JP2004111082A - Electroluminescence display device and pattern layout method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the use efficiency of a space is low and it is not suitable for high densification since the interval of each signal line and a drive wire is set according to a color to which an area is set most widely. <P>SOLUTION: The difference of life due to materials is adjusted for every color component by setting the length of a pixel area in a row direction according to the life of a luminescent material. Furthermore, a margin is set in the row or column direction within the pixel area to cope with the change of the material after the design, and a light emitting area is formed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a color display device using electroluminescence (hereinafter referred to as EL) self-luminous element and a thin film transistor (TFT), and a design method thereof.
[0002]
[Prior art]
In recent years, an EL display device using an EL element has attracted attention as a display device replacing a CRT or an LCD. As a method of colorizing the EL display device, a method of separately using a light emitting material emitting three primary colors of red, green, and blue, and a method of using a color filter or a color conversion layer for a single color light emitting material have been proposed. I have.
[0003]
In the case of the coloring method, different light-emitting materials are used for each color. These light-emitting materials have unique characteristics such as chromaticity, lifetime, and luminous efficiency. Generally, in a display for displaying a color image, in order to obtain a white balance, the luminance required for each light emission is automatically determined from the chromaticity of each light emitting material. Since their luminance is almost proportional to the applied current density, in order to obtain the required brightness in a light-emitting material having low luminous efficiency, a higher current density must be applied than in other light-emitting regions. However, in the case of such a material having low luminous efficiency, the load on the luminescent material itself is increased as the current density is increased, so that the life of the luminescent material is shortened. As a result, the life of the entire EL display device is also shortened. There was a problem.
[0004]
FIG. 9 is a plan view schematically showing an organic EL display device disclosed in Japanese Patent Application Laid-Open No. 2000-290441 in view of the above problem. A region surrounded by the gate signal line 51, the drain signal line 52, and the power supply drive line 53 is formed in a matrix. Light emitting regions R90, G90, and B90 having different areas for each color are formed in the region, and this indicates a region where light emission can be visually recognized. In this figure, R indicates red, G indicates green, and B indicates blue.
[0005]
The criterion for making the light emitting area different for each color is the luminous efficiency of the light emitting material showing each color. Since a desired luminance is secured by making a light-emitting region using a light-emitting material with low luminous efficiency larger than other light-emitting regions, it is not necessary to apply an excessive current density to the light-emitting material with low luminous efficiency. be able to.
[0006]
[Patent Document 1]
JP-A-2000-290441 (FIG. 1)
[0007]
[Problems to be solved by the invention]
However, as shown in FIG. 9, the intervals between the signal lines and the drive lines are set according to the color whose area is set to be the widest, so that the space utilization efficiency is low, and it is not suitable for high density.
[0008]
[Means for Solving the Problems]
The present invention has been made in view of the above points, and has the following features.
[0009]
First, in an electroluminescence display device in which a plurality of pixel regions capable of forming a light emitting region are arranged according to a predetermined rule, the plurality of pixel regions are respectively associated with a specific color component, and At least one color component of the components is formed to have a different area from the other color components, and the light emitting region corresponding to the at least one color component has a length within the pixel region in a first direction that is equal to the length of the pixel region. Are equal to each other, and are formed to be shorter or equal in length to the pixel region in a second direction intersecting the first direction.
[0010]
As a result, the space can be used effectively, and the light emitting area can be enlarged.
[0011]
Secondly, in a pattern layout method for an electroluminescent display device in which a plurality of pixel regions capable of forming a light emitting region are arranged in a predetermined rule, the first direction is determined according to the characteristics of a light emitting material showing each assumed color. Determining the lengths of the pixel regions associated with the respective color components in the above, and commonly determining the length of the pixel regions in a second direction that intersects the first direction; In the region, one of the first direction and the second direction is set to have the same length as the pixel region, and the other is set to have a shorter length than the pixel region. Determining a corresponding light emitting area.
