though the drive signal line and the drive power supply line are formed in the same layer.
[0029]
In the display device of the present invention, either the thin film transistor for switching or the thin film transistor for driving the light emitting element is disposed on one side with respect to the drive power line, and the other thin film transistor is on the other side. The display device is arranged.
[0030]
The drive signal lines and the drive power supply lines are alternately arranged, and the switching thin film transistors and the self-light emitting element drive thin film transistors are alternately arranged between the drive signal lines and the drive power supply lines. Display device.
[0031]
Further, the drive signal lines and the drive power supply lines extend in the column direction and are alternately arranged in the row direction, and the switching signal lines are arranged between the alternately arranged drive signal lines and drive power supply lines. It is a display device in which a thin film transistor or a thin film transistor for driving a self-luminous element is arranged.
[0032]
In the display device of the present invention, a plurality of the display pixels each exhibiting a predetermined color are periodically arranged in the row direction, a plurality of the display pixel rows are provided, and the display pixels are predetermined in adjacent rows. The drive power supply lines arranged in a row direction by pixels and extending in the column direction are display devices connected to the display pixels of different colors for each row.
[0033]
The drive signal line is a display device connected to the display pixel of the same color for each row.
[0034]
Further, in each of the display pixel rows, a display device in which pixels exhibiting red, green, and blue are periodically arranged in the row direction.
[0035]
Furthermore, in the display device, the arrangement of the display pixels of each color is a stripe arrangement or a delta arrangement.
[0036]
The self-luminous element is a display device that is an electroluminescent element.
[0037]
By adopting such a configuration, the drive signal line and the drive power supply line are formed in the same layer, but both lines are not short-circuited, and the switching signal can be efficiently performed in the region between the drive signal line and the drive power supply line. The TFTs and the self-light emitting element driving TFTs can be arranged, and the TFTs can be prevented from being short-circuited with each other due to mixing of dust or the like during the manufacturing process, and display defects can be prevented in the display pixels of the respective colors.
[0038]
In addition, the drive signal line and the drive power supply line are short-circuited and display defects do not occur, so that it can be employed as a good monitor for a personal computer or the like or a display device requiring high resolution.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
The case where the present invention is employed in an EL display device will be described below.
[0040]
1 is a plan view of a display pixel region of the organic EL display device, FIG. 2A is a cross-sectional view taken along line AA in FIG. 1, and FIG. A cross-sectional view taken along the line -B is shown, and FIG. 2C shows a cross-sectional view taken along the line CC in FIG.
[0041]
In this embodiment mode, a case where display pixels including EL elements are arranged in a stripe pattern will be described.
[0042]
In the present embodiment, each of the TFTs 30 and 40 provided in the EL display device that emits light of each color is a so-called top-gate TFT in which a gate electrode is provided above the active layer via a gate insulating film. The p-Si film that is polycrystallized by irradiating the a-Si film with laser light is used.
[0043]
Here, description will be made by paying attention to a display pixel region surrounded by the gate signal line 51a, the gate signal line 51b, the drain signal line 52b and the drain signal line 52c.
[0044]
As shown in FIGS. 1 and 2, a plurality of gate signal lines 51a, 51b, 51c extend in the row direction (left and right in the figure), and the drive signal lines 52a, 51a, 51c extend in the column direction (up and down in the figure). A plurality of 52b and 52c are extended. These two signal lines intersect each other, and a region surrounded by these both signal lines is a display pixel region 110, which is arranged in a matrix. A first TFT 30 that is a switching TFT is provided near the intersection of both signal lines 51a and 52b, and the source 33s of the TFT 30 also serves as a capacitor electrode 55 that forms a capacitance with the storage capacitor electrode line 54. The second TFT 40, which is an EL element driving TFT, is connected to the gate 41, the source 43 s of the second TFT is connected to the anode 61 of the organic EL element 60, and the other drain 43 d is connected to the organic EL element 60. It is connected to a drive power supply line 53 which is a current source to be supplied. The drive signal lines 52a, 52b, and 52c and the drive power supply lines 53a, 53b, and 53c are connected to display pixels of the same color.
