JP2007250553A - Organic electroluminescent display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent display device capable of improving uniformity of luminance by compensating voltage drop of power supply voltage by arranging a cathode bus line on at least both sides of a pixel region. <P>SOLUTION: The organic electroluminescent display device can compensate voltage drop of a power supply voltage line by arranging a plurality of contact holes asymmetrically. The organic electroluminescent display device 200 comprises a pixel region 260 in which a plurality of pixels are arranged, a first power supply line 221 to supply power supply voltage to the pixels of the pixel region 260, an electrode which is arranged at the upper part of the pixel region 260 and supply a voltage of a prescribed level to the pixels, and a second power supply line 222 which has at least a region to be superposed with the electrode for supplying voltage to the electrode. The second power supply line 222 is provided with a plurality of contact holes for connecting to the electrode, and the plurality of contact holes are arranged asymmetrically with a bisector of the superposed region of the second power supply line 222 and the electrode as a reference. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic light emitting display, and more particularly, an organic light emitting display capable of compensating a voltage drop of a power supply voltage line by asymmetrically forming a plurality of contact holes for connecting a cathode electrode and a cathode power supply line. The present invention relates to a display device.

  FIG. 12 is a plan view illustrating an organic light emitting display device.

  Referring to FIG. 12, the organic light emitting display 300 includes a pixel area 360 having a plurality of pixels, and an upper power voltage line 310 that is arranged on the upper, left, and right sides of the pixel area 360 to apply a power voltage. A lower power supply voltage line 330 that is arranged below the pixel region 360 to apply a power supply voltage, and the upper power supply voltage line 310 and the lower power supply voltage line 330 are connected to the pixel region 360. The pixel power supply voltage lines 311 arranged in correspondence with each other, a scan driver 340 that outputs a selection signal, and a data driver 350 that outputs a data signal are provided.

  The organic light emitting display 300 further includes a cathode electrode 322 arranged corresponding to the pixel region 360 and a cathode power line 320 formed on one side of the pixel region 360. Although not shown in the drawing, the cathode power supply line 320 includes a contact hole for connection with the cathode electrode 322.

  FIG. 13 shows a planar structure of a cathode power supply line having one contact hole for connection with a cathode electrode in a conventional organic light emitting display device.

  Referring to FIG. 13, conventionally, one contact hole 321 is arranged in the cathode power supply line 320, and the cathode power supply line 320 is connected to the cathode electrode 322 through the contact hole 321, and the cathode power supply line is connected from an external terminal. A cathode voltage provided to 320 is provided to the cathode electrode 322 through the contact hole 321.

  In the conventional organic light emitting display having the above-described configuration, a selection signal and a data signal are applied to the pixel region 360 from the scan driver 340 and the data driver 350, and a power supply voltage and a cathode power supply line are supplied from the power supply lines 310 and 330. When a cathode voltage is applied from 320 to the cathode electrode 322, a switching transistor and a driving transistor (not shown) that constitute each pixel arranged in the pixel region 360 are driven to drive an EL element (not shown in the drawing). ) Will be emitted.

  FIG. 14 shows the distribution of power supply voltage provided from the cathode power supply line 320 to the pixel region 360 in the organic light emitting display device shown in FIG.

  Referring to FIG. 14, the distribution of the power supply voltage in the pixel region 360 is such that the voltage drop increases with increasing distance from the portion to which the power supply voltage is supplied, and the portion to which the power supply voltage is applied. The voltage drop is smaller as the distance is closer, and it can be divided into regions where a relatively high power supply voltage is applied.

  From FIG. 14, it can be seen that the power supply voltage applied to the pixel region becomes lower as the distance from the portion to which the power supply voltage is supplied, that is, the external terminal to which the power supply voltage is input, is decreased. . Further, the power supply voltage becomes lower as the distance from the cathode power supply line 320 becomes longer and from the external terminal to which the cathode voltage is applied. At this time, the level of the equipotential line of the power supply voltage decreases as it goes from the lower side to the upper side of the pixel region 360. This is because the resistance of the power supply line increases as the distance from the supply side of the power supply voltage increases. This is because the voltage drop (IR drop) increases as the cathode power supply line resistance increases as the distance from the cathode voltage supply side increases.

  That is, since the voltage drop width of the power supply voltage line varies depending on the position from the supply side of the power supply voltage, a relatively high power supply voltage is provided with a small voltage drop in the portion close to the supply voltage supply side. A relatively low power supply voltage is provided in a portion far away on the supply side because of a large voltage drop.