[0012]
As a result, the space can be used effectively, and the light emitting area can be enlarged.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a plan view showing a light emitting region of the EL display device according to the first embodiment. In this figure, light-emitting areas corresponding to each color component of three primary colors (red: R, green: G, blue: B) are periodically arranged in the row direction, and the same colors are arranged in the same column. The case of an array is shown. It is assumed that the life of each component is in a relationship of G>R> B. Note that the term “lifetime” as used herein refers to a half-life of luminance at which the luminance becomes 50% of the initial luminance when light is continuously emitted at a specific current density, and is one of the factors indicating the state of deterioration of a light-emitting material over time. It is.
[0014]
Pixel area P in the figure _R , P _G , P _B Is a light emitting area E in which light emission of each color component is visually recognized. _R , E _G , E _B Where a common height (length in the vertical direction) H and a unique width W corresponding to a color component are formed. _R , W _G , W _B (Length in the horizontal direction). Further, a light emitting area E for emitting each color is provided. _R , E _G , E _B Is the pixel area P _R , P _G , P _B Height H, which is lower than the height H _R , H _G , H _B And the width W equal to the corresponding light emitting area _R , W _G , W _B Respectively. Thereby, the pixel area P _R , P _G , P _B Are formed along one side of the margin M (hatching in the figure) having the same height. A method for setting the height and width of the pixel region and the light emitting region, that is, a pattern layout method will be described later. Further, the height H of the light emitting area _R , H _G , H _B Is equal to the height H of the corresponding pixel area, and the width W of the light emitting area is _R , W _G , W _B Is a unique value W shorter than the width of each light emitting region. _R ', W _G ', W _B 'Also good. Alternatively, a combination of these may be used.
[0015]
Around the plurality of pixel regions P arranged as described above, a plurality of gate signal lines 51 are formed in a horizontal direction, and a plurality of drain signal lines 52 and a plurality of drive power supply lines 53 are formed in a vertical direction. Distance D from gate signal line 51 to pixel area _H , The distance D from the drive power supply line 53 to the pixel area _W Represents each pixel area P _R , P _G , P _B Width W _R , W _G , W _B Is set to be constant regardless of This is because when the gate signal lines 51 and the drive power supply lines 53 are arranged around each pixel region P, the spaces formed above and on the left side of the pixel region P have a common shape. The planar structure around the pixel region P will be described later, but this allows the components such as the TFT and the storage capacitor electrode provided in the region surrounded by each signal line to have a common structure and arrangement. There is an advantage that the design in the region is facilitated, and further, when the light emitting material described later is changed, the structure and arrangement of those components need not be changed. Note that the layout around the pixel area is not limited to this. _H , D _W May be provided at the lower side, the right side, or a combination thereof.
[0016]
In the layout as described above, the space in each pixel region is not wasted, and a margin necessary for correcting the area of the light emitting region can be secured.
[0017]
FIG. 2A is a flowchart illustrating a pattern layout method according to the present embodiment. Hereinafter, how to set and change each area will be described along this chart.
[0018]
In step S1, the luminance of each light emitting material is measured. First, based on the chromaticity of the light emitting material of each color, an ideal luminance L such that white balance can be obtained. _I Is determined for each color component. On the other hand, the current density I such that the luminance half-lives of all the luminescent materials become the approximate target value T ₀ For each material, and the emission luminance L at that time ₀ Are measured in advance.
[0019]
In step S2, the luminance L measured in step S1 ₀ And ideal luminance L _I Ratio L _I / L ₀ (Luminance ratio) is taken for each color component, and the width W of each pixel region P is set so that the luminance ratio for each color component corresponds to the width of the pixel region P corresponding to each color component. _R , W _G , W _B Is set respectively. For example, when the luminance ratio of each color is R: G: B = 2: 1: 3, the width of the pixel region is set to W. _R : W _G : W _B = 2: 1: 3.