[0045]
A storage capacitor electrode line 54 is arranged in parallel with the gate signal line 51. The storage capacitor electrode line 54 is made of chromium or the like, and forms a capacitor by accumulating electric charges between the capacitor electrode 55 connected to the source 33s of the TFT via the gate insulating film 12. This storage capacitor is provided to hold the voltage applied to the gate electrode 41 of the second TFT 40.
[0046]
The organic EL element 60 includes an anode 61 as a first electrode, a light emitting element layer 66 made of a light emitting material, and a cathode 67 as a second electrode.
[0047]
As shown in FIG. 2, the organic EL display device is formed by sequentially laminating TFTs and organic EL elements on a substrate 10 such as a substrate made of glass or synthetic resin, a conductive substrate, or a semiconductor substrate. However, when a conductive substrate and a semiconductor substrate are used as the substrate 10, SiO 2 is formed on these substrates 10. ₂ After forming an insulating film such as SiN or SiN, the first and second TFTs and the organic EL element are formed. Both TFTs have a so-called top gate structure in which the gate electrode is above the active layer via the gate insulating film.
[0048]
First, the first TFT 30 that is a switching TFT will be described.
[0049]
As shown in FIG. 2A, an amorphous silicon film (hereinafter referred to as “a-Si film”) is formed on an insulating substrate 10 made of quartz glass, non-alkali glass or the like by a CVD method or the like. The a-Si film is formed and irradiated with laser light to be melted and recrystallized to form a polycrystalline silicon film (hereinafter referred to as “p-Si film”). On top of that, SiO ₂ A single layer or stacked body of a film or a SiN film is formed as the gate insulating film 12. Furthermore, a gate signal line 51a also serving as the gate electrode 11 made of a refractory metal such as Cr or Mo is formed thereon. At this time, the gate electrode 11 has a so-called double gate structure including two gate electrodes. Since the first TFT 30 has a switching function, this structure is employed in order to suppress off-state current.
[0050]
The active layer 13 is ion-doped with a channel 13c below the gate electrode 11 and both sides of the channel 13c using the gate electrode 11 on the channel 13c as a mask, and the gate electrode 11 and both sides thereof are covered with a resist. Then, a low concentration region 13LD is provided on both sides of the gate electrode 11, and a high concentration region source 13s and a drain 13d are provided on the outside thereof. That is, a so-called LDD structure.
[0051]
The entire surface of the gate insulating film 12 and the active layer 13 is made of SiO. ₂ Film, SiN film and SiO ₂ An interlayer insulating film 15 is formed in the order of the films, and a drain signal line 52b also serving as the drain electrode 16 is provided by filling a contact hole provided corresponding to the drain 13d with a metal such as Al. At the same time, the drive power supply line 53b is formed of Al. Further, a planarization insulating film 17 made of an organic resin and flattening the surface is formed on the entire surface.
[0052]
Next, the second TFT 40 that is a driving TFT of the organic EL element will be described.
[0053]
As shown in FIG. 2B, on the insulating substrate 10 made of quartz glass, non-alkali glass or the like, an active layer 43 made of a p-Si film that is polycrystallized by irradiating the a-Si film with laser light. And the capacitor electrode 55, the gate insulating film 12, and the gate electrode 41 and the storage capacitor electrode line 54 made of a refractory metal such as Cr and Mo are formed in this order, and the active layer 43 includes a channel 43c and the channel A source 43s and a drain 43d are provided on both sides of 43c. Then, SiO 2 is deposited on the entire surface of the gate insulating film 12 and the active layer 43. ₂ Film, SiN film and SiO ₂ A drive power supply line 53b and a source electrode connected to a drive power supply are formed by forming an interlayer insulating film 15 laminated in the order of the films, filling a contact hole provided corresponding to each of the drain 43d and the source 43s with a metal such as Al. 44 is arranged. Although the case where the gate electrode 41 has a single gate structure is shown, it is a driving TFT 40 having a function of supplying a current to the EL element 60. Therefore, the gate electrode 41 may have a double gate structure with two gate electrodes. Further, a flattening insulating film 17 made of, for example, an organic resin and flattening the surface is provided over the entire surface. Then, a contact hole is formed at a position corresponding to the source electrode 44 of the planarization insulating film 17, and a transparent electrode made of ITO that is in contact with the source electrode 44 through this contact hole, that is, the anode 61 of the organic EL element is planarized. Provided on the insulating film 17. The anode 61 is separately formed in an island shape for each display pixel.
