JP4466115B2 - ORGANIC ELECTROLUMINESCENT DEVICE, METHOD FOR PRODUCING ORGANIC ELECTROLUMINESCENT DEVICE, AND ELECTRONIC DEVICE - Google Patents

Description

  The present invention relates to an organic electroluminescent device, a method for manufacturing an organic electroluminescent device, and an electronic apparatus.

In recent years, development of light-emitting devices using organic substances has been accelerated as a spontaneous emission type display that replaces a liquid crystal display. In a manufacturing method of an organic electroluminescence device (referred to as an organic EL device throughout this specification) using such an organic material as a light-emitting material, the function of the organic EL material or the like is achieved by using an inkjet method (droplet discharge method). A method of forming a conductive material by a coating method is known. In the ink jet method, liquid droplets having a diameter of the order of μm can be discharged and applied with high resolution, so that high-definition patterning of a functional material is possible (for example, see Patent Document 1).
JP 2002-252083 A

  By the way, in the case of patterning a functional material using the above method, a liquid material is prepared by dissolving or dispersing the functional material and a solvent, and the liquid material is applied (discharged) as a micro liquid on a substrate. ing. Here, since the solvent has volatility, it generally has a property of drying quickly. Therefore, drying of the micro liquid applied on the substrate is extremely fast, and the micro liquid applied to the pixel area is likely to evaporate at the peripheral portion (upper end, lower end, right end, left end) of the application area on the substrate. And since the solvent molecular partial pressure is low, it dries faster than the central part of the substrate. Since the liquid material applied on such a substrate has a different degree of drying depending on the applied part, drying unevenness occurs. As a result, unevenness in the cross-sectional shape (profile) and film thickness of the functional material formed on the substrate occurs, resulting in luminance unevenness and display unevenness. Specifically, there is a problem in that the luminance at the periphery of the substrate is lower than that at the center of the substrate, and the light emission characteristics become non-uniform.

  Furthermore, in the ink jet method, after applying the liquid material while scanning the ejection head from one end of the substrate to the other end, the ejection head is turned in a direction perpendicular to the scanning direction, and the ejection head is again connected. The liquid material is applied while scanning. By performing such an operation, unevenness called a line feed streak occurs corresponding to the vicinity of the end of the ejection head that scans on the substrate, causing the problem of uneven brightness and display unevenness as described above. It was. Specifically, there is a problem in that the luminance in the vicinity of the line feed stripe is higher than that in other portions, and the light emission characteristics are not uniform.

  The present invention was devised in view of the above-described problems, and an organic electroluminescence device capable of achieving uniform display characteristics by suppressing occurrence of luminance unevenness and display unevenness in a light emitting region, a method for manufacturing an organic electroluminescent device, And it aims at providing an electronic device.

In order to achieve the above object, the present invention employs the following configuration.
The organic EL device of the present invention is an organic EL device having a plurality of pixels in a light emitting region, and the light emitting region is composed of a plurality of pixel groups having different pixel luminances, and a pixel aperture area ratio of the plurality of pixel groups. Is substantially equal to the reciprocal of the pixel luminance ratio of the plurality of pixel groups. Further, it is preferable that the variation in the pixel aperture area ratio and the pixel luminance ratio is within ± 10%.

Here, the pixel luminance means the luminance per pixel.
Thus, each pixel area ratio is approximately equal to the reciprocal of the luminance ratio, so that the area is set large for pixels with low luminance, and the area is set small for pixels with high luminance. The difference can be effectively corrected, and an organic EL device having uniform luminance and display characteristics over the entire light emitting region can be realized.

  Further, since the difference in luminance is corrected by increasing the pixel area with respect to the pixel having low luminance in this way, the dummy region provided in the conventional organic EL device becomes unnecessary. Therefore, an organic EL device with a small frame can be realized.

  In the organic EL device, the plurality of pixel groups include a first pixel group and a second pixel group having different pixel luminances, and a pixel opening area ratio between the first pixel group and the second pixel group is , Being substantially equal to the reciprocal of the pixel luminance ratio of the first pixel group and the second pixel group.

Thus, since the area ratio of the first pixel and the second pixel is substantially equal to the reciprocal of the luminance ratio, the area is set large for pixels with low luminance, and the area is set small for pixels with high luminance. Therefore, the difference in luminance can be effectively corrected, and an organic EL device having uniform luminance and display characteristics as a whole light emitting region can be realized.
Therefore, conventionally, luminance unevenness and display unevenness have occurred due to the difference in the drying speed of the solvent applied on the substrate, but these problems can be solved by adopting the above configuration. In addition, it is possible to prevent light emission unevenness due to line feed streaks of the ejection head in the ink jet method.

Further, in the organic EL device, the light emitting region includes the first pixel group in a central portion, the second pixel group in a peripheral portion, and each of the second pixel groups rather than the first pixel group. It is characterized by a large pixel aperture area.
Here, conventionally, the micro liquid applied to the peripheral portion (the upper end, the lower end, the right end, and the left end) in the application region on the substrate is likely to evaporate, and the solvent molecule partial pressure in the peripheral portion is low. It dries faster than the center. As a result, there is a problem in that the luminance of the peripheral part of the light emitting region located in the peripheral part of the coating region is lower than that of the central part of the light emitting region and the light emission characteristics become non-uniform. Since the second pixel has a larger area than the first pixel in the central portion, an organic EL device that effectively corrects a difference in luminance between the central portion and the peripheral portion and has uniform luminance and display characteristics as the entire light emitting region. Can be realized.

Further, in the organic EL device, the light emitting region is rectangular, and a third pixel group is provided at a corner of the light emitting region, and each pixel opening area of the third pixel group is larger than that of the second pixel group. It is characterized by being large.
Here, in the rectangular light emitting region, the solvent molecule partial pressure in the corners (upper right corner, lower right corner, upper left corner, and lower left corner) is lower than that of the upper end, the lower end, the right end, and the left end. Therefore, the micro liquid applied to the corners dries faster than the peripheral part. Thereby, the brightness | luminance of the corner | angular part in a rectangular application area | region falls rather than a light emission area periphery part, and the light emission characteristic will become non-uniform | heterogenous. On the other hand, as described as a feature point of the present invention, the third pixel group having a pixel opening area larger than that of the second pixel is provided at the corner of the light emitting region, so that the luminance difference between the peripheral portion and the corner can be reduced. It can be corrected effectively. Furthermore, it is possible to realize an organic EL device having uniform luminance and display characteristics as the entire light emitting regions in the central portion, the peripheral portion, and the corner portion.

In the organic EL device, a fourth pixel group is provided between the plurality of pixel groups, and pixel opening areas of the fourth pixel group are continuously different.
In this way, since the pixel opening areas of the pixels of the fourth pixel group are continuously different, it is possible to cause the fourth pixels to emit light having continuously different luminances. Here, in the case where the fourth pixel group is provided between any two pixel groups of the first pixel group, the second pixel group, and the third pixel group, the fourth pixel group is between the two pixel groups. A gradient can be provided in the luminance distribution of the pixels.

  Further, when the first pixel group, the second pixel group, and the third pixel group are adjacent to each other without providing the fourth pixel group, the emitted light between the pixel groups is displayed as a clear luminance difference. However, by providing the fourth pixel group as described above, the light emission luminance between the pixel groups can be continuously varied. That is, the luminance distribution of the fourth pixel group provided between the first pixel group, the second pixel group, and the third pixel group has a gradient, and the luminance difference between the pixel groups is blurred to emit light. it can.

In the organic EL device, a driving method for controlling the gradation of the pixel group to emit light is any one of a voltage gradation method, a pulse width gradation method, and an area gradation method. It is a feature.
In this way, the brightness of the panel is expressed by adjusting the voltage or the pulse width of the applied voltage or the number of pixels assigned to light emission, so that even if each pixel area is different, each of the pixels Light is emitted according to the voltage amount, pulse width, or number of light emitting pixels. Therefore, a suitable luminance gradation can be expressed according to the voltage amount, the pulse width, or the number of light emitting pixels.