[0020]
In step S3, the height of the pixel region P is set to a common height H. At this time, the height H is set to the predicted height H of the light emitting region E. _R , H _G , H _B It is set to be slightly longer than that, and a space is provided in which a margin M can be provided. Height H of light emitting area E _R , H _G , H _B Is set again, or when the light emitting material is changed. By the previous step S2 and step S3, a pixel area P in which the light emitting area E can be maximized is set.
[0021]
In step S4, the light emitting area E _R , E _G , E _B Is set respectively. First, the width of the light emitting region E is set to the width W of the corresponding pixel region P. _R , W _G , W _B Set equal to Next, the value of the height of the light emitting region E, which is predicted in step S3, H _R , H _G , H _B (H _R = H _G = H _B ). In this case, the width W of each pixel region _R , W _G , W _B Are set in accordance with the luminance ratio, so that the light emitting area E corresponding to each color component _R , E _G , E _B Corresponds to the luminance ratio.
[0022]
In step S5, a prototype or simulation is performed using the values set in the above steps, and it is checked whether there is any problem in display. For example, whether or not a white balance is obtained. If there is no problem, the layout ends, and if there is a problem, the process returns to step S4. For example, if it is found that the luminance of B is insufficient, the height H of the light emitting area corresponding to B is obtained. _B May be raised.
[0023]
According to the above method, the pixel region and the light emitting region corresponding to each color component can be set according to the luminance half life of the light emitting material. In the present embodiment, the height of the light emitting region is all common, but the present invention is not limited to this, and the height of the light emitting region may be set. In that case, the light emitting area can be made to correspond to the luminance ratio by making the width of the pixel region P corresponding to each color component roughly correspond to the luminance ratio and adjusting the height of the light emitting region E for each color component.
[0024]
FIG. 2B is a flowchart illustrating a method of changing the light emitting region when the light emitting material is changed due to improvement of the material or other reasons. As an example, the current density at the luminance half-life T is I ₀ From I ₁ (> I ₀ ).
[0025]
In step S1, the luminance of the changed material is measured. The current density I such that the luminance half-life of the changed light emitting material of B becomes an approximate target value T ₁ And the emission luminance L at that time ₁ Is measured.
[0026]
In step S2, the height of the light emitting area of B is set. The current density I measured in step S1 ₁ Brightness L at ₁ And the current density I of B before the change ₀ Luminance L at ₀ And change rate X (= L ₁ / L ₀ ), The height of the light emitting area E corresponding to each color component is changed. There are three ways to make this change, and these methods will be described below.
[0027]
In the first method, the heights of the light emitting regions corresponding to R and G other than B whose light emitting material is changed are made higher than before the change according to the change ratio X (H _R → H _R ', H _G → H _G ', X = H _R '/ H _R = H _G '/ H _G This is a way to balance each color. In the present embodiment, when a pixel area and a light emitting area are first set, a margin M is provided in all corresponding pixel areas. For this reason, if a change for expanding the light emitting area is made, the luminance of each color increases, and the overall luminance also increases.
[0028]
In the second method, the height of the light-emitting region corresponding to B in which the light-emitting material is changed is made lower than before the change in accordance with the change ratio X described above (H _B → H _B ', X = H _B / H _B ') Is a way to balance each color. This method is effective when at least one of the light emitting regions R and G without material change is already at the same height as the pixel region due to repeated height correction or the like, and the height cannot be further increased. .
[0029]
The third method is a combination of the first method and the second method. In this case, since there is a degree of freedom in changing, a flexible response can be made.
[0030]
The above method has only a problem that the luminance for realizing the luminance half-life T changes due to the material change. However, in practice, the chromaticity often changes when the material changes. The ideal luminance changes for each color component. Therefore, the luminance ratio is calculated again for each color component described above, and the height of the light emitting region is reset so that the luminance ratio corresponds to the light emitting area corresponding to each color component. In this case, the third method is effective and practical.