[0054]
Then, as shown by a dotted line, an insulating film 19 having an opening 68 as a region surrounded by the dotted line is disposed in the anode 61 of FIG. That is, the insulating film 19 overlaps with the anode 61 around the entire periphery of the anode 61. In other words, the insulating film having the opening 68 in a region corresponding to a part of the anode 61, that is, a region surrounded by a dotted line in FIG. 19 is formed on the anode 61 and the planarization insulating film 17. Accordingly, at the end of the anode 61, the end of the anode 61 is separated from the light emitting element layer 66 and the cathode 67 by the insulating film 19. The insulating film 19 may be formed so as not to cause disconnection of the light emitting layer due to a step due to the thickness of the anode 61 or to cause electric field concentration at the corners of the periphery of the anode. Only one of the light emitting element layer 66 and the cathode 67 may be separated by the film 19. The insulating film 19 is made of SiO. ₂ An insulating film made of a film, a single layer of SiN film or a laminate thereof, a flattened film made of an SOG film, or a flattened insulating film made of a photosensitive resin may be used. By using a flattened insulating film, the cathode 67 formed thereabove can be formed flat, and disconnection can be prevented, which is preferable.
[0055]
Here, the position where the drive power supply line 53b is arranged will be described below.
[0056]
As shown in FIG. 2C, a gate insulating film 12 and SiO 2 are formed on an insulating substrate 10 made of quartz glass, non-alkali glass or the like. ₂ Film, SiN film and SiO ₂ A drive power supply line 53b connected to a drive power supply by filling a contact hole provided corresponding to each of the drain 43d and the source 43s and filling a metal such as Al with the interlayer insulating film 15 stacked in the order of the films, and a drive power supply line 53b Signal lines 52b and 52c are arranged. Further, a flattening insulating film 17 made of, for example, an organic resin and flattening the surface is provided over the entire surface. Then, a transparent electrode made of ITO that is in contact with the source electrode 44 through a contact hole corresponding to the source electrode 44 of the planarization insulating film 17, that is, an anode 61 of the organic EL element is provided on the planarization insulating film 17. ing. The anode 61 is separately formed in an island shape for each display pixel.
[0057]
Here, as described above, the insulating film 19 overlaps the anode 61 around the entire periphery of the anode 61. In other words, an opening is formed in a region corresponding to a part of the anode 61, that is, a region surrounded by a dotted line in FIG. An insulating film 19 having a portion 68 is formed on the anode 61 and the planarizing insulating film 17. Accordingly, at the end of the anode 61, the end of the anode 61 is separated from the light emitting element layer 66 and the cathode 67 by the insulating film 19.
[0058]
A first hole transport layer 62 made of MTDATA and a second hole transport layer 63 made of TPD are deposited on the entire surface of the anode 61 and the insulating film 19 by vapor deposition, and a light emitting layer 64 made of Bebq 2 containing a quinacridone derivative is displayed on each surface. Corresponding to the pixel, it is deposited in an island shape by vapor deposition, and an electron transport layer 65 made of Bebq2 is further deposited thereon. Thus, a light emitting element layer 66 composed of the first hole transport layer 62, the second hole transport layer 63, the light emitting layer 64, and the electron transport layer 65 is formed. Further, a cathode 67 made of a laminate of lithium fluoride (LiF) and aluminum (Al) or a magnesium / indium alloy is laminated on the electron transport layer 65. Thus, an EL element having a structure in which each layer is deposited is formed. In addition, the EL element 60 formed in each display pixel forms red (R), green (G), and blue (B) light emitting layer materials by vapor deposition, and emits one color for each display pixel. . That is, display pixels exhibiting R, G, and B colors are periodically arranged in the row direction.
[0059]
Here, the drive power supply line 53b is not arranged adjacent to the drive signal line 52c in parallel as in the prior art. That is, the drive power supply line 53b is provided below the anode 61 via the planarization insulating film 17, and the position of the drive power supply line 53b is approximately the center of the anode 61, and is further spaced from the drive signal line 52c. ing.
