JP2009069323A - Pixel display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pixel display device forming a stripe-like light emitting layer and capable of achieving high degree of fineness and reducing its size by devising the arrangement of pixels. <P>SOLUTION: In the pixel display device, the light emitting layer is formed like stripe, and two adjacent pixel rows 17, 17' have a stripe-like light emitting layer forming region W13 (B) provided with at least a blue-color light emitting layer 13 in common. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pixel display device in which light emitting layers are formed in a stripe shape.

  Currently, full color display devices are essential. In the case of performing color display, normally, dots (subpixels) each having a minimum display unit include dots exhibiting red (R), green (G), and blue (B) colors. That is, the red dot, the green dot, and the blue dot are collectively referred to as one pixel (pixel), which is the minimum unit for color display.

  As the arrangement of dots (sub-pixels) constituting such a pixel, stripe arrangement, mosaic arrangement, delta arrangement, etc. are known, but in general, the same number of red, green, and blue are all arranged. Is.

  On the other hand, it is known that in human retinal cone sensory organs, blue is only 1/10 of red and green. That is, since human vision is insensitive to blue, it is known that there is no problem in resolution even if blue is thinned out somewhat. Utilizing this fact, studies have been made to share subpixels among a plurality of pixels (Patent Document 1).

  On the other hand, a method for realizing an increase in the size and definition of a display device (Patent Document 2) has been studied in a method of separately forming red, green, and blue light-emitting elements using a vapor deposition method using a metal mask. ing. Furthermore, among them, a method (Patent Document 3) that achieves high definition by devising the arrangement method of dots (subpixels) constituting a pixel has been studied.

  By the way, in the display device of an organic EL display, studies have been made to apply and form an organic layer with the aim of thin and light flexible and low cost. Examples of the coating formation method include an inkjet method, a dispense coating method (including nozzle printing), a printing method, and the like. Among them, a dispense coating method (Patent Document 4) in which a light emitting layer is formed in a stripe shape is the most practical. It is attracting attention as a method close to the realization.

  Since this dispense application method is a method in which the ink ejected from the nozzles is continuously applied without interruption, the light emitting layer can only be formed in stripes.

  A conventional pixel column will be described with reference to FIG. 6. A light emitting layer is applied and formed by a dispense application method between polyimide banks 55 for pixel separation (color mixing prevention) formed on a lower electrode. That is, red 51, green 52, and blue 53 of the light emitting layer are repeatedly applied in this order with the same width, and one pixel (one pixel) 54 or 54 ′ is a dot (the same width and the same area of the three colors). Subpixel). That is, if the dot (sub-pixel) width of each color is W51 (R), W52 (G), and W53 (B), respectively, W51 (R) = W52 (G) = W53 (B), One pixel column 57 is configured.

  Here, the pixel row 57 is a block in which one pixel (pixel) 54 ′ is vertically arranged in the coating direction (direction parallel to the bank). The light emitting layer forming region is a single color coating region applied between the banks by the dispense coating method, and is a coating region indicated by reference numerals 51, 52, and 53 in FIG.

JP 2004-335169 A JP 2000-68053 A JP-A-2005-203351 JP 2003-217842 A

  However, in the dispense coating method in which the light emitting layer is formed in a stripe shape, at present, about 50 μm as the coating width is the lower limit due to restrictions on the nozzle diameter, discharge pressure, and relative speed.

  Therefore, for the purpose of miniaturization and high definition of the display device, the lower electrode (ITO, etc.) and the partition walls for pixel separation are formed by the photolithography process. At the order level) there is no problem.

  On the other hand, in the method of coating the organic layer in stripes using a dispenser device, the coating width is about 50 μm, which is the lower limit, and this determines the limit of miniaturization and high definition of the display device. For this reason, when realizing a high image quality of full HD, the size of the panel is 13 inches, which is the limit of miniaturization.

  On the other hand, in the high definition technique (Patent Documents 1 to 3) in which the conventional dot arrangement is devised, the green light emitting layer and the red light emitting layer are alternately arranged symmetrically with respect to the blue light emitting layer. That is, since the green light emitting layer and the red light emitting layer are discrete and discontinuous, they cannot be applied and formed by the “dispense coating method” in which the light emitting layer is continuously applied and formed.