In the organic EL device, the light emitting region includes pixel electrodes formed corresponding to the plurality of pixels, and each pixel electrode has the same area and is formed on the pixel electrode. Each pixel opening area is determined by adjusting the opening area of the inter-pixel member.
In this way, it is possible to realize common use of pixel electrode patterns of all pixel groups constituting the light emitting region. Moreover, the pixel area in each pixel group and the area ratio between different pixel groups can be determined only by adjusting the opening area of the inter-pixel member. Therefore, each pixel area ratio can be adjusted without increasing the number of components such as organic EL elements constituting the pixels or driving elements for driving the organic EL elements.

Further, in the organic EL device, each of the plurality of pixels is composed of a plurality of unit dots having different emission colors, and a ratio of a product of pixel luminance and area of the plurality of unit dots in the same pixel group is It is characterized by being identical.
Here, the plurality of unit dots having different emission colors means, for example, unit dots that emit light in respective colors of R (red), G (green), and B (blue). Then, in the pixel having the plurality of unit dots, considering the brightness of the emission color, the lifetime, and the balance of full-color display, the area of each unit dot is designed to be a predetermined area ratio and the specification is determined. It is common.
Therefore, even when the pixel areas are different as in the first to fourth pixel groups, the ratio of the product of the luminance of the unit dots to the area is the same, so the luminance and lifetime of the emission color, and the balance of full color display can be balanced. It can be realized according to the design and specifications.

Further, the organic EL device manufacturing method of the present invention is a method for manufacturing an organic EL device having a plurality of pixels in a light emitting region, wherein each pixel aperture area ratio of a plurality of pixel groups forming the light emitting region is It is characterized by being approximately equal to the reciprocal of each pixel luminance ratio.
Thus, each pixel area ratio is approximately equal to the reciprocal of the luminance ratio, so that the area is set large for pixels with low luminance, and the area is set small for pixels with high luminance. It is possible to effectively correct the difference, and it is possible to realize an organic EL device having uniform luminance and display characteristics over the entire light emitting region.
Therefore, conventionally, luminance unevenness and display unevenness have occurred due to the difference in the drying speed of the solvent applied on the substrate, but these problems can be solved by adopting the above configuration. In addition, it is possible to prevent light emission unevenness due to line feed streaks of the ejection head in the ink jet method.

In the method for manufacturing the organic EL device, the plurality of pixel groups include a first pixel group and a second pixel group having different pixel luminances, and a pixel opening area of the first pixel group and the second pixel group. The ratio is substantially equal to the reciprocal of the pixel luminance ratio of the first pixel group and the second pixel group.
Thus, since the area ratio of the first pixel group and the second pixel group is substantially equal to the reciprocal of the luminance ratio, the area is set large for the pixel group with low luminance, and the pixel group with high luminance is set. Since the area is set small, it is possible to effectively correct the difference in luminance, and an organic EL device having uniform luminance and display characteristics as a whole light emitting region can be realized.

The organic EL device manufacturing method is characterized in that the plurality of pixels are formed by using a droplet discharge method.
Here, since the inkjet method is a method that can realize equipment cost reduction, material reduction, and process number reduction, a low-cost organic EL device can be manufactured.

Further, in the method for manufacturing the organic EL device, the droplet discharge method is characterized in that the plurality of pixel groups are formed by changing the number of discharges of the liquid material discharged to the plurality of pixel groups. Yes.
Thus, the amount of the functional material in the pixel can be changed by changing the number of ejections. Accordingly, by increasing the number of ejections, a large amount of functional material is ejected, and the functional material wets and spreads over the pixel electrode, so that a pixel with a large area can be formed. In addition, since the functional material is discharged in a small amount by reducing the number of discharges, a pixel with a small area can be formed. Therefore, it is not necessary to change the discharge amount in one discharge operation, and a plurality of pixels having different areas can be formed only by changing the number of discharges.

  Further, in the method of manufacturing the organic EL device, the droplet discharge method includes forming a plurality of pixels by discharging a liquid material from a plurality of nozzles provided in the discharge head, and an end portion of the discharge head. A nearby nozzle discharges the liquid material to form the first pixel group, and a nozzle near the center of the discharge head discharges the liquid material to form the second pixel group. .

  In general, due to the difference in the length of the ink flow path to each nozzle of the ejection head, the amount of ink ejected from the nozzles at both ends of the head is smaller than the amount of ink ejected at the center, so it corresponds to both ends of the head. In the pixel, the thickness of the light emitting layer tends to be thin, so that the electric field applied to the light emitting layer is high and the luminance is likely to be high. Therefore, according to the pixel area determination method of the present invention, the second pixel group often has a larger area than the first pixel group.

  Thus, the nozzles near the end of the ejection head eject the liquid material to form the first pixel group, and the nozzles near the center of the ejection head eject the liquid material to form the second pixel group. Thus, it is possible to solve the problem that the luminance in the vicinity of the line feed line is higher than that in other portions and the light emission characteristics are not uniform as in the prior art. Therefore, even when the droplet discharge method is used, an organic EL device having uniform luminance and display characteristics over the entire light emitting region can be realized.

  As a specific droplet discharge method, the same effect as described above can be obtained by reducing the number of discharges of the liquid material near the center of the discharge head and increasing near the end of the discharge head. Further, the same effect as described above can be obtained by making the discharge amount per discharge constant.

  Further, the same effect as described above can be obtained by reducing the discharge amount per one time discharged from the nozzle near the center of the discharge head and increasing near the end of the discharge head. Furthermore, the same effect as described above can be obtained by making the number of ejections per pixel constant.

In the method for manufacturing the organic EL device, the plurality of pixels have the same length in the width direction, and the lengths of the plurality of pixel groups are made different by changing the length in the direction orthogonal to the width direction. It is characterized by adjusting the pixel area.
In this way, the pixel area can be determined and the pixel area can be adjusted by changing only the length in the direction orthogonal to the width direction without changing the length in the width direction. .
In addition, by making the direction orthogonal to the width direction coincide with the scanning direction of the ejection head, the ejection operation can be performed without stopping the scanning operation. Accordingly, the pixel area can be adjusted while performing the scanning operation.

In the method of manufacturing the organic EL device, a plurality of pixels having the same pixel opening area are formed on a substrate, the plurality of pixels emit light under the same conditions, and the pixel luminance in the light emitting region is measured. The pixel luminance ratio of each pixel group in the light emitting region is calculated, and the pixel aperture area is calculated by multiplying the pixel area of the same area by the reciprocal of the pixel luminance ratio.
Thus, since the dummy organic EL device is actually formed and the luminance of the dummy organic EL device is measured to calculate the luminance ratio and the area ratio, the area based on the measurement result can be calculated.

Further, a plurality of pixel groups are formed based on a calculation result of pixel opening areas of the first pixel group and the second pixel group.
In this way, each pixel can be formed with an area based on the measurement result.

In addition, an electronic apparatus according to the present invention is characterized by including the organic EL device described above.
Examples of such electronic devices include information processing devices such as mobile phones, mobile information terminals, watches, word processors, and personal computers. Moreover, a television having a large display screen, a large monitor, and the like can be exemplified. Thus, by employing the organic EL device of the present invention for the display unit of an electronic device, it is possible to provide an electronic device with good display characteristics.

The present invention will be described in detail below.
This embodiment shows a part of the present invention and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in each figure shown below, in order to make each layer and each member the size which can be recognized on drawing, the scale is varied for each layer and each member.

(First embodiment of organic EL device)
First, an embodiment of the organic EL device (organic electroluminescence device) of the present invention will be described. FIG. 1 is a schematic diagram showing a wiring structure of the organic EL device of this embodiment. In FIG. 1, reference numeral 1 denotes the organic EL device.

  This organic EL device 1 is of an active matrix type using a thin film transistor (TFT) as a switching element, and has a plurality of scanning lines 101... And a plurality of signal lines extending in a direction perpendicular to each scanning line 101. 102 and a plurality of power supply lines 103 extending in parallel to each signal line 102, and unit dots D are formed in the vicinity of the intersections of the scanning lines 101 and the signal lines 102. It is.