[0060]
For example, the drive signal lines 52a, 52b, and 52c and the drive power supply lines 53a, 53b, and 53c all have a line width of about 10 μm, and the size of the anode of one display pixel is about 90 μm × about 250 μm. The distance between the anodes adjacent to each other in the direction) is about 30 μm. Each drive signal line extends approximately near the center between the anodes. Accordingly, the distance between the center of each drive power supply line and the center of each drive signal line is about 6055 μm, and foreign matter such as dust adheres in the manufacturing process, which may cause a short circuit between the drive signal line and the drive power supply line. Can be prevented. In FIG. 1, the anode is drawn in a shape close to a square for convenience, but the size of the display pixel including the anode can be selected as appropriate.
[0061]
Further, the position where the drive power supply line is disposed is substantially the center of the anode in the above-described embodiment, but the present invention is not limited to this, and may be close to one drive signal line. The distance between the drive signal line and the drive power supply line may not be short-circuited. Preferably, as described above, it is desirable that the drive signal line and the drive power supply line are arranged at approximately the center between the adjacent drive signal lines so that the drive signal line and the drive power supply line are most spaced. By doing so, even when the size of each display pixel is reduced and the interval between the drive signal lines is reduced, it is possible to prevent a short circuit with the drive power supply line.
[0062]
In this way, the drive power line 53b and the drive signal line 52c, which are simultaneously formed of the same material in the same layer, are spaced apart from each other, that is, the drive signal line 52c is disposed at a conventional position, and the drive power line 53b is disposed. By disposing at approximately the center of the anode 61, it is possible to prevent the drive signal line 52c and the drive power supply line 53b from being short-circuited.
[0063]
In addition, as shown in FIG. 1, the drive power supply line is spaced apart from the drive signal line and arranged in the approximate center of the display pixel, so that it is between the drive signal line and the drive power supply line, that is, on the left and right sides of the drive power supply line. The switching TFT 30 and the EL element driving TFT 40 can be formed, the TFTs can be arranged efficiently, and the mutual TFTs can be prevented from being short-circuited. Furthermore, each TFT having a required TFT size can be formed because there is room in the area where each TFT is provided. That is, when the light emission efficiency of each color material of each light emitting element layer is different, the size of the EL element driving TFT for each color that supplies current to the EL element is the highest in the case of the color of the material with high light emission efficiency. Even when the size is reduced and the size of the EL element driving TFTs is sequentially increased as the light emission efficiency is lowered, the TFTs having the respective TFT sizes can be formed.
[0064]
Further, the light emitted from the light emitting element layer is emitted downward in FIG. 2 (c). Even if the drive power supply line is arranged in the lower layer, that is, the viewer side of the emitted light, the EL element is Since the emitted light is emitted radially because it is a self-luminous element, the decrease in luminance caused by the drive power line can be ignored when observing the display. good.
<Second Embodiment>
3 is a plan view of a display pixel region of the organic EL display device, FIG. 4A is a cross-sectional view taken along line AA in FIG. 3, and FIG. 4B is B in FIG. A cross-sectional view taken along line -B is shown, and FIG. 4C shows a cross-sectional view taken along line CC in FIG.
[0065]
The difference between the present embodiment and the first embodiment is that the display pixels are arranged in a so-called delta arrangement, whereby the colors of the display pixels connected to the drive power supply line are different.
[0066]
As shown in FIGS. 3 and 4, in the direction (row direction) in which each gate signal line 51a, 51b, 51c extends, a plurality of display pixels display red (R), green (G), and blue (B). It is repeatedly arranged as one cycle. The display pixels connected to the adjacent gate signal lines are shifted from each other in the direction in which the gate signal lines extend between the adjacent gate signal lines. This is a so-called delta arrangement.
[0067]
That is, a plurality of display pixels arranged in the row direction and a plurality of display pixels arranged in the same row direction in the next display pixel row adjacent to the plurality of display pixels are arranged in the row direction by a predetermined number of display pixels. It is arranged in a row. In the present embodiment, display pixels of the same color are shifted in the row direction by approximately 0.7 display pixels.
[0068]
For example, when attention is paid to the adjacent gate signal line 51a and gate signal line 51b, each display pixel connected to the gate signal line 51a and each display pixel connected to the gate signal line 51b are described in this embodiment. In the case of the display pixels of the same color, they are arranged so as to be shifted from each other by approximately 0.7 display pixels in the extending direction of the gate signal lines.