  Similarly, the cathode voltage distribution in the conventional cathode power supply line 320 is the same as the power supply voltage distribution of the power supply voltage line, and the resistance of the cathode power supply line increases with increasing distance from the external terminal to which the cathode voltage is input. Since the voltage drop increases due to the component, a relatively high cathode voltage is provided at a portion near the external terminal with a small voltage drop amount, and a relatively low cathode voltage is supplied at a portion far from the external terminal with a large voltage drop amount. Is done. That is, it can be seen that the lower the cathode voltage is distributed, the farther the distance from the cathode voltage supply side of the cathode power supply line 320 is.

  Therefore, in the past, a large voltage drop of the cathode electrode occurs in the pixel area where the voltage drop of the power supply voltage is large. Therefore, the voltage drop of the power supply voltage and the voltage drop of the cathode electrode overlap, resulting in uneven brightness in the pixel area. There was a problem that the problem became even more serious. Further, conventionally, since the cathode power supply line is formed only on one side of the pixel region, the cathode voltage distribution becomes more non-uniform, which causes a problem that the emission luminance of the pixel region becomes more non-uniform.

  Therefore, the present invention is to solve the above-mentioned conventional problems, and the cathode bus lines are arranged on at least both sides of the pixel region to compensate for the voltage drop of the power supply voltage, thereby improving the luminance uniformity. An object of the present invention is to provide an organic light emitting display that can be improved.

  Another object of the present invention is to provide an organic light emitting display capable of compensating for luminance unevenness due to a voltage drop of a power supply voltage by forming a plurality of contact holes for connecting a cathode electrode and a cathode power supply line asymmetrically. There is.

  To this end, the present invention provides a pixel region in which a plurality of pixels each having an organic thin film layer interposed between the first and second electrodes and the first and second electrodes are arranged, and a first electrode of the pixel region. A first power supply line having at least a region overlapping with the first electrode for providing a first level voltage, and at least the second level voltage for providing a second level voltage to the second electrode of the pixel region. A second power supply line having a region overlapping with the two electrodes, wherein the overlapping region of the second electrode and the second power supply line is a plurality of contact holes for connecting the second electrode and the second power supply line. And the total perimeter of the contact hole is larger than the total perimeter of the overlapping region of the second electrode and the second power supply line.

  The contact hole is characterized in that the circumference of the contact hole in a region where the voltage drop is relatively large is larger than the circumference of the contact hole in a region where the voltage drop is relatively small. The circumference of the contact hole may increase sequentially as the distance from the external terminal increases in the long axis direction of the second power supply line. The contact hole is characterized in that an area of the contact hole in a region having a relatively large voltage drop is larger than an area of the contact hole in a region having a relatively small voltage drop.

  The area of the contact hole may increase sequentially as the distance from the external terminal increases in the long axis direction of the second power supply line. The contact holes are characterized in that an interval between contact holes in a region where a voltage drop is relatively large is smaller than an interval between contact holes in a region where the voltage drop is relatively small. The distance between the contact holes decreases sequentially as the distance from the external terminal increases in the long axis direction of the second power supply line.

  The contact hole is characterized in that the number of contact holes in a region having a relatively large voltage drop is larger than the number of contact holes in a region having a relatively small voltage drop. The contact holes may be arranged in the same number in the shortening direction of the second power supply line. The contact holes have the same area. The contact hole is characterized in that the size of the contact hole in a region with a relatively large voltage drop is larger than the size of the contact hole in a region with a relatively small voltage drop. The size of the contact hole may increase sequentially as the distance from the external terminal increases in the long axis direction of the second power supply line.

In the present invention as described above, a cathode power supply line is formed at least on both sides of the pixel region so as to correspond to the power supply voltage line, and a plurality of contact holes of the cathode power supply line are formed to be asymmetric. Since a voltage drop opposite to the voltage drop due to the distance to the power supply voltage line is generated, the luminance of the pixel region becomes uniform, and there is an effect that it is easy to control the current applied together.
Although the detailed description of the present invention has been given by taking a specific embodiment of the present invention as an example, the present invention is not limited to this, and within the technical field to which the present invention belongs without departing from the concept of the present invention. It goes without saying that various forms or modifications by those having ordinary knowledge are included in the concept of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view of an organic light emitting display according to an embodiment of the present invention. Referring to FIG. 1, an organic light emitting display 200 according to an embodiment of the present invention includes a pixel region 260 in which a plurality of pixels are arranged, an upper side, a left side, and a right side of the pixel region 260. The upper power supply voltage line 210 provided to the pixel region 260, the lower power supply voltage line 230 arranged below the pixel region 260 and providing the power supply voltage to the pixel region 260, the upper power supply voltage line 210, and the lower power supply A pixel power supply voltage line 211 arranged corresponding to the pixel region 260 to be connected to the voltage line 230, a scan driver 240 that outputs a selection signal to the pixel region 260, and a data signal to the pixel region 260. A data driver 250 for output is included.

