JP2001134214A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device which is capable of obtaining satisfactory display by preventing a driving signal line and a driving signal line from being short-circuited while suppressing the increase of processes by the forming of them on different layers. SOLUTION: This device is a display device in which display pixels 110 which are respectively provided with an EL element 60 having a light emitting layer between a cathode 67 and a anode 61, a TFT for switching 30 supplying a driving signal to the element 60 and a TFT for driving an EL element supplying a current to the EL element 60 are arranged in a matrix shape and which is provided with driving signal lines 52a, 52b supplying a driving signal to the TFT for switching 30 and driving power source lines 53a, 53b supplying a current corresponding to the driving signal to the EL element 60 and the driving signal lines 52a, 52b are arranged by being made to be away from the driving power source lines 53a, 53b in this device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a display device, and more particularly to an electroluminescence display device having an electroluminescence element and a thin film transistor.

[0002]

2. Description of the Related Art In recent years, electroluminescence (Elec)
tro Luminescence: Hereinafter, referred to as “EL”. A display device using an element has attracted attention as a display device replacing a CRT or an LCD. For example, a thin film transistor (Thin F) is used as a switching element for driving the EL element.
ilm Transistor: Hereinafter, referred to as “TFT”. Research and development of display devices equipped with) are also in progress.

As a method of arranging display pixels of a display device,
There are a so-called stripe arrangement and a 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 of a personal computer, and the delta arrangement is effective as a display having a high resolution and displaying a moving image.

FIG. 5 is a plan view showing the vicinity of a display pixel of a conventional EL display device in which display pixels are arranged in stripes.
FIG. 6A is a cross-sectional view taken along the line AA in FIG.
FIG. 6B is a cross-sectional view taken along the line BB in FIG.
FIG. 5C is a cross-sectional view taken along the line CC in FIG.

As shown in FIG. 5, a plurality of gate signal lines 51a, 51b extend in a row direction (horizontal direction in the figure), and drive signal lines 53a, 53 extend in a column direction (vertical direction in the figure).
b extend a plurality of lines, intersect each other, and a region surrounded by both signal lines is a display pixel region 11.
In each of the display pixel regions 110, an EL display element 60, a switching TFT 30, a storage capacitor 50, and an EL element driving TFT 40 are arranged.

The EL of the display pixel region 110 surrounded by the gate signal lines 51a and 51b and the drive signal lines 53a and 53b
Display element 60, switching TFT 30, storage capacitor 5
0 and EL element driving TFT 40 FIGS. 5 and 6
It will be described according to.

The switching TFT 30 includes a gate electrode 11 connected to a gate signal line 51a and supplied with a gate signal, a drain electrode 16 connected to a drive signal line 52a and supplied with a drive signal, and an EL element. And a source electrode 13s connected to the gate electrode 41 of the driving TFT 40. A polycrystalline silicon film (hereinafter, referred to as a “p-Si film”) as an active layer is formed on an insulating substrate 10, and a gate electrode 11 is formed thereover via a gate insulating film 12. .

A storage capacitor electrode line 54 is arranged in parallel with the gate signal line 51a. This storage capacitor electrode line 5
Reference numeral 4 denotes a capacitor that accumulates electric charge between the capacitor electrode 55 formed in the lower layer via the gate insulating film 12 to form a capacitor. The storage capacitor 50 extends 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.

The EL element driving TFT 40 includes a gate electrode 41 connected to the source 13 s of the switching TFT 30, a source electrode 44 connected to the anode 61 of the EL element 60 and connected to the source 43 s, and an EL element 60. Drain 43 connected to supplied drive power supply line 53b
d.

The EL element 60 has a source electrode 43s
, A cathode 67 serving as a common electrode, and a light emitting element layer 66 interposed between the anode 61 and the cathode 67.