  A data line driving circuit 100 including a shift register, a level shifter, a video line, and an analog switch is connected to the signal line 102. Further, a scanning line driving circuit 80 including a shift register and a level shifter is connected to the scanning line 101.

  Further, each unit dot D holds a switching TFT 112 to which a scanning signal is supplied to the gate electrode via the scanning line 101 and a pixel signal shared from the signal line 102 via the switching TFT 112. A capacitor 113, a driving TFT 123 to which a pixel signal held by the holding capacitor 113 is supplied to the gate electrode, and driving from the power line 103 when electrically connected to the power line 103 through the driving TFT 123 A pixel electrode 23 into which a current flows and a light emitting functional layer 11 sandwiched between the pixel electrode 23 and the cathode 50 are provided. The pixel electrode 23, the cathode 50, and the light emitting functional layer 11 constitute a light emitting element, that is, an organic EL element.

  Here, the light emitting functional layer 11 is composed of light emitting functional layers 11R, 11G, and 11B that emit RGB colors as described later (see FIG. 6). And unit dot D is provided according to such light emission functional layers 11R, 11G, and 11B, respectively. Further, one pixel is constituted by the three unit dots D for emitting RGB.

  According to the organic EL device 1 having such a configuration, when the scanning line 101 is driven and the switching TFT 112 is turned on, the potential of the signal line 102 at that time is held in the holding capacitor 113, and The on / off state of the driving TFT 123 is determined according to the state. Then, a current flows from the power supply line 103 to the pixel electrode 23 through the channel of the driving TFT 123, and further a current flows to the cathode 50 through the light emitting functional layer 11. Then, the light emitting functional layer 11 emits light according to the amount of current flowing therethrough. Further, full-color display is realized by gradation of the light emission amounts of the light emitting functional layers 11, that is, the light emitting functional layers 11R, 11G, and 11B that emit RGB colors. Here, any of a voltage gradation method, a pulse width gradation method, and an area gradation method is employed as a method for gradation of the light emission amounts of the light emitting functional layers 11R, 11G, and 11B.

Next, a specific aspect of the organic EL device 1 of the present embodiment will be described with reference to FIG. FIG. 2 is a plan view schematically showing the configuration of the organic EL device 1.
As shown in FIG. 2, the organic EL device 1 according to the present embodiment includes a pixel unit 3 (within a one-dot chain line in FIG. 2) on a substrate 20 having light transparency and electrical insulation. A rectangular light emitting region 4 (within a two-dot chain line frame in the figure) is provided. Further, scanning line drive circuits 80 and 80 are disposed on both sides of the light emitting region 4 in FIG. 2, and an inspection circuit 90 is disposed on the light emitting region 4 on the upper side in FIG. 2. The inspection circuit 90 is a circuit for inspecting the operating state of the organic EL device 1 and includes, for example, inspection information output means (not shown) for outputting the inspection result to the outside, and a display device during manufacture or at the time of shipment. The quality and defect inspection can be performed.

  The light emitting region 4 includes a plurality of pixels arranged in a matrix. Each of the plurality of pixels is composed of three unit dots that emit RGB colors. A driving TFT 123 (see FIG. 1) for emitting light from the light emitting functional layer 11 is provided in each color unit dot. The drive TFT 123 is connected to power lines 103 for supplying power for causing the light emitting functional layer 11 to emit light.

FIG. 3 is an enlarged plan view for explaining the light emitting region 4 in detail.
As shown in FIG. 3, the light emitting region 4 has a central portion 4a, a peripheral portion 4b, and an intermediate portion 4c.
In such a light emitting region 4, a central pixel group (first pixel group) 7a composed of a plurality of pixels is formed in the central portion 4a, and each of the peripheral portion 4b and the intermediate portion 4c is composed of a plurality of pixels. A peripheral pixel group (second pixel group) 7b and an intermediate pixel group (fourth pixel group) 7c are formed. Here, the peripheral pixel group 7b is a pixel group on the outermost periphery of the light emitting region 4, that is, a region including at least pixels located near the outer periphery of the substrate 20, and as shown in FIG. 80 or a position close to the inspection circuit 90 or the like. The intermediate pixel group 7c is a pixel group provided between the central portion 4a and the peripheral portion 4b, and is located between the central pixel group 7a and the peripheral pixel group 7b.
Further, as described later, the pixel area in the peripheral pixel group 7b is larger than that in the central pixel group 7a.

FIG. 4 is an enlarged plan view for explaining a main part of the intermediate pixel group 7c, and shows a pixel row straddling the central pixel group 7a, the peripheral pixel group 7b, and the intermediate pixel group 7c.
As shown in FIG. 4, the intermediate pixel group 7c is located between the central pixel group 7a and the peripheral pixel group 7b. Here, the area of the intermediate pixel group 7c is continuously varied from the central pixel group 7a toward the peripheral pixel group 7b. That is, the area of the intermediate pixel group 7c is set to gradually decrease from the peripheral pixel group 7b having a larger pixel area than the central pixel group 7a toward the central pixel group 7a.

FIG. 5 is a diagram illustrating the relationship between the positions of the central pixel group 7a, the peripheral pixel group 7b, and the intermediate pixel group 7c along the line AA ′ in FIG. 3 and the pixel area in each pixel group. Here, x0 to x5 in FIG. 5 correspond to the positions x0 to x5 in the x direction (lateral direction of the drawing) in FIG.
As shown in FIG. 5, the pixel areas of the pixel groups 7a, 7b, and 7c along the line AA ′ in FIG. 3 are small in the central portion 4a, large in the peripheral portion 4b, and further in the middle. The part 4c is continuously different. Further, as will be described later, the pixel area in the central pixel group 7a and the pixel area in the peripheral pixel group 7b are made different at a predetermined ratio.

Next, referring to FIG. 6, the cross-sectional structure of the pixels in the organic EL device 1 will be described, and the pixel structure in each of the pixel groups 7a, 7b, and 7c will be described in detail.
FIG. 6 is an enlarged cross-sectional view of a pixel at an arbitrary position in the light emitting region 4.

  As shown in FIG. 6, the organic EL device 1 includes a substrate 20 and a sealing substrate 30 that are bonded to each other via a sealing resin (not shown). A getter agent 45 that absorbs moisture and oxygen is attached to the inner surface of the sealing substrate 30 between the substrate 20 and the sealing substrate 30. The space is filled with nitrogen gas to form a nitrogen gas filled layer 46. Under such a configuration, moisture and oxygen are prevented from penetrating into the organic EL device 1, thereby extending the lifetime of the organic EL device 1. Such an organic EL device 1 is a so-called bottom emission type organic EL device that extracts emitted light from the substrate 20 side.

In such a bottom emission type, since the emitted light is extracted from the substrate 20 side, a transparent or translucent material is employed for the substrate 20. For example, glass, quartz, resin (plastic, plastic film) and the like can be mentioned, and a glass substrate is particularly preferably used.
As the sealing substrate 30, for example, a plate-like member having electrical insulation can be employed. The sealing resin 40 is made of, for example, a thermosetting resin or an ultraviolet curable resin, and it is particularly preferable to employ an epoxy resin that is a kind of thermosetting resin.

  A driving TFT 123 and a pixel electrode 23 are provided on the substrate 20. The driving TFT 123 and the pixel electrode 23 are conductive, and power is supplied to the pixel electrode 23. Further, each of the pixel electrodes 23 is provided with light emitting functional layers 11R, 11G, and 11B, and a cathode 50 is provided so as to cover the entire surface of the light emitting functional layers 11R, 11G, and 11B. Each of such light emitting functional layers 11R, 11G, and 11B constitutes a unit dot D, and the three light emitting functional layers 11R, 11G, and 11B constitute one pixel. Such light emitting functional layers 11R, 11G, and 11B emit light with gradations of R (red), G (green), and B (blue) in accordance with the potential of the driving TFT 123. .

  The organic EL device 1 includes a first partition (inter-pixel member) 75a and a second partition (inter-pixel member) 75b so as to partition the pixel electrode 23 and the light emitting functional layers 11R, 11G, and 11B. The first partition wall 75 a and the second partition wall 75 b are formed in a stacked manner, and both are disposed above the driving TFT 123. Further, the first partition 75a is provided adjacent to the pixel electrode 23, and the second partition 75b is provided adjacent to the light emitting functional layers 11R, 11G, and 11B.