  In addition, the organic light emitting display according to an embodiment of the present invention is arranged such that the cathode electrode 220 is arranged on the pixel region 260 and the cathode electrode 220 is overlapped on one side of the pixel region 260. A first cathode power supply line 221 for providing a cathode voltage to the cathode electrode 220 and a cathode voltage to the cathode electrode 220 arranged to overlap the cathode electrode 220 on the other side of the pixel region 260. The second cathode power line 222 is further provided.

  Each of the first and second cathode power supply lines 221 and 222 includes a plurality of contact holes 223 for connection to the cathode electrode 220. The plurality of contact holes of the first and second cathode power supply lines 221 and 222 are asymmetrically arranged. As shown in FIGS. 2 to 11, the plurality of contact holes are asymmetrically arranged with at least two contact holes so as to compensate for a voltage drop generated through the cathode power supply line.

(First embodiment)
FIG. 2 illustrates a planar structure of the cathode power supply line in the organic light emitting display according to the first embodiment of the present invention, which is limited to a region overlapping the cathode electrode 220.

  Referring to FIG. 2, the cathode power supply lines 221 and 222 have a plurality of contact holes 223 arranged asymmetrically in the overlapping region with the cathode electrode 220. At this time, the plurality of contact holes 223 are asymmetrically arranged with respect to the bisector in the major axis direction of the overlapping region of the cathode power supply lines 221 and 222 with the cathode electrode. That is, the contact hole 223 is not arranged in a portion adjacent to the external terminal to which the cathode voltage is supplied in the region overlapping with the cathode electrode 220, and a plurality of portions are separated from the external terminal to which the cathode voltage is supplied by a certain distance. The contact holes 223 are arranged.

  According to the first embodiment of the present invention, the plurality of contact holes 223 are arranged in a matrix of columns and rows while maintaining the same pitch between adjacent contact holes. And the number of contact holes arranged in each column and row, that is, the major axis and the shortening direction are preferably the same.

  In the organic light emitting display, the power supply voltage supplied from the upper and lower power supply voltage lines 210 and 230 to the pixel region 260 through the pixel power supply voltage line 211 is distributed according to the position of the power supply voltage lines 210 and 230. Are different. That is, the voltage drop is relatively small and the power supply voltage is high in the portion close to the external terminal, and the voltage drop is relatively large and the power supply voltage is low in the portion far from the external terminal.

  Therefore, when the power supply voltage is provided to the pixel region 260 through the power supply voltage lines 210 and 230, the pixels arranged on the upper side of the pixel region 260 far away from the external terminal as shown in FIG. The voltage drop of the power supply voltage lines 210 and 230 is relatively large and a low power supply voltage is provided, and the voltage drop of the power supply voltage lines 210 and 230 is relatively small for the pixels arranged below the pixel region 260. High power supply voltage will be provided.

  Therefore, according to the present invention, a plurality of contact holes 223 are formed in the cathode power supply lines 221 and 222 corresponding to the portion where the voltage drop of the power supply voltage line is large, and the power supply voltage lines of the cathode power supply lines 221 and 222 are formed. The contact hole 223 is not formed in a portion corresponding to a portion where the voltage drop of 210 and 230 is small. That is, the contact holes 223 arranged in the cathode power supply lines 221 and 222 have at least two contact holes 223 having the same number in the major axis and the shortening direction in the portion where the voltage drop is large, and adjacent contacts. The distances t53 and t54 in the shortening direction of the hole 223 are the same, and the intervals t51 and t52 in the major axis direction are the same. Therefore, the current density in the cathode power supply lines 221 and 222 is concentrated in the peripheral portion of the contact hole 223, and the current density is reduced in the central portion of the contact hole 223.

  Therefore, when a plurality of contact holes are formed as in the present invention, the total length of the contact holes including the circumferences of the respective contact holes is increased as compared with the conventional case of forming contact holes. Thus, the current mobility of the cathode power supply line is increased, thereby preventing the voltage drop of the cathode bus line. At this time, it is preferable that the total circumference of the plurality of contact holes arranged in the region where the cathode electrode and the cathode power supply line overlap is larger than the circumference of the overlapping region of the cathode electrode and the cathode power supply line.