When a gate signal from the gate signal line 51a is applied to the gate electrode 11, the switching TFT 3
0 turns on. Therefore, a drive signal is supplied from the drive signal line 52 a to the gate electrode 41 of the EL element driving TFT 40, and the potential of the gate electrode 41 is changed to the drain signal line 5.
The potential becomes the same as the potential of 2a. Then, a current corresponding to the current value supplied to the gate electrode 41 is supplied to the EL element 60 from the driving power supply line 53b connected to the driving power supply. Thereby, the EL element 60 emits light.

The EL element 60 is made of ITO (Indium T
Anode 61 consisting of a transparent electrode such as hin Oxide), MTDA
TA (4,4'-bis (3-methylphenylphenylamino) bipheny
l), the first hole transport layer 62 composed of TPD (4,4 ', 4 "-t
The second hole transport layer 63 made of ris (3-methylphenylphenylamino) triphenylanine, quinacridone
ne) A light emitting layer 64 made of Bebq2 (10-benzo [h] quinolinol-beryllium complex) containing a derivative and Bebq2
a light-emitting element layer 66 composed of an electron transport layer 65 composed of q2;
A cathode 67 made of a laminate of lithium fluoride (LiF) and aluminum (Al) or a magnesium-indium alloy is laminated in this order.

In the EL device, holes injected from the anode and electrons injected from the cathode are recombined inside the light emitting layer, and excite the organic molecules forming the light emitting layer to generate excitons. Light is emitted from the light emitting layer during the process of radiation deactivation of the excitons, and the light is emitted from the transparent anode to the outside through the transparent insulating substrate to emit light.

FIG. 7 is a plan view showing the vicinity of display pixels of a conventional delta-array EL display device, and FIG.
FIG. 8B is a sectional view taken along line AA in FIG.
FIG. 8C shows a cross-sectional view along the line BB in FIG.
FIG. 3 shows a cross-sectional view along the line CC in FIG.

As shown in FIG. 7, each gate signal line 51
In the direction (row direction) in which a, 51b, and 51c extend, a plurality of display pixels display red (R), green (G), and blue (B) in one.
It is arranged repeatedly as a cycle. The display pixels connected to the adjacent gate signal lines are arranged so as to be shifted from each other in the direction in which the gate signal lines extend. This is a so-called delta arrangement.

That is, the plurality of display pixels arranged in the row direction and the plurality of display pixels similarly arranged in the row direction on the next row adjacent to the plurality of display pixels are mutually shifted by a predetermined display pixel in the row direction. It is arranged with a shift.

The drive power supply line 53a is a driving element for driving the EL element of the display pixel 110R corresponding to the gate signal line 51a.
Connected to the drain of the FT and the gate signal line 51b
Is connected to the drain of the EL element driving TFT of the display pixel 110G corresponding to.

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 a display pixel adjacent to the display pixel 110R.
In addition, they are arranged in parallel with a drive signal line 52a that supplies a drive signal to a display pixel adjacent to the display pixel 110G.

[0019]

By the way, as shown in FIGS. 5 and 7, in a so-called stripe arrangement in which display pixels of the same color are arranged in the column direction, and in a delta arrangement shifted by a predetermined display pixel for each row. In either case, the drive signal lines and the drive power supply lines are formed simultaneously from the same material in order to avoid an increase in the number of manufacturing steps.

That is, the two lines 52c and 53b are simultaneously formed by depositing Al, which is the material of both lines, on the interlayer insulating film 15 by a CVD method or the like, forming a resist pattern thereon, and etching the Al. The material is formed in the same layer.

However, when the two lines are formed, minute dust or foreign matter adheres to a mask or the like for forming the pattern, and the foreign matter or the like cannot form the pattern into the shape of the two lines where the pattern should be originally formed. In such a case, Al etched based on the pattern will be left behind so as to straddle both lines.

In this case, there is a disadvantage that the drive signal line and the drive power supply line formed in the same layer are short-circuited.

In order to solve this drawback, these wirings may be formed in different layers, but this has the drawback that the number of steps increases and the cost increases.

Accordingly, the present invention has been made in view of the above-mentioned conventional disadvantages, and 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. The purpose is to provide.