The first partition 75 a is disposed adjacent to the pixel electrode 23 and is formed so as to cover a part of the upper surface of the pixel electrode 23. The first partition 75a is lyophilic with respect to the liquid material. As such a lyophilic material, various materials such as an inorganic material and an organic material are employed. In this embodiment, SiO ₂ is employed as the inorganic material.

  The second partition 75b is formed on the upper surface of the first partition 75a. The second partition 75b has liquid repellency with respect to a liquid material, and an organic material such as acrylic or polyimide is adopted as the material. Note that the “lyophilicity” of the first partition 75a in the present embodiment means that the lyophilicity is higher than at least materials such as acrylic and polyimide constituting the second partition 75b.

  By disposing such first partition 75a and second partition 75b, partition openings 77R, 77G, and 77B that receive the light emitting functional layers 11R, 11G, and 11B are formed. Each of the light emitting functional layers 11R, 11G, and 11B is formed by using an inkjet method described later for each of the partition opening portions 77R, 77G, and 77B.

Here, the areas of the light emitting functional layers 11R, 11G, and 11B (unit dot areas) are defined by adjusting the opening areas of the partition wall openings 77R, 77G, and 77B. The total area of the light emitting functional layers 11R, 11G, and 11B corresponds to the area per pixel. Therefore, in other words, the pixel area is defined by adjusting the opening areas of the partition wall openings 77R, 77G, and 77B.
With such a structure, the pixels of the central pixel group 7a, the peripheral pixel group 7b, and the intermediate pixel group 7c are configured, and the pixel areas of the pixel groups 7a are different.

The pixel area in the central pixel group 7a and the pixel area in the peripheral pixel group 7b are determined by a predetermined area ratio (pixel opening area ratio). The predetermined area ratio is substantially equal to the reciprocal of the luminance ratio (pixel luminance ratio) in the central pixel group 7a and the luminance ratio (pixel luminance ratio) in the peripheral pixel group 7b.
Accordingly, since the luminance of the peripheral pixel group 7b is lower than the luminance of the central pixel group 7a as shown in the prior art, the pixel area in the central pixel group 7a is a reciprocal of the luminance ratio than the pixel area in the peripheral pixel group 7b. Accordingly, the pixel area is smaller than the pixel area in the peripheral pixel group 7b.

Next, a specific luminance ratio will be described as an example.
For example, when the luminance of the peripheral pixel group 7b is about 80% as compared with the central pixel group 7a, the area ratio is the reciprocal of the luminance ratio, so the area ratio is 1 / 0.8 = 1.25. Calculated as double. Then, according to the area ratio, the pixel area in the peripheral pixel group 7b is formed 1.25 times wider than that in the central pixel group 7a.

Further, it is preferable that the variation in the area ratio and the luminance ratio is within ± 10%.
Therefore, when the area ratio is 1.25 times, the variation is ± 0.125 (1.25 × 0.1), and the actual area ratio is 1.375 (1.25 + 0.125) times to It becomes about 1.125 (1.25-0.125).

  In addition, in all the pixels of the light emitting region 4 including the central pixel group 7a and the peripheral pixel group 7b, the ratio of (brightness × area) of each color dot of the light emitting functional layers 11R, 11G, and 11B is the same. By setting in this way, emitted light having a balanced RGB color is emitted regardless of the size of the pixel area.

In the present embodiment, the first partition wall 75a and the second partition wall 75b are formed, and the opening areas of the partition wall openings 78R, 78G, and 78B are adjusted, so that the pixel areas in the central pixel group 7a and the peripheral pixel group 7b are reduced. Although different, this is not a limitation.
For example, in the central pixel group 7a and the peripheral pixel group 7b, the pattern of the second partition 75b is formed the same, only the pattern of the first partition 75a is adjusted, and the areas of the partition openings 78R, 78G, 78B are made different. Also good. In this way, even if the same amount of the material of the light emitting functional layers 11R, 11G, and 11B is disposed in the central pixel group 7a and the peripheral pixel group 7b, the light emitting functional layers 11R, 11G, and 11B are in contact with the pixel electrode 23. Since the area is adjusted, it is the same as the case of adjusting the opening areas of the partition wall openings 78R, 78G, 78B as described above.

Next, details of the pixel electrode 23, the light emitting functional layer 11, and the cathode 50 shown in FIG. 6 will be described.
Each of the light emitting functional layers 11R, 11G, and 11B has a configuration in which a hole injection layer 70, light emitting layers 60R, 60G, and 60B, and an electron injection layer 65 are stacked from the pixel electrode 23 side. The hole injection layer 70 is a layer film that injects / transports holes from the pixel electrode 23 to the light emitting layers 60R, 60G, and 60B. The electron injection layer 65 is a layer film that injects / transports electrons from the cathode 50 described later to the light emitting layers 60R, 60G, and 60B. The light emitting layers 60R, 60G, and 60B are layer films that emit light by the combination of injected holes and electrons.

  Since the pixel electrode 23 is a bottom emission type in this example, it is formed of a transparent conductive material. ITO is suitable as the transparent conductive material. In addition, for example, an indium oxide / zinc oxide amorphous transparent conductive film (Indium Zinc Oxide: IZO / registered trademark)) (Idemitsu Kosan) Etc.) can be used. In the present embodiment, ITO is used. In the case of the top emission type, it is not necessary to use a material having a light transmission property. For example, Al or the like may be provided on the lower layer side of ITO and used as a reflection layer. Here, the planar pattern of the pixel electrode 23 is formed in the same area in any of the central portion 4a, the peripheral portion 4b, and the intermediate portion 4c of the light emitting region 4.

As a material for forming the hole injection layer 70, in particular, a dispersion of 3,4-polyethylenediosithiophene / polystyrene sulfonic acid (PEDOT / PSS), that is, 3,4-polyethylenedioxy in polystyrene sulfonic acid as a dispersion medium. A dispersion in which thiophene is dispersed and further dispersed in water is preferably used.
The material for forming the hole injection layer 70 is not limited to the above-mentioned materials, and various materials can be used. For example, a material obtained by dispersing polystyrene, polypyrrole, polyaniline, polyacetylene or a derivative thereof in an appropriate dispersion medium such as polystyrene sulfonic acid can be used.

  As a material for forming the light emitting layers 60R, 60G, and 60B, a known light emitting material capable of emitting fluorescence or phosphorescence is used. In the present embodiment, the emission wavelength bands are formed corresponding to the three primary colors of light in order to perform full color display. That is, one pixel is composed of three light emitting layers, a light emitting layer 60R corresponding to red, a light emitting layer 60G corresponding to green, and a light emitting layer 60B corresponding to blue. As a result, the organic EL device 1 performs full color display as a whole.

  Specific examples of materials for forming the light emitting layers 60R, 60G, and 60B include (poly) fluorene derivative (PF), (poly) paraphenylene vinylene derivative (PPV), polyphenylene derivative (PP), polyparaphenylene derivative (PPP), Polysilanes such as polyvinylcarbazole (PVK), polythiophene derivatives, and polymethylphenylsilane (PMPS) are preferably used. In addition, these polymer materials include polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, nile red, coumarin 6, and quinacridone. It can also be used by doping a low molecular weight material such as.

  In this embodiment, MEHPPV (poly (3-methoxy6- (3-ethylhexyl) paraphenylenevinylene) is used as a material for forming the red light emitting layer 60R, and polydioctylfluorene and F8BT are used as the material for forming the green light emitting layer 60G. Polydioctylfluorene is used as a material for forming the blue light emitting layer 60B in the mixed solution of (dioctylfluorene and benzothiadiazole alternating copolymer), and these light emitting layers 60R, 60G, 60B are particularly The thickness is not limited, and a preferable film thickness is adjusted for each color.