[0069]
Further, each drive signal line 52a, 52b, 52c extends mainly in the column direction, and is connected to the display pixels of the same color, and is bent for each row according to the arrangement of the display pixels in each row, and left and right. It is arranged meandering. That is, the display pixels are arranged in the column direction while being bent by a predetermined number of adjacent display pixels in the row direction and repeating the unevenness.
[0070]
The drive power supply lines 53a, 53b, and 53c are arranged in the column direction, connected to display pixels of different colors, bent according to the arrangement of the display pixels in each row, and arranged to meander to the left and right. Yes. That is, when attention is paid to the drive power supply line 53a, the drive power supply line 53a is arranged almost at the center of the R display pixel connected to the gate signal line 51a and connected to the EL element driving TFT 40 of the display pixel. Subsequently, it is arranged at the center of the G display pixel connected to the gate signal line 51b of the next row and connected to the EL element driving TFT 40 of the display pixel, and then the gate signal line of the next row. The R display pixel connected to 51c is arranged at substantially the center and connected to the EL element driving TFT of the display pixel. The drive signal lines 52a, 52b, and 52c and the drive power supply lines 53a, 53b, and 53c are made of a conductive material such as Al, are separated from each other and do not cross each other to prevent short circuit. Is arranged. As a specific example of the position, as described in the first embodiment, the distance between the drive signal line and the drive signal line is about 60 μm.
[0071]
As described above, since the drive signal line and the drive power supply line are separated from each other even though they are formed in the same layer, they can be prevented from being short-circuited. Further, in a so-called delta arrangement, even when display pixels of different colors are connected to each drive power supply line for each display pixel group connected to each gate signal line, the drive signal line and the drive power supply line are in the same layer. Although formed, it is possible to form without intersecting. Thus, a display with high resolution can be obtained while suppressing an increase in the number of steps due to formation of the drive signal line and the drive signal line in different layers.
[0072]
The EL element emits light by controlling the current flowing in the drive power supply line at a constant value by the EL element driving TFT and supplying the current to the EL element of each color, but the current flows in the drive power supply line. Even if the current value is constant, it is possible to connect the drive power supply line to the EL element driving TFT 40 of the display pixel of a different color, so that the drive signal line and the drive power supply line are the same in the delta arrangement. It was possible to form without crossing the layers.
[0073]
The EL element 60 includes an anode 61a connected to the source electrode 43s, a cathode 67 as a common electrode, and a light emitting element layer 66 sandwiched between the anode 61 and the cathode 67. In each display pixel, red (R), green (G), and blue (B) light emitting layer materials are formed by vapor deposition, and each display pixel emits one color.
[0074]
The above-described switching TFT, storage capacitor, EL element driving TFT, and EL element are arranged in this order from the gate signal line side downward in the figure. By arranging in this way, the distance between the light emitting layers of the display pixels positioned above and below can be increased, and when the light emitting layers of the respective colors of the EL element are deposited, the distance between the adjacent light emitting layers of other colors due to wraparound is increased. Mixing can be prevented. Further, similarly to the first embodiment, the driving power supply line is arranged at substantially the center between the driving signal lines, so that the switching TFT is arranged on the left side of the driving power supply line and the EL element driving TFT is arranged on the left side. In addition to being able to arrange, it is possible to design with sufficient margin even when the TFT size of the EL element driving TFT is made different for each color.
[0075]
When the gate signal from the gate signal line 51a is applied to the gate electrode 11, the switching TFT 30 is turned on. Therefore, a drive signal is supplied from the drive signal line 52a to the gate electrode 41 of the EL element driving TFT 40, and the potential of the gate electrode 41 becomes the same as the potential of the drive signal line 52a. Then, a current corresponding to the current value supplied to the gate electrode 41 is supplied to the EL element 60 from the drive power supply line 53b connected to the drive power supply. As a result, the EL element 60 emits light.