[0025]

A display device according to the present invention supplies a self-luminous element having a light-emitting layer between a cathode and an anode, and a drive signal for controlling the timing of supplying a current to the self-luminous element. A display signal comprising a switching thin film transistor and a self-luminous element driving thin film transistor for supplying a current to the self-luminous element is arranged in a matrix, and a driving signal line for supplying a driving signal to the switching thin film transistor; A drive power supply line for supplying a current to the self-luminous element in accordance with the drive signal, wherein one of the drive signal line and the drive power supply line is arranged to overlap the anode. Is what is being done.

Further, in the display device, one of the drive signal line and the drive power supply line is arranged so as to overlap with the lower layer of the anode via an insulating film.

The driving power supply line is a display device which is arranged substantially at the center of the driving signal lines adjacent to each other.

By adopting such a configuration, it is possible to prevent a display defect from occurring due to short-circuiting of both the drive signal line and the drive power supply line even though they are formed in the same layer.

Further, in the display device according to the present invention, one of the switching thin film transistor and the self-luminous element driving thin film transistor is disposed on one side of the driving power supply line, and the other thin film transistor is disposed on the other side. Is a display device arranged on the side of.

The drive signal lines and the drive power supply lines are alternately arranged, and the switching thin film transistor and the self-light emitting element drive thin film transistor are alternately provided between each drive signal line and the drive power supply line. It is a display device arranged in.

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 between the alternately arranged drive signal lines and drive power supply lines, A display device in which the switching thin film transistor or the self-light emitting element driving thin film transistor is arranged.

In the display device of the present invention, a plurality of display pixels each exhibiting a predetermined color are periodically arranged in a row direction, a plurality of display pixel rows are provided, and the display pixels are arranged in adjacent rows. The driving device is a display device in which pixels are arranged by being shifted by a predetermined pixel in the row direction, and the driving power supply line extending in the column direction is connected to the display pixels of different colors for each row.

Further, in the display device, the drive signal lines are connected to the display pixels of the same color for each row.

Further, there is provided a display device in which red, green, and blue pixels are periodically arranged in a row direction in each of the display pixel rows.

Still further, in the display device, the arrangement of the display pixels of each color is a stripe arrangement or a delta arrangement.

Further, in the display device, the self-luminous element is an electroluminescent element.

By adopting such a configuration, the drive signal line and the drive power supply line are formed in the same layer, but the two lines are not short-circuited and the efficiency between the drive signal line and the drive power supply line is reduced. The switching TFT and the self-luminous element driving TFT can be arranged well, and these TFTs may be short-circuited to each other by dust or the like during the manufacturing process, causing display defects in display pixels of each color. Can be prevented.

Further, the present invention can be employed as a good monitor for a personal computer or the like without causing a display defect due to a short circuit between a drive signal line and a drive power supply line, or as a display device requiring a high resolution.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The case where the present invention is applied to an EL display device will be described below.

FIG. 1 is a plan view of a display pixel region of an organic EL display device, FIG. 2A is a cross-sectional view taken along line AA in FIG. 1, and FIG. FIG. 2C shows a cross-sectional view along the line BB in FIG. 1, and FIG. 2C shows a cross-sectional view along the line CC in FIG.

In the present embodiment, a case where display pixels having EL elements are arranged in a stripe shape will be described.

In the present embodiment, each of the TFTs 30 and 40 provided in the EL display device that emits each color is a so-called top gate TFT in which a gate electrode is provided above an active layer via a gate insulating film. A- as an active layer
A polycrystalline p-Si film is used by irradiating the Si film with laser light.

Here, the gate signal line 51a, the gate signal line 51b, the drain signal line 52b, and the drain signal line 5
The following description focuses on the display pixel area surrounded by 2c.