The electron injection layer 65 is formed on the light emitting layers 60R, 60G, and 60B. The material of the electron injection layer 65 is appropriately selected according to various materials of the light emitting layers 60R, 60G, and 60B. Specific materials include alkali metal fluorides such as LiF (lithium fluoride), NaF (sodium fluoride), KF (potassium fluoride), RbF (rubidium fluoride), CsF (cesium fluoride), etc. Alternatively, an alkali metal oxide, that is, Li ₂ O (lithium oxide), Na ₂ O (sodium oxide), or the like is preferably used. The thickness of the electron injection layer 65 is preferably about 0.5 nm to 10 nm.

  The cathode 50 has an area larger than the total area of the light emitting region 4 and is formed so as to cover each of them. The first cathode made of a low work function metal provided on the electron injection layer 65 and the first cathode The second cathode is provided on one cathode and protects the first cathode. The metal having a low work function for forming the first cathode is preferably a metal having a work function of 3.0 eV or less, specifically, Ca (work function; 2.6 eV), Sr (work function; 2 .1 eV) and Ba (work function; 2.5 eV) are preferably used. The second cathode is provided to cover the first cathode and protect it from oxygen, moisture, and the like, and to increase the conductivity of the entire cathode 50. The material for forming the second cathode is not particularly limited as long as it is chemically stable and has a relatively low work function, and any material such as a metal or an alloy can be used. Al (aluminum), Ag (silver) or the like is preferably used.

In addition, although the organic EL device 1 having the above configuration has a bottom emission type structure, it is not limited thereto. The organic EL device 1 can also be applied to a so-called top emission type in which emitted light is extracted from the sealing substrate 30 side.
In the case of the top emission type organic EL device, since the emitted light is extracted from the sealing substrate 30 side which is the opposite side of the substrate 20, either a transparent substrate or an opaque substrate can be used. Examples of the opaque substrate include a thermosetting resin and a thermoplastic resin in addition to a ceramic sheet such as alumina and a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation.

As described above, in the organic EL device of this embodiment, the pixel area ratio (pixel aperture area ratio) in each of the central pixel group 7a and the peripheral pixel group 7b is equal to the luminance ratio of the central pixel group 7a and the peripheral pixel group 7b. Since it is substantially equal to the reciprocal, the area is set large for the peripheral pixel group 7b with low luminance, and the area is set small for the central pixel group 7a with high luminance. Accordingly, it is possible to effectively correct the difference in luminance, and the organic EL device 1 having uniform luminance and display characteristics as a whole of the light emitting region 4 can be realized.
Further, conventionally, there has been a problem that the luminance of the peripheral portion 4b is lower than that of the central portion 4a and the light emission characteristics become non-uniform, but this problem can be solved by adopting the above configuration.

  Further, since the difference in luminance is corrected by increasing the pixel area in the peripheral pixel group 7b with respect to the peripheral pixel group 7b having such low luminance, the dummy region provided in the conventional organic EL device is It becomes unnecessary. Therefore, an organic EL device with a small frame can be realized.

  Further, conventionally, the minute liquid applied to the peripheral portion 4b (upper end, lower end, right end, and left end) in the application region on the substrate is likely to evaporate, and the solvent molecule partial pressure of the peripheral portion 4b is low. Although there was a problem that drying was performed faster than the central portion 4a and the light emission characteristics became non-uniform, in this embodiment, the pixels in the peripheral pixel group 7b have a larger area than that of the central pixel group 7a. The difference in luminance between the central pixel group 7a and the peripheral pixel group 7b is effectively corrected, and the organic EL device 1 having uniform luminance and display characteristics as the entire light emitting region can be realized.

  Further, since the intermediate pixel group 7c is provided between the central pixel group 7a and the peripheral pixel group 7b, and the pixel areas of the intermediate pixel group 7c are continuously changed, the intermediate pixels are set so that the luminance is continuously different. The group 7c can emit light. Further, since the intermediate pixel group 7c is provided between the central pixel group 7a and the peripheral pixel group 7b, it is possible to provide a gradient in the luminance distribution of the intermediate pixel group 7c between the pixel groups 7a and 7b.

  Further, when the pixel groups 7a and 7b are adjacent to each other without providing the intermediate pixel group 7c, the emitted light of the pixel groups 7a and 7b is displayed as a clear luminance difference. By providing the pixel group 7c, the light emission luminance between the pixel groups 7a and 7b can be continuously varied. That is, the luminance distribution of the fourth pixel group provided between the pixel groups 7a and 7b has a gradient, and the luminance difference between the pixel groups 7a and 7b can be blurred to emit light.

  Further, the driving method for controlling the gradation of all the pixel groups 7a, 7b, and 7c to emit light is any one of the voltage gradation method, the pulse width gradation method, and the area gradation method, which is preferable. An organic EL device exhibiting display characteristics can be realized. Specifically, the brightness of the panel is expressed by adjusting the voltage or the pulse width of the applied voltage or the number of pixels assigned to light emission, so that even if each pixel area is different, each pixel has a voltage. Light is emitted according to the amount, pulse width, or number of light emitting pixels. Therefore, a suitable luminance gradation can be expressed according to the voltage amount, the pulse width, or the number of light emitting pixels.

Further, since the pattern of the pixel electrode 23 is the same even when the pixel areas are different as in all the pixel groups 7 a, 7 b and 7 c in the light emitting region 4, all the pixel groups constituting the light emitting region 4 are formed. The common use of the pixel electrode patterns 7a, 7b, and 7c can be realized.
Here, if the opening pattern of the second partition 75b is formed to have the same size over the entire light emitting region 4, and the pixel opening area is determined only by the first partition 75a, the opening of the first partition 75a is determined. Since only one photomask for forming the opening pattern needs to be changed, the manufacturing cost can be reduced. Further, it is not necessary to change the ink discharge method by the ink jet method for each dot, and the throughput is improved.

  Further, since the first partition 75a and the second partition 75b are formed between the plurality of pixel electrodes 23, the opening areas of the first partition 75a and the second partition 75b (the partition openings 77R, 77G, and 77B By adjusting the (aperture area), it is possible to determine the pixel area in each of the pixel groups 7a, 7b, 7c and the area ratio between different pixel groups. Further, such an effect can be obtained without increasing the number of components of the organic EL device 1.

  Each of the plurality of pixels in the light emitting region 4 has a unit dot D that emits RGB emission colors, and the ratio of the unit dot D (the product of the brightness of each dot and the area of each dot) in the same pixel. Therefore, it is possible to achieve the balance between the brightness of the luminescent color, the lifetime, and the full color display according to the design and specifications.

(Second Embodiment of Organic EL Device)
Next, a second embodiment of the organic EL device will be described.
In the present embodiment, only the parts different from the first embodiment will be described, and the same components will be denoted by the same reference numerals and the description will be simplified.
FIG. 7 is an enlarged plan view for explaining in detail the light emitting region 4 ′ of the present embodiment.
As shown in FIG. 7, the light emitting region 4 ′ has a central portion 4a, a peripheral portion 4b, an intermediate portion 4c, and a corner portion 4d. A corner pixel group (third pixel group) 7d is formed in the corner portion 4d.
The intermediate portion 4c is not only formed between the central portion 4a and the peripheral portion 4b, but also formed between the central portion 4a and the corner portion 4d and between the peripheral portion 4b and the corner portion 4d. . Further, the intermediate pixel group 7c is set so that the area thereof is continuously different from the central pixel group 7a toward the corner pixel group 7d and from the peripheral pixel group 7b toward the corner pixel group 7d.

FIG. 8 is a diagram illustrating the relationship between the positions of the central pixel group 7a, the peripheral pixel group 7b, the intermediate pixel group 7c, and the corner pixel group 7d along the line BB ′ in FIG. 7 and the pixel area in each pixel group. is there. Here, P0 to P5 in FIG. 8 correspond to the position from the substrate end point P0 to the center point O of the central portion 4a and the position from the center point O to the substrate end point P5 in FIG.
As shown in FIG. 8, in each of the pixel groups 7a, 7b, 7c, and 7d along the line BB ′ in FIG. 7, the pixel area of the peripheral pixel group 7b is larger than that of the central pixel group 7a. The pixel area of the corner pixel group 7d is larger than that of the group 7b (sd> sb). Further, the pixel areas of the intermediate pixel group 7c are continuously different.