  Therefore, as in the present invention, no contact hole is formed in the portion corresponding to the portion where the voltage drop of the power supply line is small in the cathode power supply lines 221, 222, that is, the portion close to the external terminal. In the portion corresponding to the portion where the voltage drop of the power supply line is large, that is, the portion far from the external terminal, the voltage drop of the cathode power line is reduced by forming a plurality of contact holes.

  This will be described in detail. A plurality of contact holes 223 are formed in the cathode power supply lines 221 and 222 corresponding to a portion where the voltage drop of the power supply voltage lines 210 and 230 is large in the pixel region 260 in the overlapping region with the cathode electrode 220. By arranging the cathode power supply line 221, current applied to the cathode via the anode of the organic EL element (not shown) is concentrated in the plurality of contact holes 223 arranged in the cathode power supply lines 221, 222. On the other hand, the voltage drop of 222 is reduced, and the contact hole 223 is not formed corresponding to the portion where the voltage drop of the power supply voltage lines 210 and 230 is small, so the voltage drop of the cathode power supply lines 221 and 222 is increased.

  Therefore, in the first embodiment of the present invention, the cathode power supply line is formed on both sides of the pixel region to compensate for the voltage drop of the cathode power supply line, and a plurality of contact holes are formed asymmetrically in the cathode power supply line. Thus, a voltage drop generated along the cathode power supply line can be prevented, and a power supply voltage distribution as shown in FIG. 5 can be obtained. As shown in FIG. 5, the equipotential lines have a cathode voltage line arranged on both sides of the pixel region to form a plurality of contact holes asymmetrically in the cathode power supply line. It can be seen that the equipotential line interval ΔV4 is larger than the conventional equipotential line interval ΔV1 shown in FIG.

  In the first embodiment of the present invention, the cathode power supply line is exemplified as having a plurality of contact holes arranged on both sides of the pixel region and asymmetrically arranged. However, as shown in FIG. The power supply voltage distribution as shown in FIG. 4 can also be obtained when a plurality of contact holes are arranged asymmetrically only on the side. Even when the cathode power supply line is formed only on one side of the pixel region, the power supply voltage is asymmetrically arranged as shown in FIG. Since the interval ΔV2 is larger than the conventional ΔV1 shown in FIG. 14, the voltage drop of the power supply voltage is compensated.

  Also, the voltage drop compensation effect as in the present invention can be obtained when the cathode power supply lines are arranged on both sides of the pixel region and the plurality of contact holes are arranged symmetrically. That is, as shown in FIG. 3, when the power supply lines are formed on both sides of the pixel region, the equipotential lines of the power supply voltage are not only arranged symmetrically, but also the interval between the equipotential lines of the power supply voltage. It can be seen that ΔV3 is larger than the conventional ΔV1 shown in FIG. 14 due to the decrease in the voltage drop of the cathode power supply line. Therefore, in the present invention, if a plurality of contact holes are arranged asymmetrically on at least one of the plurality of side surfaces of the pixel, the voltage drop of the power supply voltage can be compensated for by preventing the voltage drop of the cathode power supply line.

  According to the conventional power supply voltage distribution shown in FIG. 14 and the power supply voltage distribution of the present invention shown in FIGS. 3 to 5, the voltage drop of the cathode power supply line is reduced as compared with the prior art. It can be seen that the intervals ΔV2, ΔV3, ΔV4 between equipotential lines of the present invention are larger than the interval ΔV1. That is, the interval ΔV3 or ΔV4 between equipotential lines when a plurality of contacts are arranged asymmetrically is larger than the interval ΔV2 between equipotential lines when a plurality of contact holes are arranged symmetrically, It can be seen that V2 is larger than the conventional equipotential line interval ΔV1.

  Therefore, the voltage drop in the cathode power supply line can be induced opposite to the voltage drop in the power supply voltage line to compensate for the voltage drop due to the power supply voltage line, thereby improving the uneven brightness due to the voltage drop in the power supply line.

(Second Embodiment)
FIG. 6 illustrates a planar structure of a cathode power supply line having a contact hole for connection with a cathode electrode in an organic light emitting display according to a second embodiment of the present invention.

  Referring to FIG. 6, the cathode voltage lines 221 and 222 have a plurality of contact holes 224 arranged asymmetrically in the overlapping region with the cathode electrode 220. At this time, the plurality of contact holes 224 are asymmetrically arranged with reference to the bisector in the major axis direction of the overlapping region of the cathode power supply lines 221 and 222 with the cathode electrode. That is, the contact hole 224 is not arranged in a portion adjacent to the external terminal to which the cathode voltage is supplied, but the contact hole 224 is arranged in a portion separated from the external terminal to which the cathode voltage is supplied by a certain distance.