As shown in FIGS. 1 and 2, a plurality of gate signal lines 51a, 51b and 51c extend in the row direction (horizontal direction in the figure), and drive signals in the column direction (vertical direction in the figure). A plurality of lines 52a, 52b, 52c extend. These two signal lines intersect each other, and a region surrounded by the two signal lines is a display pixel region 110, which is arranged in a matrix. A first TFT 3 serving as a switching TFT is provided near the intersection of the two signal lines 51a and 52b.
0, the source 33 s of the TFT 30 also serves as a capacitance electrode 55 that forms a capacitance with the storage capacitance electrode line 54, and the second T TFT that is a TFT for driving an EL element.
The second TFT connected to the gate 41 of the FT 40
The source 43s is connected to the anode 61 of the organic EL element 60, and the other drain 43d is connected to the drive power supply line 53 which is a current source supplied to the organic EL element 60. The drive signal lines 52a, 52b, 52c and the drive power lines 53a, 53b, 53c are connected to display pixels of the same color.

A storage capacitor electrode line 54 is arranged in parallel with the gate signal line 51. This storage capacitor electrode line 54
Is made of chromium or the like, and forms a capacitor by storing charges between the capacitor 33 and the source 33 s of the TFT via the gate insulating film 12. This storage capacity
It is provided to hold a voltage applied to the gate electrode 41 of the second TFT 40.

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.

As shown in FIG. 2, the organic EL display device comprises:
A TFT and an organic EL element are sequentially laminated on a substrate 10 such as a substrate made of glass or synthetic resin, a conductive substrate, or a semiconductor substrate. However, substrate 1
When a substrate having conductivity and a semiconductor substrate are used as 0, an insulating film such as SiO ₂ or SiN is formed on the substrate 10 and the first and second TFTs and the organic EL are formed.
An element is formed. Each of the TFTs has a so-called top gate structure in which a gate electrode is located above an active layer via a gate insulating film.

First, the first TFT 30, which is a switching TFT, will be described.

As shown in FIG. 2A, an amorphous silicon film (hereinafter, referred to as an "a-Si film") is formed on an insulating substrate 10 made of quartz glass, non-alkali glass, or the like.
The a-Si film is irradiated with a laser beam and melted and recrystallized to form a polycrystalline silicon film (hereinafter referred to as “p-
It is referred to as “Si film”. ), And this is the active layer 13.
A single layer or a stack of a SiO ₂ film and a SiN film is formed thereon as the gate insulating film 12. In addition, C
A gate signal line 51a also serving as a gate electrode 11 made of a high melting point metal such as r or Mo is formed. 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 to suppress off-state current.

The active layer 13 is ion-doped on the channel 13c below the gate electrode 11 and on both sides of the channel 13c using the gate electrode 11 on the channel 13c as a mask. Cover and ion dope the gate electrode 1
1, a low concentration region 13LD is provided on both sides, and a source 13s and a drain 13d of a high concentration region are provided outside the low concentration region 13LD. That is, it is a so-called LDD structure.

Then, the gate insulating film 12 and the active layer 13
On the entire upper surface, an interlayer insulating film 15 laminated in the order of a SiO ₂ film, a SiN film, and a SiO ₂ film is formed, and a contact hole provided corresponding to the drain 13d is filled with a metal such as Al. A drain signal line 52b also serving as the drain electrode 16 is provided. At this time, the driving power supply line 5
3b is formed of Al. Further, a flattening insulating film 17 made of an organic resin and flattening the surface is formed on the entire surface.

Next, the second TFT 40 which is a driving TFT of the organic EL element will be described.

As shown in FIG. 2B, a-S is placed on an insulating substrate 10 made of quartz glass, non-alkali glass or the like.
The active layer 43 and the capacitor electrode 55, the gate insulating film 12, and the active layer 43, which are made of a p-Si film polycrystallized by irradiating the i film with a laser beam,
Electrode 4 made of high melting point metal such as Cr and Mo
1 and a storage capacitor electrode line 54 are formed in this order. A channel 43 c and a channel 43 c are formed in the active layer 43.
A source 43s and a drain 43d are provided on both sides of c. Then, on the entire surface of the gate insulating film 12 and the active layer 43, an interlayer insulating film 15 laminated in the order of the SiO ₂ film, the SiN film, and the SiO ₂ film was formed, and provided corresponding to the drain 43d and the source 43s, respectively. A drive power supply line 53b and a source electrode 44 connected to a drive power supply by filling a contact hole with a metal such as Al are arranged. Although the case where the gate electrode 41 has a single gate structure with one gate electrode is shown, since the driving TFT 40 has a function of supplying a current to the EL element 60, a double gate structure with two gate electrodes may be used. Further, a planarizing insulating film 17 made of, for example, an organic resin and flattening the surface is provided on the entire surface. Then, the source electrode 44 of the planarizing insulating film 17 is formed.
A transparent electrode made of ITO, which is in contact with the source electrode 44 through this contact hole, that is, the anode 61 of the organic EL element
Is provided on the planarizing insulating film 17. The anode 61 is formed in an island shape for each display pixel.