[0031]
Subsequently, in step S3, similarly to step S5 in FIG. 2A, it is determined whether there is no problem with the settings so far. Prototype or simulation is performed using the values set in step S2, and it is confirmed whether there is no problem as a display device.
[0032]
According to the method described above, it is possible to cope with a change in the light emission characteristics due to a change in the material only by changing the height of the light emitting region E without changing the layout other than the light emitting region. Therefore, the change of the mask used in the manufacturing process can be minimized. Specifically, at least one mask for defining the light emitting region is changed. Further, even if the height of the light emitting region E corresponding to one color component is formed equal to the height H of the pixel region P, it is possible to change the material by adjusting the height of the light emitting region of another color component. It is possible to cope with the accompanying change in the light emission characteristics. In this case, it is preferable that the light emitting region formed at a height equal to the height H of the pixel region is a light emitting region corresponding to a color component whose light emitting area needs to be formed the largest. Although only the case where the light emitting material of B is changed is described in the present embodiment, the same applies to the case of G or R, and the case where the light emitting material of two or more colors is changed can be applied. Further, in the present embodiment, the margin M is provided above the light emitting region to cope with a material change or the like. However, the same applies to the case where the margin M is provided below the light emitting region E or at one of the left and right sides. In addition, the width of the light emitting region E provided with the margin M can be changed to cope with the material change. In this case, the width of the light emitting region may be changed while the height of the light emitting region is fixed.
[0033]
FIG. 3 shows a pixel region P according to the present embodiment. _B FIG. 4A is a plan view showing a peripheral structure, and FIGS. 4A and 4B are cross-sectional views taken along lines AA and BB of FIG. Hereinafter, the structure of the pixel region P and the periphery thereof according to the present embodiment will be described with reference to FIG.
[0034]
Light emitting area E _B Is the pixel area P _B Is provided with a margin M above the pixel region P. _B Is located within. In addition, two first TFTs 10 connected in series, and a part of the storage capacitor electrode line 54 and the capacitor electrode 55 are partially connected to the pixel region P. _B And the gate electrode 51. Further, the gates 11 of the two TFTs 10 are connected to gate signal lines 51, respectively. Further, the drain 13 d of the TFT 10 on the drain signal line 52 side is connected to the drain signal line 52. The source 13 s of the TFT 10 that is not directly connected to the drain signal line 52 is connected to a capacitance electrode 55 that forms a capacitance with the storage capacitance electrode line 54. Further, the source 13 s of the TFT 10 is connected to the gate electrodes 21 of two second TFTs 20 connected in parallel. The sources 23s of the two TFTs 20 are connected to the drive power supply line 53, respectively. The drains 23d of the two TFTs 20 are connected to the drain electrode 26, and further connected to the anode 61 of the organic EL element 70 via the drain electrodes 26.
[0035]
The storage capacitor electrode line 54 is formed so as to face the conductive layer 13 serving also as the capacitor electrode 55 connected to the source 13 s of the TFT 10 via the gate insulating film 12. Thereby, a charge is accumulated between the storage capacitor electrode line 54 and the capacitor electrode 55 to form a capacitor. This capacitance serves as a storage capacitor that holds a voltage applied to the gate electrode 21 of the second TFT 20.
[0036]
In this figure, a pixel area P _B And light emitting area E _B Is shown as a rectangle, but it may not actually be a rectangle in order to secure a light emitting area at all or for design reasons. In the present specification, a non-rectangular shape is regarded as a rectangle if it can be roughly regarded as a rectangle. Further, the place where the margin M is provided is not limited to the present embodiment, but may be biased to one side of the pixel region. Note that, in this drawing, in the pixel region P corresponding to B, _B And its peripheral structure, the pixel regions P corresponding to G and R _G And P _R And its peripheral structure are almost the same.