  In such a light emitting region 4 ', the pixel area in each of the central pixel group 7a, the peripheral pixel group 7b, and the corner pixel group 7d is substantially equal to the reciprocal of the luminance ratio of each pixel group. That is, when the luminance ratio of the central pixel group 7a, the peripheral pixel group 7b, and the corner pixel group 7d is L: M: N, the area ratio is 1 / L: 1 / M: 1 / N. Is set to

  As described above, in the present embodiment, the corner portion 4d of the light emitting region 4 has the corner pixel group 7d, and the pixels in the corner pixel group 7d have a larger area than that of the peripheral pixel group 7b. The organic EL device 1 having uniform luminance and display characteristics as a whole of the light emitting region 4 including the pixel group 7a, the peripheral pixel group 7b, and the corner pixel group 7d can be realized. Specifically, in the rectangular light emitting region 4, the solvent molecule partial pressure at the corner 4d (upper right corner, lower right corner, upper left corner, and lower left corner) is lower than the upper end, lower end, right end, and left end, The micro liquid applied to the corner portion 4d dries faster than the peripheral portion 4b. As a result, the luminance of the corner 4d in the rectangular application region (light emitting region 4) is lower than that in the peripheral portion 4b, and the light emission characteristics become non-uniform. On the other hand, in the present embodiment, since the corner pixel group 7d is provided, the luminance difference between the peripheral portion 4b and the corner portion 4d can be effectively corrected.

  Further, the pixel area in each of the central pixel group 7a, the peripheral pixel group 7b, and the corner pixel group 7d is substantially equal to the reciprocal of the luminance ratio of each of the pixel groups 7a, 7b, 7d. The organic EL device 1 having uniform luminance and display characteristics can be realized as the entire light emitting region 4 including the central pixel group 7a, the peripheral pixel group 7b, and the corner pixel group 7d.

  In addition, the intermediate pixel group 7c is provided between the central pixel group 7a, the peripheral pixel group 7b, and the corner pixel group 7d, and the pixel areas of the intermediate pixel group 7c are continuously different. The intermediate pixel group 7c can emit light so that the luminance is continuously different. The intermediate pixel group 7c is provided between the central pixel group 7a and the peripheral pixel group 7b, between the central pixel group 7a and the corner pixel group 7d, and between the peripheral pixel group 7b and the corner pixel group 7d. Therefore, a gradient can be provided in the luminance distribution of the intermediate pixel group 7c between the pixel groups 7a, 7b, and 7d.

  Further, when the pixel groups 7a, 7b, and 7d are adjacent to each other without providing the intermediate pixel group 7c, the emitted light of the pixel groups 7a, 7b, and 7d is displayed as a clear luminance difference. By providing the intermediate pixel group 7c as described above, it is possible to continuously vary the light emission luminance between the pixel groups 7a, 7b, and 7d. That is, the luminance distribution of the fourth pixel group provided between the pixel groups 7a, 7b, and 7d has a gradient, and the luminance difference between the pixel groups 7a, 7b, and 7d can be blurred to emit light.

(First Embodiment of Manufacturing Method of Organic EL Device)
Next, a method for manufacturing the organic EL device 1 will be described with reference to FIGS.
First, before the organic EL device 1 is formed, a test device for determining the area ratio between the central pixel group 7a and the peripheral pixel group 7b is manufactured. That is, as shown in FIG. 9, a test apparatus 1 ′ is formed. The difference between the test device 1 'and the organic EL device 1 will be described. The organic EL device 1 has a pixel area and a central portion 4a and a peripheral portion 4b. Pixels having the same pixel opening area are formed on 1 ′. Further, other components in the test apparatus 1 ′ shown in FIG. 9 are the same as those of the organic EL apparatus 1.

Next, the luminance distribution of the light emitting region 4 in the test apparatus 1 ′ is measured.
Specifically, first, in a state where all the red dots forming the pixels of the light emitting region 4 are made to emit light under the same conditions, an image of the entire light emitting region is captured using the pixel inspection device, and each pixel is handled. Image luminance information is assigned as the luminance of each pixel. At this time, the luminance information corresponding to all the pixel dots may not be captured, but the luminance information may be captured and assigned as a certain group of dots (for example, every 10 dots). Based on the result of such luminance distribution measurement, the luminance distribution in the light emitting region 4 is confirmed. This can also be measured for the green and blue dot groups, and the brightness can be measured for all dots forming the pixels of the light emitting region 4. In this test, the target brightness for the red, blue, and green tests may be set to the standard operating brightness for use as a device. For example, when it is used as a display, it is preferable to use a luminance ratio that takes white balance. Of course, this is not the case when used as a monochromatic display or monochromatic light emitting device (for example, a printer head using a photoconductor).
Thus, when all the luminance values of each dot of RGB are obtained, A = (target luminance as a panel) × (pixel dot opening area of the test apparatus) / (dot luminance obtained by the test) is the dot area. To do. Here, the target luminance as a panel is different for each of RGB. For example, in case of outputting the luminance 300 cd / ^{m 2} as a panel, when white balance, and R luminance 200 Cd ^{/ m} 2, G luminance 1000 Cd ^{/ m} 2, B luminance 400 cd / ^{m 2.} Of course, this target value varies depending on the average pixel (dot) aperture ratio of the panel, the pixel area, and the RGB emission spectra. Of course, the value of A may be different for all dots in the light emitting region 4.
In the following description, a case will be described in which the result that the luminance of the peripheral portion 4b is lower than that of the central portion 4a is obtained.

Next, based on the luminance distribution of the test apparatus 1 ′, the organic EL device 1 having different pixel areas shown in FIGS.
Accordingly, the driving TFT 123 is formed on the substrate 20, and the pixel electrode 23 is formed via an interlayer insulating film (not shown). Next, a first partition wall 75a with SiO _2, to form the second partition wall 75b made of resin banks. In such a process of forming the first partition 75a and the second partition 75b, the brightness ratio between the low brightness region (peripheral portion 4b) and the high brightness region (center portion 4a) is calculated based on the brightness distribution of the test apparatus 1 ′. After that, the first partition 75a and the second partition 75b are formed so that the opening area is formed at a reciprocal ratio of the luminance ratio. For example, if the brightness of the peripheral part in the test apparatus 1 ′ is 80% compared to the central part, the opening area ratio is 1 / 0.8 = 1.25 times, and the opening of the peripheral part 4b of the organic EL device 1 is The area is formed 1.25 times wider than the central portion 4a.

  In the present embodiment, the first partition wall 75a and the second partition wall 75b are formed to adjust the opening area. However, the present invention is not limited to this. As described above, if only the first partition 75a is adjusted and the second partition 75b is designed so that the opening area thereof is increased in advance, the same amount of functional material is applied to the partition openings 77R, 77G, and 77B. Even if it is driven, the pixel emission area can be effectively changed.

Next, O ₂ plasma treatment, CF ₄ plasma treatment, or the like is performed to make the pixel electrode 23 lyophilic and to make the second partition 75b lyophobic. Next, PEDOT: PSS ink was ejected by the ink jet method to form the hole injection layer 70, and further, the light emitting layer 60 of each color of RGB was formed thereon by the ink jet method.

  Next, a method for forming pixels with different areas using an inkjet method will be described with reference to FIG. This is effective when the second partition 75b is changed for each pixel. FIG. 10 is an enlarged plan view showing the pixels of the organic EL device 1 shown in FIG. 2, and shows a state after the ejection head ejects the material of the light emitting layer 60 to each unit dot. FIG. 10A is a diagram showing the central pixel group 7a in the central portion 4a, and FIG. 10B is a diagram showing the peripheral pixel group 7b in the peripheral portion 4b.