Then, as shown by a dotted line in the anode 61 of FIG.
9 is arranged. That is, the insulating film 19 overlaps with the anode 61 all around the anode 61, in other words, an insulating film having an 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. Therefore, 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 break the light emitting layer due to a step due to the thickness of the anode 61 or to form an electric field concentration at a corner of the anode periphery. It is sufficient that only one of the light emitting element layer 66 and the cathode 67 is separated by the film 19. The insulating film 19 is made of Si.
The insulating film may be an O ₂ film, a single layer of a SiN film or a laminate thereof, a flattening film of an SOG film, or a flattening insulating film of a photosensitive resin. The flattened insulating film is preferable because the cathode 67 formed thereon can be formed flat and the disconnection can be prevented.

Here, the position where the drive power supply line 53b is arranged will be described below.

As shown in FIG. 2C, a gate insulating film 12, a SiO ₂ film, a SiN film, and a SiO ₂ film were laminated in this order on an insulating substrate 10 made of quartz glass, non-alkali glass or the like. An interlayer insulating film 15 is formed, and a drain 43 is formed.
A drive power supply line 53b and drive signal lines 52b and 52c connected to a drive power supply by filling contact holes provided respectively corresponding to d and the source 43s with metal such as Al are arranged. Further, a flattening insulating film 17 made of, for example, an organic resin and flattening the surface is provided on the entire surface. Then, a transparent electrode made of ITO in contact with the source electrode 44 via a contact hole at a position corresponding to the source electrode 44 of the flattening insulating film 17, that is, an anode 61 of an organic EL element is provided on the flattening insulating film 17. ing. The anode 61 is formed in an island shape for each display pixel.

Here, as described above, the insulating film 19 overlaps the anode 61 all around the anode 61, in other words, a region corresponding to a part of the anode 61, that is, is surrounded by a dotted line in FIG. An insulating film 19 having an opening 68 in the region is formed on the anode 61 and the planarizing insulating film 17. Therefore, 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.

An MTDAT is formed on the anode 61 and the insulating film 19.
A first hole transport layer 62 made of A, and second hole transport layer 62 made of TPD
A hole transport layer 63 is deposited on the entire surface by an evaporation method, a light emitting layer 64 made of Bebq2 containing a quinacridone derivative is deposited in an island shape corresponding to each display pixel by an evaporation method, and an electron transport layer made of Bebq2 is further formed thereon. Deposit 65.
Thus, the first hole transport layer 62 and the second hole transport layer 6
3. A light emitting element layer 66 including a light emitting layer 64 and an electron transport layer 65 is formed. Further, on the electron transport layer 65, a cathode 67 made of a laminate of lithium fluoride (LiF) and aluminum (Al) or a magnesium-indium alloy
Are formed by lamination. Thus, an EL element having a structure in which each layer is deposited is formed. The EL element 60 formed in each display pixel is formed by emitting a red (R), green (G), and blue (B) light emitting layer material by an evaporation method, and emits one color for each display pixel. . That is, R,
Display pixels exhibiting each color of G and B are periodically arranged in the row direction.

Here, the drive power supply line 53b is not arranged adjacent to and parallel to the drive signal line 52c as in the conventional case. In other words, the drive power supply line 53b is provided below the anode 61 with the planarization insulating film 17 interposed therebetween, and is arranged almost at the center of the anode 61, and is further arranged at a distance from the drive signal line 52c. ing.