[0037]
Here, the structure of the first TFT 10 which is a bottom gate type TFT for switching will be described. A gate electrode 11 and a storage capacitor electrode line 54 made of a high melting point metal such as chromium (Cr) and molybdenum (Mo) are formed on a substrate 10. An active layer 13 made of a polycrystalline silicon (hereinafter abbreviated as p-Si) film is laminated thereon via a gate insulating film 12. On the active layer 13, a stopper 14 is formed at a position corresponding to the gate electrode 11 and serves as a mask for ion implantation into the active layer 13. The active layer 13 is provided with a drain 13d, a source 13s, and a channel 13c located therebetween. Thereby, the first TFT 10 and the storage capacitor are formed. Further, the entire surface of the gate insulating film 12, the active layer 13, and the stopper 14 is covered with SiO 2. ₂ An interlayer insulating film 15 made of a film, a SiN film or the like is formed. A drain electrode 16 made of a metal such as Al is provided through a contact hole formed at a position corresponding to the drain 13d of the interlayer insulating film 15, and a flattening film 17 made of an organic resin and flattening the surface is provided on the entire surface of the substrate. Is formed.
[0038]
Next, the structure of the second TFT 20, which is a bottom gate type TFT for driving the organic EL element, will be described. On a substrate 10, a gate electrode 21 made of a refractory metal such as Cr and Mo, a gate insulating film 12, and an active layer 23 made of a p-Si film are sequentially formed. A stopper 24 is formed on the active layer 23 at a position corresponding to the gate electrode 21 to serve as a mask for ion implantation into the active layer 23. The active layer 23 is provided with a drain 23d, a source 23s, and a channel 23c located therebetween. Thus, a second TFT is formed. Then, the entire surface on the gate insulating film 12 and the active layer 23 is covered with SiO 2 ₂ An interlayer insulating film 15 made of a film, a SiN film or the like is formed, and is connected to a drain electrode 26 made of metal and a driving power supply through contact holes formed at positions corresponding to the drain 23d and the source 23s of the interlayer insulating film 15. And a driving power supply line 53. Further, a flattening film 17 made of an organic resin for flattening the surface is laminated. 17 is formed. Next, on the anode 61, a light-emitting element layer 65 including a hole transport layer 62, a light-emitting layer 63, and an electron transport layer 64 is laminated and formed. A cathode 66 made of an alloy or the like is formed. Here, a second flattening film 67 made of an insulating resin is laminated between the hole transport layer 62 and the anode 61, and an opening provided on the anode 61 limits a region where the anode 61 is exposed. are doing. That is, the light emitting region E is defined by the opening of the second planarization film 67. Further, the pixel region P in the figure is defined by the anode 61.
[0039]
As a method of manufacturing the light emitting region E of the EL display device of the present embodiment into a set shape, in addition to the above-described first method using the second flattening film 67, the second flattening film 67 may be used. As shown in FIG. 5A, there is a second method of adjusting the shape of the anode 61 of the organic EL element without using the method. In this case, the light emitting region E is defined by the anode 61, and the pixel region P is defined by the light emitting layer 63. In addition, there is also a third method in which the second flattening film 67 is not used and adjustment is performed by the light emitting layer 63 as shown in FIG. In this case, the light emitting region E is defined by the light emitting layer 63, and the pixel region P is defined by the anode 61.
[0040]
FIGS. 6A to 6D are cross-sectional views illustrating a method of manufacturing the EL display device according to the present embodiment, which is performed according to different manufacturing steps. These drawings correspond to the sectional view taken along the line BB of FIG. The manufacturing process of the EL display device using the first method will be described with reference to FIG.
[0041]
FIG. 6A is a cross-sectional view in the first step. In this step, first, the second TFT 20 is formed by an existing method, the interlayer insulating film 15 is laminated so as to cover the TFT 20, and then the driving power supply line 53 connected to the source 23s of the TFT 20 and the drain 23d of the TFT 20 are formed. The connected drain electrode 26 is formed. After laminating the flattening film 17 thereon, a contact hole CT penetrating the flattening film 17 and reaching the drain electrode 26 is formed. Then, through this contact hole CT, a transparent anode material, ITO 28, which covers the entire surface of the flattening film 17, is deposited by sputtering.