  According to the second embodiment of the present invention, the plurality of contact holes 224 are arranged in a matrix form of columns and rows, and the number of contact holes arranged in each row is the same and contacts arranged in each column. At least two contact holes are arranged in each column and row so that the number of holes is the same.

  At this time, as the contact hole 224 becomes farther from the external terminals of the cathode power supply lines 221 and 222, the size of the contact hole increases, and the distances t61 and t62 in the major axis direction between adjacent contact holes are the same. The distance t63 in the shortening direction between adjacent contact holes 224 in the region 231 where the power supply voltage drop is large in the cathode power supply line overlapping the cathode electrode is the shortening direction of the adjacent contact holes 224 in the region 232 where the voltage drop is small. Shorter than the interval t64. Therefore, as described above, the area 231 where the voltage drop is large has a larger area of the contact holes 224 included in each row than the area 232 where the voltage drop is small.

  That is, when the region 231 having a large voltage drop and the region 232 having a small voltage drop have the same size and the same number of contact holes are arranged, two adjacent contact holes in the region 231 having a large voltage drop are arranged. The distance L61 between them is larger than the two contact holes adjacent in the region 232 where the voltage drop is small and the distance L62 between them. The distances t61 and t62 between the contact holes in the major axis direction are the same, but the distance t64 between the contact holes in the shortening direction is larger than t63, so that the total perimeter and total area of the contact holes in the region 231 where the voltage drop is large The total perimeter and total area of the contact hole in the region 232 where the voltage drop is small.

  Therefore, since the current density increases as the voltage drop goes from the small voltage drop to the large voltage drop, a voltage drop due to the size of the contact holes 224 arranged and the gap deviation occurs. Accordingly, the voltage distribution of the cathode power supply lines 221 and 222 has a voltage distribution opposite to that of the power supply voltage lines 210 and 230, so that the voltage drop of the power supply voltage lines 210 and 230 is offset. . At this time, it is preferable that the total circumference of the plurality of contact holes 224 arranged in the region where the cathode electrode and the cathode power supply line overlap is larger than the circumference of the overlapping region of the cathode electrode and the cathode power supply line.

(Third embodiment)
FIG. 7 is a plan view of a cathode power line having a plurality of contact holes in an organic light emitting display according to a third embodiment of the present invention.

  Referring to FIG. 7, the cathode power supply lines 221 and 222 have a plurality of contact holes 225 arranged asymmetrically in the overlapping region with the cathode electrode 220. At this time, the plurality of contact holes 225 are asymmetrically arranged with reference to the bisector in the major axis direction of the overlapping region of the cathode power supply lines 221 and 222 with the cathode electrode. That is, the contact hole 225 is not arranged in a portion adjacent to the external terminal to which the cathode voltage is supplied in the region overlapping with the cathode electrode 220, and a plurality of portions are separated from the external terminal to which the cathode voltage is supplied by a certain distance. The contact holes 225 are arranged.

  According to the third embodiment of the present invention, the plurality of contact holes 225 are arranged in a matrix form of columns and rows, and the number of contact holes arranged in each row is the same and contacts arranged in each column. Arranged so that the number of holes is the same, the size of each contact hole is the same.

  That is, at least three contact holes are formed in the major axis direction of the cathode power supply line, and the contact holes adjacent to each other in the major axis direction of the cathode power supply lines 221 and 222 in the region 233 where the voltage drop is large. The interval t73 is smaller than the interval t74 between contact holes adjacent in the major axis direction of the cathode power supply lines 221 and 222 in the region 234 where the voltage drop is small.

  Therefore, the current density increases as the voltage drop goes from the small voltage drop to the large voltage drop, so that a voltage drop occurs due to the gap between the arranged contact holes 225. Accordingly, the voltage distribution of the cathode power supply lines 221 and 222 has a voltage distribution opposite to that of the power supply voltage lines 210 and 230, so that the voltage drop of the power supply voltage lines 210 and 230 is offset. . At this time, it is preferable that the total circumference of the plurality of contact holes 225 arranged in the region where the cathode electrode and the cathode power supply line overlap is larger than the circumference of the overlapping region of the cathode electrode and the cathode power supply line.

(Fourth embodiment)
FIG. 8 illustrates a planar structure of a cathode power supply line having a contact hole for connection with a cathode electrode in an organic light emitting display according to a fourth embodiment of the present invention.