For example, the drive signal lines 52a, 52b, 52
c and the drive power supply lines 53a, 53b, 53c have a line width of about 10 μm, the size of the anode of one display pixel is about 90 μm × about 250 μm, and the distance between the anodes adjacent in the row direction (left-right direction). The spacing is about 30 μm. Each drive signal line extends approximately in the vicinity of the center between the anodes. Therefore, the distance between the center of each drive power supply line and the center of each drive signal line is about 6055 μm, and the drive signal line and the drive power supply line may be short-circuited due to the attachment of foreign matter such as dust in the manufacturing process. Can be prevented. In FIG. 1, the anode is drawn in a shape close to a square for convenience, but the size of a display pixel including the anode can be appropriately selected.

In the above-described embodiment, the position where the drive power supply line is disposed is substantially at the center of the anode. However, the present invention is not limited to this, and is located near one drive signal line. The distance may be any distance as long as the drive signal line and the drive power supply line do not short circuit. Preferably, as described above, it is desirable to arrange the driving signal lines and the driving power supply lines at substantially the center between the adjacent driving signal lines so that the driving signal lines and the driving power supply lines have the largest distance. 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.

As described above, the position where the drive power supply line 53b and the drive signal line 52c simultaneously formed in the same layer and of the same material are spaced apart, that is, the drive signal line 52c is located at the conventional position and By arranging the line 53b substantially at the center of the anode 61, short circuit between the drive signal line 52c and the drive power supply line 53b can be prevented.

Further, as shown in FIG. 1, by arranging the drive power supply line at a position substantially apart from the drive signal line and substantially at the center of the display pixel, the drive power supply line is provided between the drive signal line and the drive power supply line. Left and right switching TFTs 30 and E
An L element driving TFT 40 can be formed.
Can be efficiently arranged, and short-circuiting between the TFTs can be prevented. Further, since there is room in the area where each TFT is provided, each TFT having a required TFT size is provided.
Can be formed. That is, when the luminous efficiencies of the materials of the respective colors of the light emitting element layers are different, the size of the TFT for driving the EL element for each color for supplying a current to the EL element is the most suitable for the color of the material having the high luminous efficiency. As the luminous efficiency decreases, the TFT for driving the EL element becomes smaller.
When increasing the size of each TFT in order, the T
An FT can be formed.

Further, light emitted from the light emitting element layer is shown in FIG.
(C) The emitted light is emitted downward. Even if a drive power supply line is arranged below the layer, that is, on the observer side of the emitted light, the emitted light is radial because the EL element is a self-emitting element. Therefore, since the decrease in luminance due to the driving power supply line can be ignored when observing the display, it may be arranged below the anode. <Second Embodiment> FIG. 3 is a plan view of a display pixel region of an organic EL display device, and FIG. 4A is a cross-sectional view taken along line AA in FIG. FIG. 4B shows a cross-sectional view along the line BB in FIG. 3, and FIG. 4C shows a cross-sectional view along the line CC in FIG.

This embodiment is different from the first embodiment in that the arrangement of the display pixels is a so-called delta arrangement, whereby the colors of the display pixels connected to the drive power supply line are different. is there.

As shown in FIGS. 3 and 4, in the direction (row direction) in which the gate signal lines 51a, 51b, 51c extend, a plurality of display pixels are provided with red (R), green (G), blue ( B) is repeated as one cycle. The display pixels connected to the adjacent gate signal lines are arranged so as to be shifted from each other in the direction in which the gate signal lines extend. This is a so-called delta arrangement.

That is, a plurality of display pixels arranged in the row direction and a plurality of display pixels similarly arranged in the row direction on the next display pixel row adjacent to the plurality of display pixels are separated from each other by a predetermined display pixel. It is arranged only shifted in the row direction. In the present embodiment, display pixels of the same color are shifted in the row direction by approximately 0.7 display pixels.