[0042]
FIG. 6B is a cross-sectional view in the second step. In this step, first, a resist is applied on the ITO 28, exposed using a mask, and developed to pattern the resist. Next, the anode 28 is formed by etching the ITO 28 using the resist as a mask.
[0043]
FIG. 6C is a cross-sectional view in the third step. In this step, first, a second planarizing film material made of an organic resin is laminated on the anode 61 and the planarizing film 17 by a spin coating method or the like. Next, the second planarizing film material is exposed to light using the mask 105 and developed to form a second planarizing film 67. The mask 105 used here has a plurality of openings R50, G50, and B50, for example, as shown in FIG. Each opening R50, G50, B50 of the mask determines a light emitting area and has a predetermined width W. _R , W _G , W _B And height H _R , H _G , H _B Having. Thus, an opening of the second planarization film 67 is formed at a shape and position corresponding to the light emitting region E. The anode 61 is exposed in the region where the opening is formed.
[0044]
FIG. 6D is a cross-sectional view in the fourth step. In this step, first, a hole transport layer 62 is deposited on the flattening film 67 over the entire surface of the substrate so as to cover the exposed anode 61. Next, a light-emitting material is deposited using a mask to form a light-emitting layer 63. Subsequently, an electron transport layer 64 is deposited on the entire surface of the substrate. A cathode 66 is deposited using a mask on the light emitting element layer 65 including the hole transport layer 62, the light emitting layer 63, and the electron transport layer 64 formed as described above. Since the resistance of these light-emitting materials is relatively high, the light-emitting element layer 65 in a region between the anode and the cathode serves as a light-emitting region. Although the hole transport layer 62 and the electron transport layer 64 are both formed on the entire surface of the substrate, different transport layer materials may be used for each light emitting material.
[0045]
As described above, a color display device using an organic EL element having a desired light emitting region for each color can be obtained.
[0046]
Next, a second method, that is, a manufacturing method of adjusting the light emitting region E by the anode 61 will be described. This method may be substantially the same as the first method described above, except that the second planarizing film 67 is not formed. That is, the anode 61 is formed in the same shape and position as the light emitting region using the mask, and the light emitting element layer 65 and the cathode 66 covering the anode 61 are formed thereon. As a result, an EL display device having a sectional structure as shown in FIG. Note that, as the mask for forming the anode 61, for example, a mask having an opening at a position and a shape corresponding to the light emitting region E may be used, similarly to the mask of FIG.
[0047]
Next, a third method, that is, a manufacturing method of adjusting the light emitting region E by the light emitting layer 63 will be described. This method may be substantially the same as the second method described above, except that the anode 61 is formed larger than the light emitting region, and the light emitting layer 63 is formed in the same shape and position as the light emitting region E using a mask. Thus, an EL display device having a cross-sectional structure as shown in FIG. 5B is obtained. Note that, as the mask for forming the light emitting layer 63, for example, a mask having an opening at a position and a shape corresponding to the light emitting region E may be used, similarly to the mask of FIG. However, since a different light emitting material is used for each color component, masks are required in that number. In this case, each mask has an opening corresponding to the light emitting region E corresponding to one color component.
[0048]
In the present embodiment, by setting the light emitting region E by providing a margin M in the pixel region P, the height of the light emitting region within the range of the pixel region can be maintained without changing the width of the light emitting region already designed. Can be adjusted. Thus, the same white balance can be obtained even when the material is changed. At this time, since it is not necessary to change the size and layout of the region itself surrounded by the gate signal line 51, the drain signal line 52, and the drive power supply line 53, the number of masks to be changed can be minimized to one. For example, when an EL display device is manufactured using the second planarization film 67, the height of the opening of the mask 105 for forming the second planarization film 67 is changed in accordance with the change in the height of the light emitting region. Just do it. That is, it can be dealt with by changing only one mask for forming the second flattening film 67. The anode 61 may be formed larger than the light emitting region E but smaller than the pixel region P, that is, the pixel region P may not be defined by the anode 61. In this case, when the height of the light emitting region E is higher than that of the anode 61 by increasing the height of the light emitting region E, the mask for forming the second planarization film 67 is changed to change the height of the light emitting region E, and the anode 61 is changed. The forming mask must also be changed. In this case, it is necessary to change two masks.