  Referring to FIG. 8, the cathode voltage lines 221 and 222 have a plurality of contact holes 226 arranged asymmetrically in the overlapping region with the cathode electrode 220. At this time, the plurality of contact holes 226 are asymmetrically arranged with respect to the bisector in the major axis direction of the overlapping region of the cathode power supply lines 221 and 222 with the cathode electrode. That is, the contact hole 226 is not arranged in a portion adjacent to the external terminal to which the cathode voltage is supplied, but the contact hole 226 is arranged in a portion separated from the external terminal to which the cathode voltage is supplied by a certain distance.

  At this time, the distance between adjacent contact holes 226 is the same as the voltage drop is increased from the portion where the voltage drop is small, but the contacts configured in each column according to the voltage drop of the power supply voltage lines 210 and 230 are the same. The number of holes 226 is different. At this time, at least the contact holes arranged in each column have the same size. At least two contact holes are arranged along the shortening direction of the cathode power supply line, and different numbers are arranged along the major axis direction of the cathode power supply line.

  Therefore, when the size of the contact holes arranged in each column in the shortened direction of the cathode power supply line is C1, C2, C3, C4, C5, and C6, the major axis direction of the cathode power supply line is caused by the voltage drop of the power supply voltage. Since the number of arranged contact holes is different, the total (total) of the lengths C1, C2, C3, C4, C5, and C6 of the contact holes 226 in the AA ′ region where the voltage drop is large is the BB ′ region where the voltage drop is small. It is larger than the total (total) of the lengths C1, C2, and C3 of the contact holes 226.

  Accordingly, as the voltage drop of the power supply voltage lines 210 and 230 increases, the number of the contact holes 226 arranged in the shortening direction of the cathode power supply line increases, so that the current density increases. As the voltage drop decreases, the contact hole 226 increases. Therefore, the current density is reduced and the voltage drop of the power supply voltage lines 210 and 230 is canceled out. At this time, it is preferable that the total circumference (total) of the plurality of contact holes 226 arranged in the region where the cathode electrode and the cathode power supply line overlap is larger than the circumference of the overlapping region of the cathode electrode and the cathode power supply line.

(Fifth embodiment)
FIG. 9 is a plan view of a cathode power line having a plurality of contact holes in an organic light emitting display according to a fifth embodiment of the present invention.

  Referring to FIG. 9, a plurality of contact holes 227 a and 227 b are asymmetrically arranged in the cathode power supply lines 221 and 222 in the overlapping region with the cathode electrode 220. At this time, the plurality of contact holes 227a and 227b are arranged asymmetrically with reference to the bisector in the major axis direction of the overlapping region of the cathode power supply lines 221 and 222 with the cathode electrode. That is, contact holes 227a and 227b are not arranged in a portion adjacent to the external terminal to which the cathode voltage is supplied in the region overlapping with the cathode electrode 220, and is separated from the external terminal to which the cathode voltage is supplied by a certain distance. A plurality of contact holes 227a and 227b are arranged in the portion.

  According to the fifth embodiment of the present invention, the cathode power supply lines 221 and 222 are arranged in a line in the long axis direction, the intervals t91 and t92 between adjacent contact holes are the same, and the size of each contact hole is the same. Different. The contact holes are arranged in at least two or more in the major axis direction of the cathode power supply line, and the voltage is larger than the length L65 of the cathode power supply lines 221 and 222 of the contact hole 227a in the major axis direction in a region where the voltage drop is large. In the region where the drop is small, the length L66 in the major axis direction of the cathode power supply lines 221 and 222 of the contact hole 227b is small. Further, if the area of the contact hole 227a in the region where the voltage drop is large is referred to as S1, and the area of the contact hole 227b in the region where the voltage drop is small is referred to as S2, the area of the contact hole 227a is the voltage drop in the region where the voltage drop is large. Is larger than the area of the contact hole 227b in the small region. At this time, it is preferable that the total (total) of the peripheral lengths of the plurality of contact holes arranged in the region where the cathode electrode and the cathode power supply line overlap is larger than the peripheral length of the overlapping region of the cathode electrode and the cathode power supply line.

  Therefore, since the current density increases as the voltage drop goes from the small voltage drop to the large voltage drop, the voltage drop occurs due to the size of the contact holes 227a and 227b arranged. Accordingly, the voltage distribution of the cathode power supply lines 221 and 222 has a voltage distribution opposite to that of the power supply voltage lines 210 and 230, so that the voltage drop of the power supply voltage lines 210 and 230 is offset. .

(Sixth embodiment)
FIG. 10 is a plan view of a cathode power supply line having a plurality of contact holes in an organic light emitting display according to a sixth embodiment of the present invention.