For example, when attention is paid to the adjacent gate signal lines 51a and 51b, each display pixel connected to the gate signal line 51a and each display pixel connected to the gate signal line 51b are In the embodiment, when viewed with display pixels of the same color, they are arranged to be shifted from each other by approximately 0.7 display pixels in the extending direction of each gate signal line.

Each drive signal line 52a, 52b, 52
“c” mainly extends in the column direction, is connected to display pixels of the same color, and is arranged to bend in each row and meander left and right according to the arrangement of the display pixels in each row. That is,
They are arranged in the column direction while being bent by a predetermined number of display pixels in the adjacent row direction and repeating the unevenness.

The driving power supply lines 53a, 53b, 53
c is arranged in the column direction, is connected to display pixels of different colors, and is bent and meanders left and right according to the arrangement of the display pixels in each row. That is, the driving power supply line 53a
Note that the driving power supply line 53a is arranged substantially at the center of the R display pixel connected to the gate signal line 51a and is connected to the EL element driving TFT 40 of the display pixel. It is arranged at substantially the center of the G display pixel connected to the gate signal line 51b of the row, and the E of that display pixel is
It is connected to the L-element driving TFT 40, and is disposed at substantially the center of the R display pixel connected to the gate signal line 51c of the next row, and the EL element driving TFT of the display pixel is connected.
It is connected to the. The drive signal lines 52a, 52
The drive power supply lines 53a, 53b, 53c are made of a conductive material such as Al, and are separated from each other to prevent a short circuit and are arranged so as not to cross each other. As an example of a specific position, as described in the first embodiment, the driving signal lines are arranged such that the distance between the driving signal lines is about 60 μm.

As described above, since the drive signal line and the drive power supply line are separated from each other although they are formed in the same layer, it is possible to prevent a short circuit between them. Further, in a so-called delta arrangement, even if 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 lines and the drive power supply lines are in the same layer. It can be formed without crossing while being formed. Thus, a display with high resolution can be obtained while suppressing an increase in steps due to the formation of the drive signal lines and the drive signal lines in different layers.

The EL element emits light by supplying a current to the EL element of each color by controlling the current flowing through the driving power supply line at a constant value by the EL element driving TFT and emitting light. Even if the flowing current value is constant, the driving power supply line can be connected to the EL element driving TFTs 40 of the display pixels of different colors, so that the driving signal line and the driving power supply line are arranged in a delta arrangement. Can be formed in the same layer without intersecting.

The EL element 60 has a source electrode 43s
, An anode 61a connected to the anode and a cathode 67 as a common electrode;
And a light-emitting element layer 66 sandwiched between the anode 61 and the cathode 67. A red (R), green (G), and blue (B) light emitting layer material is formed in each display pixel by a vapor deposition method, and each display pixel emits one color.

The above-described switching TFT, storage capacitor,
Each region of the EL element driving TFT and the EL element is arranged in this order from the gate signal line side to the lower side in the drawing. By arranging in this way, the distance between the light emitting layers of the display pixels located above and below can be increased, and when the light emitting layers of each color of the EL element are deposited, the distance between the adjacent light emitting layers of other colors due to wraparound can be increased. Mixing can be prevented. Also, as in the first embodiment, the driving power supply line is disposed substantially at the center between the driving signal lines, so that the switching TFT is disposed on the left side of the driving power supply line and the EL element driving TFT is disposed on the left side. In addition to the arrangement, it is possible to design with a margin even when the size of the TFT for driving the EL element is increased by making it different for each color.

When a gate signal from the gate signal line 51a is applied to the gate electrode 11, the switching TFT 3
0 turns 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 is changed to the drive signal line 52a.
And the same potential as Then, a current corresponding to the current value supplied to the gate electrode 41 is supplied to the EL element 60 from the driving power supply line 53b connected to the driving power supply. Thereby, the EL element 60 emits light.

In order to emit R, G, and B light of each color as shown in FIG. 1, first, a metal mask having an opening at a position where the R light emitting material is disposed is placed on the anode and the flattening film. A light emitting material of R is deposited, a light emitting material of G is deposited on a metal mask having an opening at a position where the light emitting material of G is disposed, and a metal having an opening at a position where the light emitting material of B is further disposed. A light-emitting material of B is deposited using a mask to form a light-emitting layer. At this time, it is necessary to prevent different colors of light-emitting materials from entering adjacent light-emitting layers of different colors and mixing the colors.