[0049]
Next, FIG. 8 is a plan view showing a light emitting region of the EL display device according to the second embodiment. In FIG. 8, a pixel region P set in the same manner as in the first embodiment is shown. _R , P _G , P _B And light emitting area E _R , E _G , E _B Are arranged so as to be shifted from each other by approximately 1.5 pixel regions in the odd-numbered rows and the even-numbered rows, and a combination of R, G, and B is obtained regardless of how three pixel regions adjacent to each other are selected. It has become.
[0050]
The pixel region P and the light emitting region E are the same as in the first embodiment, and a plurality of gate signal lines 51 are arranged in a horizontal direction so as to surround the pixel region and the light emitting region. Further, a plurality of drain signal lines 52 and a plurality of drive power supply lines 53 are arranged in the vertical / horizontal direction in the figure. Further, the gate signal line 51 and the drain signal line 52 or the drive power supply line 53 cross each other.
[0051]
In the case of the delta arrangement as in the present embodiment, the widths of the pixel regions of the same color arranged in adjacent rows may be slightly different due to the pattern layout. The height or width of the light emitting region may be adjusted so that In the present embodiment, even when the light emitting material is changed, it is only necessary to change the light emitting region, and the number of masks to be changed can be suppressed to a minimum of one.
[0052]
The present invention is not limited to the above embodiments, and the arrangement method of each light emitting region may be a diagonal arrangement other than the stripe arrangement and the delta arrangement. The shape of the light emitting region is not limited to a rectangle, but may be a parallelogram or an L-shape. In the case of the L-shape, a rectangle or the like is rationally extracted from the L-shape, and the height is taken as the height H of the light emitting region. _R , H _G , H _B By adjusting this height in accordance with the luminance ratio of each color component, the light emitting area may be set and laid out again. The light emitting region may be manufactured by using a conventional TFT manufacturing method and each material. The structure of the TFT may be not only a bottom gate type but also a so-called top gate type in which a gate electrode is provided on an active layer. Also, only the setting and changing of the light emitting area based on the luminance half-life has been described. However, for example, the light emitting area is set based on a characteristic unique to the light emitting material or a characteristic that changes with time, such as luminous efficiency. It is also possible to set and change. In that case, the life may be read as luminous efficiency or the like.
[0053]
In this embodiment mode, a bottom emission type EL display device in which light from the light emitting layer is output to the back surface side through the TFT substrate side is described. However, a top emission type EL device in which light from the light emitting layer is output from the front surface side of the TFT substrate. Of the present invention can be applied to the EL display device.
[0054]
【The invention's effect】
As described above, according to the present invention, since the light emitting regions can be arranged without generating useless space, each light emitting region can be formed larger. In addition, since the life of each light emitting material can be made uniform, a high-quality EL display device in which a white balance is maintained even when the accumulated use time is long can be provided.