  The object of the present invention is obtained as a result of intensive studies in view of the above problems, and in a pixel display device in which a stripe-shaped light emitting layer is formed, by devising the pixel arrangement, high definition and Realization of miniaturization.

As means for solving the above problems, the present invention provides:
A pixel display device in which light emitting layers are formed in stripes,
A stripe-shaped light emitting layer forming region provided with at least a blue light emitting layer is shared by two adjacent pixel columns.

  According to the present invention, high definition and miniaturization can be realized.

  Embodiments of the present invention will be specifically described below, but the present invention is not limited to these embodiments.

<Embodiment 1>
FIG. 1 is a schematic view of a part of the pixel display device according to the first embodiment of the present invention as viewed from above.

  A red light emitting layer 11, a green light emitting layer 12, and a blue light emitting layer 13 are applied and formed between the banks 15. Each light emitting layer is repeatedly arranged in the order of RGBG (RGBGRGBGRGBG...), And the coating widths thereof are the same.

  In FIG. 1, the width of the light emitting layer forming region of the red light emitting layer 11 is W11 (R), the width of the light emitting layer forming region of the green light emitting layer 12 is W12 (G), and the width of the light emitting layer forming region of the blue light emitting layer 13 is. Let W13 (B). In the illustrated example, one pixel (1 pixel) 14 has a width of W11 (R) / 2 + W12 (G) + W13 (B) / 2. That is, the two light emitting layer forming regions of the red light emitting layer 11 and the blue light emitting layer 13 are shared by adjacent pixel columns.

  For this reason, two pixel columns (17 and 17 ') can be formed from the four RGBG light emitting layer formation regions. In other words, compared to the conventional case where two pixel columns are formed from six light emitting layer forming regions, the resolution can be increased by 1.5 times.

  Since the pixel display device having the above configuration does not reduce the number of green having high human visual resolution in the RGBG column (relative to the RGBRGB column), the image quality in the horizontal direction of the green (direction perpendicular to the bank stripe direction) I do not feel any deterioration. Although the number of blue has been reduced to half, the human visual resolution for blue is low, so there is no degradation in image quality. The number of reds has also been reduced by half, which is a level at which the horizontal image quality of red is felt.

  As described above, in the pixel display device in which the light emitting layers are formed in a stripe shape, when a full HD panel is realized with the conventional RGBRGB row arrangement, 13 inches is the limit of miniaturization. However, the pixel display device having the above configuration can realize a 9-inch panel having a size that is 2/3 of the size, and the use of the panel is expanded.

  That is, even in a pixel display device in which a stripe-shaped light emitting layer is formed, a small size and high definition can be achieved.

  In addition, since the number of light emitting layer forming regions is 2/3 of the conventional one, the manufacturing process can be reduced in cost (approximately 33% reduction). According to the present invention, an inexpensive and small high-definition pixel display device can be achieved. Can provide.

  FIG. 2 is a cross-sectional view schematically showing an organic EL element constituting the pixel display device of the present invention.

  A lower electrode 62 is formed on a substrate 61 on which a pixel driving circuit (not shown) is formed, and an organic layer 63 including a hole injection layer, a light emitting layer, an electron injection layer, and the like is stacked thereon, and further, An upper electrode 64 is formed.

  There is no restriction | limiting in particular as the board | substrate 61, such as glass, metal foil, and a polymer film.

  The lower electrode 62 is preferably a transparent conductive film such as ITO (indium tin oxide) or IZO (indium zinc oxide), and is formed on the substrate 61 by, for example, a photolithography method. Incidentally, in the present embodiment, in the red light emitting layer forming region and the blue light emitting layer forming region, a plurality of (two) lower electrodes 62 are formed in the width direction of the light emitting layer forming region (left and right direction in FIG. 1). It is set as the structure corresponding to this pixel.

  The organic layer 63 includes a hole injection layer, a light emitting layer, an electron injection layer, and the like, and is not particularly limited. However, the light emitting layer of the present embodiment is formed by applying a solution dissolved in an organic solvent by a dispense coating method. In FIG. 2, partition walls (banks 65) are formed between the light emitting layers for the purpose of preventing color mixture between pixels (red, green, blue, etc.).