  Referring to FIG. 10, a plurality of contact holes 228 a, 228 b, and 228 c are arranged asymmetrically in the cathode power supply lines 221 and 222 in the overlapping region with the cathode electrode 220. At this time, the plurality of contact holes 228a, 228b, and 228c are asymmetrically arranged with reference to the bisector in the major axis direction of the overlapping region of the cathode power supply lines 221 and 222 with the cathode electrode. That is, the space between the adjacent contact holes among the contact holes 228a, 228b, 228c is mutually separated by a certain distance from a portion adjacent to the external terminal to which the cathode voltage is supplied in the region overlapping with the cathode electrode 220. Arrange them differently.

  According to the sixth embodiment of the present invention, at least three or more cathode power supply lines 221 and 222 are arranged in a line in the long axis direction, and the size of each contact hole is the same. The contact hole has a large voltage drop, and the cathode power supply line between the contact holes 228b and 228c has a smaller voltage drop than the interval t15 in the major axis direction between the cathode power supply lines 221 and 222 between the adjacent contact holes 228a and 228b. The interval t16 in the major axis direction of 221 and 222 is small. At this time, it is preferable that the total circumference (total) of the plurality of contact holes 228a-228c arranged in the region where the cathode electrode and the cathode power supply line overlap is larger than the circumference of the overlapping region of the cathode electrode and the cathode power supply line. .

  Therefore, since the current density increases as the voltage drop goes from the small voltage drop to the large voltage drop, a voltage drop due to the interval between the arranged contact holes 228a, 228b, 228c occurs. Accordingly, the voltage distribution of the cathode power supply lines 221 and 222 has a voltage distribution opposite to that of the power supply voltage lines 210 and 230, so that the voltage drop of the power supply voltage lines 210 and 230 is offset. .

(Seventh embodiment)
FIG. 11 is a plan view of a cathode power line having a plurality of contact holes in an organic light emitting display according to a seventh embodiment of the present invention.

  Referring to FIG. 11, the cathode power supply lines 221 and 222 have a plurality of contact holes 229 arranged asymmetrically in the overlapping region with the cathode electrode 220. At this time, the plurality of contact holes 229 are asymmetrically arranged with respect to the bisector in the major axis direction of the overlapping region of the cathode power supply lines 221 and 222 with the cathode electrode.

  According to the seventh embodiment of the present invention, at least two contact holes 229 are arranged in the shortening direction of the cathode power supply lines 221, 222, and at least the length of the contact hole 229 in the major axis direction is the same. Different. At this time, the size of the contact hole 229 in the shortening direction of the cathode power supply line and the interval between adjacent contact holes can be the same or different. At this time, it is preferable that the total circumference (total) of the plurality of contact holes 229 arranged in the region where the cathode electrode and the cathode power supply line overlap is larger than the circumference of the overlapping region of the cathode electrode and the cathode power supply line.

  When the size of the contact holes arranged in each column in the shortened direction of the cathode power supply line is C7, C8, C9, C10, C11 and C12, the contact in the major axis direction of the cathode power supply line is caused by the voltage drop of the power supply voltage. Since the lengths of the holes are different, the total (total) of the lengths C7, C8, C9, C10, C11, and C12 of the contact hole 229 in the CC ′ region having a large voltage drop is the contact hole in the DD ′ region having a small voltage drop. It is larger than the total (total) of lengths C7, C8, and C9 of 229. Therefore, the total area (total) of the contact holes 229 in the CC ′ region where the voltage drop is large is also larger than the total area (total) of the contact holes 229 in the DD ′ area where the voltage drop is small.

  Accordingly, the voltage distribution of the cathode power supply lines 221 and 222 has a voltage distribution opposite to that of the power supply voltage lines 210 and 230, so that the voltage drop of the power supply voltage lines 210 and 230 is offset. Become.

  In the embodiment of the present invention, the cathode power supply lines are formed on both sides of the pixel region, and a plurality of contact holes are asymmetrically arranged on the cathode power supply lines arranged on both sides. A cathode power supply line may be formed on at least one side of the pixel region, and a plurality of contact holes may be asymmetrically arranged in the cathode power supply line.

  As described above, since the current density in the cathode power supply line is concentrated on the periphery of the contact hole, the size of the contact holes and the arrangement state of the contact holes are different as in the embodiment of the present invention. In addition to the method of compensating for the voltage drop, all methods of arranging the contact holes asymmetrically so that the voltage drops of the cathode power supply line cancel each other in accordance with the voltage drop of the power supply voltage can be applied.