As shown in FIGS. 10A and 10B, in the ink jet method, the light emitting layers 60R, 60G, and 60B are formed by discharging the liquid material L to each unit dot D while scanning the discharge head. . In addition, the unit dot width DW and the pixel width W in the central pixel group 7a and the peripheral pixel group 7b are all the same. The areas of the central pixel group 7a and the peripheral pixel group 7b are adjusted by changing the lengths of the unit dots D in the long side direction (ejection head scanning direction). In addition, since the scanning direction of the ejection head and the arrangement direction of the droplets L are the same, only the number of droplet ejections is changed without changing the scanning direction of the ejection head, so that the light emitting layer in each unit dot is changed. The area is adjusted. Furthermore, when the same liquid material L is discharged, the discharge amount per drop is all made the same. Therefore, when forming unit dots of the same color with different areas, the discharge amount per droplet is constant, and only the number of discharges is changed.
In addition, when forming the light emitting layer of each color of RGB, the discharge amount per drop is not necessarily the same. The discharge amount per droplet discharged to each color of RGB is suitably set in consideration of the light emission characteristics and life of RGB or the component ratio of the material and the solvent contained in the liquid material.

  Then, the unit material D is formed by ejecting the liquid material L having a predetermined number of droplets as described above, and the central pixel group 7a and the peripheral pixel group 7b are provided by providing the unit dot D for each RGB. Are each formed. Furthermore, as shown in the above embodiment, since the area of the peripheral pixel group 7b is larger than that of the central pixel group 7a, the number of droplets ejected to the peripheral pixel group 7b is made larger than that of the central pixel group 7a. In FIG. 10, the number of droplets ejected to the central pixel group 7a is three, and the number of droplets ejected to the peripheral pixel group 7b is four.

  Next, after forming the light emitting layers 60R, 60G, and 60B as described above, lithium fluoride 2 nm to be the electron injection layer 65 is formed on the entire surface, and calcium and aluminum to be the cathode 50 are respectively 20 nm and 200 nm films. Vapor deposited with thickness.

  In the above embodiment, the method of forming the central pixel group 7a and the peripheral pixel group 7b has been described. However, the same applies to the case of forming the corner pixel group 7c.

As described above, in the present embodiment, since the organic EL device 1 described above can be manufactured, the same effects as the organic EL device 1 can be obtained.
In addition, since the above-described organic EL device manufacturing method uses an ink jet method, it is possible to reduce the equipment cost, material, and the number of processes, and to manufacture a low-cost organic EL device.

  In the ink jet method, the total amount of the liquid material in the unit dots is adjusted by changing the number of ejections of the liquid material, so that the pixel area can be easily adjusted. Therefore, when the second partition 75b is changed for each dot, the central pixel group 7a and the peripheral pixel group 7b having different pixel areas can be formed. Further, by increasing the number of ejections, a large amount of the liquid material L is ejected, and the liquid material L wets and spreads on the pixel electrode 23, so that a large-area pixel can be formed. In addition, since the liquid material L is ejected less by reducing the number of ejections, a pixel with a small area can be formed. Therefore, it is not necessary to change the discharge amount per droplet, and the central pixel group 7a and the peripheral pixel group 7b can be formed only by changing the number of discharges.

  In addition, when the second partition 75b is changed with each dot, the width of the pixels of the organic EL device 1 is all the same size, and the area is adjusted by changing the length direction of the pixels. By making the length direction coincide with the scanning direction of the ejection head, the ejection operation can be performed without stopping the scanning operation. Accordingly, the pixel area can be adjusted while performing the scanning operation.

  Moreover, in the manufacturing method of the organic EL device 1, the test device 1 ′ is manufactured, the luminance distribution of the test device 1 ′ is measured and the luminance ratio is calculated, and the pixel area is calculated based on the reciprocal of the luminance ratio. Therefore, the pixel area based on the measurement result can be calculated, and the pixel dot that forms the light emitting region 4 can be formed with the pixel area.

(Second Embodiment of Manufacturing Method of Organic EL Device)
Next, a second embodiment of the method for manufacturing an organic EL device will be described with reference to FIGS.
Here, FIG. 11A is a plan view showing the light emitting region 4 of the organic EL device 1. 11B and 11C are diagrams showing the luminance distribution in the X direction of the light emitting region, FIG. 11B is a luminance distribution diagram showing luminance unevenness, and FIG. 11C is a uniform luminance. FIG. FIG. 12 is a plan view showing the nozzle surface of the ejection head.
Differences between the present embodiment and the first embodiment will be described. In the first embodiment, the area ratio is defined based on the reciprocal of the luminance ratio in the central portion 4a and the peripheral portion 4b, whereas in the present embodiment, the reciprocal of the luminance ratio due to the line feed streak of the ejection head. The area ratio is defined based on
In the present embodiment, only the parts different from the above-described embodiment will be described, and the same components will be denoted by the same reference numerals to simplify the description.

FIG. 11A shows the scanning direction of the ejection head H on the plane of the light emitting region 4 of the organic EL device 1. It is assumed that the horizontal direction on the paper is the X direction and the vertical direction is the Y direction.
As shown in FIG. 11A, in the ink jet method, the liquid material L is ejected from the nozzles of the ejection head while the ejection head H scans the light emitting region 4 in the Y direction. When the ejection head H reaches the end of the light emitting region 4, the ejection head H moves in the X direction (new line) and scans in the Y direction again. Alternatively, the stage on which the discharge head H is fixed and the substrate is placed may move in the XY directions.

  As shown in FIG. 12, the ejection head H includes a plurality of nozzles Na and Nb. Here, the nozzle Na is a nozzle located near the center of the ejection head H, and the nozzle Nb is a nozzle located near the end of the ejection head H. Accordingly, the nozzle Na discharges the liquid material L to a position farther than the line feed portion in FIG. 11A, and the nozzle Nb discharges the liquid material L to a position close to the line feed portion. In general, due to the difference in the length of the ink flow path to each nozzle of the ejection head H, the ejection amount of ink from the nozzles at both ends of the ejection head H is smaller than the ejection amount of ink in the central portion. In the pixels corresponding to both ends of H, the thickness of the light emitting layer tends to be thin. Therefore, the electric field applied to the light emitting layer is high, and the luminance tends to be high.

When the ejection operation as shown in FIG. 11A is performed, the luminance on the light emitting region 4 scanned near the end of the ejection head H increases as shown in FIG. However, the luminance on the light emitting region 4 to be scanned is lowered, and uneven luminance is caused.
Therefore, the pixel dot aperture area was calculated according to the test apparatus 1 ′ of the first embodiment to create a substrate. The liquid material L is discharged from the nozzle Nb with a large number of discharges, and the liquid material L is discharged from the nozzle Na with a small number of discharges. Then, a large area pixel (second pixel group) is formed by the liquid material L ejected from the nozzle Nb, and a small area pixel (first pixel group) is formed by the liquid material L ejected from the nozzle Na. Note that when the liquid material L is discharged at different discharge times in this way, the discharge amount per time is constant.
When the light emitting region 4 having such large area pixels and small area pixels emits light, a uniform luminance distribution is obtained as shown in FIG.

  Note that the large area pixel and the small area pixel may be formed by changing the discharge amount per one time discharged from the nozzle. In this case, the liquid material L is discharged with a large discharge amount by the nozzle Nb, and the liquid material L is discharged with a small discharge amount by the nozzle Na. Even in such a case, a large area pixel and a small area pixel are formed.

  As described above, even in the ink jet method having the scanning of the ejection head H and the line feed operation, the nozzles Na and Nb eject the liquid material L with different ejection amounts or different ejection amounts, thereby increasing the area. Pixels and small area pixels can be formed. Accordingly, it is possible to solve the problem that the luminance in the vicinity of the line feed stripe of the ejection head H is higher than that of other portions and the light emission characteristics are not uniform. Therefore, even when the ink jet method is used, the organic EL device 1 having uniform luminance and display characteristics as the entire light emitting region 4 can be realized.