  As the upper electrode 64, Al (aluminum) is preferable because of the work function of the organic EL element.

  On the upper electrode 64, a thin film sealing layer 66, an organic resin layer 67, and a glass substrate 68 are formed in this order for the purpose of sealing.

<Embodiment 2>
FIG. 3 is a schematic view of a part of the pixel display device according to the second embodiment of the present invention as viewed from above.

  In the present embodiment, the width W23 (B) of the light emitting layer forming region of the blue light emitting layer 23 is set to the width W21 (R) of the light emitting layer forming region of the red light emitting layer 21 for the purpose of matching the luminances of red, green and blue. 1.8 times. Further, the width W22 (G) of the light emitting layer forming region of the green light emitting layer 22 is set to 1.2 times the width W21 (R) of the light emitting layer forming region of the red light emitting layer 21. Others were the same as in Embodiment 1, and a pixel display device was formed.

  That is, one pixel (one pixel) 24 (24 ') has a width of W21 (R) / 2 + W22 (G) + W23 (B) / 2. The two light emitting layer forming regions of the red light emitting layer 21 and the blue light emitting layer 23 are shared by adjacent pixel columns.

  Therefore, two pixel columns (27 and 27 ') can be formed in the four RGBG light emitting layer forming regions. That is, compared with the conventional case where two pixel columns are formed from six light emitting layer forming regions, the resolution can be increased 1.15 times (3 / 2.6).

  Moreover, the brightness | luminance between three colors was match | combined by adjusting the width | variety of the light emitting layer formation area of the red light emitting layer 21, the green light emitting layer 22, and the blue light emitting layer 23 to 1: 1.2: 1.8. By doing so, the lifetime between the three colors becomes the same, and the lifetime of the entire display device can be extended.

  As described above, the pixel display device according to the present embodiment can also achieve high definition in a display device in which the light emitting layers are formed in stripes. In addition, since the number of rows of the light emitting layer forming region is 2/3 of the conventional one, the manufacturing process can be reduced in cost (approximately 33% reduction). Therefore, an inexpensive and high-definition organic EL display device can be provided.

<Embodiment 3>
FIG. 4 is a schematic view of a part of the pixel display device according to the third embodiment of the present invention as seen from above.

  In the present embodiment, the width W33 (B) of the light emitting layer forming region of the blue light emitting layer 33 is increased, and half of the light emitting layer forming region is shared by the left and right pixel columns. That is, one pixel (one pixel) 34 (34 ') is configured with W31 (R) + W32 (G) + W33 (B) / 2 width. Others were the same as in Embodiment 1, and a pixel display device was formed.

  Therefore, two pixel columns (37 and 37 ') can be formed in the five RGBRG light emitting layer forming regions. That is, compared with the conventional case where two pixel columns are formed from six light emitting layer forming regions, the resolution can be increased by 1.2 times.

  Further, compared with the first embodiment, the red light-emitting layer forming region is not divided and used, so that the red resolution is high. As for blue, the horizontal resolution is low, but since blue has low human visual resolution, it does not feel blue image quality degradation. Therefore, compared with the first embodiment, there is less deterioration in image quality.

  As described above, the pixel display device of this embodiment can achieve high definition in the pixel display device in which the light emitting layers are formed in a stripe shape. In addition, since the number of the light emitting layer forming regions and the number of TFTs is 5/6, it is possible to reduce the manufacturing process cost (approximately 17% reduction). Therefore, an inexpensive and small high-definition organic EL display device can be provided.

<Embodiment 4>
FIG. 5 is a schematic view of a part of the pixel display device according to the fourth embodiment of the present invention as viewed from above.

  In the present embodiment, the width W43 (B) of the light emitting layer forming region of the blue light emitting layer 43 is made larger than usual (W43 (B)> W53 (B) FIG. 6), and the light emitting layer forming region of the blue light emitting layer 43 is used. The whole was shared by the left and right pixel columns (47 and 47 ′). Others were the same as those in the first embodiment, and a pixel display device was created.

  Compared with Embodiment 3, the aperture ratio of the blue element is larger. In addition, the blue element shared by the left and right adjacent pixels was illuminated with the average luminance required by the left and right pixels.