[0076]
Further, in order to emit R, G, and B for each color as shown in FIG. 1, first, a metal mask having an opening is placed on the anode and the planarizing film at the place where the R light emitting material is disposed, and R light emission is performed. The material is vapor-deposited, and then the G light-emitting material is vapor-deposited with a metal mask having an opening at a position where the G light-emitting material is disposed, and further, the metal mask with an opening is disposed at a position where the B light-emitting material is disposed. A light emitting layer is formed by evaporating the light emitting material of B. At this time, it is necessary to prevent the light emitting materials of different colors from entering the adjacent light emitting layers of different colors and mixing the colors.
[0077]
In this embodiment, the meandering pitch of the drive signal lines is 0.7 display pixels, but the present invention is not limited to this.
[0078]
In this embodiment, a polycrystalline silicon film is used as the active layer. However, a microcrystalline silicon film in which the entire active layer is not completely crystallized may be used.
[0079]
An insulating substrate is an insulating substrate made of glass or synthetic resin, or a surface of a conductive substrate or semiconductor substrate such as SiO. ₂ A substrate in which an insulating film such as a film or SiN is formed and the substrate surface is insulative.
[0080]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which prevented the display defect by both lines short-circuiting can be provided, suppressing the increase in the process by forming a drive signal line and a drive signal line in a different layer. .
[Brief description of the drawings]
FIG. 1 is a plan view of an EL display device according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of an EL display device showing a first embodiment of the present invention.
FIG. 3 is a plan view of an EL display device showing a second embodiment of the present invention.
FIG. 4 is a cross-sectional view of an EL display device showing a second embodiment of the present invention.
FIG. 5 is a plan view of a conventional EL display device.
FIG. 6 is a cross-sectional view of a conventional EL display device.
FIG. 7 is a plan view of a conventional EL display device.
FIG. 8 is a cross-sectional view of a conventional EL display device.
[Explanation of symbols]
11, 41 Gate electrode
13, 43 Active layer
13s, 43s source area
13d, 43d drain region
13c, 43c channel region
16 Source electrode
30 Switching TFT
40 EL element driving TFT
51a, 51b, 51c Gate signal line
52a, 52b, 52c Drive signal line
53a, 53b Driving power line
60 EL elements
61 anode
66 Light emitting layer
67 Cathode
68 opening
110 display area

Claims (8)

A self-light-emitting element having a light-emitting layer between a cathode and an anode, a switching thin film transistor that supplies a drive signal to the self-light-emitting element, and a self-light-emitting element drive thin film transistor that supplies a current to the self-light-emitting element A display device having display pixels arranged in a matrix, a drive signal line for supplying a drive signal to the switching thin film transistor, and a drive power supply line for supplying a current to the light-emitting element in accordance with the drive signal Because
A plurality of the display pixels each exhibiting a predetermined color are periodically arranged in a row direction, a plurality of the display pixel rows are provided, and the display pixels are arranged adjacent to the display pixels having different colors in a column direction. Has been
And the driving signal line and the driving power supply line is formed in the same layer of the same material,
The driving power supply line is arranged to be spaced apart from the drive signal line superimposed through an insulating film on a lower layer of the anode,
The driving power supply line extending in the column direction is connected to the display pixels of different colors adjacent to each other in the column direction for each row ,
The display device, wherein the drive signal line is connected to the display pixel of the same color for each row.   2. The display device according to claim 1, wherein the drive power supply line is arranged substantially at the center between the drive signal lines adjacent to each other.   One of the switching thin film transistor and the self light emitting element driving thin film transistor is disposed on one side with respect to the driving power line, and the other thin film transistor is disposed on the other side. The display device according to claim 1.   The driving signal lines and the driving power supply lines are alternately arranged, and the switching thin film transistors and the self-light emitting element driving thin film transistors are alternately arranged between the driving signal lines and the driving power supply lines. The display device according to claim 1, wherein the display device is disposed on the screen.   The drive signal lines and the drive power supply lines extend in the column direction and are alternately arranged in the row direction, and the switching signal lines and the drive power supply lines are arranged between the alternately arranged drive signal lines and drive power supply lines. The display device according to claim 1, wherein a thin film transistor or the thin film transistor for driving the self-luminous element is disposed.   2. The display device according to claim 1, wherein each of the display pixel rows includes pixels exhibiting red, green, and blue periodically arranged in a row direction.   The display device according to claim 1, wherein the arrangement of display pixels of different colors is a delta arrangement.   The display device according to claim 1, wherein the self-luminous element is an electroluminescence element.

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