(Electronics)
Next, an example of an electronic apparatus including the organic EL device according to the above embodiment will be described.
FIG. 13A is a perspective view showing an example of a mobile phone. In FIG. 13A, reference numeral 500 denotes a mobile phone main body, and reference numeral 501 denotes a display unit including an organic EL device.
FIG. 13B is a perspective view illustrating an example of a portable information processing device such as a word processor or a personal computer. In FIG. 13B, reference numeral 600 denotes an information processing apparatus, reference numeral 601 denotes an input unit such as a keyboard, reference numeral 603 denotes an information processing body, and reference numeral 602 denotes a display unit including an organic EL device.
FIG. 13C is a perspective view illustrating an example of a wristwatch type electronic device. In FIG. 13C, reference numeral 700 denotes a watch body, and reference numeral 701 denotes an EL display unit including an organic EL device.
Since the electronic devices shown in FIGS. 13A to 13C are provided with the organic EL device described in the previous embodiment, the electronic devices have good display characteristics.

  Further, the present invention can be used not only as a display application but also as a head of an LED printer using a photoreceptor. In this case, the number of light emitting points is usually one or at most about 10, and the number of columns is smaller than the number of dummy regions required when forming by the ink jet method. Therefore, in the past, the width has become very wide, and when driving TFTs, the number of wafers taken from one wafer has decreased, and the unit price has increased. Therefore, if the present invention is used, it is not necessary to provide a dummy area, and therefore the width of the head can be very narrow (can be about 1 mm in width), so that the number that can be obtained from one wafer can be increased. Yes, so the unit price can be lowered.

  In addition, as an electronic device, it is not restricted to the said electronic device, It can apply to a various electronic device. For example, a desktop computer, a liquid crystal projector, a multimedia personal computer (PC) and an engineering workstation (EWS), a pager, a word processor, a television, a viewfinder type or a monitor direct view type video tape recorder, an electronic notebook, an electronic The present invention can be applied to electronic devices such as a desktop computer, a car navigation device, a POS terminal, a device provided with a touch panel, or an optical writing type layer recording device, an image forming device, or an image storage device.

The schematic diagram which shows the wiring structure which shows the organic electroluminescent apparatus of 1st Embodiment of this invention. The top view which shows the schematic structure which shows the organic electroluminescent apparatus of 1st Embodiment of this invention. The plane enlarged view which shows the light emission area | region in the schematic structure of the organic electroluminescent apparatus of FIG. FIG. 4 is an enlarged plan view of a main part in the light emitting region of FIG. The figure which shows the relationship between the position of each pixel group in the light emission area | region of FIG. 3, and a pixel area. FIG. 4 is an enlarged cross-sectional view of a main part in the light emitting region of FIG. 3. The plane enlarged view which shows the light emission area | region of 2nd Embodiment in the organic electroluminescent apparatus of this invention. The figure which shows the relationship between the position of each pixel group in the light emission area | region of FIG. 7, and a pixel area. The figure for demonstrating 1st Embodiment in the manufacturing method of the organic electroluminescent apparatus of this invention. The figure for demonstrating the manufacturing method of the organic electroluminescent apparatus of 1st Embodiment of this invention. The figure for demonstrating the manufacturing method of the organic electroluminescent apparatus of 2nd Embodiment of this invention. The figure for demonstrating the manufacturing method of the organic electroluminescent apparatus of 2nd Embodiment of this invention. The figure which shows an electronic device provided with the organic electroluminescent apparatus of this invention.

Explanation of symbols

1 ... Organic EL device (Organic electroluminescence device)
4 ... Light emitting area 4a ... Central part 4b ... Peripheral part 4d ... Corner part 7a ... Central pixel group (first pixel group)
7b ... peripheral pixel group (second pixel group)
7c: Intermediate pixel group (fourth pixel group)
7d ... Corner pixel group (third pixel group)
23 ... Pixel electrode 75a ... First partition (inter-pixel member)
75b ... 2nd partition (inter-pixel member)
D ... Unit dot H ... Discharge head Na, Nb ... Nozzle

Claims (15)

An organic electroluminescence device having a plurality of pixels in a light emitting region,
The light emitting region includes a plurality of pixel groups including a first pixel group and a second pixel group having different pixel luminances, and includes the first pixel group at a central portion and the first pixel group at a peripheral portion in plan view. with 2 pixel groups, wherein and each of the pixel opening area of the second pixel group than the first group of pixels is increased, further, the pixel opening area ratio of the second pixel group and the first group of pixels wherein An organic electroluminescence device characterized by being substantially equal to a reciprocal of a pixel luminance ratio between the first pixel group and the second pixel group . 2. The organic electroluminescence device according to claim 1, wherein a variation in pixel opening area of a plurality of pixels included in the same pixel group is within ± 10%. The light emitting area is rectangular;
A third pixel group is provided at a corner of the light emitting region,
The organic electroluminescent device according to claim 1 or claim 2, wherein the pixel aperture area of each of the third pixel group is greater than the second pixel group. The light emitting region includes a fourth pixel group between the first pixel group and the second pixel group,
Toward a position of the second pixel group from the location of the first pixel group, any one of claims 3 that claim 1, characterized in that the pixel opening area of the fourth pixel group is different from the continuous The organic electroluminescent device according to 1. The driving method for controlling the gradation of the pixel group to emit light is any one of a voltage gradation method, a pulse width gradation method, and an area gradation method. 5. The organic electroluminescence device according to any one of 4 above. The light emitting region includes pixel electrodes formed corresponding to the plurality of pixels,
The area of each pixel electrode is formed the same,
An inter-pixel member having an opening for exposing at least a part of the pixel electrode is provided on the pixel electrode, and the area of the pixel electrode exposed in the opening of the inter-pixel member is adjusted. the organic electroluminescent device according to any one of claims 1 to 5, characterized in that each pixel opening area is determined. Each of the plurality of pixels is composed of a plurality of unit dots having different emission colors, and the ratio of the product of the brightness and area of each unit dot to the whole of the plurality of unit dots in the same pixel group is the total of the light emitting region. the organic electroluminescent device according to any one of claims 1 to 6, characterized in that the same in pixel. A method of manufacturing an organic electroluminescence device having a plurality of pixels in a light emitting region,
The light emitting region includes a plurality of pixel groups including a first pixel group and a second pixel group having different pixel luminances, and includes the first pixel group at a central portion and the first pixel group at a peripheral portion in plan view. 2 pixel groups, each pixel opening area of the second pixel group is larger than the first pixel group,
Production of the organic electroluminescent device characterized by substantially equal to the first pixel group pixel opening area ratio of the second pixel group, the reciprocal of the pixel intensity ratio of the second pixel group and the first pixel group Method. 9. The method of manufacturing an organic electroluminescence device according to claim 8 , wherein the plurality of pixels are formed by using a droplet discharge method. 10. The method according to claim 8 , wherein in the droplet discharge method, the plurality of pixel groups are formed by changing the number of discharges of the liquid material discharged to the plurality of pixel groups. A method for manufacturing an organic electroluminescence device. In the droplet discharge method, the plurality of nozzles provided in the discharge head discharge the liquid material to form the plurality of pixels,
A nozzle near the end of the discharge head discharges the liquid material to form the first pixel group, and a nozzle near the center of the discharge head discharges the liquid material to form the second pixel group. method of manufacturing an organic electroluminescent device according to claim 8 to claim 10, characterized in that. The plurality of pixels have the same length in the width direction, and the pixel areas of the plurality of pixel groups are adjusted by changing the length in a direction orthogonal to the width direction. method of manufacturing an organic electroluminescent device according to any one of claims 11 to 8. Forming a plurality of pixels having the same pixel opening area on a substrate;
The plurality of pixels are caused to emit light under the same conditions, and the pixel luminance in the light emitting region is measured,
Calculating a pixel luminance ratio of each pixel group in the light emitting region;
Method of manufacturing an organic electroluminescent device according to the reciprocal of the pixel luminance ratio claim 8, characterized in that calculating the pixel opening area of each multiplying the pixel area of the same area in any one of claims 12. Based on the calculation result of the pixel opening area of the first pixel group and the second pixel group, an inter-pixel member in which an opening that exposes at least a part of the pixel electrode is formed on the pixel electrode is provided. according to claim 13, characterized in that the area of the pixel electrode exposed to the opening of the inter-pixel members forming the plurality of pixel groups to be different between the second pixel group and the first pixel group A method for manufacturing an organic electroluminescence device. An electronic apparatus, comprising an organic electroluminescent device as claimed in any one of claims 7.

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