1 is a plan view illustrating an organic light emitting display according to an embodiment of the present invention. FIG. 3 is a plan view of a cathode power supply line having a plurality of contact holes for connection with a cathode electrode in the organic light emitting display according to the first embodiment of the present invention. 1 is a schematic view illustrating a distribution of power supply voltage in an organic light emitting display device having two cathode power supply lines according to the present invention. 1 is a schematic view illustrating a distribution of power supply voltage in an organic light emitting display having one cathode power supply line according to the present invention. FIG. 6 is a schematic view illustrating a distribution of power supply voltage in an organic light emitting display having two other cathode power supply lines according to the present invention. FIG. 6 is a plan view of a cathode power supply line having a plurality of contact holes for connection with a cathode electrode in an organic light emitting display according to a second embodiment of the present invention. FIG. 6 is a plan view of a cathode power supply line having a plurality of contact holes for connection with a cathode electrode in an organic light emitting display according to a third embodiment of the present invention. FIG. 9 is a plan view of a cathode power supply line including a plurality of contact holes for connection with a cathode electrode in an organic light emitting display according to a fourth embodiment of the present invention. FIG. 10 is a plan view of a cathode power supply line having a plurality of contact holes for connection with a cathode electrode in an organic light emitting display according to a fifth embodiment of the present invention. In the organic light emitting display device according to the sixth embodiment of the present invention, a plan view of a cathode power supply line having a plurality of contact holes for connection with a cathode electrode. In the organic light emitting display according to the seventh embodiment of the present invention, a plan view of a cathode power supply line having a plurality of contact holes for connection with a cathode electrode. The top view which showed the organic electroluminescent display apparatus. FIG. 6 is a plan view of a cathode power supply line having a contact hole for connection with a cathode electrode in a conventional organic light emitting display device. FIG. 13 is a diagram showing a distribution of power supply voltage in the organic light emitting display device of FIG. 12.

Explanation of symbols

200 organic electroluminescence display device 210 upper power supply voltage line 211 pixel power supply voltage line 220 cathode electrode 221 first cathode power supply line 222 second cathode power supply line 223-226, 227a, 227b, 228a, 228b, 228c contact hole 230 lower power supply voltage Line 240 Scan driver 250 Data driver

Claims (12)

A pixel region in which a plurality of pixels each having an organic thin film layer interposed between the first and second electrodes and the first and second electrodes are arranged;
A first power supply line including at least a region overlapping the first electrode for providing a first level voltage to the first electrode of the pixel region;
A second power line for providing a second level voltage to the second electrode of the pixel region, and having a region overlapping at least the second electrode;
The overlapping region of the second electrode and the second power supply line includes a plurality of contact holes for connecting the second electrode and the second power supply line,
2. The organic light emitting display as claimed in claim 1, wherein the total perimeter of the contact hole is larger than the total perimeter of the overlapping region of the second electrode and the second power line.   2. The contact hole according to claim 1, wherein a circumference of the contact hole in a region having a relatively large voltage drop is greater than a circumference of the contact hole in a region having a relatively small voltage drop. Organic electroluminescent display device.   The organic light emitting display as claimed in claim 2, wherein the peripheral length of the contact hole sequentially increases as the distance from the external terminal increases in the long axis direction of the second power supply line.   2. The organic electric field according to claim 1, wherein the contact hole has an area of a contact hole in a region having a relatively large voltage drop larger than an area of the contact hole in a region having a relatively small voltage drop. Luminescent display device.   5. The organic light emitting display as claimed in claim 4, wherein the area of the contact hole increases sequentially as the distance from the external terminal increases in the long axis direction of the second power supply line.   2. The contact hole according to claim 1, wherein an interval between contact holes in a region having a relatively large voltage drop is smaller than an interval between contact holes in a region having a relatively small voltage drop. Organic electroluminescent display device.   The organic light emitting display as claimed in claim 6, wherein the distance between the contact holes sequentially decreases as the distance from the external terminal increases in the long axis direction of the second power supply line.   2. The organic electric field according to claim 1, wherein the number of contact holes in a region having a relatively large voltage drop is greater than the number of contact holes in a region having a relatively small voltage drop. Luminescent display device.   The organic light emitting display as claimed in claim 8, wherein the same number of the contact holes are arranged in a shortening direction of the second power line.   9. The organic light emitting display as claimed in claim 8, wherein the contact holes have the same area.   2. The organic material according to claim 1, wherein a size of the contact hole in a region having a relatively large voltage drop is larger than a size of the contact hole in a region having a relatively small voltage drop. Electroluminescent display device.   The organic light emitting display as claimed in claim 11, wherein the size of the contact hole sequentially increases as the distance from the external terminal increases in the long axis direction of the second power supply line.

Images