  The pixel display device having the above structure can form two pixel columns in five RGBRG light emitting layer forming regions. In other words, compared to the conventional case where the two pixel columns are formed from the six light emitting layer forming regions, the number of pixels used is 5/6, so the number of pixels is increased by 1.2 times. It can be refined.

  Further, as in Embodiment 3, there is no deterioration of the red element and the green element as compared with the conventional example (Comparative Example 1 below). Regarding the blue element, the lateral resolution is low, but since blue has low human visual resolution, the blue element does not feel deterioration.

  As described above, the pixel display device according to the present embodiment can achieve high definition in the pixel display device in which the light emitting layers are formed in stripes. In addition, since the number of rows of the light emitting layer forming regions is 5/6 of the conventional one, the manufacturing process can be reduced in cost (approximately 17% reduction). Therefore, an inexpensive and small high-definition organic EL display device can be provided.

<Comparative Example 1>
FIG. 6 shows a pixel (element) arrangement of a conventional pixel display device.

  In FIG. 6, the width of the light emitting layer forming region of the red light emitting layer 51 is W51 (R), the width of the light emitting layer forming region of the green light emitting layer 52 is W52 (G), and the width of the light emitting layer forming region of the blue light emitting layer 53 is. Let W53 (B). In the illustrated example, the widths of the respective light emitting layer forming regions are equal, and W51 (R) = W52 (G) = W53 (B). Others were the same as in Embodiment 1, and a pixel display device was formed.

  In this comparative example, one pixel column 57 is formed in three columns of light emitting layer forming regions of RGB.

  In the comparative example, the pixel display device formed by the process of applying and forming the light emitting layer in a stripe shape (for example, the dispensing application method or the nozzle printing method) has a limit on the application width of the light emitting layer (current lower limit value: about 50 μm). There is. For this reason, one pixel (one pixel) 54 (54 ′) cannot be made smaller than this, and one pixel (one pixel) 54 (54 ′) can be reduced to (W51 (R) + W52 (G) + W53 (B)). Cannot be less than the width. That is, it was not possible to achieve a higher definition than the application width limit of the dispenser.

It is a figure explaining RGBG row arrangement | positioning and 1 pixel (1 pixel) of the pixel display apparatus (Embodiment 1) of this invention. It is the figure which showed the cross-sectional block diagram of the organic EL element. It is a figure explaining RGBG row arrangement | positioning and 1 pixel (1 pixel) of the pixel display apparatus (Embodiment 2) of this invention. It is a figure explaining RGBRG row | line | column arrangement | positioning and 1 pixel (1 pixel) of the pixel display apparatus (Embodiment 3) of this invention. It is a figure explaining RGBRG column arrangement | positioning and 1 pixel (1 pixel) of the pixel display apparatus (Embodiment 4) of this invention. It is a figure explaining RGB row arrangement | positioning and 1 pixel (1 pixel) of the pixel display apparatus (comparative example 1) of this invention.

Explanation of symbols

11, 21, 31, 41, 51 Red light emitting layer 12, 22, 32, 42, 52 Green light emitting layer 13, 23, 33, 43, 53 Blue light emitting layer 14, 14 ', 24, 24', 34, 34 ' , 44, 44 ', 54, 54' 1 pixel (1 pixel)
15, 25, 35, 45, 55, 65 Banks 16, 26, 36, 46, 56, 66 Anode electrodes 17, 17 ', 27, 27', 37, 37 ', 47, 47', 57 Pixel row W11 ( R), W21 (R), W31 (R), W41 (R), W51 (R) Red light emitting layer formation region width W12 (G), W22 (G), W32 (G), W42 (G), W52 (G) Green light emitting layer formation region width W13 (B), W23 (B), W33 (B), W43 (B), W53 (B) Blue light emitting layer formation region width

Claims (3)

A pixel display device in which light emitting layers are formed in stripes,
A pixel display device characterized in that at least a stripe-shaped light emitting layer forming region provided with a blue light emitting layer is shared by two adjacent pixel columns.   2. The pixel display device according to claim 1, wherein a plurality of lower electrodes are formed in the width direction of the stripe-shaped light emitting layer forming region.   The pixel display device according to claim 1, wherein the light emitting layer is formed by a dispense coating method.

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