In the present embodiment, the meandering pitch of the drive signal line is set to 0.7 display pixels, but the present invention is not limited to this.

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.

An insulating substrate is an insulating substrate made of glass, synthetic resin, or the like, or an insulating film such as a SiO ₂ film or SiN formed on a conductive substrate or a semiconductor substrate. Refers to a substrate having an insulating property.

[0080]

According to the present invention, there is provided a display device which suppresses a display defect due to a short circuit between both lines while suppressing an increase in steps due to the formation of drive signal lines and drive signal lines in different layers. Can be provided.

[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 the EL display device according to the first embodiment of the present invention.

FIG. 3 is a plan view of an EL display device according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of an EL display device according to 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 sectional view of a conventional EL display device.

[Explanation of symbols]

11, 41 Gate electrode 13, 43 Active layer 13s, 43s Source region 13d, 43d Drain region 13c, 43c Channel region 16 Source electrode 30 Switching T
FT 40 T for EL element drive
FT 51a, 51b, 51c Gate signal line 52a, 52b, 52c Driving signal line 53a, 53b Driving power supply line 60 EL element 61 Anode 66 Light emitting layer 67 Cathode 68 Opening 110 Display area

Continued on the front page F term (reference) 3K007 AB08 AB18 BA06 CA01 DA02 FA01 5C094 AA21 AA42 AA43 BA03 BA12 BA29 CA19 CA24 DA13 EA03 EA04 EA07 EA10 FA10

Claims (11)

[Claims] A self-luminous element having a light-emitting layer between a cathode and an anode, a switching thin-film transistor for supplying a drive signal to the self-luminous element, and a self-luminous element for supplying a current to the self-luminous element A display pixel including a thin film transistor is arranged in a matrix, a driving signal line for supplying a driving signal to the switching thin film transistor, and a driving power supply line for supplying a current to the self-luminous element according to the driving signal. And wherein one of the drive signal line and the drive power supply line is disposed so as to overlap with the anode. 2. The device according to claim 1, wherein one of the drive signal line and the drive power supply line is arranged so as to overlap a lower layer of the anode via an insulating film. Display device. 3. The display device according to claim 1, wherein the drive power supply lines are arranged substantially at the center between the drive signal lines adjacent to each other. 4. The switching thin film transistor and the thin film transistor for driving the self-luminous element are arranged on one side with respect to the driving power supply line, and the other thin film transistor is arranged on the other side with respect to the driving power supply line. The display device according to any one of claims 1 to 3, wherein the display device is arranged. 5. The driving signal line and the driving power supply line are alternately arranged, and between each driving signal line and the driving power supply line, the switching thin film transistor and the self-luminous light are provided at every interval. The display device according to claim 1, wherein the element driving thin film transistors are alternately arranged. 6. The drive signal line and the drive power supply line extend in a column direction and are alternately arranged in a row direction, and each of the drive signal lines and the drive power supply line which are alternately arranged is provided. 6. The switching thin-film transistor or the self-light-emitting element driving thin-film transistor is disposed between them.
The display device according to item. 7. A plurality of display pixels each exhibiting a predetermined color are periodically arranged in a row direction, and a plurality of display pixel rows are provided. 7. The driving power supply line arranged in a direction shifted in the column direction and extending in the column direction is connected to the display pixels of different colors for each row. 8. The display device according to the above. 8. The display device according to claim 1, wherein the drive signal line is connected to the display pixels of the same color for each row. 9. The display device according to claim 7, wherein red, green, and blue pixels are periodically arranged in a row direction in each of the display pixel rows. Display device. 10. The display device according to claim 1, wherein the arrangement of the display pixels of each color is a stripe arrangement or a delta arrangement. 11. The light-emitting device according to claim 1, wherein the light-emitting device is an electroluminescence device.
The display device according to claim 1.