[0055]
Further, since the light emitting region is provided in the pixel region, by changing the size of the light emitting region within the range of the pixel region, the aging of the light emitting material after the material is changed, such as the life and luminous efficiency, is changed. It can respond to the characteristics of Therefore, there is no need to change the layout of the TFT and the storage capacitor other than the light emitting region, and the design time and the manufacturing time of the planar layout can be shortened. In addition, when the plane layout is changed, it is necessary to redesign and manufacture the layers forming the components of the EL display device accordingly. However, in the present invention, since only the light emitting region is changed, the design of each layer is changed.・ The time required for manufacturing changes can be shortened. Therefore, by shortening the design / manufacturing period, the cost required for the design / manufacturing can be significantly reduced. At this time, it is only necessary to re-make, of the anode which is a component of the EL element related to the light emitting region, the flattening film formed on the anode, and the light emitting layer which need to be changed. In other words, it is only necessary to recreate only the masks for forming the changed constituent elements, and the number of masks to be changed may be at least one. Therefore, the cost caused by recreating the mask can be significantly reduced.
[0056]
[Brief description of the drawings]
FIG. 1 is a plan view showing a light emitting region of an EL display device according to an embodiment of the present invention.
FIG. 2 is a flowchart of a layout of the EL display device according to the embodiment of the present invention.
FIG. 3 is a plan view around a pixel region of the EL display device according to the embodiment of the present invention.
FIG. 4 is a cross-sectional view of an EL display device according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view of a second TFT of an EL display device according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view of the EL display device according to the embodiment of the present invention, which is manufactured by different manufacturing steps.
FIG. 7 is a mask for forming an anode electrode of an EL display device according to an embodiment of the present invention.
FIG. 8 is a plan view showing a light emitting region of an EL display device according to another embodiment of the present invention.
FIG. 9 is a plan view showing a light emitting area of a conventional EL display device.
[0057]
[Explanation of symbols]
11, 21 Gate electrode
12 Gate insulating film
13s, 23s sauce
13d, 23d drain
16, 26 drain electrode
10, 20 TFT
51 Gate signal line
52 Drain signal line
53 Drive power supply line
54 Storage capacitance electrode wire
61 anode
62 Hole transport layer
63 Light-emitting layer
64 electron transport layer
66 cathode
67 Flattening film

Claims (8)

In an electroluminescent display device in which a plurality of pixel regions capable of forming a light emitting region are arranged according to a certain rule,
The plurality of pixel regions are respectively associated with specific color components, and at least one color component of the plurality of color components is formed in a different area from other color components;
The light emitting region corresponding to at least one color component has a length equal to the pixel region in the first direction in the pixel region, and is longer than the pixel region in a second direction intersecting the first direction. An electroluminescent display device characterized by having a short length. 2. The electroluminescence according to claim 1, wherein one of the plurality of pixel regions associated with each color component has an equal length in the first direction and the second direction. Display device. The signal line according to claim 2, wherein a plurality of signal lines are provided along the arrangement of the plurality of pixel regions, and the plurality of signal lines are respectively formed at a fixed distance from the plurality of pixel regions. Electroluminescence display device. A plurality of drive power lines are provided along the arrangement of the plurality of pixel regions, and the plurality of drive power lines are formed at a fixed distance from the plurality of pixel regions, respectively. An electroluminescent display device as described in the above. The electroluminescent display device according to any one of claims 2 to 4, wherein the length of the pixel region in the first direction is set according to a change over time in characteristics of a light emitting material showing each color. . In a pattern layout method for an electroluminescent display device, in which a plurality of pixel regions capable of forming a light emitting region are arranged according to a certain rule,
Determining a length of the pixel region associated with each color component in the first direction, in accordance with a property of the light emitting material indicating each assumed color;
Commonly determining the length of the pixel region in a second direction that intersects the first direction;
In the pixel region, at least one of the first direction and the second direction is set to have a length equal to the pixel region, and the other is set to a length shorter than the pixel region. Determining the light emitting area corresponding to the component;
A pattern layout method for an electroluminescent display device, comprising: The electroluminescent display device according to claim 6, wherein the length of the other one of the light emitting regions is changed and the light emitting region is laid out again according to a change in the characteristic accompanying the change of the light emitting material. Pattern layout method. 8. The pattern layout method for an electroluminescent display device according to claim 7, wherein the characteristic of the light emitting material is based on a temporal change of the light emitting material.

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